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Sample records for schistosomiasis mansoni magnetic

  1. Brain magnetic resonance imaging findings in young patients with hepatosplenic schistosomiasis mansoni without overt symptoms.

    PubMed

    Manzella, Adonis; Borba-Filho, Paulo; Brandt, Carlos T; Oliveira, Keyla

    2012-06-01

    The purpose of this study was to describe the brain magnetic resonance imaging (MRI) findings in young patients with hepatosplenic schistosomiasis mansoni without overt neurologic manifestations. This study included 34 young persons (age range = 9-25 years) with hepatosplenic schistosomiasis mansoni who had been previously treated. Patients were scanned on a 1.5-T system that included multiplanar pre-contrast and post-contrast sequences, and reports were completed by two radiologists after a consensus review. Twenty (58.8%) patients had MRI signal changes that were believed to be related to schistosomiasis mansoni. Twelve of the 20 patients had small focal hyperintensities on T2WI in the cerebral white matter, and eight patients had symmetric hyperintense basal ganglia on T1WI. There was a high frequency of brain MRI signal abnormalities in this series. Although not specific, these findings may be related to schistosomiasis. PMID:22665605

  2. Human schistosomiasis: Schistosoma mansoni antigen detection in renal glomeruli.

    PubMed

    Hoshino-Shimizu, S; De Brito, T; Kanamura, H Y; Canto, A L; Silva, A O; Campos, A R; Penna, D O; Da Silva, L C

    1976-01-01

    Twelve kidney, five biopsy and seven necropsy specimens, all from schistosomiasis mansoni patients were studied by light and immunoflurescent microscopy in an attempt to detect antigen in the glomerular walls. Deposits of IgM, IgG,I gA, IgE, complement C3 and fibrinogen were observered in most cases. Antigen was successfully detected in two cases(one biopsy and one necropsy specimen), both exhibiting proliferative glomerulonephritis. The only clinical manifestation was a slight proteinuria. IgG antibodies eluted from the sutopsy kidney homogenates showed specific binding mostly to Schistosoma mansoni gut, thus spggesting that the fixed antibodies (eluates) are, at least partially, consituted by antibodies similar to the anti-circulating antigen. These data reinfroce the hypothesis that renal injury in schistosomiasis is mediated through an immune complex disease. PMID:65811

  3. Splenectomy Improves Hemostatic and Liver Functions in Hepatosplenic Schistosomiasis Mansoni

    PubMed Central

    Leite, Luiz Arthur Calheiros; Pimenta Filho, Adenor Almeida; Ferreira, Rita de Cássia dos Santos; da Fonseca, Caíque Silveira Martins; dos Santos, Bianka Santana; Montenegro, Silvia Maria Lucena; Lopes, Edmundo Pessoa de Almeida; Domingues, Ana Lúcia Coutinho; Owen, James Stuart; Lima, Vera Lucia de Menezes

    2015-01-01

    Background Schistosomiasis mansoni is a chronic liver disease, in which some patients (5–10%) progress to the most severe form, hepatosplenic schistosomiasis. This form is associated with portal hypertension and splenomegaly, and often episodes of gastrointestinal bleeding, even with liver function preserved. Splenectomy is a validated procedure to reduce portal hypertension following digestive bleeding. Here, we evaluate beneficial effects of splenectomy on blood coagulation factors and liver function tests in hepatosplenic schistosomiasis mansoni compared to non-operated patients. Methodology/Principal Findings Forty-five patients who had undergone splenectomy surgery were assessed by laboratory analyses and ultrasound examination and compared to a non-operated group (n = 55). Blood samples were obtained for liver function tests, platelet count and prothrombin time. Coagulation factors (II, VII, VIII, IX and X), protein C and antithrombin IIa, plasminogen activator inhibitor-1 were measured by routine photometric, chromogenic or enzyme-linked immunosorbent assays, while hyperfibrinolysis was defined by plasminogen activator inhibitor-1 levels. Both groups had similar age, gender and pattern of periportal fibrosis. Splenectomized patients showed significant reductions in portal vein diameter, alkaline phosphatase and bilirubin levels compared to non-operated patients, while for coagulation factors there were significant improvement in prothrombin, partial thromboplastin times and higher levels of factor VII, VIII, IX, X, protein C and plasminogen activator inhibitor-1. Conclusion/Significance This study shows that the decrease of flow pressure in portal circulation after splenectomy restores the capacity of hepatocyte synthesis, especially on the factor VII and protein C levels, and these findings suggest that portal hypertension in patients with hepatosplenic schistosomiasis influences liver functioning and the blood coagulation status. PMID:26267788

  4. COMPARATIVE STUDY ON IMMUNOBLOT VERSUS PCR IN DIAGNOSIS OF SCHISTOSOMIASIS MANSONI IN EXPERIMENTAL INFECTED MICE.

    PubMed

    Ismail, Mousa A M; Mousa, Wahed Mohammed Ali; Abu-Sarea, Enas Yahia; Basyouni, Maha M A; Mohammed, Samah Sayed

    2016-04-01

    This study compared PCR and Western blot techniques in diagnosis of schistosomiasis mansoni. Forty Swiss albino mice were used, thirty two mice were infected with cercariae of S. mansoni and eight mice were kept uninfected which were used as a control. Blood was obtained from four infected mice weekly beginning from the 1st week to the 8th week post infection. The study found that PCR was positive from the first week post infection, while Western blot technique was positive from the second week post infection. Thus, PCR diagnosed schistosomiasis mansoni earlier than Western blot technique, but both were able to diagnose. PMID:27363045

  5. From Incidentaloma to Suspicion of Malignancy: The Diverse Clinical Presentation of Gonadal Schistosomiasis mansoni

    PubMed Central

    Almeida, Laiana do Carmo; de Oliveira, Marbele Guimarães; Castro Pereira, Fábio Meira; de Bessa Júnior, José

    2013-01-01

    Schistosomiasis is the second most widespread parasitic disease in the world, second only to malaria. The usual places the Schistosoma mansoni can be found in are the rectal and sigmoidal venules, as well as other segments of the large intestine of men. It may also be present in other ectopic topographies. Gonadal schistosomiasis is an unusual presentation of Schistosomiasis mansoni and its different clinical signs and symptoms disrupt correct diagnosis and culminate in surgical treatment that is, in most cases, unnecessary. In this study, we report four cases of gonadal Schistosomiasis mansoni, two in the ovary and two in the testicles. These cases were clinically investigated as a bacterial infection, a benign neoplasm, and a suspected cancer, whilst one of them was an incidentaloma. PMID:24392230

  6. [Schistosomiasis mansoni in the southwest of the State of Minas Gerais (Brazil)].

    PubMed

    Carvalho, O dos S; Massara, C L; Rocha, R S; Katz, N

    1989-08-01

    A new focus of schistosomiasis mansoni at Passos, a town in the Southwest of the State of Minas Gerais (Brazil), region until now considered free of the disease is reported. Malacological surveys showed Biophalaria glabrata naturally infected with Schistosoma mansoni in a country club near Passos. All B. straminea captured at the pisciculture station of the Furnas hydroelectric dam were negative. Six out of seven individuals living in the country club were found to be infected with S. mansoni, including four children who had never been out of Passos. The epidemiological importance of these findings is discussed. PMID:2517153

  7. Potential Use of Biomphalaria alexandrina Snail Antigens for Serodiagnosis of Schistosomiasis Mansoni by Immunoblot Analysis

    PubMed Central

    Basyoni, Maha MA; EL-Wahab, Azza Abd

    2013-01-01

    Background The aim of this study was to evaluate the possible use of Biomphalaria alexandrina snail antigens in diagnosis of schistosomiasis mansoni using enzyme linked immunolectrotransfere blot (EITB). Methods S. mansoni adult worm crude antigens (AWA), feet and visceral humps of B. alexandrina and Bulinus truncatus were used. Hyperimmune mice sera (HIS) versus each antigen were prepared for diagnosis of S. mansoni using western blot (WB). Results Snail foot antigens were more specific in antibodies detection than visceral hump antigens. Three of five polypeptides of B. alexandrina foot antigen identified by S. mansoni HIS showed specific positive reactivity. These polypeptides were at MW of 31/32 and 43 kDa. While, only one of the six polypeptides of B. alexandrina hepatopancrease antigen identified by S. mansoni HIS, at a MW of 43 kDa was specific. Similarly, 2 polypeptides at MW of 44 and 55 kDa were specific in detection of anti- S. haematobium antibodies. However, the antigenically active polypeptide of B. truncatus hepatopancrease antigen had no specific reactivity towards anti-S. haematobium antibodies. Conclusion B. alexandrina foot antigens were the most specific of the tested snail antigens in diagnosis of schistosomiasis mansoni. PMID:23682262

  8. Schistosomiasis

    PubMed Central

    Tucker, Matthew S.; Karunaratne, Laksiri B.; Lewis, Fred A.; Freitas, Tori C.; Liang, Yung-san

    2014-01-01

    Schistosomiasis is the second most important parasitic disease in the world in terms of public health impact. Globally, it is estimated that the disease affects over 200 million people and is responsible for 200,000 deaths each year. The three major schistosomes infecting humans are Schistosoma mansoni, S. japonicum, and S. haematobium. Much immunological research has focused on schistosomiasis because of the pathological effects of the disease, which include liver fibrosis and bladder dysfunction. This Unit covers a wide range of aspects of maintaining the life cycles of these parasites, including preparation of schistosome egg antigen, maintenance of intermediate snail hosts, infection of the definitive and intermediate hosts, and others. The Unit primariiy focues on S. mansoni, but also includes coverage of S. japonicum and S. haematobium life cycles. PMID:18432750

  9. Protective Effect of Chronic Schistosomiasis in Baboons Coinfected with Schistosoma mansoni and Plasmodium knowlesi.

    PubMed

    Nyakundi, Ruth K; Nyamongo, Onkoba; Maamun, Jeneby; Akinyi, Mercy; Mulei, Isaac; Farah, Idle O; Blankenship, D'Arbra; Grimberg, Brian; Hau, Jann; Malhotra, Indu; Ozwara, Hastings; King, Christopher L; Kariuki, Thomas M

    2016-05-01

    Malaria and schistosomiasis coinfections are common, and chronic schistosomiasis has been implicated in affecting the severity of acute malaria. However, whether it enhances or attenuates malaria has been controversial due the lack of appropriately controlled human studies and relevant animal models. To examine this interaction, we conducted a randomized controlled study using the baboon (Papio anubis) to analyze the effect of chronic schistosomiasis on severe malaria. Two groups of baboons (n = 8 each) and a schistosomiasis control group (n = 3) were infected with 500 Schistosoma mansoni cercariae. At 14 and 15 weeks postinfection, one group was given praziquantel to treat schistosomiasis infection. Four weeks later, the two groups plus a new malaria control group (n = 8) were intravenously inoculated with 10(5) Plasmodium knowlesi parasites and monitored daily for development of severe malaria. A total of 81% of baboons exposed to chronic S. mansoni infection with or without praziquantel treatment survived malaria, compared to only 25% of animals infected with P. knowlesi only (P = 0.01). Schistosome-infected animals also had significantly lower parasite burdens (P = 0.004) than the baboons in the P. knowlesi-only group and were protected from severe anemia. Coinfection was associated with increased spontaneous production of interleukin-6 (IL-6), suggesting an enhanced innate immune response, whereas animals infected with P. knowlesi alone failed to develop mitogen-driven tumor necrosis factor alpha and IL-10, indicating the inability to generate adequate protective and balancing immunoregulatory responses. These results indicate that chronic S. mansoni attenuates the severity of P. knowlesi coinfection in baboons by mechanisms that may enhance innate immunity to malaria. PMID:26883586

  10. BLOCKADE OF PGE2, PGD2 RECEPTORS CONFERS PROTECTION AGAINST PREPATENT SCHISTOSOMIASIS MANSONI IN MICE.

    PubMed

    Abdel-Ghany, Rasha; Rabia, Ibrahim; El-Ahwany, Eman; Saber, Sameh; Gamal, Rasha; Nagy, Faten; Mahmoud, Olaa; Hamad, Rabab Salem; Barakat, Walled

    2015-12-01

    Schistosomiasis is a chronic disease with considerable social impact. Despite the availability of affordable chemotherapy, drug treatment has not significantly reduced the overall number of disease cases. Among other mechanisms, the parasite produces PGE2 and PGD2 to evade host immune defenses. To investigate the role of PGE2 and PGD2 in schistosomiasis, we evaluated the effects of L-161,982, Ah6809 (PGE2 receptor antagonists alone of combined with each other) and MK-0524 (PGD2 receptor antagonist) during prepatent Schistosoma mansoni infection. Drugs were administered intraperitoneally an hour before and 24 hours after infection of C57BL/6 mice with 100 Schistosoma mansoni cercariae. L-161,982, Ah6809, their combination and MK-0524 caused partial protection against pre-patent S. mansoni infection which was mediated by biasing the immune response towards Th1 phenotype. These results showed that blockade of PGE2 and PGD2 receptors confers partial protection against pre-patent S. mansoni infection in mice and that they may be useful as adjunctive therapy to current anti-schistosomal drugs or vaccines. PMID:26939228

  11. Human Schistosomiasis mansoni associated with hepatocellular carcinoma in Egypt: current perspective.

    PubMed

    El-Tonsy, Manar Mahmoud; Hussein, Hesham Mohammed; Helal, Thanaa El-Sayed; Tawfik, Rania Ayman; Koriem, Khalid Mohamed; Hussein, Hend Mohamed

    2016-09-01

    Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. It was reported to account for about 4.7 % of chronic liver disease in Egyptian patients. The present study aimed at studying the different factors that may be implicated in the relationship of schistosomiasis mansoni with HCC in Egypt. A total of 75 Egyptian patients with primary liver tumours (HCC) were enrolled in this study. They were subjected to full history taking and indirect hemagglutination assay (IHA) for the diagnosis of schistosomiasis. According to the results, the patients were categorized into two groups: Group I: 29 patients with negative IHA for schistosomiasis and hepatitis C virus (HCV) positive with no history or laboratory evidence of previous or current Schistosoma mansoni infection. Group II: 46 patients with positive IHA for schistosomiasis and HCV positive. The significant higher proportion of HCC patients in the present study had concomitant HCV and schistosomiasis (61.3 %) compared to HCC patients with HCV alone (38.7 %) suggesting that the co-infection had increased the incidence of HCC among these patients. Analysis of the age distribution among HCC patients revealed that patients in Group II were younger in age at time of diagnosis of HCC with mean age 57.1 years, as compared to patients in Group I with mean age 64.3 years with a highly significant statistical difference between the 2 groups. HCC in Group II was more common in rural residents while it was more common in urban areas in Group I with a significant statistical difference between the 2 groups. Analysis of the sex distribution among the studied groups showed that HCC was more common in males than females in both groups. As regards the aggression of HCC, it was more commonly multifocal and larger in size in patients with concomitant infection than in patients with HCV alone. PMID:27605822

  12. Cytokine Pattern of T Lymphocytes in Acute Schistosomiasis mansoni Patients following Treated Praziquantel Therapy.

    PubMed

    Silveira-Lemos, Denise; Fernandes Costa-Silva, Matheus; Cardoso de Oliveira Silveira, Amanda; Azevedo Batista, Mauricio; Alves Oliveira-Fraga, Lúcia; Soares Silveira, Alda Maria; Barbosa Alvarez, Maria Carolina; Martins-Filho, Olindo Assis; Gazzinelli, Giovanni; Corrêa-Oliveira, Rodrigo; Teixeira-Carvalho, Andréa

    2013-01-01

    Acute schistosomiasis is associated with a primary exposure and is more commonly seen in nonimmune individuals traveling through endemic regions. In this study, we have focused on the cytokine profile of T lymphocytes evaluated in circulating leukocytes of acute Schistosomiasis mansoni-infected patients (ACT group) before and after praziquantel treatment (ACT-TR group). Our data demonstrated increased values of total leukocytes, eosinophils, and monocytes in both groups. Interestingly, we have observed that patients treated with praziquantel showed increased values of lymphocytes as compared with noninfected group (NI) or ACT groups. Furthermore, a decrease of neutrophils in ACT-TR was observed when compared to ACT group. Analyses of short-term in vitro whole blood stimulation demonstrated that, regardless of the presence of soluble Schistosoma mansoni eggs antigen (SEA), increased synthesis of IFN-γ and IL-4 by T-cells was observed in the ACT group. Analyses of cytokine profile in CD8 T cells demonstrated higher percentage of IFN-γ and IL-4 cells in both ACT and ACT-TR groups apart from increased percentage of IL-10 cells only in the ACT group. This study is the first one to point out the relevance of CD8 T lymphocytes in the immune response induced during the acute phase of schistosomiasis. PMID:23401741

  13. Cytokine Pattern of T Lymphocytes in Acute Schistosomiasis mansoni Patients following Treated Praziquantel Therapy

    PubMed Central

    Silveira-Lemos, Denise; Fernandes Costa-Silva, Matheus; Cardoso de Oliveira Silveira, Amanda; Azevedo Batista, Mauricio; Alves Oliveira-Fraga, Lúcia; Soares Silveira, Alda Maria; Barbosa Alvarez, Maria Carolina; Martins-Filho, Olindo Assis; Gazzinelli, Giovanni; Corrêa-Oliveira, Rodrigo; Teixeira-Carvalho, Andréa

    2013-01-01

    Acute schistosomiasis is associated with a primary exposure and is more commonly seen in nonimmune individuals traveling through endemic regions. In this study, we have focused on the cytokine profile of T lymphocytes evaluated in circulating leukocytes of acute Schistosomiasis mansoni-infected patients (ACT group) before and after praziquantel treatment (ACT-TR group). Our data demonstrated increased values of total leukocytes, eosinophils, and monocytes in both groups. Interestingly, we have observed that patients treated with praziquantel showed increased values of lymphocytes as compared with noninfected group (NI) or ACT groups. Furthermore, a decrease of neutrophils in ACT-TR was observed when compared to ACT group. Analyses of short-term in vitro whole blood stimulation demonstrated that, regardless of the presence of soluble Schistosoma mansoni eggs antigen (SEA), increased synthesis of IFN-γ and IL-4 by T-cells was observed in the ACT group. Analyses of cytokine profile in CD8 T cells demonstrated higher percentage of IFN-γ and IL-4 cells in both ACT and ACT-TR groups apart from increased percentage of IL-10 cells only in the ACT group. This study is the first one to point out the relevance of CD8 T lymphocytes in the immune response induced during the acute phase of schistosomiasis. PMID:23401741

  14. Role of Host Granulomatous Response in Murine Schistosomiasis Mansoni

    PubMed Central

    Olds, G. Richard; Mahmoud, Adel A. F.

    1980-01-01

    Eosinophils form 50% of cells in the host granulomatous response to Schistosoma mansoni eggs, but their functional role in these granulomas and their relation to egg destruction is unknown. We have studied the course of S. mansoni infection in mice treated with normal rabbit serum (NRS) or depleted of their eosinophils by monospecific anti-eosinophil serum (AES). At 6-wk of infection (after 2 wk of egg deposition) the AES-treated animals were similar to NRS-treated controls with the exception that hepatic granulomas in the AES-treated animals were 50% smaller and devoid of eosinophils. At 8 wk of infection, AES-treated mice had significantly higher mortality, spleen weight, portal pressure, and 80% more eggs retained in their livers. These data suggest that eosinophil depletion delayed egg destruction. We subsequently studied destruction of eggs injected into the pulmonary microvasculature of sensitized mice. 2,000 S. mansoni eggs were intravenously injected into the tail veins of mice treated with NRS, anti-neutrophil serum, AES or ATG (anti-thymocyte globulin); at time intervals the remaining eggs were recovered from the lungs by tissue digestion. Egg recovery from NRS- or anti-neutrophil serum-treated mice began to decrease by day 16 and the percent recovery of eggs at day 24 was 55 and 52%, respectively. In contrast, animals treated with AES had smaller lung granulomas that were devoid of eosinophils and a marked delay of egg destruction was seen. It took until day 44 for 50% of the eggs to be destroyed. In ATG-treated animals smaller granulomas were seen that had diminished lymphocytes and also 75% less eosinophils. ATG treatment apparently slowed egg destruction but was not statistically significant. Our data define the role of the eosinophils in destruction of schistosome eggs in vivo and delineates the protective function of these cells within the host granulomatous response. PMID:7440710

  15. Miltefosine Lipid Nanocapsules for Single Dose Oral Treatment of Schistosomiasis Mansoni: A Preclinical Study

    PubMed Central

    Eissa, Maha M.; El-Moslemany, Riham M.; Ramadan, Alyaa A.; Amer, Eglal I.; El-Azzouni, Mervat Z.; El-Khordagui, Labiba K.

    2015-01-01

    Miltefosine (MFS) is an alkylphosphocholine used for the local treatment of cutaneous metastases of breast cancer and oral therapy of visceral leishmaniasis. Recently, the drug was reported in in vitro and preclinical studies to exert significant activity against different developmental stages of schistosomiasis mansoni, a widespread chronic neglected tropical disease (NTD). This justified MFS repurposing as a potential antischistosomal drug. However, five consecutive daily 20 mg/kg doses were needed for the treatment of schistosomiasis mansoni in mice. The present study aims at enhancing MFS efficacy to allow for a single 20mg/kg oral dose therapy using a nanotechnological approach based on lipid nanocapsules (LNCs) as oral nanovectors. MFS was incorporated in LNCs both as membrane-active structural alkylphospholipid component and active antischistosomal agent. MFS-LNC formulations showed high entrapment efficiency (EE%), good colloidal properties, sustained release pattern and physical stability. Further, LNCs generally decreased MFS-induced erythrocyte hemolytic activity used as surrogate indicator of membrane activity. While MFS-free LNCs exerted no antischistosomal effect, statistically significant enhancement was observed with all MFS-LNC formulations. A maximum effect was achieved with MFS-LNCs incorporating CTAB as positive charge imparting agent or oleic acid as membrane permeabilizer. Reduction of worm load, ameliorated liver pathology and extensive damage of the worm tegument provided evidence for formulation-related efficacy enhancement. Non-compartmental analysis of pharmacokinetic data obtained in rats indicated independence of antischistosomal activity on systemic drug exposure, suggesting possible gut uptake of the stable LNCs and targeting of the fluke tegument which was verified by SEM. The study findings put forward MFS-LNCs as unique oral nanovectors combining the bioactivity of MFS and biopharmaceutical advantages of LNCs, allowing targeting

  16. Clinico-epidemiological study of Schistosomiasis mansoni in Waja-Timuga, District of Alamata, northern Ethiopia

    PubMed Central

    2014-01-01

    Background Intestinal schistosomiasis, caused by digenetic trematodes of the genus Schistosoma, is the most prevalent water related disease that causes considerable morbidity and mortality. Although prevalence of Schistosoma mansoni infection has been reported for the present study area, earlier studies have not estimated intensity of infections in relation to periportal fibrosis, which would have been crucial for epidemiological and clinical evaluations. Hence, a community based cross sectional study was conducted from December 2011 to March 2012 to assess prevalence of infection and schistosomal periportal fibrosis in Waja-Timuga, northern Ethiopia. Methods In a cross sectional study involving 371 randomly selected individuals, fresh stool samples were collected and processed by the Kato-Katz method and examined microscopically. Ultrasonography was used to determine status of schistosomal periportal fibrosis and to detect hepatomegaly and/or splenomegaly. Serum was collected for assay of hepatic activity. Statistical analysis was performed using STATA 11 statistical soft ware. P-value <0.05 was reported as statistically significant. Results The prevalence of S.mansoni infection was 73.9%, while the prevalence of schistosomal periportal fibrosis was 12.3% and mean intensity of infection was 234 eggs per gram of stool. Peak prevalence and intensity of S.mansoni infection was documented in the age range of 10–20 years. Among the study individuals, hepatomegaly was recorded in 3.7% and splenomegaly was recorded in 7.4% of the study individuals. Similarly, among the study individuals who had definite periportal fibrosis, 5.9% had elevated liver enzyme levels. Conclusion The high prevalence of Schistosoma mansoni infection and schistosomal periportal fibrosis observed in the study area calls for a periodic deworming program to reduce disease, morbidity and transmission. Preventive chemotherapy complemented with other control measures is highly required for

  17. Some personal views on the control of schistosomiasis mansoni.

    PubMed

    Kloetzel, K

    1992-01-01

    Our views are based, among other, on a recent study of a district of União dos Palmares (Alagoas). Although being a very compact community (32 city blocks holding two thousand families), transmission is very uneven, the geometric mean egg counts in the various blocks ranging between extremes of 96 and 1920. (Results do not correlate with the availability of domestic water supply). We thus are led to conclude that: (a) transmission is primarily peridomestic, resulting from pollution of open ditches and other collections of water; (b) control of transmission can be done on a selective basis, requiring quite modest investments. Given the inefficacy of population-based chemotherapy, when used alone, the author insists that this alternative cannot any longer be overlooked. He also regrets the emphasis placed upon vaccine development; allegations that this would, at any rate, prevent severe morbidity can be dismissed, since-whatever the cause-morbidity due to schistosomiasis has been rapidly declining in Northeast Brazil. PMID:1343899

  18. Synthesis of angiotensins by cultured granuloma macrophages in murine schistosomiasis mansoni

    SciTech Connect

    Weinstock, J.V.; Blum, A.M.

    1986-03-01

    Components of the angiotensin system are present in granulomas of murine schistosomiasis mansoni. Angiotensins may have immunoregulatory function. Granuloma macrophages cultured for up to 3 days generated substantial angiotensin I (AI) and angiotensin II (AII) which appeared in the culture supernatants. Macrophage monolayers were incubated with (/sup 3/H) amino acids, and culture supernatants were extracted with acetone and analyzed by HPLC. Radiolabeled products eluded at times corresponding to those of authentic angiotensins. Immunoadsorption of angiotensins with angiotensin antisera removed reputed radiolabeled angiotensins from the supernatants. Treatment of the elution fraction corresponding to that of authentic AI with angiotensin converting enzyme resulted in the generation of radiolabeled polypeptides which co-eluted with authentic AII and His-Leu. Similar experiments conducted with nonadherent granuloma cells devoid of macrophages failed to demonstrate angiotensin production. These results suggest that granuloma macrophages can synthesize angiotensin.

  19. Effect of artemether on cytokine profile and egg induced pathology in murine schistosomiasis mansoni

    PubMed Central

    Madbouly, Neveen A.; Shalash, Ibraheem R.; El Deeb, Somaya O.; El Amir, Azza M.

    2014-01-01

    Artemether (ART), the methylated derivative of artemisinin, is an efficacious antimalarial drug that also displays antischistosomal properties. This study was designed to evaluate the immunomodulatory action of a single intramuscular dose (50 mg/kg body weight) of ART in comparison with PZQ treatment (42 days PI). ART administration was 7, 14, 21 and 45 days PI. ART effect was studied parasitologically, histopathologically and immunologically. It was found that maximum effect was reached when ART treatment interfered with 14 or 21 days old schistosomula. ART treatment 14 or 21 days PI was associated with shift from Th2 to Th1 predominancy (decrease in IL-4 and upgrading of serum IFN-γ levels). In conclusion, ART is a promising drug in control of schistosomiasis mansoni due to its reductive effect on worm burden and its role in improvement of hepatic granulomatous lesions. PMID:26644922

  20. Cytokine patterns in experimental schistosomiasis mansoni infected mice treated with silymarin.

    PubMed

    El-Sayed, Nagwa Mostafa; Fathy, Ghada Mahmoud; Abdel-Rahman, Sara Abdel-Rahman; El-Shafei, Mahmoud Abdel-Atei

    2016-09-01

    The purpose of this study was to determine cytokine patterns in experimental schistosomiasis mansoni infected mice treated with silymarin. The study was conducted upon 100 mice that were divided into five groups; 20 each: uninfected control group, Schistosoma mansoni infected untreated mice (infected control), infected mice treated with praziquantel (PZQ), infected mice treated with silymarin and infected mice treated with both praziquantel and silymarin. 10 mice from each group were sacrificed at 10th and 18th weeks post infection respectively. Histopathological investigations were performed. Liver sections were stained with hematoxylin-eosin and Masson's trichrome stain to evaluate changes of granuloma sizes and numbers. Serum levels of the cytokines (TNF-α, IFN-γ, IL-4 and TGF-β1) were assessed in the sera of all groups by immunoassay. The measured levels of cytokines (IFN-γ, IL-4, TNF-α, TGF-β1) were found to be significantly increased in infected mice compared to normal control. At the same time, treated groups with silymarin alone or combined with PZQ showed significant decrease in IL-4, TNF-α and TGF-β1 levels compared to infected control. On the other hand, there was a significant increase in IFN-γ level observed in all treated groups compared to infected control. In addition, the histopathological examination of the liver in the group treated with PZQ showed a reduction in the number of livers eggs granuloma at all periods of sacrification compared with the infected untreated group. However, there was more decrease in granulomas diameter in both silymarin treated group or combined with PZQ at all periods of sacrification when compared to infected untreated group. In conclusion; treatment with silymarin combined with PZQ in murine schistosomiasis could reduce hepatic fibrosis by their action on the production of pro-inflammatory cytokines. PMID:27605811

  1. Miltefosine lipid nanocapsules: Intersection of drug repurposing and nanotechnology for single dose oral treatment of pre-patent schistosomiasis mansoni.

    PubMed

    El-Moslemany, Riham M; Eissa, Maha M; Ramadan, Alyaa A; El-Khordagui, Labiba K; El-Azzouni, Mervat Z

    2016-07-01

    A dual drug repurposing/nanotechnological approach was used to develop an alternative oral treatment for schistosomiasis mansoni using miltefosine (MFS), an anticancer alkylphosphocholine, and lipid nanocapsules (LNCs) as oral nanovectors. We demonstrated earlier that MFS possesses significant activity against different developmental stages of Schistosoma mansoni in the mouse model using 5 successive 20mg/kg/day oral doses. Moreover, an effective single dose (20mg/kg) oral treatment against the adult stage of S. mansoni in mice was developed using LNCs, particularly modified with CTAB, a positive charge imparting agent (MFS-LNC-CTAB(+)), or oleic acid as membrane permeabilizer (MFS-LNC-OA). Efficacy enhancement involved, at least in part, targeting of the worm tegument with MFS-LNCs as a new therapeutic entity. As the tegument surface charge and composition may differ in pre-patent stages of the parasite, it was of importance in the present study to assess the efficacy of a single oral dose of the two MFS-LNC formulations against invasive and immature stages for potential advantage relative to praziquantel. Results indicated potent schistosomicidal effects against both invasive and immature stages of S. mansoni in infected mice, efficacy being both formulation and developmental stage dependent. This was indicated by the significant reduction in the total worm burden of the invasive stage by 91.6% and 76.8% and the immature stage by 82.7% and 96.7% for MFS-LNC-CTAB+ and MFS-LNC-OA, respectively. Histopathological findings indicated amelioration of hepatic pathology with regression of the granulomatous inflammatory reaction and reduction in granulomas number and size, verifying marked improvement in architecture of hepatic lobules. From a clinical perspective, MFS-LNCs offer potential as an alternative single oral dose nanomedicine with a wide therapeutic profile for the mass chemotherapy of schistosomiasis mansoni. PMID:27039667

  2. Prophylactic effect of artemether on human schistosomiasis mansoni among Egyptian children: A randomized controlled trial.

    PubMed

    Elmorshedy, Hala; Tanner, Marcel; Bergquist, Robert N; Sharaf, Soraya; Barakat, Rashida

    2016-06-01

    A double-blind, randomized controlled trial was conducted in an endemic focus for Schistosoma mansoni in Kafr El-Sheikh Governorate, Northern Nile Delta, Egypt, to evaluate the prophylactic effect of artemether (ART) given in conjunction with praziquantel (PZQ). The study encompassed 913 primary school children randomly assigned to two treatment groups PZQ/ART and PZQ/ART-placebo. At baseline, both groups received 40 mg/kg body weight of PZQ twice four weeks apart, after which one group received 6 mg/kg body weight of ART every 3 weeks in 5 cycles during the transmission season and the other group received ART-placebo. At the end of the study, prevalence of infection among the PZQ/ART was approximately half that of the PZQ/ART-placebo group, i.e. 6.7% versus 11.6%, and incidence of new infections for the PZQ/ART was 2.7% versus 6.5% for the PZQ/ART-placebo. In conclusion, PZQ/ART combined therapy might be considered as an adjunct measure against human schistosomiasis, by specifically reducing transmission and therefore contribute to disease elimination. PMID:26921676

  3. The detection limits for estimates of infection intensity in schistosomiasis mansoni established by a study in non-human primates.

    PubMed

    Alan Wilson, R; van Dam, Govert J; Kariuki, Thomas M; Farah, Idle O; Deelder, André M; Coulson, Patricia S

    2006-10-01

    In human schistosomiasis mansoni, it is impossible to directly determine worm burden and hence infection intensity, so surrogates must be used. Studies on non-human primates revealed a linear relationship between worm burden and three surrogates, faecal egg output, circulating anodic and circulating cathodic antigens. By regression, the thresholds of detection were determined as 40, 24 and 47 worms, respectively. These observations provide a quantitative basis for the contention that low intensity infections in humans are being missed. The significance for estimates of disease prevalence, evaluation of the effects of chemotherapy and the implementation of vaccine trials is emphasised. PMID:16930605

  4. Schistosome-induced cholangiocyte proliferation and osteopontin secretion correlate with fibrosis and portal hypertension in human and murine schistosomiasis mansoni

    PubMed Central

    Pereira, Thiago A.; Syn, Wing-Kin; Machado, Mariana V.; Vidigal, Paula V.; Resende, Vivian; Voieta, Izabela; Xie, Guanhua; Otoni, Alba; Souza, Márcia M.; Santos, Elisângela T.; Chan, Isaac S.; Trindade, Guilherme V.M.; Choi, Steve S.; Witek, Rafal P.; Pereira, Fausto E.; Secor, William E.; Andrade, Zilton A.; Lambertucci, José Roberto

    2015-01-01

    Schistosomiasis is a major cause of portal hypertension worldwide. It associates with portal fibrosis that develops during chronic infection. The mechanisms by which the pathogen evokes these host responses remain unclear. We evaluated the hypothesis that schistosome eggs release factors that directly stimulate liver cells to produce osteopontin (OPN), a pro-fibrogenic protein that stimulates hepatic stellate cells to become myofibroblasts. We also investigated the utility of OPN as a biomarker of fibrosis and/or severity of portal hypertension. Cultured cholangiocytes, Kupffer cells and hepatic stellate cells were treated with soluble egg antigen (SEA); OPN production was quantified by quantitative reverse transcriptase polymerase chain reaction (qRTPCR) and ELISA; cell proliferation was assessed by BrdU (5-bromo-2'-deoxyuridine). Mice were infected with Schistosoma mansoni for 6 or 16 weeks to cause early or advanced fibrosis. Liver OPN was evaluated by qRTPCR and immunohistochemistry (IHC) and correlated with liver fibrosis and serum OPN. Livers from patients with schistosomiasis mansoni (early fibrosis n=15; advanced fibrosis n=72) or healthy adults (n=22) were immunostained for OPN and fibrosis markers. Results were correlated with plasma OPN levels and splenic vein pressures. SEA-induced cholangiocyte proliferation and OPN secretion (P<0.001 compared with controls). Cholangiocytes were OPN (+) in Schistosoma-infected mice and humans. Liver and serum OPN levels correlated with fibrosis stage (mice: r=0.861; human r=0.672, P=0.0001) and myofibroblast accumulation (mice: r=0.800; human: r=0.761, P=0.0001). Numbers of OPN (+) bile ductules strongly correlated with splenic vein pressure (r=0.778; P=0.001). S. mansoni egg antigens stimulate cholangiocyte proliferation and OPN secretion. OPN levels in liver and blood correlate with fibrosis stage and portal hypertension severity. PMID:26201095

  5. Evaluation of the use of C-terminal part of the Schistosoma mansoni 200kDa tegumental protein in schistosomiasis diagnosis and vaccine formulation.

    PubMed

    Carvalho, Gardênia Braz Figueiredo de; Pacífico, Lucila Gonçalves Grossi; Pimenta, Deborah Laranjeira Ferreira; Siqueira, Liliane Maria Vidal; Teixeira-Carvalho, Andréa; Coelho, Paulo Marcos Zech; Pinheiro, Carina da Silva; Fujiwara, Ricardo Toshio; Oliveira, Sergio Costa; Fonseca, Cristina Toscano

    2014-04-01

    Schistosoma mansoni tegument is involved in essential functions for parasite survival and represents a target for screening candidates for vaccine and diagnosis. Our group using reverse vaccinology selected six candidates, previously demonstrated by proteomics studies to be expressed in the parasite tegument, among them was Sm200. In this work we have cloned and expressed a recombinant form of Sm200 C-terminal (1069-1520) region. The efficacy of rSm200 (1069-1520) in the diagnosis of schistosomiasis and in the formulation of a vaccine against S. mansoni was assessed respectively in an ELISA based diagnostic assay and immunization protocols in mice. Significant differences between non-infected and acutely infected or chronically infected animals were observed and no cross-recognition was observed with sera from Ascaris suum or Ancylostoma ceylanicum infected mice. rSm200-ELISA test could also discriminate infected individuals from healthy donors not living in endemic area for schistosomiasis but failed to discriminate between individuals from a low endemic area for schistosomiasis known to have positive or negative stools after examination. Recombinant Sm200 also failed to induce protection against schistosomiasis, demonstrating that the C-terminal part of Sm200 is unable to induce protective immune response in mice. Therefore rSm200 (1069-1520)-ELISA represents an important tool to be used in the diagnosis of schistosomiasis. PMID:24560833

  6. Schistosomiasis

    MedlinePlus

    ... zi-a), is a disease caused by parasitic worms. Infection with Schistosoma mansoni, S. haematobium , and S. japonicum causes ... or washing in contaminated water. Within several weeks, worms grow inside the blood vessels of the body ...

  7. Lipid core peptide targeting the cathepsin D hemoglobinase of Schistosoma mansoni as a component of a schistosomiasis vaccine

    PubMed Central

    Dougall, Annette M; Dougall, Annette M

    2014-01-01

    The self-adjuvanting lipid core peptide (LCP) system offers a safe alternative vaccine delivery strategy, eliminating the need for additional adjuvants such as CpG Alum. In this study, we adopted the LCP as a scaffold for an epitope located on the surface of the cathepsin D hemoglobinase (Sm-CatD) of the human blood fluke Schistosoma mansoni. Sm-CatD plays a pivotal role in digestion of the fluke’s bloodmeal and has been shown to be efficacious as a subunit vaccine in a murine model of human schistosomiasis. Using molecular modeling we showed that S. mansoni cathepsin D possesses a predicted surface exposed α-helix (A263K) that corresponds to an immunodominant helix and target of enzyme–neutralizing antibodies against Necator americanus APR-1 (Na-APR-1), the orthologous protease and vaccine antigen from blood-feeding hookworms. The A263K epitope was engineered as two peptide variants, one of which was flanked at both termini with a coil maintaining sequence, thereby promoting the helical characteristics of the native A263K epitope. Some of the peptides were fused to a self-adjuvanting lipid core scaffold to generate LCPs. Mice were vaccinated with unadjuvanted peptides, peptides formulated with Freund’s adjuvants, or LCPs. Antibodies generated to LCPs recognized native Sm-CatD within a soluble adult schistosome extract, and almost completely abolished its enzymatic activity in vitro. Using immunohistochemistry we showed that anti-LCP antibodies bound to the native Sm-CatD protein in the esophagus and anterior regions of the gastrodermis of adult flukes. Vaccines offer an alternative control strategy in the fight against schistosomiasis, and further development of LCPs containing multiple epitopes from this and other vaccine antigens should become a research priority. PMID:24231271

  8. Expression at a 20L scale and purification of the extracellular domain of the Schistosoma mansoni TSP-2 recombinant protein: a vaccine candidate for human intestinal schistosomiasis.

    PubMed

    Curti, Elena; Kwityn, Clifford; Zhan, Bin; Gillespie, Portia; Brelsford, Jill; Deumic, Vehid; Plieskatt, Jordan; Rezende, Wanderson C; Tsao, Eric; Kalampanayil, Bose; Hotez, Peter J; Bottazzi, Maria Elena

    2013-11-01

    A novel recombinant protein vaccine for human schistosomiasis caused by Schistosoma mansoni is under development. The Sm-TSP-2 schistosomiasis vaccine is comprised of a 9 kDa recombinant protein corresponding to the extracellular domain of a unique S. mansoni tetraspanin. Here, we describe the cloning and the expression of the external loop of Sm-TSP-2 recombinant protein secreted by Pichia Pink the process development at 20L scale fermentation, and the two-steps purification, which resulted in a protein recovery yield of 31% and a protein purity of 97%. The developed processes are suitable for the production of purified protein for subsequent formulation and Phase 1 clinical studies. PMID:23899507

  9. Factors associated with schistosomiasis mansoni in a population from the municipality of Jaboticatubas, State of Minas Gerais, Brazil.

    PubMed

    Massara, Cristiano Lara; Peixoto, Sérgio Viana; Barros, Héliton da Silva; Enk, Martin Johannes; Carvalho, Omar dos Santos; Schall, Virgínia

    2004-01-01

    Jaboticatubas is a municipality in the metropolitan region of Belo Horizonte which has been a target of a wide media release as "the capital of schistosomiasis" since the 1960's. In order to give support to a work based on an integrated control, we sought to identify the disease determinants at the site. A transversal study was carried out aimed at identifying prevalence rates of the disease and factors associated with the infection in the district of São José de Almeida, and two close localities, Cipó Velho and São José da Serra, all of them located in the municipality of Jaboticatubas. A parasitological survey was performed, applying the Kato-Katz method with two slides per sample in 1186 schoolchildren which represents 77% of all registered pupils in four public schools in 2001. Among these schoolchildren a number of 101 (8.6%) proved positive for Schistosoma mansoni eggs in their stool samples. A total of 64 families, whose schoolchildren had shown to be positive for schistosomiasis, also undertook examinations. As negative control, a random sample was collected from the 206 families, whose children had proven negative for schistosomiasis. The prevalence among 270 families (1304 people) was 12%. To assess those who continued to have contact with possibly contaminated water, 1061 (81.4%) people of the 270 families were interviewed. A multivariate analysis identified the following factors associated with the infection: time of residence in the area (short period), garbage disposal (use of deserted areas), gender (male), age (from 10 to 29 years), and water contact (daily and weekly). Further analysis of these factors revealed a close correlation between water contact and the disease, with a positive significant frequency concerning almost all those items. Depending on gender and age significant variations of water contact patterns associated with leisure and professional activities were found. A malacological survey on water collections in the area

  10. Sustaining Control of Schistosomiasis Mansoni in Western Côte d’Ivoire: Results from a SCORE Study, One Year after Initial Praziquantel Administration

    PubMed Central

    Assaré, Rufin K.; Tian-Bi, Yves-Nathan T.; Yao, Patrick K.; N’Guessan, Nicaise A.; Ouattara, Mamadou; Yapi, Ahoua; Coulibaly, Jean T.; Meïté, Aboulaye; Hürlimann, Eveline; Knopp, Stefanie; Utzinger, Jürg; N’Goran, Eliézer K.

    2016-01-01

    Background The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) has launched several large-scale trials to determine the best strategies for gaining and sustaining control of schistosomiasis and transitioning toward elimination. In Côte d’Ivoire, a 5-year cluster-randomized trial is being implemented in 75 schools to sustain the control of schistosomiasis mansoni. We report Schistosoma mansoni infection levels in children one year after the initial school-based treatment (SBT) with praziquantel and compare with baseline results to determine the effect of the intervention. Methodology The baseline cross-sectional survey was conducted in late 2011/early 2012 and the first follow-up in May 2013. Three consecutive stool samples were collected from 9- to 12-year-old children in 75 schools at baseline and 50 schools at follow-up. Stool samples were subjected to duplicate Kato-Katz thick smears. Directly observed treatment (DOT) coverage of the SBT was assessed and the prevalence and intensity of S. mansoni infection compared between baseline and follow-up. Principal Findings The S. mansoni prevalence in the 75 schools surveyed at baseline was 22.1% (95% confidence interval (CI): 19.5–24.4%). The DOT coverage was 84.2%. In the 50 schools surveyed at baseline and one year after treatment, the overall prevalence of S. mansoni infection decreased significantly from 19.7% (95% CI: 18.5–20.8%) to 12.8% (95% CI: 11.9–13.8%), while the arithmetic mean S. mansoni eggs per gram of stool (EPG) among infected children slightly increased from 92.2 EPG (95% CI: 79.2–105.3 EPG) to 109.3 EPG (95% CI: 82.7–135.9 EPG). In two of the 50 schools, the prevalence increased significantly, despite a DOT coverage of >75%. Conclusions/Significance One year after the initial SBT, the S. mansoni prevalence had decreased. Despite this positive trend, an increase was observed in some schools. Moreover, the infection intensity among S. mansoni-infected children

  11. Clinical-epidemiologic study of schistosomiasis mansoni in Ponte do Pasmado, a village in the municipality of Itinga, state of Minas Gerais, Brazil, 1992.

    PubMed

    Rodrigues, R N; Murta, C; Teixeira Júnior, M A; Cury, G C; Rocha, M O

    1995-01-01

    A clinical-epidemiologic study of schistosomiasis mansoni was conducted in the population of Ponte do Pasmado, a village in the municipality of Itinga, state of Minas Gerais, Brazil. Faecal parasitology by the Kato-Katz method and clinical examination were performed in 93.8% and 82.8% of the local population, respectively. A socioeconomic survey was also made and the signs and symptoms presented by the patients were recorded, as well as their contacts with natural waters. The rate of Schistosoma mansoni infection was 50.3%; the peak of infection occurred during the second decade of life; there was a predominance of low egg counts in faeces (85.89% of positive patients eliminated less than 500 eggs per gram of faeces); the splenomegaly rate was 1.23%. When the risk factors for S. mansoni infection were studied, significant risks were detected in activities such as fetching water, washing dishes, bathing, and crossing streams. PMID:7569646

  12. Experimental evaluation of Candonocypris novaezelandiae (Crustacea: Ostracoda) in the biocontrol of Schistosomiasis mansoni transmission

    PubMed Central

    Yousif, Fouad; Hafez, Sherif; El Bardicy, Samia; Tadros, Menerva; Taleb, Hoda Abu

    2013-01-01

    Objective To test Candonocypris novaezelandiae (Baird) (C. novaezelandiae), sub-class Ostracoda, obtained from the Nile, Egypt for its predatory activity on snail, Biomphalaria alexandrina (B. alexandrina), intermediate host of Schistosoma mansoni (S. mansoni) and on the free-living larval stages of this parasite (miracidia and cercariae). Methods The predatory activity of C. novaezelandiae was determined on B. alexandrina snail (several densities of eggs, newly hatched and juveniles). This activity was also determined on S. mansoni miracidia and cercariae using different volumes of water and different numbers of larvae. C. novaezelandiae was also tested for its effect on infection of snails and on the cercarial production. Results C. novaezelandiae was found to feed on the eggs, newly hatched and juvenile snails, but with significant reduction in the consumption in the presence of other diet like the blue green algae (Nostoc muscorum). This ostracod also showed considerable predatory activity on the free-living larval stages of S. mansoni which was affected by certain environmental factors such as volume of water, density of C. novaezelandiae and number of larvae of the parasite. Conclusions The presence of this ostracod in the aquatic habitat led to significant reduction of snail population, infection rate of snails with schistosme miracidia as well as of cercarial production from the infected snails. This may suggest that introducing C. novaezelandiae into the habitat at schistosome risky sites could suppress the transmission of the disease. PMID:23620849

  13. Evaluation of the Schistosoma mansoni Y-box-binding protein (SMYB1) potential as a vaccine candidate against schistosomiasis.

    PubMed

    Dias, Sílvia R C; Boroni, Mariana; Rocha, Elizângela A; Dias, Thomaz L; de Laet Souza, Daniela; Oliveira, Fabrício M S; Bitar, Mainá; Macedo, Andrea M; Machado, Carlos R; Caliari, Marcelo V; Franco, Glória R

    2014-01-01

    Schistosomiasis is a neglected tropical disease, and after malaria, is the second most important tropical disease in public health. A vaccine that reduces parasitemia is desirable to achieve mass treatment with a low cost. Although potential antigens have been identified and tested in clinical trials, no effective vaccine against schistosomiasis is available. Y-box-binding proteins (YBPs) regulate gene expression and participate in a variety of cellular processes, including transcriptional and translational regulation, DNA repair, cellular proliferation, drug resistance, and stress responses. The Schistosoma mansoni ortholog of the human YB-1, SMYB1, is expressed in all stages of the parasite life cycle. Although SMYB1 binds to DNA or RNA oligonucleotides, immunohistochemistry assays demonstrated that it is primarily localized in the cytoplasm of parasite cells. In addition, SMYB1 interacts with a protein involved in mRNA processing, suggesting that SMYB1 functions in the turnover, transport, and/or stabilization of RNA molecules during post-transcriptional gene regulation. Here we report the potential of SMYB1 as a vaccine candidate. We demonstrate that recombinant SMYB1 stimulates the production of high levels of specific IgG1 antibodies in a mouse model. The observed levels of specific IgG1 and IgG2a antibodies indicate an actual protection against cercariae challenge. Animals immunized with rSMYB1 exhibited a 26% reduction in adult worm burden and a 28% reduction in eggs retained in the liver. Although proteins from the worm tegument are considered optimal targets for vaccine development, this study demonstrates that unexposed cytoplasmic proteins can reduce the load of intestinal worms and the number of eggs retained in the liver. PMID:24966869

  14. Environmental epidemiology of intestinal schistosomiasis and genetic diversity of Schistosoma mansoni infections in snails at Bugoigo village, Lake Albert.

    PubMed

    Levitz, Sarah; Standley, Claire J; Adriko, Moses; Kabatereine, Narcis B; Stothard, J Russell

    2013-11-01

    Intestinal schistosomiasis continues to be hyper-endemic in the fishing community of Bugoigo located on the eastern shore of Lake Albert, Uganda. Our study aimed to identify the factors that determine the local distribution and abundance of Biomphalaria, as well as infection(s) with Schistosoma mansoni inclusive of their genetic diversity. In addition, a DNA barcoding approach was taken to genotype schistosome cercariae, exploring the micro-epidemiology of infections. Over a 3-week period in June-July 2010, several hundred Biomphalaria spp. were collected, together with environmental information, from 10 selected sites, representative of both putative wave-exposed (n=5) and wave-sheltered shorelines (n=5). A Mann-Whitney U-test and a generalized linear model were used to assess associations with snail abundance and parasite infections across the shoreline. Levels of local wave action were recorded over the 19-day period using digital accelerometers. The general absence of wave action on the sheltered shoreline likely helped to raise and focalize other environmental parameters, such as water conductivity by lack of mixing, that foster transmission of intestinal schistosomiasis. Over the study period, a total of 10 infected snails were encountered and a selection of schistosome cercariae from each infected snail was harvested for analysis by DNA barcoding. In total, 91 DNA barcodes were generated with 15 unique barcode types identified. Of these, 4 barcodes had been found previously in Lake Albert and (or) Victoria, the remaining 11 were newly encountered here and described. The distribution of DNA barcodes across infected snails and sampled locations revealed a complicated spatial sub-structuring. By shedding new light on the fine-scale patterning of infections, DNA barcoding has revealed a rather heterogeneous landscape of cercariae, likely inclusive of multi-miracidial infections within the snail, which will in turn interplay with human water contact activities to

  15. Evaluation of a 25-Year-Program for the Control of Schistosomiasis Mansoni in an Endemic Area in Brazil

    PubMed Central

    Sarvel, Ana K.; Oliveira, Áureo A.; Silva, Alexandre R.; Lima, Anna C. L.; Katz, Naftale

    2011-01-01

    Background Various studies showed that chemotherapy can control schistosomiasis morbidity, but association of measures (water supply, sewage disposal and increase of socioeconomic conditions) is necessary for transmission control. Methodology/Principal Findings A survey dealing with socioeconomic conditions, snail survey, contact with natural waters, and clinical and stool examinations was undertaken at an endemic area in the State of Minas Gerais, Brazil. The methodology used was the same for both evaluations (1981 and 2005). Four hundred and seventy-five out of 1,474 individuals studied in 1981 could be contacted. From these, 358 were submitted to stool examination, and 231 of them were clinically examined. Patients eliminating S. mansoni eggs in their stools were treated. The results showed that the prevalence rate in Comercinho, a municipality of the State of Minas Gerais, Brazil, was substantially reduced to 70.4% and 1.7% in 1981 and 2005, respectively, as well as the frequency of the hepatosplenic form (7% to 1.3%) after five treatments effectuated between 1981 and 1992. No other new case of this form was detected from 1981 onwards. Another important aspect to be considered was the improvement of people's living standard that occurred in the region after more than two decades' efforts (better housing, professional skill and adequate basic sanitation). Conclusion/Significance The control of morbidity and very significant decrease of schistosomiasis transmission in an area until then considered as hyperendemic was possible by means of association of successive specific treatments of the local population, together with the construction of privies, water supply in the houses and improvement of socioeconomic conditions. PMID:21423644

  16. Structure-Based Design and Synthesis of Novel Inhibitors Targeting HDAC8 from Schistosoma mansoni for the Treatment of Schistosomiasis.

    PubMed

    Heimburg, Tino; Chakrabarti, Alokta; Lancelot, Julien; Marek, Martin; Melesina, Jelena; Hauser, Alexander-Thomas; Shaik, Tajith B; Duclaud, Sylvie; Robaa, Dina; Erdmann, Frank; Schmidt, Matthias; Romier, Christophe; Pierce, Raymond J; Jung, Manfred; Sippl, Wolfgang

    2016-03-24

    Schistosomiasis is a major neglected parasitic disease that affects more than 265 million people worldwide and for which the control strategy consists of mass treatment with the only available drug, praziquantel. In this study, a series of new benzohydroxamates were prepared as potent inhibitors of Schistosoma mansoni histone deacetylase 8 (smHDAC8). Crystallographic analysis provided insights into the inhibition mode of smHDAC8 activity by these 3-amidobenzohydroxamates. The newly designed inhibitors were evaluated in screens for enzyme inhibitory activity against schistosome and human HDACs. Twenty-seven compounds were found to be active in the nanomolar range, and some of them showed selectivity toward smHDAC8 over the major human HDACs (1 and 6). The active benzohydroxamates were additionally screened for lethality against the schistosome larval stage using a fluorescence-based assay. Four of these showed significant dose-dependent killing of the schistosome larvae and markedly impaired egg laying of adult worm pairs maintained in culture. PMID:26937828

  17. Crystal Structure of Schistosoma mansoni Arginase, a Potential Drug Target for the Treatment of Schistosomiasis

    PubMed Central

    2015-01-01

    The X-ray crystal structure of arginase from Schistosoma mansoni (SmARG) and the structures of its complexes with several amino acid inhibitors have been determined at atomic resolution. SmARG is a binuclear manganese metalloenzyme that catalyzes the hydrolysis of l-arginine to form l-ornithine and urea, and this enzyme is upregulated in all forms of the parasite that interact with the human host. Current hypotheses suggest that parasitic arginases could play a role in host immune evasion by depleting pools of substrate l-arginine that would otherwise be utilized for NO biosynthesis and NO-dependent processes in the immune response. Although the amino acid sequence of SmARG is only 42% identical with that of human arginase I, residues important for substrate binding and catalysis are strictly conserved. In general, classical amino acid inhibitors such as 2(S)-amino-6-boronohexanoic acid (ABH) tend to bind more weakly to SmARG than to human arginase I despite identical inhibitor binding modes in each enzyme active site. The identification of a patch on the enzyme surface capable of accommodating the additional Cα substitutent of an α,α-disubstituted amino acid inhibitor suggests that such inhibitors could exhibit higher affinity and biological activity. The structures of SmARG complexed with two different α,α-disubstituted derivatives of ABH are presented and provide a proof of concept for this approach in the enhancement of enzyme–inhibitor affinity. PMID:25007099

  18. Early detection of circulating anodic antigen (CAA) in a case of acute schistosomiasis mansoni with Katayama fever.

    PubMed

    Gundersen, S G; Ravn, J; Haagensen, I

    1992-01-01

    A 34-year-old male developed acute Katayama fever with fever, diarrhoea, joint pains, headache, urticarial rash and eosinophilia 18 days after falling into and spending 15 min in the water during water-skiing in the outlet of the Volta river. Low anti-schistosomal antibody titres were found by the immunofluorescence assay after 4 weeks, and the first Schistosoma mansoni eggs were found in faeces after 6 weeks. Both symptoms and eosinophilia increased the first days after treatment with oxamniquine, after which he improved gradually. Examination of frozen sera by the newly developed Magnetic Beads Antigen Capture-EIA (MBAC-EIA) later demonstrated a peak in schistosomal circulating anodic antigen (CAA) levels of diagnostic significance already 4 weeks after he was infected. PMID:1411323

  19. Relationship between serum cytokines profiles and hepatic fibrosis in schistosomiasis mansoni: an experimental study.

    PubMed

    El-Gamal, Reda R; Nada, Soad M; Moustafa, Nahed E; Afify, Hany A; Fathy, Ghada M; Ashraf; Metwally, S; Hamza, Rania S

    2009-12-01

    Forty of eighty mice (10 each group) were infected with S. mansoni cercariae and sacrificed at 3 weeks (G-A), 6 weeks (G-B), 12 weeks (G-C) and 16 weeks (G-D) post infection (P.I). The other forty mice were used as control groups of ten mice each. There were highly significant difference between egg counts after 12 weeks & 16 weeks of infection compared to 6 weeks P.I. The maximum egg count and mature eggs were in 6th week P.I while dead eggs reached the peak at 16th weeks P.I. Liver egg counts showed maximum followed by intestinal and then, stool egg counts. A highly significant differences in hydroxyproline, TGF-Bland IL-4 of infected than in controls and their peak at 16 weeks P.I. A significant difference in the IFN-gamma in the infected than in controls with peak occurred at 6 weeks P.I. and declined after that reaching a low level at 16 weeks P.I. A highly significant positive correlation was between TGF-Bland IL4 and significant negative correlation between IFN-gamma and both IL4 & TGF-B1. A highly significant and significant negative correlation between TGF-B1 and egg count at 12 & 16 weeks P.I respectively. Negative correlation was between IL-4 and egg count at 16 weeks P.I. But, significant positive correlation was between IFN-gamma with the egg count at 16 weeks P.I. A significant negative correlation was between TGF-B1 and oogram at 6 & 16 weeks P.I, but highly significant positivity was between IFN-gamma and oogram at 16 weeks P.I. A significant negative correlation was between IL-4 and oogram at 16 weeks P.I. A significant positive correlation was between levels of hydroxyproline and TGF-B1 at 12 & 16 weeks P.I. Highly significant negative correlation between hydroxyproline and IFN-gamma was at 12 weeks P.I with significant and highly significant positive correlation between hydroxyproline and IL4 at 12 & 16 weeks P.I. PMID:20120754

  20. Study of the Activity of 3-benzyl-5-(4-chloro-arylazo)-4-thioxo-imidazolidin-2-one against Schistosomiasis Mansoni in Mice

    PubMed Central

    da Silva, Andréa Cristina Apolinário; Neves, Juliana Kelle de Andrade Lemoine; Irmão, João Inácio; Costa, Vláudia Maria Assis; Souza, Valdênia Maria Oliveira; de Medeiros, Paloma Lys; da Silva, Eliete Cavalcanti; de Lima, Maria do Carmo Alves; Pitta, Ivan da Rocha; Albuquerque, Mônica Camelo Pessoa de Azevedo; Galdino, Suely Lins

    2012-01-01

    Previous studies conducted with the imidazolidinic derivative 3-benzyl-5-(4-chloro-arylazo)-4-thioxo-imidazolidin-2-one (LPSF-PT05) show outstanding activity against adult Schistosoma mansoni worms in vitro. In the first phase of this study, S. mansoni-infected mice were treated, orally, with 100 mg/Kg of the LPSF-PT05 in three formulations: Tween 80 and saline solution, oil/water (70 : 30) emulsion, and solid dispersion with polyethylene glycol (PEG). In the second phase, three other doses of the LPSF-PT05 in PEG were tested: 3, 10, 30 mg/kg. These treatment regimens significantly reduced the number of recovered worms due to increases in the solubility of the compound in this formulation; the greatest reduction (70.5%) was observed at the dose of 100 mg/kg. There was no changes in the pattern of mature egg compared to immature eggs; however there was a significant increase in the number of dead eggs. Histopathological analysis of liver tissue showed changes in morphological aspects of the hepatic parenchyma with decrease exudative-productive hepatic granuloma stages, although we found no significant differences in IFN-γ, IL-4, IL-10, or NO production in response to the specific antigen SEA. The results show the derivative LPSF-PT05 to be a potential candidate in the etiological treatment of schistosomiasis with a possible dampening effect of the granulomatous process. PMID:22623908

  1. Evaluation of parasitological and molecular techniques for the diagnosis and assessment of cure of schistosomiasis mansoni in a low transmission area

    PubMed Central

    Siqueira, Liliane Maria Vidal; Gomes, Luciana Inácia; Oliveira, Edward; de Oliveira, Eduardo Ribeiro; de Oliveira, Áureo Almeida; Enk, Martin Johannes; Carneiro, Nídia Figueiredo; Rabello, Ana; Coelho, Paulo Marcos Zech

    2015-01-01

    This study evaluated parasitological and molecular techniques for the diagnosis and assessment of cure of schistosomiasis mansoni. A population-based study was performed in 201 inhabitants from a low transmission locality named Pedra Preta, municipality of Montes Claros, state of Minas Gerais, Brazil. Four stool samples were analysed using two techniques, the Kato-Katz® (KK) technique (18 slides) and the TF-Test®, to establish the infection rate. The positivity rate of 18 KK slides of four stool samples was 28.9% (58/201) and the combined parasitological techniques (KK+TF-Test®) produced a 35.8% positivity rate (72/201). Furthermore, a polymerase chain reaction (PCR)-ELISA assay produced a positivity rate of 23.4% (47/201) using the first sample. All 72 patients with positive parasitological exams were treated with a single dose of Praziquantel® and these patients were followed-up 30, 90 and 180 days after treatment to establish the cure rate. Cure rates obtained by the analysis of 12 KK slides were 100%, 100% and 98.4% at 30, 90 and 180 days after treatment, respectively. PCR-ELISA revealed cure rates of 98.5%, 95.5% and 96.5%, respectively. The diagnostic and assessment of cure for schistosomiasis may require an increased number of KK slides or a test with higher sensitivity, such as PCR-ELISA, in situations of very low parasite load, such as after therapeutic interventions. PMID:25946244

  2. Diagnostic significance of Schistosoma mansoni proteins Sm31 and Sm32 in human schistosomiasis in an endemic area in Egypt.

    PubMed

    El-Sayed, L H; Ghoneim, H; Demian, S R; El-Sayed, M H; Tawfik, N M; Sakr, I; Abou-Basha, L M; Renganathan, E; Klinkert, M Q; Abou-Rawash, N

    1998-09-01

    We performed a series of ELISAs to evaluate the diagnostic significance of two Schistosoma mansoni proteins, Sm31 (cysteine proteinase, cathepsin B) and Sm32 (asparaginyl endopeptidase). Our study populations were chosen from two villages in an endemic area close to Alexandria. Using fusion proteins MS2-Sm31 and MS2-Sm32 as antigens, 70% and 78.9%, respectively, of patient sera from 134 parasitologically confirmed cases reacted positively. The percentage of seropositivity increased to 84.5% when parasite-derived proteins Sm31 and Sm32 were used. The serum levels of antibodies to these two proteins in recombinant or native forms do not correlate with intensity of infection and hence are detected even when egg counts are low, which makes proteins Sm31 and Sm32 useful antigens in the identification of S. mansoni infected cases, particularly in endemic areas in Egypt. PMID:9754667

  3. Characterization of antigens from Schistosoma mansoni and construction of a cDNA library for the study of schistosomiasis

    SciTech Connect

    Bugra, K.

    1986-01-01

    To examine the antigens of adult Schistosoma mansoni, /sup 35/S-methionine-labelled, detergent-extracted proteins were immunoprecipitated and analyzed on SDS-PAGE. Human infection serum immunoprecipitated 14 polypeptides with M/sub r/'s of 120, 105, 88, 86, 66, 64, 54, 48, 42, 38, 35, 32, 29, and 20 Kd. Upon digestion with endoglycosidase F polypeptides with M/sub r/'s of 120, 105, 54, 48, and 29 appeared to have carbohydrate moieties. Extracts of female and male S. mansoni were analyzed by immunoprecipitation and immunoblotting. Two polypeptides with M/sub r/'s of 86 Kd and 54 Kd were detected only in extracts of males. Polyadenylated RNA was extracted from S. mansoni and translated in rabbit reticulocyte lysates. Among the in vitro translation products, polypeptides with 120, 94, 64, 43, 37, 35, 30, 26 and 22 Kd apparent molecular weights were immunoprecipitated by human infection serum. When the translation products of female worms and male worms were compared, the polypeptides with M/sub r/'s of 94 and 64 Kd were only observed in males.

  4. [Schistosomiasis caused by Schistosoma mansoni in the Kou valley: Characterization of the transmission system and socioeconomic impact].

    PubMed

    Kpoda, Noëllie W; Sorgho, Herman; Poda, Jean-Noël; Ouédraogo, Jean Bosco; Kabré, Gustave B

    2013-01-01

    Schistosomiasis is one of the waterborne diseases which benefit from environmental and behavioral changes induced by the mobilization of surface water resources in Sahelian countries, such as Burkina Faso. Studies have established the existence of human schistosomiasis in the Kou valley, one of the oldest hydro-agricultural zones in the country. However, the role of population behavior in the transmission pattern of this disease and its socioeconomic impact in this valley are poorly understood. It is in response to these questions that this study was undertaken. The objectives of this study were to identify activities that exposed most of the Valley's population to infection by schistosomiasis, and to contribute knowledge on the consequences of this disease. The study was conducted in the cold dry season at the Kou Valley, located in the South Sudanese area of Burkina Faso. It has adopted the strategy of direct observation to examine host-parasites interactions. The study of the socioeconomic consequences of the infection has been first to identify subjects that actually carry the parasite by screening the population by the Kato-Katz method. These were then subjected to a questionnaire. Data were analyzed using Epi Info 6.4. This work has revealed six activities at risk of infection for the residents of the Valley with an increased risk of factor for rice farming, household activities and swimming. In view of these activities, women and young people seem to be most vulnerable to infection. This disease causes significant economic losses as a function of socio-professional categories of infected persons. PMID:23916204

  5. Cutaneous ectopic schistosomiasis: diagnostic challenge.

    PubMed

    Barros, Cláudia Renata Castro do Rêgo; Maia, Daniela Cristina Caetano; dos Santos, Josemir Belo; Medeiros, Camila Carolina Queiroz; de Araújo, Jessica Guido

    2016-01-01

    Cutaneous schistosomiasis is a rare clinical manifestation of schistosomiasis, an infectious and parasitic disease, caused in Brazil by the trematode Schistosoma mansoni. The lesions are due to the deposition of eggs or, rarely, adult worms, usually involving the genital and groin areas. Extra-genital lesions occur mainly on the torso as papules of zosteriform appearance. The case of a patient with ectopic cutaneous schistosomiasis is reported in this article, due to the rarity of its occurrence and its difficult clinical diagnosis. PMID:26982792

  6. CT of hepatic schistosomiasis mansoni

    SciTech Connect

    Fataar, S.; Bassiony, H.; Satyanath, S.; Rudwan, M.A.; Khaffaji, S.; El Magdy, W.; Al-Ansari, A.G.; Hanna, R.

    1985-07-01

    Schistosomal periportal fibrosis produced a typical pattern on computed tomography in five patients. Low-density periportal tissue, present throughout the liver, enhanced strongly after the administration of contrast medium. While rounded in cross section, the thickened periportal tissue produced linear and branching patterns when imaged in longitudinal section. In all cases, the sonographic features were typical of schistosomal periportal fibrosis. A lack of awareness of the distinctive features of periportal fibrosis may result in a mistaken diagnosis of hepatic metastases.

  7. Immunization of Baboons with Schistosoma mansoni Cercariae attenuated by gamma irradiation

    SciTech Connect

    Stek, M.; Minard, P.; Dean, D.A.; Hall, J.E.

    1981-06-01

    Studies on the efficacy of a vaccine against schistosomiasis in young baboons (Papio anubis) disclosed that immunization with Schistosoma mansoni cercariae attenuated by gamma irradiation induced significant protection against subsequent infection with normal, viable S. mansoni cercariae. Such immunization resulted in reduced worm burdens (70 percent) and egg excretion rates (82 percent). These results support immunization as a potential method for schistosomiasis control.

  8. Immunization of baboons with Schistosoma mansoni cercariae attenuated by gamma irradiation

    SciTech Connect

    Stek, M. Jr.; Minard, P.; Dean, D.A.; Hall, J.E.

    1981-06-26

    Studies on the efficacy of a vaccine against schistosomiasis in young baboons (Papio anubis) disclosed that immunization with Schistosoma mansoni cercariae attenuated by gamma irradiation induced significant protection against subsequent infection with normal, viable S. mansoni cercariae. Such immunization resulted in reduced worm burdens (70%) and egg excretion rates (82%). These results support immunization as a potential method for schistosomiasis control.

  9. Spinal cord schistosomiasis

    PubMed Central

    Adeel, Ahmed Awad

    2015-01-01

    Acute myelopathy is increasingly being recognized as a common neurological complication of schistosomiasis. Schistosome eggs reach the spinal cord either as egg emboli or as eggs produced by ectopic worms. This leads to inflammatory reaction and granuloma formation around the eggs. Patients with spinal schistosomiasis may not have clinical evidence of schistosomiasis. The typical clinical picture is that of lumbar pain preceded by other symptoms by hours or up to 3 weeks. Patients may present with paraparesis, urinary retention or paraplegia. Definitive diagnosis of spinal cord schistosomiasis is by detection of the eggs in a spinal cord biopsy or at autopsy. However, most cases are diagnosed based on a presumptive diagnosis that depends on a suggestive clinical picture, history or evidence of active schistosomiasis and exclusion of other conditions. Investigations include stools and urine examination for schistosome eggs, blood tests, magnetic resonance imaging (MRI) and examination of the cerebrospinal fluid. Treatment of cases is mainly by praziquantel, corticosteroids, surgical intervention and rehabilitation.

  10. Ultrasound assessment of schistosomiasis.

    PubMed

    Richter, J; Botelho, M C; Holtfreter, M C; Akpata, R; El Scheich, T; Neumayr, A; Brunetti, E; Hatz, C; Dong, Y; Dietrich, C F

    2016-07-01

    In 2000, the World Health Organization (WHO) issued an ultrasound field protocol for assessing the morbidity due to Schistosoma (S.) haematobium and S. mansoni. The experience with this classification has recently been reviewed systematically. The WHO protocol was well accepted worldwide. Here we review the use of ultrasound to assess the morbidity due to schistosomiasis with emphasis on easy, quick, and reproducible ways that can be used in the field. Findings obtained with high-end ultrasound scanners in the hospital setting that might eventually have applications in the field are also described. PMID:27429103

  11. Metabolic profiling of a Schistosoma mansoni infection in mouse tissues using magic angle spinning-nuclear magnetic resonance spectroscopy.

    PubMed

    Li, Jia V; Holmes, Elaine; Saric, Jasmina; Keiser, Jennifer; Dirnhofer, Stephan; Utzinger, Jürg; Wang, Yulan

    2009-04-01

    In order to enhance our understanding of physiological and pathological consequences of a patent Schistosoma mansoni infection in the mouse, we examined the metabolic responses of different tissue samples recovered from the host animal using a metabolic profiling strategy. Ten female NMRI mice were infected with approximately 80 S. mansoni cercariae each, and 10 uninfected age- and sex-matched animals served as controls. At day 74 post infection (p.i.), mice were killed and jejunum, ileum, colon, liver, spleen and kidney samples were removed. We employed (1)H magic angle spinning-nuclear magnetic resonance spectroscopy to generate tissue-specific metabolic profiles. The spectral data were analyzed using multivariate modelling methods including an orthogonal signal corrected-projection to latent structure analysis and hierarchical principal component analysis to assess the differences and/or similarities in metabolic responses between infected and non-infected control mice. Most tissues obtained from S. mansoni-infected mice were characterized by high levels of amino acids, such as leucine, isoleucine, lysine, glutamine and asparagine. High levels of membrane phospholipid metabolites, including glycerophosphoryl choline and phosphoryl choline were found in the ileum, colon, liver and spleen of infected mice. Additionally, low levels of energy-related metabolites, including lipids, glucose and glycogen were observed in ileum, spleen and liver samples of infected mice. Energy-related metabolites in the jejunum, liver and renal medulla were found to be positively correlated with S. mansoni worm burden upon dissection. These findings show that a patent S. mansoni infection causes clear disruption of metabolism in a range of tissues at a molecular level, which can be interpreted in relation to the previously reported signature in a biofluid (i.e. urine), giving further evidence of the global effect of the infection. PMID:19068218

  12. [Parasitological characteristics, epidemiological and clinical features, and current control approaches for three major kinds of human schistosomiasis].

    PubMed

    Xu, Xiao-Lin; Zhu, Rong; Zhang, Li-Juan; Guo, Jia-Gang

    2013-06-01

    Schistosomiasis is a tropical disease, which could do serious damage to the people's health, and it hinders the development of the social economy but may be neglected. After a positive control, some countries and regions have blocked the spread of schistosomiasis. However, in the past few years, with the development of social economy, due to the global movement of people, schistosomiasis not only poses a threat to control areas, but also may cause new endemic areas. This article reviews the parasitological characteristics, clinical manifestations, epidemiological situation, and control approaches of three major kinds of human schistosomiasis, schistosomiasis japonica, schistosomiasis haematobia, and schistosomiasis mansoni. PMID:24024456

  13. Effectiveness of hyperbaric oxygen for experimental treatment of schistosomiasis mansoni using praziquantel-free and encapsulated into liposomes: assay in adult worms and oviposition.

    PubMed

    Frezza, Tarsila Ferraz; de Souza, Ana Luiza Ribeiro; Prado, César Corat Ribeiro; de Oliveira, Claudineide Nascimento Fernandes; Gremião, Maria Palmira Daflon; Giorgio, Selma; Dolder, Mary Anne Heidi; Joazeiro, Paulo Pinto; Allegretti, Silmara Marques

    2015-10-01

    The treatment of schistosomiasis depends on a single drug: praziquantel (PZQ). However, this treatment presents limitations such as low and/or erratic bioavailability that can contribute to cases of tolerance. Improvements to the available drug are urgently needed and studies with a controlled system of drug release, like liposomes, have been gaining prominence. The present study evaluated the activity and synergy between liposomal-praziquantel (lip.PZQ) and hyperbaric oxygen therapy (HBO). Mice received doses of 60 or 100mg/kg PZQ or lip.PZQ, 50 days post-infection, and after the treatment, were exposed to HBO (3 atmosphere absolute - ATA) for 1h. The viability of adult worms and oviposition were analyzed, by necropsy and Kato-Katz examination performed after 15 days of treatment. A concentration of 100mg/kg of lip.PZQ+HBO was more effective (48.0% reduction of worms, 83.3% reduction of eggs/gram of feces) and 100% of the mice had altered of oograms (indicating interruption of oviposition) compared to other treatments and to the Control group (infected and untreated). It is known that PZQ requires participation of the host immune system to complete its antischistosomal activity and that HBO is able to stimulate the immune system. The drug became more available in the body when incorporated into liposomes and, used with HBO, the HBO worked as an adjuvant. This explains the decreases of oviposition and worms recovered form hepatic portal system. PMID:26215128

  14. Studies on Parasitologic and Haematologic Activities of an Enaminone Derivative of 4-Hydroxyquinolin-2(1H)-one Against Murine Schistosomiasis Mansoni

    PubMed Central

    El-Shennawy, Amal M.; Mohamed, Amira H.; Mohamed Abass

    2007-01-01

    The activity of a novel enaminone derivative of 4–hydroxyquinoline, BDHQ, was screened for its effectiveness against murine schistosomiasis by electron microscopy and parasitologic studies. The correlation of these studies with serum levels of IFN–gamma and IgE is described. Two groups of 10 mice each were treated with different doses of BDHQ, and their results were correlated with the control and praziquantel (PZQ)–treated groups. Parasitologic study revealed significant reduction in mature worms and tissue egg loads in BDHQ– and PZQ–treated groups, whereas immature worms revealed significant reduction in BDHQ groups only. The group treated with a higher dose of BDHQ showed significant reductions in intestinal ova count when compared with the PZQ–treated group. Ultrastructural examination of the worm revealed significant degeneration of the spines and tegument in all treated groups, while the genital system was affected in BDHQ–treated groups only. BDHQ showed considerable effect on cellular activation where serum levels of IFN–gamma were significantly increased in comparison to control, while anti–soluble worm antigen preparation (SWAP) IgE was significantly increased in comparison to both the control and PZQ–treated groups. Ultrastructural examination revealed cellular activation in buffy coat and the liver in both the BDHQ– and PZQ–treated groups in comparison to the untreated one, whereas in the bone marrow and spleen, evidence of cellular activation was remarkable in the BDHQ–treated groups. In conclusion, BDHQ exhibits high levels of activity against adult and juvenile stages of these parasites, which may be due to its mixed cellular and humoral immunologic mechanisms, as demonstrated by the significant increase of serum levels of IgE and IFN–gamma shown on electron microscopy. Therefore, our results support the comparative advantage that BDHQ has over PZQ. PMID:17435624

  15. Long term study on the effect of mollusciciding with niclosamide in stream habitats on the transmission of schistosomiasis mansoni after community-based chemotherapy in Makueni District, Kenya

    PubMed Central

    2013-01-01

    Background Schistosoma mansoni infection is a persistent public health problem in many Kenyan communities. Although praziquantel is available, re-infection after chemotherapy treatment is inevitable, especially among children. Chemotherapy followed by intermittent mollusciciding of habitats of Biomphalaria pfeifferi, the intermediate host snail, may have longer term benefits, especially if timed to coincide with natural fluctuations in snail populations. Methods In this cohort study, the Kambu River (Intervention area) was molluscicided intermittently for 4 years, after mass chemotherapy with praziquantel in the adjacent community of Darajani in January 1997. The nearby Thange River was selected as a control (Non-intervention area), and its adjacent community of Ulilinzi was treated with praziquantel in December 1996. Snail numbers were recorded monthly at 9–10 sites along each river, while rainfall data were collected monthly, and annual parasitological surveys were undertaken in each village. The mollusciciding protocol was adapted to local conditions, and simplified to improve prospects for widespread application. Results After the initial reduction in prevalence attributable to chemotherapy, there was a gradual increase in the prevalence and intensity of infection in the non-intervention area, and significantly lower levels of re-infection amongst inhabitants of the intervention area. Incidence ratio between areas adjusted for age and gender at the first follow-up survey, 5 weeks after treatment in the non-intervention area and 4 months after treatment in the intervention area was not significant (few people turned positive), while during the following 4 annual surveys these ratios were 0.58 (0.39-0.85), 0.33 (0.18-0.60), 0.14 (0.09-0.21) and 0.45 (0.26-0.75), respectively. Snail numbers were consistently low in the intervention area as a result of the mollusciciding. Following termination of the mollusciciding at the end of 2000, snail populations and

  16. Ectopic Schistosoma mansoni Eggs Inside a Lipoma.

    PubMed

    Sabino, Kelly Renata; Nunes, Maurício Buzelin; Petroianu, Andy

    2016-01-01

    Ectopic schistosomiasis is uncommon and tends to occur when the parasite's eggs or adult forms are located far from their normal site. This report presents the first described case of ectopic Schistosoma mansoni eggs inside a subcutaneous lipoma far from the tissues of this worm's life cycle and with no connection to either portal veins or any other vascular system. These eggs were found inside giant cells surrounded by inflammatory cells. In conclusion, in humans, ectopic S. mansoni eggs can be found far from the tissues of the described life cycle of this worm, with no connection to portal veins or other blood vessels used for their migration. PMID:26598562

  17. [Developmental bilharziasis caused by Schistosoma mansoni discovered 37 years after infestation].

    PubMed

    Chabasse, D; Bertrand, G; Leroux, J P; Gauthey, N; Hocquet, P

    1985-01-01

    The authors report a case of Mansoni Schistosomiasis whose course in always running thirty-seven years after the first and alone infestation in a fifty-six old man who come back from Madagascar in February 1948 and lives in France since this period eggs of schistosomiasis were living in a biopsy of rectal and sigmoid mucosea. Problem of adult worms longevity and clinical importance of such prolonged inapparent schistosomiasis are discussed. PMID:3936631

  18. A next-generation proteome array for Schistosoma mansoni.

    PubMed

    de Assis, Rafael Ramiro; Ludolf, Fernanda; Nakajima, Rie; Jasinskas, Al; Oliveira, Guilherme C; Felgner, Philip L; Gaze, Soraya T; Loukas, Alex; LoVerde, Philip T; Bethony, Jeffrey M; Correa-Oliveira, Rodrigo; Calzavara-Silva, Carlos E

    2016-06-01

    A proteome microarray consisting of 992 Schistosoma mansoni proteins was produced and screened with sera to determine antibody signatures indicative of the clinical stages of schistosomiasis and the identification of subunit vaccine candidates. Herein, we describe the methods used to derive the gene list for this array (representing approximately 10% of the predicted S. mansoni proteome). We also probed a pilot version of the microarray with sera from individuals either acutely or chronically infected with S. mansoni from endemic areas in Brazil and sera from individuals resident outside the endemic area (USA) to determine if the array is functional and informative. PMID:27131510

  19. Proteomic Analysis of Schistosoma mansoni Egg Secretions

    PubMed Central

    Cass, Cynthia L.; Johnson, Jeffrey R.; Califf, Lindsay L.; Xu, Tao; Hernandez, Hector J.; Stadecker, Miguel J.; Yates, John R.; Williams, David L.

    2007-01-01

    Schistosomiasis remains a largely neglected, global health problem. The morbid pathology of the disease stems from the host's inflammatory response to parasite eggs trapped in host tissues. Long term host/parasite survival is dependent upon the successful modulation of the acute pathological response, which is induced by egg antigens. In this study, using Multidimensional Protein Identification Technology, we identified the Schistosoma mansoni egg secretome consisting of 188 proteins. Notably we identified proteins involved in redox balance, molecular chaperoning and protein folding, development and signaling, scavenging and metabolic pathways, immune response modulation, and 32 novel, previously uncharacterized schistosome proteins. We localized a subset of previously-characterized schistosome proteins identified in egg secretions in this study, to the surface of live S. mansoni eggs using the circumoval precipitin reaction. The identification of proteins actively secreted by live schistosome eggs provides important new information for understanding immune modulation and the pathology of schistosomiasis. PMID:17644200

  20. Ultrasonography of gallbladder abnormalities due to schistosomiasis.

    PubMed

    Richter, Joachim; Azoulay, Daniel; Dong, Yi; Holtfreter, Martha C; Akpata, Robert; Calderaro, Julien; El-Scheich, Tarik; Breuer, Matthias; Neumayr, Andreas; Hatz, Christoph; Kircheis, Gerald; Botelho, Monica C; Dietrich, Christoph F

    2016-08-01

    After malaria, schistosomiasis remains the most important tropical parasitic disease in large parts of the world. Schistosomiasis has recently re-emerged in Southern Europe. Intestinal schistosomiasis is caused by most Schistosoma (S.) spp. pathogenic to humans and leads to chronic inflammation and fibrosis of the colon as well as to liver fibrosis. Gallbladder abnormalities usually occur in patients with advanced hepatic portal fibrosis due to Schistosoma mansoni infection. Occasionally, gallbladder abnormalities have been seen also in children and occurring without associated overt liver abnormalities.The specific S. mansoni-induced gallbladder abnormalities detectable by ultrasound include typical hyperechogenic wall thickening with external gallbladder wall protuberances. The luminal wall surface is smooth. The condition is usually clinically silent although some cases of symptomatic cholecystitis have been described. The ultrasonographic Murphy response is negative. Gallbladder contractility is impaired but sludge and calculi occur rarely. Contrary to other trematodes such as liver flukes, S. mansoni does not obstruct the biliary tract. Advanced gallbladder fibrosis is unlikely to reverse after therapy. PMID:27169865

  1. A rapid diagnostic test for schistosomiasis mansoni

    PubMed Central

    Mello-Silva, Clélia Christina; João, Roberto Carlos; Augusto, Ronaldo de Carvalho; Santos, Claudia Portes

    2013-01-01

    This article presents an improvement to the Kato-Katz (KK) method, making it faster and more efficient for the visualisation of fertile eggs in stool samples. This modified KK method uses sodium acetate formalin as a fixative and reveals the intensity of infection in less than 1 h, reducing the diagnostic time without increasing the cost. This modified method may contribute to future epidemiological studies in both hospitals and the field due to its rapid and precise diagnostic, which allow for immediate treatment. PMID:24402146

  2. Advancing a vaccine to prevent human schistosomiasis.

    PubMed

    Merrifield, Maureen; Hotez, Peter J; Beaumier, Coreen M; Gillespie, Portia; Strych, Ulrich; Hayward, Tara; Bottazzi, Maria Elena

    2016-06-01

    Several candidate human schistosomiasis vaccines are in different stages of preclinical and clinical development. The major targets are Schistosoma haematobium (urogenitial schistosomiasis) and Schistosoma mansoni (intestinal schistosomiasis) that account for 99% of the world's 252 million cases, with 90% of these cases in Africa. Two recombinant S. mansoni vaccines - Sm-TSP-2 and Sm-14 are in Phase 1 trials, while Smp80 (calpain) is undergoing testing in non-human primates. Sh28GST, also known as Bilhvax is in advanced clinical development for S. haematobium infection. The possibility remains that some of these vaccines may cross-react to target both schistosome species. These vaccines were selected on the basis of their protective immunity in preclinical challenge models, through human immune-epidemiological studies or both. They are being advanced through a combination of academic research institutions, non-profit vaccine product development partnerships, biotechnology companies, and developing country vaccine manufacturers. In addition, new schistosome candidate vaccines are being identified through bioinformatics, OMICs approaches, and moderate throughput screening, although the full potential of reverse vaccinology for schistosomiasis has not yet been realized. The target product profiles of these vaccines vary but many focus on vaccinating children, in some cases following mass treatment with praziquantel, also known as vaccine-linked chemotherapy. Several regulatory pathways have been proposed, some of which rely on World Health Organization prequalification. PMID:27036511

  3. Schistosomiasis-associated kidney disease: A review

    PubMed Central

    da Silva, Geraldo Bezerra; Duarte, Daniella Bezerra; Barros, Elvino José Guardão; Daher, Elizabeth De Francesco

    2013-01-01

    Schistosomiasis is a parasitic disease caused by organisms from the genus Schistosoma. The disease is endemic in tropical areas, where there are currently millions of people living in areas with transmission risk. Schistosomiasis-associated kidney disease is not frequently described in literature. The disease has a chronic evolution, with variable severity. Glomerulonephritis is described in 10-12% in autopsy studies. Proteinuria is reported in 20% of patients with S. mansoni infection. Schistosomal glomerulopathy generally occur in young patients, male, with hepato-splenomegaly. The glomerular lesion in schistosomiasis has an immunological nature. Antigens from the parasite seem to be related to glomerulopathy and have been found in the sera of humans and animals infected by the S. mansoni. Vesical involvement is common in the infection by S. haematobium, a parasitic disease prevalent in African countries. In the S. haematobium infection, hematuria and dysuria can be observed due to inflammation and ulceration in the bladder mucosa, generaly occuring 3 to 4 months after primary infection. Specific antiparasitic treatment is indicated to all patients infected by Schistosoma. There are 2 drugs available for treatment, praziquantel and oxamniquine. We revise the general aspects of the disease and describe the features of renal involvement in schistosomiasis.

  4. Schistosomiasis vaccines

    PubMed Central

    Siddiqui, Bilal A.; Ganley-Leal, Lisa

    2011-01-01

    Schistosomiasis is a major neglected tropical disease of public health importance to a billion people. An estimated 200 million people are currently infected; an additional 779 million individuals are at risk to acquire the infection in 74 countries. Despite many years of implementation of mass anti-parasitic drug therapy programs and other control measures, this disease has not been contained and continues to spread to new geographic areas.  The discovery of a protective vaccine still remains the most potentially effective means for the control of this disease, especially if the vaccine provides long-term immunity against the infection. A vaccine would contribute to the reduction of schistosomiasis morbidity through induced immune responses leading to decrease in parasite load and reduced egg production. This vaccine could be administered to children between the ages of 3 and 12 years to prevent severe infection in a particularly high risk population. This review summarizes the current status of schistosomiasis vaccine development. PMID:22048120

  5. Human Schistosomiasis: Clinical Perspective: Review

    PubMed Central

    Barsoum, Rashad S.; Esmat, Gamal; El-Baz, Tamer

    2013-01-01

    The clinical manifestations of schistosomiasis pass by acute, sub acute and chronic stages that mirror the immune response to infection. The later includes in succession innate, TH1 and TH2 adaptive stages, with an ultimate establishment of concomitant immunity. Some patients may also develop late complications, or suffer the sequelae of co-infection with other parasites, bacteria or viruses. Acute manifestations are species-independent; occur during the early stages of invasion and migration, where infection-naivety and the host’s racial and genetic setting play a major role. Sub acute manifestations occur after maturity of the parasite and settlement in target organs. They are related to the formation of granulomata around eggs or dead worms, primarily in the lower urinary tract with Schistosoma haematobium, and the colon and rectum with Schistosoma mansoni, Schistosoma japonicum, Schistosoma intercalatum and Schistosoma mekongi infection. Secondary manifestations during this stage may occur in the kidneys, liver, lungs or other ectopic sites. Chronic morbidity is attributed to the healing of granulomata by fibrosis and calcification at the sites of oval entrapment, deposition of schistosomal antigen-antibody complexes in the renal glomeruli or the development of secondary amyloidosis. Malignancy may complicate the chronic lesions in the urinary bladder or colon. Co-infection with salmonella or hepatitis viruses B or C may confound the clinical picture of schistosomiasis, while the latter may have a negative impact on the course of other co-infections as malaria, leishmaniasis and HIV. Prevention of schistosomiasis is basically geared around education and periodic mass treatment, an effective vaccine being still experimental. Praziquantel is the drug of choice in the treatment of active infection by any species, with a cure rate of 80%. Other antischistosomal drugs include metrifonate for S. haematobium, oxamniquine for S. mansoni and Artemether and, possibly

  6. Use of Geospatial Modeling to Predict Schistosoma mansoni Prevalence in Nyanza Province, Kenya

    PubMed Central

    Woodhall, Dana M.; Wiegand, Ryan E.; Wellman, Michael; Matey, Elizabeth; Abudho, Bernard; Karanja, Diana M. S.; Mwinzi, Pauline M. N.; Montgomery, Susan P.; Secor, W. Evan

    2013-01-01

    Background Schistosomiasis, a parasitic disease that affects over 200 million people, can lead to significant morbidity and mortality; distribution of single dose preventative chemotherapy significantly reduces disease burden. Implementation of control programs is dictated by disease prevalence rates, which are determined by costly and labor intensive screening of stool samples. Because ecological and human factors are known to contribute to the focal distribution of schistosomiasis, we sought to determine if specific environmental and geographic factors could be used to accurately predict Schistosoma mansoni prevalence in Nyanza Province, Kenya. Methodology/Principal Findings A spatial mixed model was fit to assess associations with S. mansoni prevalence in schools. Data on S. mansoni prevalence and GPS location of the school were obtained from 457 primary schools. Environmental and geographic data layers were obtained from publicly available sources. Spatial models were constructed using ArcGIS 10 and R 2.13.0. Lower S.mansoni prevalence was associated with further distance (km) to Lake Victoria, higher day land surface temperature (LST), and higher monthly rainfall totals. Altitude, night LST, human influence index, normalized difference vegetation index, soil pH, soil texture, soil bulk density, soil water capacity, population, and land use variables were not significantly associated with S. mansoni prevalence. Conclusions Our model suggests that there are specific environmental and geographic factors that influence S. mansoni prevalence rates in Nyanza Province, Kenya. Validation and use of schistosomiasis prevalence maps will allow control programs to plan and prioritize efficient control campaigns to decrease schistosomiasis burden. PMID:23977096

  7. Comparative Study of the Accuracy of Different Techniques for the Laboratory Diagnosis of Schistosomiasis Mansoni in Areas of Low Endemicity in Barra Mansa City, Rio de Janeiro State, Brazil

    PubMed Central

    Espírito-Santo, Maria Cristina Carvalho; Alvarado-Mora, Mónica Viviana; Pinto, Pedro Luiz Silva; Sanchez, Maria Carmen Arroyo; Dias-Neto, Emmanuel; Castilho, Vera Lúcia Pagliusi; Gonçalves, Elenice Messias do Nascimento; Chieffi, Pedro Paulo; Luna, Expedito José de Albuquerque; Pinho, João Renato Rebello; Carrilho, Flair José; Gryschek, Ronaldo Cesar Borges

    2015-01-01

    Schistosomiasis constitutes a major public health problem, with an estimated 200 million people infected worldwide. Many areas of Brazil show low endemicity of schistosomiasis, and the current standard parasitological techniques are not sufficiently sensitive to detect the low-level helminth infections common in areas of low endemicity (ALEs). This study compared the Kato-Katz (KK); Hoffman, Pons, and Janer (HH); enzyme-linked immunosorbent assay- (ELISA-) IgG and ELISA-IgM; indirect immunofluorescence technique (IFT-IgM); and qPCR techniques for schistosomiasis detection in serum and fecal samples, using the circumoval precipitin test (COPT) as reference. An epidemiological survey was conducted in a randomized sample of residents from five neighborhoods of Barra Mansa, RJ, with 610 fecal and 612 serum samples. ELISA-IgM (21.4%) showed the highest positivity and HH and KK techniques were the least sensitive (0.8%). All techniques except qPCR-serum showed high accuracy (82–95.5%), differed significantly from COPT in positivity (P < 0.05), and showed poor agreement with COPT. Medium agreement was seen with ELISA-IgG (Kappa = 0.377) and IFA (Kappa = 0.347). Parasitological techniques showed much lower positivity rates than those by other techniques. We suggest the possibility of using a combination of laboratory tools for the diagnosis of schistosomiasis in ALEs. PMID:26504777

  8. Comparative Study of the Accuracy of Different Techniques for the Laboratory Diagnosis of Schistosomiasis Mansoni in Areas of Low Endemicity in Barra Mansa City, Rio de Janeiro State, Brazil.

    PubMed

    Espírito-Santo, Maria Cristina Carvalho; Alvarado-Mora, Mónica Viviana; Pinto, Pedro Luiz Silva; Sanchez, Maria Carmen Arroyo; Dias-Neto, Emmanuel; Castilho, Vera Lúcia Pagliusi; Gonçalves, Elenice Messias do Nascimento; Chieffi, Pedro Paulo; Luna, Expedito José de Albuquerque; Pinho, João Renato Rebello; Carrilho, Flair José; Gryschek, Ronaldo Cesar Borges

    2015-01-01

    Schistosomiasis constitutes a major public health problem, with an estimated 200 million people infected worldwide. Many areas of Brazil show low endemicity of schistosomiasis, and the current standard parasitological techniques are not sufficiently sensitive to detect the low-level helminth infections common in areas of low endemicity (ALEs). This study compared the Kato-Katz (KK); Hoffman, Pons, and Janer (HH); enzyme-linked immunosorbent assay- (ELISA-) IgG and ELISA-IgM; indirect immunofluorescence technique (IFT-IgM); and qPCR techniques for schistosomiasis detection in serum and fecal samples, using the circumoval precipitin test (COPT) as reference. An epidemiological survey was conducted in a randomized sample of residents from five neighborhoods of Barra Mansa, RJ, with 610 fecal and 612 serum samples. ELISA-IgM (21.4%) showed the highest positivity and HH and KK techniques were the least sensitive (0.8%). All techniques except qPCR-serum showed high accuracy (82-95.5%), differed significantly from COPT in positivity (P < 0.05), and showed poor agreement with COPT. Medium agreement was seen with ELISA-IgG (Kappa = 0.377) and IFA (Kappa = 0.347). Parasitological techniques showed much lower positivity rates than those by other techniques. We suggest the possibility of using a combination of laboratory tools for the diagnosis of schistosomiasis in ALEs. PMID:26504777

  9. The Menace of Schistosomiasis in Nigeria: Knowledge, Attitude, and Practices Regarding Schistosomiasis among Rural Communities in Kano State

    PubMed Central

    Dawaki, Salwa; Al-Mekhlafi, Hesham M.; Ithoi, Init; Ibrahim, Jamaiah; Abdulsalam, Awatif M.; Ahmed, Abdulhamid; Sady, Hany; Nasr, Nabil A.; Atroosh, Wahib M.

    2015-01-01

    Background Schistosomiasis is one of the most common neglected tropical diseases, especially in the developing countries in Africa, Asia and South America, with Nigeria having the greatest number of cases of schistosomiasis worldwide. This community-based study aims to evaluate the knowledge, attitude and practices (KAP) regarding schistosomiasis among rural Hausa communities in Kano State, Nigeria. Methods A cross-sectional study was carried out among 551 participants from Hausa communities in five local government areas in Kano State, North Central Nigeria. Demographic, socioeconomic and environmental information as well as KAP data were collected using a pre-tested questionnaire. Moreover, faecal and urine samples were collected and examined for the presence of Schistosoma mansoni and S. haematobium eggs respectively. Results The overall prevalence of schistosomiasis was 17.8%, with 8.9% and 8.3% infected with S. mansoni and S. haematobium respectively, and 0.5% had co-infection of both species. Moreover, 74.5% of the participants had prior knowledge about schistosomiasis with 67.0% of them how it is transmitted and 63.8% having no idea about the preventive measures. Three-quarters of the respondents considered schistosomiasis a serious disease while their practices to prevent infections were still inadequate, with only 34.7% of them seeking treatment from clinics/hospitals. Significant associations between the KAP and age, gender, education and employment status were reported. Multiple logistic regression analysis revealed that age, gender, history of infection and educational level of the respondents were the most important factors significantly associated with the KAP on schistosomiasis among this population. Conclusions Schistosomiasis is still prevalent among Hausa communities in Nigeria and participants’ knowledge about the disease was poor. Mass drug administration, community mobilization and health education regarding the cause, transmission and

  10. Impact of Schistosoma mansoni on Malaria Transmission in Sub-Saharan Africa

    PubMed Central

    Ndeffo Mbah, Martial L.; Skrip, Laura; Greenhalgh, Scott; Hotez, Peter; Galvani, Alison P.

    2014-01-01

    Background Sub-Saharan Africa harbors the majority of the global burden of malaria and schistosomiasis infections. The co-endemicity of these two tropical diseases has prompted investigation into the mechanisms of coinfection, particularly the competing immunological responses associated with each disease. Epidemiological studies have shown that infection with Schistosoma mansoni is associated with a greater malaria incidence among school-age children. Methodology We developed a co-epidemic model of malaria and S. mansoni transmission dynamics which takes into account key epidemiological interaction between the two diseases in terms of elevated malaria incidence among individuals with S. mansoni high egg output. The model was parameterized for S. mansoni high-risk endemic communities, using epidemiological and clinical data of the interaction between S. mansoni and malaria among children in sub-Saharan Africa. We evaluated the potential impact of the S. mansoni–malaria interaction and mass treatment of schistosomiasis on malaria prevalence in co-endemic communities. Principal Findings Our results suggest that in the absence of mass drug administration of praziquantel, the interaction between S. mansoni and malaria may reduce the effectiveness of malaria treatment for curtailing malaria transmission, in S. mansoni high-risk endemic communities. However, when malaria treatment is used in combination with praziquantel, mass praziquantel administration may increase the effectiveness of malaria control intervention strategy for reducing malaria prevalence in malaria- S. mansoni co-endemic communities. Conclusions/Significance Schistosomiasis treatment and control programmes in regions where S. mansoni and malaria are highly prevalent may have indirect benefits on reducing malaria transmission as a result of disease interactions. In particular, mass praziquantel administration may not only have the direct benefit of reducing schistosomiasis infection, it may also

  11. Scintigraphic findings in schistosomiasis.

    PubMed

    Orduña, E; Silva, F

    1995-12-01

    Schistosomiasis mansoni is a tropical parasitic disease caused by a blood fluke which inhabits the portal system of humans. Fifteen pediatric patients with the acute disease were evaluated with liver and spleen scintigraphy (LSS). Clinical history, physical examination, and serum chemistries failed to reveal any other underlying systemic disease. Liver and spleen scintigraphies were performed before therapy, 7 months and 9 years after therapy with oxamniquine. LSS initially showed hepatomegaly in 93% of the patients. In the first follow up study a reactive spleen was evident in 78% of the cases, with an unchanged hepatic image. Long term follow up revealed that from the initially enlarged livers, 93% became normal. However, 47% of the spleens were abnormal. The scintigraphic changes observed in the liver over the years were those expected for an acute infection. The findings in the spleen might indicate the persistence of an immunologic reaction with a continuous trigger, probably an antibody. These observations suggest that the LSS can be used in the evaluation and follow-up of these patients. PMID:8637963

  12. Research and control of advanced schistosomiasis japonica in China.

    PubMed

    Wu, Wei; Feng, Aicheng; Huang, Yixin

    2015-01-01

    Among the three main schistosomes (Schistosoma japonicum, Schistosoma mansoni, and Schistosoma haematobium) known to infect humans, S. japonicum causes the most serious pathological lesions. In China, only schistosomiasis japonica is transmitted. From the 1950s, massive epidemiological investigations and active control measures for schistosomiasis japonica have been carried out. At the early stage of schistosomiasis control program, there were about 12 million schistosomiasis patients, and about 5% of schistosomiasis patients belong to advanced patients, which was 600,000. After more than a half century of active schistosomiasis control work, the schistosomiasis situation has been reduced markedly. The nearest epidemiological investigation showed that, by the end of 2012, there were still 240,000 schistosomiasis patients with the descent rate of 98% and 30,000 advanced patients with the descent rate of 95%. This paper reviews the rich experiences of advanced schistosomiasis research and control in China, including that the epidemiology researches confirm there is a family aggregation of advanced schistosomiasis and advanced schistosomiasis patients have no significance to the schistosomiasis transmission in transmission-interrupted areas but still are an infection source in endemic areas; pathogenic mechanism researches verify that genetic factors and immunoregulation play important roles in the disease developing process; ultrasound image examinations are used not only in the diagnosis and differential diagnosis of advanced schistosomiasis but also in the guidance of treatment and evaluation of therapeutic effects and, furthermore, in the risk predictions of portal hypertension and upper gastrointestinal hemorrhage; clinical practices demonstrate that praziquantel can be used in most of advanced schistosomiasis patients, and the therapy not only can interrupt the schistosomiasis transmission somewhat but also is favorable for liver fibrosis improvement; the

  13. Biosensor for Hepatocellular Injury Corresponds to Experimental Scoring of Hepatosplenic Schistosomiasis in Mice

    PubMed Central

    Sombetzki, Martina; Koslowski, Nicole; Doss, Sandra; Loebermann, Micha; Trauner, Michael; Reisinger, Emil C.; Sauer, Martin

    2016-01-01

    Severe hepatosplenic injury of mansonian schistosomiasis is caused by Th2 mediated granulomatous response against parasite eggs entrapped within the periportal tissue. Subsequent fibrotic scarring and deformation/sclerosing of intrahepatic portal veins lead to portal hypertension, ascites, and oesophageal varices. The murine model of Schistosoma mansoni (S. mansoni) infection is suitable to establish the severe hepatosplenic injury of disease within a reasonable time scale for the development of novel antifibrotic or anti-infective strategies against S. mansoni infection. The drawback of the murine model is that the material prepared for complex analysis of egg burden, granuloma size, hepatic inflammation, and fibrosis is limited due to small amounts of liver tissue and blood samples. The objective of our study was the implementation of a macroscopic scoring system for mice livers to determine infection-related organ alterations of S. mansoni infection. In addition, an in vitro biosensor system based on the detection of hepatocellular injury in HepG2/C3A cells following incubation with serum of moderately (50 S. mansoni cercariae) and heavily (100 S. mansoni cercariae) infected mice affirmed the value of our scoring system. Therefore, our score represents a valuable tool in experimental schistosomiasis to assess severity of hepatosplenic schistosomiasis and reduce animal numbers by saving precious tissue samples. PMID:27376078

  14. Biosensor for Hepatocellular Injury Corresponds to Experimental Scoring of Hepatosplenic Schistosomiasis in Mice.

    PubMed

    Sombetzki, Martina; Koslowski, Nicole; Doss, Sandra; Loebermann, Micha; Trauner, Michael; Reisinger, Emil C; Sauer, Martin

    2016-01-01

    Severe hepatosplenic injury of mansonian schistosomiasis is caused by Th2 mediated granulomatous response against parasite eggs entrapped within the periportal tissue. Subsequent fibrotic scarring and deformation/sclerosing of intrahepatic portal veins lead to portal hypertension, ascites, and oesophageal varices. The murine model of Schistosoma mansoni (S. mansoni) infection is suitable to establish the severe hepatosplenic injury of disease within a reasonable time scale for the development of novel antifibrotic or anti-infective strategies against S. mansoni infection. The drawback of the murine model is that the material prepared for complex analysis of egg burden, granuloma size, hepatic inflammation, and fibrosis is limited due to small amounts of liver tissue and blood samples. The objective of our study was the implementation of a macroscopic scoring system for mice livers to determine infection-related organ alterations of S. mansoni infection. In addition, an in vitro biosensor system based on the detection of hepatocellular injury in HepG2/C3A cells following incubation with serum of moderately (50 S. mansoni cercariae) and heavily (100 S. mansoni cercariae) infected mice affirmed the value of our scoring system. Therefore, our score represents a valuable tool in experimental schistosomiasis to assess severity of hepatosplenic schistosomiasis and reduce animal numbers by saving precious tissue samples. PMID:27376078

  15. Enhancing schistosomiasis control strategy for zimbabwe: building on past experiences.

    PubMed

    Chimbari, Moses J

    2012-01-01

    Schistosoma haematobium and Schistosoma mansoni are prevalent in Zimbabwe to levels that make schistosomiasis a public health problem. Following three national surveys to map the disease prevalence, a national policy on control of schistosomiasis and soil transmitted helminths is being developed. This paper reviews the experiences that Zimbabwe has in the area of schistosomiasis control with a view to influence policy. A case study approach to highlight key experiences and outcomes was adopted. The benefits derived from intersectoral collaboration that led to the development of a model irrigation scheme that incorporates schistosomiasis control measures are highlighted. Similarly, the benefits of using plant molluscicides and fish and duck biological agents (Sargochromis codringtonii and Cairina moschata) are highlighted. Emphasis was also placed on the importance of utilizing locally developed water and sanitation technologies and the critical human resource base in the area of schistosomiasis developed over years. After synthesis of the case studies presented, it was concluded that while there is a need to follow the WHO recommended guidelines for schistosomiasis control it is important to develop a control strategy that is informed by work already done in the country. The importance of having a policy and local guidelines for schistosomiasis control is emphasized. PMID:22655171

  16. Immunopathology of Schistosoma mansoni infection.

    PubMed Central

    Boros, D L

    1989-01-01

    Schistosomiasis mansoni is a chronic helminthic disease that affects about 100 million people in the tropics. The worms have a life span of 5 to 10 years, and they live in the mesenteric veins of the host. Lightly infected individuals are asymptomatic or manifest mild intestinal symptoms. Heavily infected individuals often develop severe morbidity with hepatosplenomegaly, sometimes with a fatal outcome. Morbidity is attributed to the strong humoral and T-cell-mediated host immune responses developed to a variety of parasite antigens and expressed as tissue inflammations. The immunopathology includes dermatitis, immune complex-mediated kidney disease, and, chiefly, T-cell-mediated granuloma formation and fibrosis around disseminated parasite eggs. This review describes the mechanisms of induction and expression of immunopathology in infected persons and experimental animals. Immunoregulatory mechanisms that modulate the enhanced immune responses and may ameliorate excessive morbidity are discussed. PMID:2504481

  17. Effect of Maternal Schistosoma mansoni Infection and Praziquantel Treatment During Pregnancy on Schistosoma mansoni Infection and Immune Responsiveness among Offspring at Age Five Years

    PubMed Central

    Tweyongyere, Robert; Naniima, Peter; Mawa, Patrice A.; Jones, Frances M.; Webb, Emily L.; Cose, Stephen; Dunne, David W.; Elliott, Alison M.

    2013-01-01

    Introduction Offspring of Schistosoma mansoni-infected women in schistosomiasis-endemic areas may be sensitised in-utero. This may influence their immune responsiveness to schistosome infection and schistosomiasis-associated morbidity. Effects of praziquantel treatment of S. mansoni during pregnancy on risk of S. mansoni infection among offspring, and on their immune responsiveness when they become exposed to S. mansoni, are unknown. Here we examined effects of praziquantel treatment of S. mansoni during pregnancy on prevalence of S. mansoni and immune responsiveness among offspring at age five years. Methods In a trial in Uganda (ISRCTN32849447, http://www.controlled-trials.com/ISRCTN32849447/elliott), offspring of women treated with praziquantel or placebo during pregnancy were examined for S. mansoni infection and for cytokine and antibody responses to SWA and SEA, as well as for T cell expression of FoxP3, at age five years. Results Of the 1343 children examined, 32 (2.4%) had S. mansoni infection at age five years based on a single stool sample. Infection prevalence did not differ between children of treated or untreated mothers. Cytokine (IFNγ, IL-5, IL-10 and IL-13) and antibody (IgG1, Ig4 and IgE) responses to SWA and SEA, and FoxP3 expression, were higher among infected than uninfected children. Praziquantel treatment of S. mansoni during pregnancy had no effect on immune responses, with the exception of IL-10 responses to SWA, which was higher in offspring of women that received praziquantel during pregnancy than those who did not. Conclusion We found no evidence that maternal S. mansoni infection and its treatment during pregnancy influence prevalence and intensity of S. mansoni infection or effector immune response to S. mansoni infection among offspring at age five years, but the observed effects on IL-10 responses to SWA suggest that maternal S. mansoni and its treatment during pregnancy may affect immunoregulatory responsiveness in childhood

  18. Intestinal schistosomiasis among preschool children along the shores of Lake Victoria in Uganda.

    PubMed

    Nalugwa, A; Olsen, A; Tukahebwa, M E; Nuwaha, F

    2015-02-01

    Schistosomiasis, a disease caused by Schistosoma trematode parasites, affects hundreds of millions of people and accounts for more than 40% of the global health burden due to neglected tropical diseases. In Uganda, intestinal schistosomiasis is endemic in 73 out of 112 districts and about 55% of the population of 36 million individuals are at risk. There is scanty information on the status and burden of schistosomiasis in preschool children less than six years of age in Uganda. This study aimed to assess the status of Schistosoma mansoni infections in children aged 1-5 years in Uganda. S. mansoni prevalence and intensity of infection were examined in 3058 children from 5 districts along Lake Victoria shoreline, eastern Uganda. For each child one stool sample was collected on three consecutive days. The Kato-Katz technique was used to prepare stool smears on slides for microscopic examination. Short interviews with a standardized pre-tested questionnaire prepared in the local language (Lusoga) were administered to each caregiver to identify risk factors associated with S. mansoni infection. An overall S. mansoni prevalence of 39.3% (95% CI: 38.0-41.1%) was estimated out of the 3058 stool samples examined. The geometric mean intensity of S. mansoni among the infected children was 273 (95% CI: 241-305) eggs per gram of faeces. Both prevalence and intensity of infection increased linearly with age (P<0.0001) and were highest in the age group 49-60 months. Majority (61%) of the children, especially in the age group 12-24 months (84.2%; 95% CI: 75.6-90.1%), were lightly infected. Short interviews with caregivers revealed that preschool children, 1-5 years old, get exposed to S. mansoni infested waters through bathing, playing or swimming. It is important that the Uganda national control programme for schistosomiasis takes preschool children into consideration and that health education on transmission of schistosomiasis is delivered to the endemic communities regularly

  19. Time to set the agenda for schistosomiasis elimination.

    PubMed

    Rollinson, David; Knopp, Stefanie; Levitz, Sarah; Stothard, J Russell; Tchuem Tchuenté, Louis-Albert; Garba, Amadou; Mohammed, Khalfan A; Schur, Nadine; Person, Bobbie; Colley, Daniel G; Utzinger, Jürg

    2013-11-01

    It is time to raise global awareness to the possibility of schistosomiasis elimination and to support endemic countries in their quest to determine the most appropriate approaches to eliminate this persistent and debilitating disease. The main interventions for schistosomiasis control are reviewed, including preventive chemotherapy using praziquantel, snail control, sanitation, safe water supplies, and behaviour change strategies supported by information, education and communication (IEC) materials. Differences in the biology and transmission of the three main Schistosoma species (i.e. Schistosoma haematobium, S. mansoni and S. japonicum), which impact on control interventions, are considered. Sensitive diagnostic procedures to ensure adequate surveillance in areas attaining low endemicity are required. The importance of capacity building is highlighted. To achieve elimination, an intersectoral approach is necessary, with advocacy and action from local communities and the health community to foster cooperative ventures with engineers, the private sector, governments and non-governmental organizations specialized in water supply and sanitation. Examples of successful schistosomiasis control programmes are reviewed to highlight what has been learnt in terms of strategy for control and elimination. These include St. Lucia and other Caribbean islands, Brazil and Venezuela for S. mansoni; Saudi Arabia and Egypt for both S. mansoni and S. haematobium; Morocco, Tunisia, Algeria, Mauritius and the Islamic Republic of Iran for S. haematobium; Japan and the People's Republic of China for S. japonicum. Additional targets for elimination or even eradication could be the two minor human schistosome species S. guineenisis and S. intercalatum, which have a restricted distribution in West and Central Africa. The examples show that elimination of schistosomiasis is an achievable and desirable goal requiring full integration of preventive chemotherapy with the tools of transmission

  20. Community Knowledge, Attitudes and Practices on Schistosomiasis in Western Kenya-The SCORE Project

    PubMed Central

    Musuva, Rosemary M.; Awiti, Alphonce; Omedo, Martin; Ogutu, Michael; Secor, W. Evan; Montgomery, Susan P.; Alaii, Jane; Mwinzi, Pauline N. M.

    2014-01-01

    In an effort to improve intervention strategies, community knowledge, attitudes, and practices on schistosomiasis were evaluated using focus group discussions involving 237 participants, in eight Schistosoma mansoni high prevalence districts in rural Nyanza Province, Kenya. The majority of participants reported having heard about schistosomiasis through schools, posters, radio announcements, and community gatherings. Participants had a variety of beliefs about contracting schistosomiasis, including associating it with dirty drinking water and uncooked or contaminated food. Avenues for seeking treatment included health centers, spiritual intervention, herbal treatments, and medicine shops, with health centers receiving the most mention. Barriers to schistosomiasis control included attitudes of community members toward the infection, especially misconceptions that lead to stigma and the perception that diagnosis and treatment are expensive. Schools were the most common avenue for receiving information, suggesting that the existing education infrastructure can be used for health education and improved sensitization about schistosomiasis control programs. PMID:24534810

  1. Community knowledge, attitudes and practices on schistosomiasis in western Kenya--the SCORE Project.

    PubMed

    Musuva, Rosemary M; Awiti, Alphonce; Omedo, Martin; Ogutu, Michael; Secor, W Evan; Montgomery, Susan P; Alaii, Jane; Mwinzi, Pauline N M

    2014-04-01

    In an effort to improve intervention strategies, community knowledge, attitudes, and practices on schistosomiasis were evaluated using focus group discussions involving 237 participants, in eight Schistosoma mansoni high prevalence districts in rural Nyanza Province, Kenya. The majority of participants reported having heard about schistosomiasis through schools, posters, radio announcements, and community gatherings. Participants had a variety of beliefs about contracting schistosomiasis, including associating it with dirty drinking water and uncooked or contaminated food. Avenues for seeking treatment included health centers, spiritual intervention, herbal treatments, and medicine shops, with health centers receiving the most mention. Barriers to schistosomiasis control included attitudes of community members toward the infection, especially misconceptions that lead to stigma and the perception that diagnosis and treatment are expensive. Schools were the most common avenue for receiving information, suggesting that the existing education infrastructure can be used for health education and improved sensitization about schistosomiasis control programs. PMID:24534810

  2. An outbreak of acute schistosomiasis following a church retreat to Mwanza, Tanzania, 2008.

    PubMed

    Chunge, Charles N; Chunge, Ruth N; Masinde, Michael S; Atinga, John N

    2011-01-01

    Clinical and laboratory findings are described from 77 persons from Nairobi, Kenya, of whom 66 were diagnosed with acute Schistosoma mansoni infection following a trip to Mwanza, Tanzania. Unusual ocular symptoms were observed as a rare manifestation of acute schistosomiasis. The outbreak highlights the risk of swimming in Lake Victoria. PMID:22017717

  3. Endomyocardial Fibrosis (EMF) in a Ugandan Child with Advanced Hepatosplenic Schistosomiasis: Coincidence or Connection?

    PubMed Central

    Bustinduy, Amaya L.; Luzinda, Kenneth; Mpoya, Simon; Gothard, Philip; Stone, Neil; Wright, Stephen; Stothard, J. Russell

    2014-01-01

    An association between late-stage hepatosplenic schistosomiasis and endomyocardial fibrosis (EMF) has been suggested but not proven. We present the case of a 12-year-old Ugandan boy with striking comorbidities, including advanced periportal fibrosis caused by Schistosoma mansoni infection and right ventricular EMF, and discuss the possible correlation between both diseases. PMID:25002295

  4. Schistosomiasis in the Democratic Republic of Congo: a literature review.

    PubMed

    Madinga, Joule; Linsuke, Sylvie; Mpabanzi, Liliane; Meurs, Lynn; Kanobana, Kirezi; Speybroeck, Niko; Lutumba, Pascal; Polman, Katja

    2015-01-01

    Schistosomiasis is a poverty-related parasitic infection, leading to chronic ill-health. For more than a century, schistosomiasis has been known to be endemic in certain provinces of the Democratic Republic of Congo (DRC). However, a clear overview on the status of the disease within the country is currently lacking, which is seriously hampering control. Here, we review the available information on schistosomiasis in DRC of the past 60 years. Findings and data gaps are discussed in the perspective of upcoming control activities.An electronic literature search via PubMed complemented by manual search of non-peer-reviewed articles was conducted up to January 2015. The search concerned all relevant records related to schistosomiasis in the DRC from January 1955 onwards. A total of 155 records were found, of which 30 met the inclusion criteria. Results were summarized by geographical region, mapped, and compared with those reported sixty years ago. The available data reported schistosomiasis in some areas located in 10 of the 11 provinces of DRC. Three species of Schistosoma were found: S. mansoni, S. haematobium and S. intercalatum. The prevalence of schistosomiasis varied greatly between regions and between villages, with high values of up to 95 % observed in some communities. The overall trend over 60 years points to the spread of schistosomiasis to formerly non-endemic areas. The prevalence of schistosomiasis has increased in rural endemic areas and decreased in urban/peri-urban endemic areas of Kinshasa. Hepatosplenomegaly, urinary tract lesions and anaemia were commonly reported in schistosomiasis endemic areas but not always associated with infection status.The present review confirms that schistosomiasis is still endemic in DRC. However, available data are scattered across time and space and studies lack methodological uniformity, hampering a reliable estimation of the current status of schistosomiasis in DRC. There is a clear need for updated prevalence data

  5. Schistosomiasis manifesting as a colon polyp: a case report

    PubMed Central

    2014-01-01

    Introduction Schistosomiasis is a rare disease with a common intestinal involvement. However, colon polyps associated with Schistosoma in the absence of inflammation have rarely been reported, especially in young people; this is the first case with the following presentation. Case presentation We describe the case of a 20-year-old Ethiopian woman living in Lebanon who presented with nonspecific abdominal symptoms. Her biochemical profile was normal in addition to the results of her stool and urine tests. A colonoscopy showed normal colonic mucosa but surprisingly a large pedunculated polyp was found in her ascending colon. Pathology revealed a hamartomatous polyp but it was full of partially calcified parasitic eggs of Schistosoma mansoni compatible with chronic schistosomiasis. Conclusions She was treated with two doses of praziquantel and showed immediate marked clinical improvement. This unusual case will give us the opportunity to discuss schistosomiasis, its occurrence in colon polyps, clinical significance and the various means of management. PMID:25296942

  6. Clinical aspects of hepatosplenic schistosomiasis: a contrast with cirrhosis.

    PubMed Central

    Rebouças, G.

    1975-01-01

    The clinical picture of liver disease in endemic areas of Schistosomiasis mansoni differs in many ways from that observed in alcoholic and other types of cirrhosis. In hepatosplenic schistosomiasis there is predominance of the clinical manifestations of portal hypertension, e.g., bleeding esophageal varices, while ascites, jaundice, and hepatic precoma or coma are much less common. Ammonia tolerance is usually normal and helps explain the low mortality rate during bleeding. Of special interest is the observation of a high incidence of persistent hepatitis B surface antigenemia among patients with hepatosplenic schistosomiasis, suggesting increased susceptibility of such patients to the development of virus-induced chronic active hepatitis. Images FIG. 1 FIG. 2 PMID:128911

  7. Structural bioinformatics study of PNP from Schistosoma mansoni.

    PubMed

    da Silveira, Nelson José Freitas; Uchôa, Hugo Brandão; Canduri, Fernanda; Pereira, José Henrique; Camera, João Carlos; Basso, Luiz Augusto; Palma, Mário Sergio; Santos, Diógenes Santiago; de Azevedo, Walter Filgueira

    2004-09-10

    The parasite Schistosoma mansoni lacks the de novo pathway for purine biosynthesis and depends on salvage pathways for its purine requirements. Schistosomiasis is endemic in 76 countries and territories and amongst the parasitic diseases ranks second after malaria in terms of social and economic impact and public health importance. The PNP is an attractive target for drug design and it has been submitted to extensive structure-based design. The atomic coordinates of the complex of human PNP with inosine were used as template for starting the modeling of PNP from S. mansoni complexed with inosine. Here we describe the model for the complex SmPNP-inosine and correlate the structure with differences in the affinity for inosine presented by human and S. mansoni PNPs. PMID:15313179

  8. The affinity of magnetic microspheres for Schistosoma eggs.

    PubMed

    Candido, Renata R F; Favero, Vivian; Duke, Mary; Karl, Stephan; Gutiérrez, Lucía; Woodward, Robert C; Graeff-Teixeira, Carlos; Jones, Malcolm K; St Pierre, Timothy G

    2015-01-01

    Schistosomiasis is a chronic parasitic disease of humans, with two species primarily causing the intestinal infection: Schistosoma mansoni and Schistosoma japonicum. Traditionally, diagnosis of schistosomiasis is achieved through direct visualisation of eggs in faeces using techniques that lack the sensitivity required to detect all infections, especially in areas of low endemicity. A recently developed method termed Helmintex™ is a very sensitive technique for detection of Schistosoma eggs and exhibits 100% sensitivity at 1.3 eggs per gram of faeces, enough to detect even low-level infections. The Helminthex™ method is based on the interaction of magnetic microspheres and schistosome eggs. Further understanding the underlying egg-microsphere interactions would enable a targeted optimisation of egg-particle binding and may thus enable a significant improvement of the Helmintex™ method and diagnostic sensitivity in areas with low infection rates. We investigated the magnetic properties of S. mansoni and S. japonicum eggs and their interactions with microspheres with different magnetic properties and surface functionalization. Eggs of both species exhibited higher binding affinity to the magnetic microspheres than the non-magnetic microspheres. Binding efficiency was further enhanced if the particles were coated with streptavidin. Schistosoma japonicum eggs bound more microspheres compared with S. mansoni. However, distinct differences within eggs of each species were also observed when the distribution of the number of microspheres bound per egg was modelled with double Poisson distributions. Using this approach, both S. japonicum and S. mansoni eggs fell into two groups, one having greater affinity for magnetic microspheres than the other, indicating that not all eggs of a species exhibit the same binding affinity. Our observations suggest that interaction between the microspheres and eggs is more likely to be related to surface charge-based electrostatic

  9. Studies on heterologous immunity in schistosomiasis*

    PubMed Central

    Amin, M. A.; Nelson, G. S.; Saoud, M. F. A.

    1968-01-01

    Previous studies on heterologous immunity in mice have indicated that Schistosoma bovis and S. mattheei could be used to limit the severity of infection resulting from subsequent challenge by S. mansoni. These observations have now been extended to study the immunizing effect in rhesus monkeys of both S. mattheei and S. bovis. The bovine schistosomes were shown to be relatively non-pathogenic in rhesus monkeys. Immunization with 1000-2000 cercariae resulted in a marked reduction in the pathogenic effect of subsequent challenge with S. mansoni. This effect was demonstrated by a decrease in the worm load and tissue egg densities in 10 immunized monkeys as compared with 5 control animals. There was no correlation between fluorescent antibody titres and the intensity of infection or the degree of acquired immunity. There was a cross-reaction between S. mansoni and the bovine schistosomes. It is suggested that natural heterologous immunity (zooprophylaxis) may be of considerable epidemiological importance in determining the severity of schistosomiasis in man. PMID:4970323

  10. Evaluation of eight serological tests for diagnosis of imported schistosomiasis.

    PubMed

    Kinkel, Hans-Friedemann; Dittrich, Sabine; Bäumer, Britta; Weitzel, Thomas

    2012-06-01

    The diagnosis of schistosomiasis in individuals from countries where the disease is not endemic is challenging, and few data are available on the accuracy of serological diagnosis in those patients. We evaluated the performance of eight serological assays, including four commercial kits, in the diagnosis of imported schistosomiasis in individuals from areas where the disease is not endemic, including six enzyme-linked immunosorbent assays using three different antigens, an indirect hemagglutination assay, and an indirect immunofluorescent-antibody test. To analyze the assays, we used a total of 141 serum samples, with 121 derived from patients with various parasitic infections (among which were 37 cases of schistosomiasis) and 20 taken from healthy volunteers. The sensitivity values for detection of schistosomiasis cases ranged from 41% to 78% and were higher for Schistosoma mansoni than for S. haematobium infections. Specificity values ranged from 76% to 100%; false-positive results were most frequent for samples from patients with cestode infections. By combining two or more tests, sensitivity improved markedly and specificity decreased only moderately. Serological tests are useful instruments for diagnosing imported schistosomiasis in countries where the disease is not endemic, but due to limitations in test sensitivities, we recommend the use of two or more assays in parallel. PMID:22441394

  11. [Identification of schistosomiasis risk areas using spatial analysis in Lauro de Freitas, Bahia State, Brazil].

    PubMed

    Cardim, Luciana Lobato; Ferraudo, Antonio Sergio; Pacheco, Selma Turrioni Azevedo; Reis, Renato Barbosa; Silva, Marta Mariana Nascimento; Carneiro, Deborah Daniela M Trabuco; Bavia, Maria Emilia

    2011-05-01

    The spread of schistosomiasis mansoni defies efforts by Brazil's Unified National Health System, thus demonstrating the need to reassess endemic control programs in the country. The aim of this study was to demarcate geographic areas at risk of schistosomiasis in Lauro de Freitas, Bahia State, Brazil, and to establish the epidemiological and socioeconomic profile of the disease in this municipality (county). Kernel density estimator exploratory analysis was used for visual identification of areas at risk. Kulldorff & Nagarwalla's spatial analysis was used to obtain statistically significant clusters and to measure risk. These technologies identified four risk areas for schistosomiasis. Clusters identified within the risk areas were characterized by lower socioeconomic conditions. Multiple correspondence analyses showed a distinct profile for positive patients in the primary cluster. The techniques employed here represent an important methodological acquisition for tracking and controlling schistosomiasis in Lauro de Freitas. PMID:21655841

  12. Rural tourism: a risk factor for schistosomiasis transmission in Brazil.

    PubMed

    Enk, Martin Johannes; Amaral, Graciela Larissa; Costa e Silva, Matheus Fernandes; Silveira-Lemos, Denise; Teixeira-Carvalho, Andréa; Martins-Filho, Olindo Assis; Correa-Oliveira, Rodrigo; Gazinnelli, Giovanni; Coelho, Paulo Marcos Zech; Massara, Cristiano Lara

    2010-07-01

    This paper reports an outbreak of acute schistosomiasis among 38 tourists who rented a country house in the district of Igarapé, the metropolitan region of Belo Horizonte, Brazil, during a holiday period in 2006. A total number of 32 individuals were positive for Schistosoma mansoni. Results of stool examinations revealed individual S. mansoni egg counts per gram of faeces (epg) ranging from 4-768 epg with a geometric mean egg count of 45. The most frequent clinical symptoms were abdominal pain (78.1%), headache (75%), fever (65.6%), dry cough (65.2%) and both diarrhoea and asthenia (59.4%). A malacological survey of the area, where 22 specimens of Biomphalaria glabrata were collected, revealed three (13.6%) specimens eliminating Schistosoma cercariae. This investigation re-confirms a recently described pattern of schistosomiasis infection, resulting in the acute form of the disease and connected to rural tourism, which contributes to the spread of the disease among the middle-class and into non-endemic areas. The lack of specific knowledge about acute schistosomiasis among health services causes an increased number of unnecessary diagnostic procedures and delays in accurate diagnosis and treatment, resulting in considerable discomfort for the patients. PMID:20721505

  13. Prevalence of hepatitis B surface antigenemia among patients with schistosoma mansoni.

    PubMed

    Al-Freihi, H M

    1993-03-01

    This case-control study was designed to determine the prevalence of persistent hepatitis B surface antigenemia (HBsAG) among patients with schistosoma mansoni and to rationalize their vaccination against hepatitis B virus (HBV) infection. Seventy consecutive patients with a confirmed diagnosis of schistosoma mansoni were matched for age, sex, nationality, and residence (for Saudis only) with 70 healthy controls. Despite identical mean ages, sex, and nationality distribution, 18 schistosomiasis patients (26%) had positive HBsAg as compared with only three of the controls (4%). The odd ratio for HBsAg antigenemia among patients as compared to controls was 7.73 (95% confidence interval (CI) = 2-35.01, P = 0.0004. Neither sex nor nationality had any influence on the positive rate for HBsAg found in schistosomiasis patients. Patients with schistosomiasis and a concomitant positive HBsAg had significantly more derangement of their hepatic enzymes (14 out of 18; 78%) as compared with those without this viral serological marker (22 out of 52; 42%) (odd ratio - 4.77; 95% CI=1.22-20.11; P = 0.009). I have concluded that patients with schistosoma mansoni are exposed to a higher risk of acquiring HBV infection and that concomitant schistosomiasis and HBV infection has a deleterious effect on hepatic enzymes as well as other liver functions. Prospective evaluation of the preventive role of HBV vaccine among these patients is warranted. PMID:17588014

  14. [Immunoenzyme assay of parasite-specific IgG4 antibodies in schistosomiasis using the monoclonal antibody BL-IgG4/1].

    PubMed

    Sauer, H; Ambrosius, H; Behn, I; Fiebig, H; Köllner, B; Leykun, J; Schubert, S; Spannemann, B

    1990-01-01

    Sera from 251 children living in endemic areas (Schistosoma mansoni or Schistosoma haematobium) and from 188 hospital outpatients in Ethiopia were evaluated for specific IgG4 antibodies reacting with Schistosoma mansoni adult worm antigen employing an enzyme-immunoassay. Patients with schistosomiasis (n = 140) possessed a significantly higher mean value of specific IgG4 antibodies than normal controls (n = 30) and individuals from different countries who had no schistosomiasis but are infected with other parasites (n = 114). Blood samples dried on filter paper were also acceptable in these test. The use of the test in diagnosis is compared and assessed with parasitological methods. PMID:2097901

  15. Prevalence of Schistosoma mansoni Infection in Four Health Areas of Kisantu Health Zone, Democratic Republic of the Congo

    PubMed Central

    Mbanzulu Makola, K.

    2016-01-01

    Background. Schistosomiasis is a public health problem in Democratic Republic of the Congo but estimates of its prevalence vary widely. The aim of this study was to determine prevalence of Schistosoma mansoni infection and associated risk factors among children in 4 health areas of Kisantu health zone. Methods. A cross-sectional study was carried out in 4 health areas of Kisantu health zone. 388 children randomly selected were screened for S. mansoni using Kato Katz technique and the sociodemographic data was collected. Data were entered and encoded using software EpiData version 3.1. Analysis was performed using SPSS version 21 software. Results. The prevalence of S. mansoni was 26.5% (103); almost two-thirds (63) (61.2%) had light infection intensity. A significant association was found between S. mansoni infection and age (p = 0.005), educational level (p = 0.001), and practices of swimming/bathing (p < 0.001) and using water from river/lake/stream for domestic use (p < 0.001). Kipasa health area had high prevalence of schistosomiasis (64.6%) (64/99; 95% CI 54.4–74.0) compared to other health areas. Conclusion. Schistosoma mansoni infection still remains a public health problem in these areas. There is a need to promote health education and promote behavioral changes in children towards schistosomiasis. PMID:27579346

  16. Prevalence of Schistosoma mansoni Infection in Four Health Areas of Kisantu Health Zone, Democratic Republic of the Congo.

    PubMed

    Khonde Kumbu, R; Mbanzulu Makola, K; Bin, Lu

    2016-01-01

    Background. Schistosomiasis is a public health problem in Democratic Republic of the Congo but estimates of its prevalence vary widely. The aim of this study was to determine prevalence of Schistosoma mansoni infection and associated risk factors among children in 4 health areas of Kisantu health zone. Methods. A cross-sectional study was carried out in 4 health areas of Kisantu health zone. 388 children randomly selected were screened for S. mansoni using Kato Katz technique and the sociodemographic data was collected. Data were entered and encoded using software EpiData version 3.1. Analysis was performed using SPSS version 21 software. Results. The prevalence of S. mansoni was 26.5% (103); almost two-thirds (63) (61.2%) had light infection intensity. A significant association was found between S. mansoni infection and age (p = 0.005), educational level (p = 0.001), and practices of swimming/bathing (p < 0.001) and using water from river/lake/stream for domestic use (p < 0.001). Kipasa health area had high prevalence of schistosomiasis (64.6%) (64/99; 95% CI 54.4-74.0) compared to other health areas. Conclusion. Schistosoma mansoni infection still remains a public health problem in these areas. There is a need to promote health education and promote behavioral changes in children towards schistosomiasis. PMID:27579346

  17. PREVALENCE AND RISK FACTORS OF SCHISTOSOMIASIS AMONG HAUSA COMMUNITIES IN KANO STATE, NIGERIA

    PubMed Central

    DAWAKI, Salwa; AL-MEKHLAFI, Hesham Mahyoub; ITHOI, Init; IBRAHIM, Jamaiah; ABDULSALAM, Awatif Mohammed; AHMED, Abdulhamid; SADY, Hany; ATROOSH, Wahib Mohammed; AL-AREEQI, Mona Abdullah; ELYANA, Fatin Nur; NASR, Nabil Ahmed; SURIN, Johari

    2016-01-01

    SUMMARY Schistosomiasis remains one of the most prevalent neglected tropical diseases especially in Nigeria which has the greatest number of infected people worldwide. A cross-sectional study was conducted among 551 participants from Kano State, North Central Nigeria. Fecal samples were examined for the presence of Schistosoma mansoni eggs using the formalin-ether sedimentation method while the urine samples were examined using the filtration technique for the presence of S. haematobium eggs. Demographic, socioeconomic and environmental information was collected using a pre-validated questionnaire. The overall prevalence of schistosomiasis was 17.8%, with 8.9% and 8.3% infected with S. mansoni and S. haematobium, respectively and 0.5% presenting co-infection with both species. The multiple logistic regression analysis revealed that age < 18 years (OR = 2.13; 95% CI; 1.34- 3.41), presence of infected family members (OR = 3.98; 95% CI; 2.13-7.46), and history of infection (OR = 2.87; 95% CI; 1.87- 4.56) were the significant risk factors associated with schistosomiasis in these communities. In conclusion, this study revealed that schistosomiasis is still prevalent among Hausa communities in Nigeria. Mass drug administration, health education and community mobilization are imperative strategies to significantly reduce the prevalence and morbidity of schistosomiasis in these communities. PMID:27410914

  18. PREVALENCE AND RISK FACTORS OF SCHISTOSOMIASIS AMONG HAUSA COMMUNITIES IN KANO STATE, NIGERIA.

    PubMed

    Dawaki, Salwa; Al-Mekhlafi, Hesham Mahyoub; Ithoi, Init; Ibrahim, Jamaiah; Abdulsalam, Awatif Mohammed; Ahmed, Abdulhamid; Sady, Hany; Atroosh, Wahib Mohammed; Al-Areeqi, Mona Abdullah; Elyana, Fatin Nur; Nasr, Nabil Ahmed; Surin, Johari

    2016-07-11

    Schistosomiasis remains one of the most prevalent neglected tropical diseases especially in Nigeria which has the greatest number of infected people worldwide. A cross-sectional study was conducted among 551 participants from Kano State, North Central Nigeria. Fecal samples were examined for the presence of Schistosoma mansoni eggs using the formalin-ether sedimentation method while the urine samples were examined using the filtration technique for the presence of S. haematobium eggs. Demographic, socioeconomic and environmental information was collected using a pre-validated questionnaire. The overall prevalence of schistosomiasis was 17.8%, with 8.9% and 8.3% infected with S. mansoni and S. haematobium, respectively and 0.5% presenting co-infection with both species. The multiple logistic regression analysis revealed that age < 18 years (OR = 2.13; 95% CI; 1.34- 3.41), presence of infected family members (OR = 3.98; 95% CI; 2.13-7.46), and history of infection (OR = 2.87; 95% CI; 1.87- 4.56) were the significant risk factors associated with schistosomiasis in these communities. In conclusion, this study revealed that schistosomiasis is still prevalent among Hausa communities in Nigeria. Mass drug administration, health education and community mobilization are imperative strategies to significantly reduce the prevalence and morbidity of schistosomiasis in these communities. PMID:27410914

  19. Polymerase Chain Reaction: A Better Method for Diagnosing Chronic Schistosoma mansoni Infections

    PubMed Central

    Abdel-Hafeez, Ekhlas Hamed; Mohamed, Rabie M.; Belal, Usama S.; Abdel-Raheem, Ehab M.; Naoi, Koji; Norose, Kazumi

    2015-01-01

    For more effective diagnosis of the acute and chronic stages of Schistosoma mansoni infection in humans, the polymerase chain reaction (PCR) technique was compared with the Kato-Katz method. A total of 150 stool samples were collected from inpatient and outpatient clinics at the Department of Tropical Medicine, Minia University Hospital, Egypt. Three groups of patients, 50 with acute intestinal schistosomiasis, 70 with chronic intestinal schistosomiasis and 30 normal healthy controls were studied. Stool samples were analyzed by PCR and the Kato-Katz method. The mean number of eggs per gram of feces was 4.6 when estimated by the Kato-Katz method in positive stool samples from acute schistosomiasis cases but only 1.7 in chronic cases. In acute intestinal schistosomiasis, 15 and 45 out of 50 cases were positive by Kato-Katz and PCR, respectively. In the chronic intestinal schistosomiasis cases, 6 and 68 out of 70 cases were positive by the Kato-Katz and PCR methods, respectively. We conclude that PCR appears to be an effective diagnostic technique for S. mansoni infection, especially where a low worm burden exists, such as in chronic cases. PMID:26865821

  20. Rapid screening for Schistosoma mansoni in western Côte d'Ivoire using a simple school questionnaire.

    PubMed Central

    Utzinger, J.; N'Goran, E. K.; Ossey, Y. A.; Booth, M.; Traoré, M.; Lohourignon, K. L.; Allangba, A.; Ahiba, L. A.; Tanner, M.; Lengeler, C.

    2000-01-01

    The distribution of schistosomiasis is focal, so if the resources available for control are to be used most effectively, they need to be directed towards the individuals and/or communities at highest risk of morbidity from schistosomiasis. Rapid and inexpensive ways of doing this are needed, such as simple school questionnaires. The present study used such questionnaires in an area of western Côte d'Ivoire where Schistosoma mansoni is endemic; correctly completed questionnaires were returned from 121 out of 134 schools (90.3%), with 12,227 children interviewed individually. The presence of S. mansoni was verified by microscopic examination in 60 randomly selected schools, where 5047 schoolchildren provided two consecutive stool samples for Kato-Katz thick smears. For all samples it was found that 54.4% of individuals were infected with S. mansoni. Moreover, individuals infected with S. mansoni reported "bloody diarrhoea", "blood in stools" and "schistosomiasis" significantly more often than uninfected children. At the school level, Spearman rank correlation analysis showed that the prevalence of S. mansoni significantly correlated with the prevalence of reported bloody diarrhoea (P = 0.002), reported blood in stools (P = 0.014) and reported schistosomiasis (P = 0.011). Reported bloody diarrhoea and reported blood in stools had the best diagnostic performance (sensitivity: 88.2%, specificity: 57.7%, positive predictive value: 73.2%, negative predictive value: 78.9%). The study, which is probably the largest of its kind ever undertaken in Africa, revealed a moderate diagnostic performance of questionnaires for identifying individuals and/or communities at high risk from S. mansoni. PMID:10812739

  1. A Loop-Mediated Isothermal Amplification (LAMP) Assay for Early Detection of Schistosoma mansoni in Stool Samples: A Diagnostic Approach in a Murine Model

    PubMed Central

    Fernández-Soto, Pedro; Gandasegui Arahuetes, Javier; Sánchez Hernández, Alicia; López Abán, Julio; Vicente Santiago, Belén; Muro, Antonio

    2014-01-01

    Background Human schistosomiasis, mainly due to Schistosoma mansoni species, is one of the most prevalent parasitic diseases worldwide. To overcome the drawbacks of classical parasitological and serological methods in detecting S. mansoni infections, especially in acute stage of the disease, development of cost-effective, simple and rapid molecular methods is still needed for the diagnosis of schistosomiasis. A promising approach is the loop-mediated isothermal amplification (LAMP) technology. Compared to PCR-based assays, LAMP has the advantages of reaction simplicity, rapidity, specificity, cost-effectiveness and higher amplification efficiency. Additionally, as results can be inspected by the naked eye, the technique has great potential for use in low-income countries. Methodology/Principal findings A sequence corresponding to a mitochondrial S. mansoni minisatellite DNA region was selected as a target for designing a LAMP-based method to detect S. mansoni DNA in stool samples. We used a S. mansoni murine model to obtain well defined stool and sera samples from infected mice with S. mansoni cercariae. Samples were taken weekly from week 0 to 8 post-infection and the Kato-Katz and ELISA techniques were used for monitoring the infection. Primer set designed were tested using a commercial reaction mixture for LAMP assay and an in house mixture to compare results. Specificity of LAMP was tested using 16 DNA samples from different parasites, including several Schistosoma species, and no cross-reactions were found. The detection limit of our LAMP assay (SmMIT-LAMP) was 1 fg of S. mansoni DNA. When testing stool samples from infected mice the SmMIT-LAMP detected S. mansoni DNA as soon as 1 week post-infection. Conclusions/Significance We have developed, for the first time, a cost-effective, easy to perform, specific and sensitive LAMP assay for early detection of S. mansoni in stool samples. The method is potentially and readily adaptable for field diagnosis and

  2. THE SUSCEPTIBILITY OF RECENT ISOLATES OF Schistosoma mansoni TO PRAZIQUANTEL

    PubMed Central

    MENDONÇA, Adriana Maria B.; FEITOSA, Ana Paula S.; VERAS, Dyana L.; MATOS-ROCHA, Thiago J.; CAVALCANTI, Marília G. dos Santos; BARBOSA, Constança Clara G. S.; BRAYNER, Fábio A.; ALVES, Luiz C.

    2016-01-01

    Introduction: Schistosomiasis is a chronic disease caused by trematode flatworms of the genus Schistosoma and its control is dependent on a single drug, praziquantel (PZQ), but concerns over PZQ resistance have renewed interest in evaluating the in vitro susceptibility of recent isolates of Schistosoma mansoni to PZQ in comparison with well-established strains in the laboratory. Material and methods: The in vitro activity of PZQ (6.5-0.003 µg/mL) was evaluated in terms of mortality, reduced motor activity and ultrastructural alterations against S. mansoni. Results: After 3 h of incubation, PZQ, at 6.5 µg/mL, caused 100% mortality of all adult worms in the three types of recent isolates, while PZQ was inactive at concentrations of 0.08-0.003 µg/mL after 3 h of incubation. The results show that the SLM and Sotave isolates basically presented the same pattern of susceptibility, differing only in the concentration of 6.5 µg/mL, where deaths occurred from the range of 1.5 h in Sotave and just in the 3 h range of SLM. Additionally, this article presents ultrastructural evidence of rapid severe PZQ-induced surface membrane damage in S. mansoni after treatment with the drug, such as disintegration, sloughing, and erosion of the surface. Conclusion: According to these results, PZQ is very effective to induce tegument destruction of recent isolates of S. mansoni. PMID:26910445

  3. How cost-effective would a vaccine be against schistosomiasis?

    PubMed

    1996-08-01

    An estimated 20 million people suffer severe disease or disability from schistosomiasis and about 50,000 die from the disease annually. While the inexpensive and effective drug praziquantel exists, there is a high risk of reinfection following treatment, necessitating long-term annual retreatment. Vaccine research has identified several antigens in Schistosoma mansoni, one of the worm species which causes human disease. However, tests of 6 of these antigens in animals for their protective potential as vaccines or vaccine components have yielded only inconsistent and largely disappointing results. The antigens are nonetheless capable of producing immune responses indicative of protection in people living in endemic areas and therefore have potential. A schistosomiasis vaccine administered to at least 80% of children in a schistosomiasis-endemic area of a low-income country, and providing protection for at least 90% of those receiving the full dose, would cost US$64-405 per healthy year of life saved. The vaccine, however, must provide protection for at least 10 years, cost no more than US$5 per completely vaccinated child, including delivery, and be delivered through the EPI system. Such a schistosomiasis vaccine would be relatively cost-effective compared with mass chemotherapy with praziquantel for children aged 6-15 years. PMID:12321483

  4. Schistosomiasis and the pulmonary vasculature (2013 Grover Conference series)

    PubMed Central

    2014-01-01

    Abstract Inflammation is associated with multiple forms of pulmonary arterial hypertension (PAH), including autoimmune (scleroderma) and infectious (HIV, schistosomiasis) etiologies. More than 200 million people worldwide are infected with Schistosoma, predominantly in Brazil, Africa, the Middle East, and South Asia. Schistosomiasis causes PAH in about 6.1% of those chronically infected and is particularly associated with the species Schistosoma mansoni. Treatment for schistosomiasis-associated PAH includes antihelminthic treatment, if active infection is present (although associated with little immediate benefit to the pulmonary hypertension), and then pharmacologic treatment with targeted pulmonary vascular therapies, including phosphodiesterase type 5 inhibitors and endothelin receptor antagonists. The pathophysiological mechanism by which this parasitic infection causes pulmonary hypertension is unknown but is unlikely to be simple mechanical obstruction of the pulmonary vasculature by parasite eggs. Preexisting hepatosplenic disease due to Schistosoma infection is likely important because of portopulmonary hypertension and/or because it allows egg embolization to the lung by portocaval shunts. Potential immune signaling originating in the periegg granulomas causing the pulmonary vascular disease includes the cytokines interleukin (IL)-4, IL-6, IL-13, and transforming growth factor β. Modulating these pathways may be possible targets for future therapy of schistosomiasis-associated PAH specifically, and study of this disease may provide novel insights into other inflammatory causes of PAH. PMID:25621148

  5. Influence of Schistosoma mansoni and Hookworm Infection Intensities on Anaemia in Ugandan Villages

    PubMed Central

    Chami, Goylette F.; Fenwick, Alan; Bulte, Erwin; Kontoleon, Andreas A.; Kabatereine, Narcis B.; Tukahebwa, Edridah M.; Dunne, David W.

    2015-01-01

    Background The association of anaemia with intestinal schistosomiasis and hookworm infections are poorly explored in populations that are not limited to children or pregnant women. Methods We sampled 1,832 individuals aged 5–90 years from 30 communities in Mayuge District, Uganda. Demographic, village, and parasitological data were collected. Infection risk factors were compared in ordinal logistic regressions. Anaemia and infection intensities were analyzed in multilevel models, and population attributable fractions were estimated. Findings Household and village-level predictors of Schistosoma mansoni and hookworm were opposite in direction or significant for single infections. S. mansoni was found primarily in children, whereas hookworm was prevalent amongst the elderly. Anaemia was more prevalent in individuals with S. mansoni and increased by 2.86 fold (p-value<0.001) with heavy S. mansoni infection intensity. Individuals with heavy hookworm were 1.65 times (p-value = 0.008) more likely to have anaemia than uninfected participants. Amongst individuals with heavy S. mansoni infection intensity, 32.0% (p-value<0.001) of anaemia could be attributed to S. mansoni. For people with heavy hookworm infections, 23.7% (p-value = 0.002) of anaemia could be attributed to hookworm. A greater fraction of anaemia (24.9%, p-value = 0.002) was attributable to heavy hookworm infections in adults (excluding pregnant women) as opposed to heavy hookworm infections in school-aged children and pregnant women (20.2%, p-value = 0.001). Conclusion Community-based surveys captured anaemia in children and adults affected by S. mansoni and hookworm infections. For areas endemic with schistosomiasis or hookworm infections, WHO guidelines should include adults for treatment in helminth control programmes. PMID:26513151

  6. Diagnosis of Schistosoma mansoni without the Stool: Comparison of Three Diagnostic Tests to Detect Schiostosoma mansoni Infection from Filtered Urine in Zambia

    PubMed Central

    Lodh, Nilanjan; Mwansa, James C. L.; Mutengo, Mable M.; Shiff, Clive J.

    2013-01-01

    Diagnosis for intestinal Schistosoma mansoni lacks sensitivity and is arduous to conduct. The standard diagnostic tests, Kato-Katz (KK) and circulating cathodic antigen (CCA) both lack sensitivity and with KK, require obtaining, transporting, and examining fresh stool. We compared diagnostic efficacy of KK, CCA, and polymerase chain reaction (PCR) to detect S. mansoni infection (species-specific DNA) from 89 filtered urine samples collected in Zambia. The PCR was the strongest indicator of positive cases with sensitivity and specificity of 100% in comparison to CCA (67% and 60%) and KK (50% and 100%). High positive and negative predictive values (100%) were also indicative of robustness of PCR. The same pattern was observed when stratified for sex and age group-specific analysis. Diagnosis of S. mansoni from filtered urine samples by PCR is an effective means to detect low intensity infection and would enhance the effectiveness of surveillance and control programs of schistosomiasis. PMID:23716406

  7. Proteomic Analysis of the Schistosoma mansoni Miracidium

    PubMed Central

    Wang, Tianfang; Zhao, Min; Rotgans, Bronwyn A.; Strong, April; Liang, Di; Ni, Guoying; Limpanont, Yanin; Ramasoota, Pongrama; McManus, Donald P.; Cummins, Scott F.

    2016-01-01

    Despite extensive control efforts, schistosomiasis continues to be a major public health problem in developing nations in the tropics and sub-tropics. The miracidium, along with the cercaria, both of which are water-borne and free-living, are the only two stages in the life-cycle of Schistosoma mansoni which are involved in host invasion. Miracidia penetrate intermediate host snails and develop into sporocysts, which lead to cercariae that can infect humans. Infection of the snail host by the miracidium represents an ideal point at which to interrupt the parasite’s life-cycle. This research focuses on an analysis of the miracidium proteome, including those proteins that are secreted. We have identified a repertoire of proteins in the S. mansoni miracidium at 2 hours post-hatch, including proteases, venom allergen-like proteins, receptors and HSP70, which might play roles in snail-parasite interplay. Proteins involved in energy production and conservation were prevalent, as were proteins predicted to be associated with defence. This study also provides a strong foundation for further understanding the roles that neurohormones play in host-seeking by schistosomes, with the potential for development of novel anthelmintics that interfere with its various life-cycle stages. PMID:26799066

  8. Proteomic Analysis of the Schistosoma mansoni Miracidium.

    PubMed

    Wang, Tianfang; Zhao, Min; Rotgans, Bronwyn A; Strong, April; Liang, Di; Ni, Guoying; Limpanont, Yanin; Ramasoota, Pongrama; McManus, Donald P; Cummins, Scott F

    2016-01-01

    Despite extensive control efforts, schistosomiasis continues to be a major public health problem in developing nations in the tropics and sub-tropics. The miracidium, along with the cercaria, both of which are water-borne and free-living, are the only two stages in the life-cycle of Schistosoma mansoni which are involved in host invasion. Miracidia penetrate intermediate host snails and develop into sporocysts, which lead to cercariae that can infect humans. Infection of the snail host by the miracidium represents an ideal point at which to interrupt the parasite's life-cycle. This research focuses on an analysis of the miracidium proteome, including those proteins that are secreted. We have identified a repertoire of proteins in the S. mansoni miracidium at 2 hours post-hatch, including proteases, venom allergen-like proteins, receptors and HSP70, which might play roles in snail-parasite interplay. Proteins involved in energy production and conservation were prevalent, as were proteins predicted to be associated with defence. This study also provides a strong foundation for further understanding the roles that neurohormones play in host-seeking by schistosomes, with the potential for development of novel anthelmintics that interfere with its various life-cycle stages. PMID:26799066

  9. Activity of epiisopiloturine against Schistosoma mansoni.

    PubMed

    Veras, L M; Guimaraes, M A; Campelo, Y D; Vieira, M M; Nascimento, C; Lima, D F; Vasconcelos, L; Nakano, E; Kuckelhaus, S S; Batista, M C; Leite, J R; Moraes, J

    2012-01-01

    Schistosomiasis, caused by blood flukes of the genus Schistosoma, still imposes a considerable public health burden on large parts of the world. The control of this disease depends almost exclusively on the drug praziquantel, and there are no alternative drugs in sight. Natural compounds have recently attracted significant attention due to their relevance to parasitic infection and potential development into new therapeutic agents. Epiisopiloturine is an imidazole alkaloid isolated from the leaves of Pilocarpus microphyllus (Rutaceae), a native plant from Brazil. Here, we report the in vitro effect of this drug on the survival time of Schistosoma mansoni of different ages, such as 3 h old and 1, 3, 5, and 7 days old schistosomula, 49-day-old adults, and on egg output by adult worms. Epiisopiloturine at a concentration of 300 μg/mL caused the death of all schistosomula within 120 h. Extensive tegumental alterations and death were observed when adult schistosomes had been exposed to 150 μg/mL of the epiisopiloturine. At the highest sub-lethal dose of alkaloid (100 μg/mL), a 100% reduction in egg laying of paired adult worms was observed. Additionally, epiisopiloturine showed selective antischistosomal activity and exhibited no cytotoxicity to mammalian cells. This report provides the first evidence that epiisopiloturine is able to kill S. mansoni of different ages and inhibit worm egg laying. PMID:22420337

  10. Eosinophils as effector cells in the destruction of Schistosoma mansoni eggs in granulomas.

    PubMed

    Hsü, S Y; Hsü, H F; Mitros, F A; Helms, C M; Solomon, R I

    1980-04-01

    Histopathological sections of wedge-biopsied liver and surgically removed gallbladder of a schistosomiasis mansoni patient were studied for the eosinophil-mediated destruction of eggs in granulomas. Apparent degranulation of eosinophils on the eggs in the granulomas and concomittant deterioration of miracidia were observed. It was construed that granule-associated enzymes may be released upon the degranulation of eosinophils, pass through the micropores of the egg shell and cause death of the miracidium inside the egg. PMID:7436603

  11. Questionnaires for rapid screening of schistosomiasis in sub-Saharan Africa.

    PubMed Central

    Lengeler, Christian; Utzinger, Jürg; Tanner, Marcel

    2002-01-01

    New initiatives are aiming to reduce the global burden of schistosomiasis, mainly through the large-scale application of chemotherapy. To target chemotherapy effectively, rapid assessment procedures are needed for identifying high-risk communities that are foci for the disease. In this review, we examine the development and validation of simple school questionnaires for screening communities for Schistosoma haematobium and S. mansoni rapidly and inexpensively. The focus is on sub-Saharan Africa, where 85% of the current schistosomiasis burden is concentrated. For more than a decade, the questionnaire approach has been validated in 10 countries, with 133 880 children interviewed in 1282 schools, and with 54 996 children examined for S. haematobium. The questionnaires were well accepted, highly reliable, and of low cost. The success of the questionnaires is explained by the fact that S. haematobium infections were easily perceived through the presence of blood in urine. Evidence from 48 258 children interviewed in 545 schools indicated that reported blood in stools and bloody diarrhoea are valuable indicators for community diagnosis of S. mansoni. However, the diagnostic performance of the questionnaires for S. mansoni was weaker than for S. haematobium, and although these results are encouraging, the questionnaires need additional validation. Recently, questionnaires were extended from community to individual diagnosis and showed considerable promise. Questionnaires are now available for promptly defining the magnitude of schistosomiasis in a large area, which will allow limited resources for morbidity control to be allocated optimally. PMID:11984610

  12. Anti-Inflammatory Properties of Menthol and Menthone in Schistosoma mansoni Infection

    PubMed Central

    Zaia, Mauricio G.; Cagnazzo, Túlio di Orlando; Feitosa, Karina A.; Soares, Edson G.; Faccioli, Lúcia H.; Allegretti, Silmara M.; Afonso, Ana; Anibal, Fernanda de Freitas

    2016-01-01

    Schistosomiasis is a parasitic disease caused by several species of trematode worms and it is believed that more than 261 million people are affected worldwide. New drug development has become essential because there is a risk of the parasite becoming resistant to Praziquantel, the only drug available for this infection. This study evaluated parasitological, immunological and histological parameters in mice infected with Schistosoma mansoni and treated with an herbal commercial medicine. This drug consists of menthol (30–55%) and menthone (14–32%). A 60 day treatment regimen with the herbal medicine decreased the number of S. mansoni eggs in the feces, liver, and intestine and reduced the number of hepatic granulomas. We observed a reduction of 84% in blood eosinophilia and a decrease in the IL-4 and IL-10 blood levels after treatment. Therefore, we propose that schistosomiasis treatment with this herbal medicine for 60 days has an immunomodulatory and anti-inflammatory action in this animal model for schistosomiasis thus contributing to the decrease in physio pathological effects caused by S. mansoni infection. PMID:27378927

  13. Anti-Inflammatory Properties of Menthol and Menthone in Schistosoma mansoni Infection.

    PubMed

    Zaia, Mauricio G; Cagnazzo, Túlio di Orlando; Feitosa, Karina A; Soares, Edson G; Faccioli, Lúcia H; Allegretti, Silmara M; Afonso, Ana; Anibal, Fernanda de Freitas

    2016-01-01

    Schistosomiasis is a parasitic disease caused by several species of trematode worms and it is believed that more than 261 million people are affected worldwide. New drug development has become essential because there is a risk of the parasite becoming resistant to Praziquantel, the only drug available for this infection. This study evaluated parasitological, immunological and histological parameters in mice infected with Schistosoma mansoni and treated with an herbal commercial medicine. This drug consists of menthol (30-55%) and menthone (14-32%). A 60 day treatment regimen with the herbal medicine decreased the number of S. mansoni eggs in the feces, liver, and intestine and reduced the number of hepatic granulomas. We observed a reduction of 84% in blood eosinophilia and a decrease in the IL-4 and IL-10 blood levels after treatment. Therefore, we propose that schistosomiasis treatment with this herbal medicine for 60 days has an immunomodulatory and anti-inflammatory action in this animal model for schistosomiasis thus contributing to the decrease in physio pathological effects caused by S. mansoni infection. PMID:27378927

  14. Saudi Guidelines on the Diagnosis and Treatment of Pulmonary Hypertension: Schistosomiasis and pulmonary arterial hypertension.

    PubMed

    Butrous, Ghazwan

    2014-07-01

    Schistosomiasis is caused by infection with the parasite Schistosoma, which is a flat-worm or fluke. The dominant species are Schistosoma mansoni, Schistosoma japonicum, and Schistosoma haematobium. Schistosomiasis is the third most common parasitic disease in the world after malaria and amoebiasis. It is endemic in more than 70 countries affecting about 200 million people worldwide, of whom 80% are in sub-Saharan Africa. There are pockets of infection in north-eastern Brazil, near the Yangtze River in China, and some pockets in south East Asia. In the East Mediterranean regions, the Schistosoma have been reported in Iraq and Egypt as well as in Sudan. The latter has the highest infection rate nowadays, particularly in the Al Jazeera area, due to the poor Schistosoma control program. In the Arabian peninsula, schistosomiasis has been reported in southwest part of Saudi Arabia, mainly in the Asir province and Jizan province, which lay in the southwest corner of Saudi Arabia and directly north of the border with Yemen. The efforts to control schistosomiasis have been very successful in Saudi Arabia due to the irrigation system control. However, the infection is prone in Yemen, where the schistosomiasis control is much less strict. Thus as a result, the problem still exists due to transmigration of the populations from both countries. As a cause of pulmonary arterial hypertension (PAH), schistosomiasis is still under diagnosed and undertreated. This article with give a highlight about the pathophysiology of the disease and both diagnostic and therapeutic strategies. PMID:25076995

  15. Modulation of the host response in human schistosomiasis

    PubMed Central

    Hofstetter, M.; Poindexter, R. W.; Ruiz-Tiben, E.; Ottesen, E. A.

    1982-01-01

    Mechanisms for modulating the host's immune response in human Schistosomiasis mansoni have been described for delayed hypersensitivity responsiveness and antibody production. Since clinical symptoms of immediate hypersensitivity (i.e. allergic reactivity) are rare in schistosomiasis despite the presence of parasite-specific immunoglobulin E, circulating parasite antigen, and normal numbers of basophils and mast cells in infected patients, it seemed likely that there was host modulation of immediate hypersensitivity responsiveness as well. Using an in vitro basophil histamine release assay we have shown that basophils from fifteen patients with S. mansoni infections are sensitized with schistosome-specific immunoglobulin E and will release histamine in an antigen-dose-dependent manner when challenged with a soluble adult worm antigen. This histamine release was suppressed by autologus, but not normal serum. Fractionation of the serum over staphylococcal protein A and antigen affinity columns identified an immunoglobulin G parasite-specific `blocking antibody', analogous to blocking antibodies elicited during immunotherapy of atopic patients, as being responsible for the modulation of this immediate hypersensitivity responsiveness in vitro. Blocking antibody specificity varied from patient to patient, an observation suggesting that different allergens were being recognized by different individuals. These studies demonstrate that in addition to the immunoregulatory mechanisms previously described in patients with schistosome infections, there is host modulation of immediate hypersensitivity responsiveness that appears to involve specific immunoglobulin G blocking antibodies. PMID:6179857

  16. Increased IL-17, a Pathogenic Link between Hepatosplenic Schistosomiasis and Amyotrophic Lateral Sclerosis: A Hypothesis

    PubMed Central

    Di Summa, Alfonsina; Capone, Loredana; Stuefer, Josef; Piccin, Andrea; Porzia, Alessandra; Capozzi, Antonella; Sorice, Maurizio; Binazzi, Raffaella; Gandini, Lathá; Rimenti, Giovanni; Mian, Peter

    2014-01-01

    The immune system protects the organism from foreign invaders and foreign substances and is involved in physiological functions that range from tissue repair to neurocognition. However, an excessive or dysregulated immune response can cause immunopathology and disease. A 39-year-old man was affected by severe hepatosplenic schistosomiasis mansoni and by amyotrophic lateral sclerosis. One question that arose was, whether there was a relation between the parasitic and the neurodegenerative disease. IL-17, a proinflammatory cytokine, is produced mainly by T helper-17 CD4 cells, a recently discovered new lineage of effector CD4 T cells. Experimental mouse models of schistosomiasis have shown that IL-17 is a key player in the immunopathology of schistosomiasis. There are also reports that suggest that IL-17 might have an important role in the pathogenesis of amyotrophic lateral sclerosis. It is hypothesized that the factors that might have led to increased IL-17 in the hepatosplenic schistosomiasis mansoni might also have contributed to the development of amyotrophic lateral sclerosis in the described patient. A multitude of environmental factors, including infections, xenobiotic substances, intestinal microbiota, and vitamin D deficiency, that are able to induce a proinflammatory immune response polarization, might favor the development of amyotrophic lateral sclerosis in predisposed individuals. PMID:25379310

  17. The hepatoprotective activity of blue green algae in Schistosoma mansoni infected mice.

    PubMed

    Mohamed, Azza H; Osman, Gamalat Y; Salem, Tarek A; Elmalawany, Alshimaa M

    2014-10-01

    This study aims to evaluate the immunomodulatory effects of a natural product, blue green algae (BGA) (100 mg/kg BW), alone or combined with praziquantel PZQ (250 mg/kg BW) on granulomatous inflammation, liver histopathology, some biochemical and immunological parameters in mice infected with Schistosoma mansoni. Results showed that the diameter and number of egg granuloma were significantly reduced after treatment of S. mansoni-infected mice with BGA, PZQ and their combination. The histopathological alterations observed in the liver of S. mansoni-infected mice were remarkably inhibited after BGA treatments. BGA decreased the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) as well as the level of total protein (TP) while the level of albumin was increased. Treatment of infected mice with BGA, PZQ as well as their combination led to significant elevation in the activities of hepatic antioxidant enzymes glutathione peroxidase (GPX) and glutathione-S-transferase (GST) as compared with control group. Combination of BGA and PZQ resulted in significant reduction in the level of intercellular adhesion molecules-1 (ICAM-1), vascular adhesion molecules-1 (VCAM-1) and tumor necrosis factor-alpha (TNF-α) when compared to those of the S. mansoni-infected group. Overall, BGA significantly inhibited the liver damage accompanied with schistosomiasis, exhibited a potent antioxidant and immunoprotective activities. This study suggests that BGA can be considered as promising for development a complementary and/or alternative medicine against schistosomiasis. PMID:25016189

  18. Schistosoma mansoni Hemozoin Modulates Alternative Activation of Macrophages via Specific Suppression of Retnla Expression and Secretion

    PubMed Central

    Truscott, Martha; Evans, D. Andrew; Gunn, Matt

    2013-01-01

    The trematode Schistosoma mansoni is one of the etiological agents of schistosomiasis, a key neglected tropical disease responsible for an estimated annual loss of 70 million disability-adjusted life years. Hematophagy represents the primary nutrient acquisition pathway of this parasite, but digestion of hemoglobin also liberates toxic heme. Schistosomes detoxify heme via crystallization into hemozoin, which is subsequently regurgitated into the host's circulation. Here we demonstrate that during experimental schistosomiasis, hemozoin accumulating in the mouse liver is taken up by phagocytes at a time coincident with the development of the egg-induced T-helper 2 (Th2) granulomatous immune response. Furthermore, the uptake of hemozoin also coincides with the hepatic expression of markers of alternative macrophage activation. Alternatively activated macrophages are a key effector cell population associated with protection against schistosomiasis, making hemozoin well placed to play an important immunomodulatory role in this disease. To systematically explore this hypothesis, S. mansoni hemozoin was purified and added to in vitro bone marrow-derived macrophage cultures concurrently exposed to cytokines chosen to reflect the shifting state of macrophage activation in vivo. Macrophages undergoing interleukin-4 (IL-4)-induced alternative activation in the presence of hemozoin developed a phenotype specifically lacking in Retnla, a characteristic alternatively activated macrophage product associated with regulation of Th2 inflammatory responses. As such, in addition to its important detoxification role during hematophagy, we propose that schistosome hemozoin also provides a potent immunomodulatory function in the coevolved network of host-parasite relationships during schistosomiasis. PMID:23090958

  19. Upregulation of Toll-like receptor 2 and nuclear factor-kappa B expression in experimental colonic schistosomiasis.

    PubMed

    Ashour, Dalia S; Shohieb, Zeinab S; Sarhan, Naglaa I

    2015-11-01

    Role of different mediators was described in the development of the granulomatous response and fibrosis observed in intestinal schistosomiasis. However, both Toll-like receptor 2 (TLR2) and nuclear factor kappa B (NF-κB) have not yet been investigated in intestinal schistosomiasis. This study aimed to characterize the role of TLR2 and NF-κB in the pathogenesis of intestinal schistosomiasis. Experimental animals were divided into two groups; group I: non-infected control group and group II: mice infected subcutaneously with S. mansoni cercariae. Colon samples were taken from infected mice, every two weeks, starting from the 6th week postinfection (PI) till 18th week PI. Samples were subjected to histopathological and immunohistochemical studies. Colon of S. mansoni infected mice showed histopathological changes in the form of mucosal degeneration, transmural mononuclear cellular infiltration and granulomas formation. Immunostained sections revealed significant increase in TLR2 and NF-κB positive cells in all layers of the colon, cells of the granuloma and those of the lymphoid follicles 10 weeks PI. All these changes decreased gradually starting from 12 weeks PI onward to be localized focally at 18 weeks PI. In conclusion, recruitment and activation of inflammatory cells to the colonic mucosa in intestinal schistosomiasis are multifactorial events involving TLR2 that can trigger the NF-κB pathways. Hence, down-regulation of both TLR2 and NF-κB could be exploited in the treatment of colonic schistosomiasis. PMID:26644925

  20. Cysteine Peptidases as Schistosomiasis Vaccines with Inbuilt Adjuvanticity

    PubMed Central

    El Ridi, Rashika; Tallima, Hatem; Selim, Sahar; Donnelly, Sheila; Cotton, Sophie; Gonzales Santana, Bibiana; Dalton, John P.

    2014-01-01

    Schistosomiasis is caused by several worm species of the genus Schistosoma and afflicts up to 600 million people in 74 tropical and sub-tropical countries in the developing world. Present disease control depends on treatment with the only available drug praziquantel. No vaccine exists despite the intense search for molecular candidates and adjuvant formulations over the last three decades. Cysteine peptidases such as papain and Der p 1 are well known environmental allergens that sensitize the immune system driving potent Th2-responses. Recently, we showed that the administration of active papain to mice induced significant protection (P<0.02, 50%) against an experimental challenge infection with Schistosoma mansoni. Since schistosomes express and secrete papain-like cysteine peptidases we reasoned that these could be employed as vaccines with inbuilt adjuvanticity to protect against these parasites. Here we demonstrate that sub-cutaneous injection of functionally active S. mansoni cathepsin B1 (SmCB1), or a cathepsin L from a related parasite Fasciola hepatica (FhCL1), elicits highly significant (P<0.0001) protection (up to 73%) against an experimental challenge worm infection. Protection and reduction in worm egg burden were further increased (up to 83%) when the cysteine peptidases were combined with other S. mansoni vaccine candidates, glyceraldehyde 3-phosphate dehydrogenase (SG3PDH) and peroxiredoxin (PRX-MAP), without the need to add chemical adjuvants. These studies demonstrate the capacity of helminth cysteine peptidases to behave simultaneously as immunogens and adjuvants, and offer an innovative approach towards developing schistosomiasis vaccines PMID:24465551

  1. Novel therapeutic and prevention approaches for schistosomiasis: review.

    PubMed

    El Ridi, Rashika A F; Tallima, Hatem A-M

    2013-09-01

    Schistosomiasis is a debilitating disease affecting approximately 600 million people in 74 developing countries, with 800 million, mostly children at risk. To circumvent the threat of having praziquantel (PZQ) as the only drug used for treatment, several PZQ derivatives were synthesized, and drugs destined for other parasites were used with success. A plethora of plant-derived oils and extracts were found to effectively kill juvenile and adult schistosomes, yet none was progressed to pre- and clinical studies except an oleo-gum resin extracted from the stem of Commiphora molmol, myrrh, which action was challenged in several trials. We have proposed an essential fatty acid, a component of our diet and cells, the polyunsaturated fatty acid arachidonic acid (ARA) as a remedy for schistosomiasis, due to its ability to activate the parasite tegument-bound neutral sphingomyelinase, with subsequent hydrolysis of the apical lipid bilayer sphingomyelin molecules, allowing access of specific antibody molecules, and eventual worm attrition. This concept was convincingly supported using larval and adult Schistosoma mansoni and Schistosoma haematobium worms in in vitro experiments, and in vivo studies in inbred mice and outbred hamsters. Even if ARA proves to be an entirely effective and safe therapy for schistosomiasis, it will not prevent reinfection, and accordingly, the need for developing an effective vaccine remains an urgent priority. Our studies have supported the status of S. mansoni calpain, glutathione-S-transferase, aldolase, triose phosphate isomerase, glyceraldehyde 3-phosphate dehydrogenase, enolase, and 2-cys peroxiredoxin as vaccine candidates, as they are larval excreted-secreted products and, contrary to the surface membrane molecules, are entirely accessible to the host immune system effector elements. We have proposed that the use of these molecules, in conjunction with Th2 cytokines-inducing adjuvants for recruiting and activating eosinophils and basophils

  2. Patterns of concurrent hookworm infection and schistosomiasis in schoolchildren in Tanzania.

    PubMed

    Lwambo, N J; Siza, J E; Brooker, S; Bundy, D A; Guyatt, H

    1999-01-01

    A cross-sectional study of 6897 schoolchildren in 59 out of the 155 primary schools in Magu District on the shores of Lake Victoria, Tanzania, was undertaken in 1997 to determine the prevalence of single- and multiple-species helminth infection. Schistosoma haematobium, hookworm (primarily Necator americanus) and S. mansoni were the most common helminth species infecting schoolchildren in the district. The prevalences of Ascaris lumbricoides and Trichuris trichiura were negligible (< 1%). Anaemia and stunting were highly prevalent and widespread. Hookworm and S. mansoni occurred more frequently in multiple infections with other helminths than as single-species infections, but triple-species infection was rare. Analysis of the frequency distribution of infection amongst schools showed that prevalences of S. haematobium and hookworm tended to be normally distributed, with medians 75% and 45%, respectively, while the distribution of S. mansoni was markedly skewed such that only 17% schools had a prevalence greater than 20%. An inverse association between S. mansoni and S. haematobium was observed. Geographical information system (GIS) analysis indicated that S. mansoni infection was highly prevalent only along the shore of Lake Victoria, whilst S. haematobium was homogeneously prevalent everywhere except the lakeshore. This pattern appears to reflect the distribution of schistosome species-specific snail intermediate hosts. The results imply that joint treatment for hookworm infection and schistosomiasis would be beneficial throughout the district. PMID:10696404

  3. Impact of gold nanoparticles on brain of mice infected with Schistosoma mansoni.

    PubMed

    Dkhil, Mohamed A; Bauomy, Amira A; Diab, Marwa S M; Wahab, Rizwan; Delic, Denis; Al-Quraishy, Saleh

    2015-10-01

    Schistosomiasis is a condition characterized by high rates of morbidity and cognitive impairment. It afflicts many people in tropical and sub-tropical countries. Our study aimed to investigate the protective role of gold nanoparticles (GNPs) on the brain of mice infected with Schistosoma mansoni. Characterizations of GNPs were determined by using high-resolution transmission electron microscopy. Three doses of GNPs (0.25, 0.5, and 1.0 mg/kg body weight) were used to treat animals after S. mansoni infection. The infection induced impairments in histological picture as a result of schistosome infection resulting in a disturbance in the content of the brain neurotransmitters, norepinephrine (NE), and dopamine (DA). Also, the infection induced significant reduction in glutathione level; oppositely, the levels of nitric oxide and malondialdehyde were increased significantly. In addition, S. mansoni was able to disregulate the infected mice brain Cacnb4, Cabp4, Vdac3, Glrb, and Adam23 messenger RNA (mRNA). On the other hand, treatment of mice with GNPs could alleviate the histological impairments, the changes in the content of NE and DA, and the brain oxidative damage. Also, GNPs could regulate the gene expression due to S. mansoni infection. Generally, GNPs could decrease the neurooxidative stress and regulated the gene expression in the brain of infected mice. Consequently, our results revealed an anti-neuroschistosomal effect of GNPs in mice infected with S. mansoni. PMID:26122996

  4. Schistosoma mansoni shares a protective carbohydrate epitope with keyhole limpet hemocyanin

    PubMed Central

    1987-01-01

    The glycanic epitope of the 38,000 Mr Schistosoma mansoni schistosomula major immunogen defined by the IPLSm1 protective mAb was identified in the hemocyanin of the marine mollusc Megathura crenulata, better known as KLH. This antigenic community was exploited to investigate further the biological properties of this epitope. KLH was shown to strongly inhibit the binding of IPLSm1 mAb to its 38,000 Mr target antigen. Immunization of naive LOU rats with KLH elicited the production of anti- S. mansoni antibodies capable of immunoprecipitating the 38,000 Mr schistosomulum antigen. Antibodies to KLH mediated a marked eosinophil- dependent cytotoxicity and passively transferred immunity towards S. mansoni infection. Finally, rats immunized with KLH were significantly protected against a challenge with S. mansoni cercariae. The deglycosylation of KLH completely abolishes its immunological and functional KLH properties, indicating the participation of an oligosaccharidic epitope of the native KLH that is also recognized by the sera of S. mansoni-infected patients. These observations provide new opportunities of access to the well-defined structure of a glycanic epitope potentially available for the immunoprophylaxis and seroepidemiology of schistosomiasis, and a new approach to the isotypic response towards a well-chemically defined epitope. PMID:2434601

  5. Detection of Schistosoma mansoni Antibodies in a Low-Endemicity Area Using Indirect Immunofluorescence and Circumoval Precipitin Test

    PubMed Central

    Carvalho do Espírito-Santo, Maria Cristina; Pinto, Pedro Luiz; Gargioni, Cybele; Viviana Alvarado-Mora, Monica; Pagliusi Castilho, Vera Lúcia; Pinho, João Ranato Rebello; de Albuquerque Luna, Expedito José; Borges Gryschek, Ronaldo Cesar

    2014-01-01

    Parasitological diagnostic methods for schistosomiasis lack sensitivity, especially in regions of low endemicity. The objective of this study was to determine the prevalence of Schistosoma mansoni infections by antibody detection using the indirect immunofluorescence assay (IFA-IgM) and circumoval precipitin test (COPT). Serum samples of 572 individuals were randomly selected. The IFA-IgM and COPT were used to detect anti-S. mansoni antibodies. Of the patients studied, 15.9% (N = 91) were IFA-IgM positive and 5.1% (N = 29) had COPT reactions (P < 0.001 by McNemar's test). Immunodiagnostic techniques showed higher infection prevalence than had been previously estimated. This study suggests that combined use of these diagnostic tools could be useful for the diagnosis of schistosomiasis in epidemiological studies in areas of low endemicity. PMID:24639303

  6. Critical analysis of molluscicide application in schistosomiasis control programs in Brazil.

    PubMed

    Coelho, Pmz; Caldeira, R L

    2016-01-01

    In Brazil, Biomphalaria glabrata, B. tenagophila, and B. straminea are naturally infected by the trematode Schistosoma mansoni, the causative agent of schistosomiasis. Despite decades of governmental efforts through official control programs, schistosomiasis remains an important public health problem in the country: thousands of people are infected with the trematode each year and millions live in endemic areas. The World Health Organization recommends using a combination of molluscicide (niclosamide) and mass chemotherapy to control the transmission of schistosomiasis, with this treatment successfully reducing the morbidity of the disease. In the past, niclosamide has been used in official schistosomiasis control programs in Brazil. However, as B. glabrata recolonizes even after molluscicide application, the use of molluscicides has gradually decreased in the country until they were discontinued in 2002, mainly due to the rising global pressure to preserve the environment and the difficulties of obtaining licenses from the Brazilian Ministry of Environment to use toxic substances in aquatic ecosystems. Therefore, the discovery of new molluscicides, which could be more selective to Biomphalaria species and less harmful to the aquatic ecosystem, is necessary. In addition, political efforts to sensitize funders to provide grants for this field of research are required. In this context, this article aims to make a critical analysis of molluscicide application in schistosomiasis control programs in Brazil. PMID:27374126

  7. Morbidity Associated with Schistosomiasis Before and After Treatment in Young Children in Rusinga Island, Western Kenya

    PubMed Central

    Davis, Stephanie M.; Wiegand, Ryan E.; Mulama, Fridah; Kareko, Edmund Ireri; Harris, Robert; Ochola, Elizabeth; Samuels, Aaron M.; Rawago, Fredrick; Mwinzi, Pauline M.; Fox, LeAnne M.; Odiere, Maurice R.; Won, Kimberly Y.

    2015-01-01

    Schistosoma mansoni infection is a major cause of organomegaly and ultimately liver fibrosis in adults. Morbidity in pre-school-aged children is less defined, and they are currently not included in mass drug administration (MDA) programs for schistosomiasis control. We report results of a study of the association of schistosomiasis with organomegaly in a convenience sample of 201 children under 7 years old in Rusinga, Kenya on two cross-sectional visits, before and after praziquantel treatment. Data included stool examination and serology for schistosomiasis, the Niamey ultrasound protocol to stage hepatosplenic morbidity including organomegaly, and potential confounders including malaria. Unadjusted and adjusted Poisson regressions were performed. The baseline prevalence of schistosomiasis by antibody and/or stool was 80.3%. Schistomiasis was associated with hepatomegaly (adjusted prevalence ratio [aPR] = 1.4; 95% confidence interval [CI]: 1.0–2.1) and splenomegaly (aPR = 2.1; 95% CI: 1.2–3.7). The association with hepatomegaly persisted posttreatment (aPR = 1.4; 95% CI: 1.1–1.6). Schistosomiasis was associated with morbidity in this cohort. Efforts to include young children in mass treatment campaigns should intensify. PMID:25758651

  8. Integrated Schistosomiasis and Soil-Transmitted Helminthiasis Control over Five Years on Kome Island, Tanzania

    PubMed Central

    Kaatano, Godfrey M.; Siza, Julius E.; Mwanga, Joseph R.; Min, Duk-Yong; Yong, Tai-Soon; Chai, Jong-Yil; Ko, Yunsuk; Chang, Su Young; Kullaya, Cyril M.; Rim, Han-Jong; Changalucha, John M.; Eom, Keeseon S.

    2015-01-01

    Integrated control strategies are important for sustainable control of schistosomiasis and soil-transmitted helminthiasis, despite their challenges for their effective implementation. With the support of Good Neighbors International in collaboration with National Institute of Medical Research, Mwanza, Tanzania, integrated control applying mass drug administration (MDA), health education using PHAST, and improved safe water supply has been implemented on Kome Island over 5 years for controlling schistosomiasis and soil-transmitted helminths (STHs). Baseline surveys for schistosomiasis and STHs was conducted before implementation of any integrated control strategies, followed by 4 cross-sectional follow-up surveys on randomly selected samples of schoolchildren and adults in 10 primary schools and 8 villages, respectively, on Kome islands. Those follow-up surveys were conducted for impact evaluation after introduction of control strategies interventions in the study area. Five rounds of MDA have been implemented from 2009 along with PHAST and improved water supply with pumped wells as other control strategies for complementing MDA. A remarkable steady decline of schistosomiasis and STHs was observed from 2009 to 2012 with significant trends in their prevalence decline, and thereafter infection rate has remained at a low sustainable control. By the third follow-up survey in 2012, Schistosoma mansoni infection prevalence was reduced by 90.5% and hookworm by 93.3% among schoolchildren while in adults the corresponding reduction was 83.2% and 56.9%, respectively. Integrated control strategies have successfully reduced S. mansoni and STH infection status to a lower level. This study further suggests that monitoring and evaluation is a crucial component of any large-scale STH and schistosomiasis intervention. PMID:26537032

  9. Integrated Schistosomiasis and Soil-Transmitted Helminthiasis Control over Five Years on Kome Island, Tanzania.

    PubMed

    Kaatano, Godfrey M; Siza, Julius E; Mwanga, Joseph R; Min, Duk-Yong; Yong, Tai-Soon; Chai, Jong-Yil; Ko, Yunsuk; Chang, Su Young; Kullaya, Cyril M; Rim, Han-Jong; Changalucha, John M; Eom, Keeseon S

    2015-10-01

    Integrated control strategies are important for sustainable control of schistosomiasis and soil-transmitted helminthiasis, despite their challenges for their effective implementation. With the support of Good Neighbors International in collaboration with National Institute of Medical Research, Mwanza, Tanzania, integrated control applying mass drug administration (MDA), health education using PHAST, and improved safe water supply has been implemented on Kome Island over 5 years for controlling schistosomiasis and soil-transmitted helminths (STHs). Baseline surveys for schistosomiasis and STHs was conducted before implementation of any integrated control strategies, followed by 4 cross-sectional follow-up surveys on randomly selected samples of schoolchildren and adults in 10 primary schools and 8 villages, respectively, on Kome islands. Those follow-up surveys were conducted for impact evaluation after introduction of control strategies interventions in the study area. Five rounds of MDA have been implemented from 2009 along with PHAST and improved water supply with pumped wells as other control strategies for complementing MDA. A remarkable steady decline of schistosomiasis and STHs was observed from 2009 to 2012 with significant trends in their prevalence decline, and thereafter infection rate has remained at a low sustainable control. By the third follow-up survey in 2012, Schistosoma mansoni infection prevalence was reduced by 90.5% and hookworm by 93.3% among schoolchildren while in adults the corresponding reduction was 83.2% and 56.9%, respectively. Integrated control strategies have successfully reduced S. mansoni and STH infection status to a lower level. This study further suggests that monitoring and evaluation is a crucial component of any large-scale STH and schistosomiasis intervention. PMID:26537032

  10. Tandem repeat recombinant proteins as potential antigens for the sero-diagnosis of Schistosoma mansoni infection.

    PubMed

    Kalenda, Yombo Dan Justin; Kato, Kentaro; Goto, Yasuyuki; Fujii, Yoshito; Hamano, Shinjiro

    2015-12-01

    The diagnosis of schistosome infection, followed by effective treatment and/or mass drug administration, is crucial to reduce the disease burden. Suitable diagnostic tests and field-applicable tools are required to sustain schistosomiasis control programs. We therefore assessed the potential of tandem repeat (TR) proteins for sero-diagnosis of Schistosoma mansoni infection using an experimental mouse model. TR genes in the genome of S. mansoni were searched in silico and 7 candidates, named SmTR1, 3, 8, 9, 10, 11 and 15, were selected. Total RNA was extracted from S. mansoni adult worms and eggs. Target TR genes were amplified, cloned, and the proteins were expressed in Escherichia coli competent cells. Female BALB/c mice were infected with 100 S. mansoni cercariae and sera were collected each week post-infection for 18 weeks. The levels of IgG antibodies to SmTR antigens were compared to those to soluble egg antigen (SEA) and to soluble worm antigen preparation (SWAP). Sera of infected mice reacted to all the antigens whereas those of naïve mice did not. IgG responses to SmTR1, 3, 9 and 10 were detected at the early stage of infection. Interestingly, antibodies reacting to SmTR3, 9, 10 and 15 dramatically decreased 4 weeks after treatment with praziquantel, while those against SEA and SWAP remained elevated. Our study suggests that TR proteins, especially SmTR10, may be suitable antigens for sero-diagnosis of infection by S. mansoni and are potential markers for monitoring and surveillance of schistosomiasis, including re-infection after treatment with praziquantel. PMID:26148816

  11. S. mansoni Bolsters Anti-Viral Immunity in the Murine Respiratory Tract

    PubMed Central

    Scheer, Sebastian; Krempl, Christine; Kallfass, Carsten; Frey, Stefanie; Jakob, Thilo; Mouahid, Gabriel; Moné, Hélène; Schmitt-Gräff, Annette; Staeheli, Peter; Lamers, Marinus C.

    2014-01-01

    The human intestinal parasite Schistosoma mansoni causes a chronic disease, schistosomiasis or bilharzia. According to the current literature, the parasite induces vigorous immune responses that are controlled by Th2 helper cells at the expense of Th1 helper cells. The latter cell type is, however, indispensable for anti-viral immune responses. Remarkably, there is no reliable literature among 230 million patients worldwide describing defective anti-viral immune responses in the upper respiratory tract, for instance against influenza A virus or against respiratory syncitial virus (RSV). We therefore re-examined the immune response to a human isolate of S. mansoni and challenged mice in the chronic phase of schistosomiasis with influenza A virus, or with pneumonia virus of mice (PVM), a mouse virus to model RSV infections. We found that mice with chronic schistosomiasis had significant, systemic immune responses induced by Th1, Th2, and Th17 helper cells. High serum levels of TNF-α, IFN-γ, IL-5, IL-13, IL-2, IL-17, and GM-CSF were found after mating and oviposition. The lungs of diseased mice showed low-grade inflammation, with goblet cell hyperplasia and excessive mucus secretion, which was alleviated by treatment with an anti-TNF-α agent (Etanercept). Mice with chronic schistosomiasis were to a relative, but significant extent protected from a secondary viral respiratory challenge. The protection correlated with the onset of oviposition and TNF-α-mediated goblet cell hyperplasia and mucus secretion, suggesting that these mechanisms are involved in enhanced immune protection to respiratory viruses during chronic murine schistosomiasis. Indeed, also in a model of allergic airway inflammation mice were protected from a viral respiratory challenge with PVM. PMID:25398130

  12. Immunology of schistosomiasis*

    PubMed Central

    1974-01-01

    This Memorandum, after summarizing the life cycle of the different species of human schistosome, reviews the present knowledge of the immunology of schistosomiasis. Each stage of the parasite contains antigen that may stimulate an immune response. However, at the moment there are no accepted serological in vitro tests that correlate with protection; this develops only after the host has experienced a living infection, which suggests that the stimulation of immunity is due to some metabolic process involving the release of protective antigen. The adult worm, however, seems to be able to escape the immune mechanism of the host. Specific antigens are also released by the eggs, and the immune response against these antigens seems to cause granuloma formation around the egg itself. The granuloma is the main lesion found in schistosomiasis. Evidence for protective immunity in experimental animals and man is reviewed, together with the possible mechanism by which the adult worm escapes the immune response of the host. A review of methods used for the diagnosis of schistosomiasis and a list of recommendations for further research are also included. PMID:4219757

  13. Current status of schistosomiasis and soil-transmitted helminthiasis in Beyla and Macenta Prefectures, Forest Guinea.

    PubMed

    Hodges, Mary; Koroma, Manso M; Baldé, Mamadou S; Turay, Hamid; Fofanah, Ibrahim; Divall, Mark J; Winkler, Mirko S; Zhang, Yaobi

    2011-11-01

    A cross-sectional survey was undertaken in children aged 9-14 years in Beyla and Macenta Prefectures, Forest Guinea. Stool samples were examined by Kato-Katz and urine samples were examined by the centrifugation method. The overall prevalence and intensity of infection was 66.2% and 462.4 eggs per gram of faeces (epg) for Schistosoma mansoni, 21.0% and 17.8 eggs per 10ml of urine for S. haematobium, 51.2% and 507.5 epg for hookworm, 8.1% and 89.1 epg for Ascaris lumbricoides and 2.4% and 16.7 epg for Trichuris trichiura. The overall prevalence of schistosomiasis (S. mansoni and/or S. haematobium) was 70.7%. The prevalence of schistosomiasis was similar to those reported in the 1990s in the region; however, the prevalence of soil-transmitted helminths has since fallen. These findings illustrate the need for schistosomiasis control in Guinea. PMID:21871646

  14. Predictive risk mapping of schistosomiasis in Brazil using Bayesian geostatistical models.

    PubMed

    Scholte, Ronaldo G C; Gosoniu, Laura; Malone, John B; Chammartin, Frédérique; Utzinger, Jürg; Vounatsou, Penelope

    2014-04-01

    Schistosomiasis is one of the most common parasitic diseases in tropical and subtropical areas, including Brazil. A national control programme was initiated in Brazil in the mid-1970s and proved successful in terms of morbidity control, as the number of cases with hepato-splenic involvement was reduced significantly. To consolidate control and move towards elimination, there is a need for reliable maps on the spatial distribution of schistosomiasis, so that interventions can target communities at highest risk. The purpose of this study was to map the distribution of Schistosoma mansoni in Brazil. We utilized readily available prevalence data from the national schistosomiasis control programme for the years 2005-2009, derived remotely sensed climatic and environmental data and obtained socioeconomic data from various sources. Data were collated into a geographical information system and Bayesian geostatistical models were developed. Model-based maps identified important risk factors related to the transmission of S. mansoni and confirmed that environmental variables are closely associated with indices of poverty. Our smoothed predictive risk map, including uncertainty, highlights priority areas for intervention, namely the northern parts of North and Southeast regions and the eastern part of Northeast region. Our predictive risk map provides a useful tool for to strengthen existing surveillance-response mechanisms. PMID:24361640

  15. A Very High Infection Intensity of Schistosoma mansoni in a Ugandan Lake Victoria Fishing Community Is Required for Association with Highly Prevalent Organ Related Morbidity

    PubMed Central

    Tukahebwa, Edridah M.; Magnussen, Pascal; Madsen, Henry; Kabatereine, Narcis B.; Nuwaha, Fred; Wilson, Shona; Vennervald, Birgitte J.

    2013-01-01

    Background In schistosomiasis control programmes using mass chemotherapy, epidemiological and morbidity aspects of the disease need to be studied so as to monitor the impact of treatment, and make recommendations accordingly. These aspects were examined in the community of Musoli village along Lake Victoria in Mayuge district, highly endemic for Schistosoma mansoni infection. Methodology and Principal Findings A cross sectional descriptive study was undertaken in a randomly selected sample of 217 females and 229 males, with a mean age of 26 years (SD ±16, range 7–76 years). The prevalence of S. mansoni was 88.6% (95% CI: 85.6–91.5). The geometric mean intensity (GMI) of S. mansoni was 236.2 (95% CI: 198.5–460.9) eggs per gram (epg) faeces. Males had significantly higher GMI (370.2 epg) than females (132.6 epg) and age was also significantly associated with intensity of infection. Levels of water contact activities significantly influenced intensity of infection and the highest intensity of infection was found among people involved in fishing. However, organomegaly was not significantly associated with S. mansoni except for very heavy infection (>2000 epg). Liver image patterns C and D indicative of fibrosis were found in only 2.2% and 0.2%, respectively. S. mansoni intensity of infection was associated with portal vein dilation and abnormal spleen length. Anaemia was observed in 36.4% of the participants but it was not associated with S. mansoni infection intensity. Considering growth in children as one of the morbidity indicators of schistosomiasis, intensity of S. mansoni was significantly associated with stunting. Conclusion Although organ-related morbidity, with the exception of periportal fibrosis, and S. mansoni infections were highly prevalent, the two were only associated for individuals with very high infection intensities. These results contrast starkly with reports from Ugandan Lake Albert fishing communities in which periportal fibrosis is more

  16. Epidemiological study on Schistosoma mansoni infection in Sanja area, Amhara region, Ethiopia

    PubMed Central

    2014-01-01

    Background The epidemiology of schistosomiasis is well documented and its geographic distribution has been mapped and there is an ongoing mapping in Ethiopia. Nevertheless, new transmission foci have been discovered in different parts of the country. The objective of this study was to assess the establishment of transmission and determine the prevalence of Schistosoma mansoni infection in school children from Sanja Town, northwest Ethiopia. Methods A cross-sectional parasitological survey involving 384 school children in two primary schools of Sanja Town was conducted between February and April 2013. Stool specimens were collected and microscopically examined using Kato-Katz and Sodium acetate-acetic acid-formalin (SAF) concentration methods. Malacological survey was also carried out to identify snail intermediate hosts and larval infection rate in the snail. The snails collected were checked for trematode infection by shedding. Observation was also made on water contact habits of the study population. Results The prevalence of Schistosoma mansoni infection using Kato-Katz method was high among male (79.5%) children in Sanja Primary school while it was high among female (75%) children in Ewket Amba Primary school. The prevalence of Schistosoma mansoni infection among Sanja Primary school children in the age groups 5–9 and 10–14 years were 84.6% and 75.2%, respectively while in Ewket Amba Primary school, the prevalence was 66% and 77.9% in the age groups 5–9 and 10–14 years respectively. The prevalence of schistosome infection in Biomphalaria pfeifferi was 16.9% and 0.027% during February and April, respectively. S. mansoni infection was successfully established in laboratory mice and adult worms were harvested after six weeks of laboratory maintenance. Observations made on water contact activities showed swimming, bathing and washing in the river and the stream as the high risk activities for Schistosoma mansoni infection. Conclusion The study has shown

  17. Efficacy of Niclosamide as a potential topical antipenetrant (TAP) against cercariae of Schistosoma mansoni in monkeys.

    PubMed

    Bruce, J I; Miller, R; Lightner, L; Yoganathan, S

    1992-01-01

    A 1% (W/V) formulation of Niclosamide (2', 5-Dichloro-4-nitrosalicylanilide) (TAP) was tested on Cebus apella monkeys as a topical prophylactic against schistosomiasis mansoni. Two experiments were conducted using the same formulation. In the first experiment, the TAP provided complete protection against schistosomiasis for 3 days. Of the 4 monkeys treated with TAP 7 days before exposure to Schistosoma mansoni cercariae, 2 were completely protected. The remaining 2 monkeys of the 7 day treatment group had a 78% or greater reduction in adult worm burdens when compared to the placebo treated monkeys. The second experiment was designed to determine the time between day 3 and 7 when the TAP no longer provided complete protection. However, all of the TAP treated monkeys in this experiment were completely protected, even the monkeys treated 7 days earlier. In both experiments, all monkeys used as infection controls and those receiving only the placebo became infected and showed typical experimental schistosomiasis. These results demonstrate that the TAP could provide fast acting, short-term protection to people who must enter cercariae infested water. PMID:1343909

  18. Discovery of new inhibitors of Schistosoma mansoni PNP by pharmacophore-based virtual screening.

    PubMed

    Postigo, Matheus P; Guido, Rafael V C; Oliva, Glaucius; Castilho, Marcelo S; da R Pitta, Ivan; de Albuquerque, Julianna F C; Andricopulo, Adriano D

    2010-09-27

    Schistosomiasis is considered the second most important tropical parasitic disease, with severe socioeconomic consequences for millions of people worldwide. Schistosoma mansoni , one of the causative agents of human schistosomiasis, is unable to synthesize purine nucleotides de novo, which makes the enzymes of the purine salvage pathway important targets for antischistosomal drug development. In the present work, we describe the development of a pharmacophore model for ligands of S. mansoni purine nucleoside phosphorylase (SmPNP) as well as a pharmacophore-based virtual screening approach, which resulted in the identification of three thioxothiazolidinones (1-3) with substantial in vitro inhibitory activity against SmPNP. Synthesis, biochemical evaluation, and structure-activity relationship investigations led to the successful development of a small set of thioxothiazolidinone derivatives harboring a novel chemical scaffold as new competitive inhibitors of SmPNP at the low-micromolar range. Seven compounds were identified with IC(50) values below 100 μM. The most potent inhibitors 7, 10, and 17 with IC(50) of 2, 18, and 38 μM, respectively, could represent new potential lead compounds for further development of the therapy of schistosomiasis. PMID:20695479

  19. Bayesian Risk Mapping and Model-Based Estimation of Schistosoma haematobium–Schistosoma mansoni Co-distribution in Côte d′Ivoire

    PubMed Central

    Chammartin, Frédérique; Houngbedji, Clarisse A.; Hürlimann, Eveline; Yapi, Richard B.; Silué, Kigbafori D.; Soro, Gotianwa; Kouamé, Ferdinand N.; N′Goran, Eliézer K.; Utzinger, Jürg; Raso, Giovanna; Vounatsou, Penelope

    2014-01-01

    Background Schistosoma haematobium and Schistosoma mansoni are blood flukes that cause urogenital and intestinal schistosomiasis, respectively. In Côte d′Ivoire, both species are endemic and control efforts are being scaled up. Accurate knowledge of the geographical distribution, including delineation of high-risk areas, is a central feature for spatial targeting of interventions. Thus far, model-based predictive risk mapping of schistosomiasis has relied on historical data of separate parasite species. Methodology We analyzed data pertaining to Schistosoma infection among school-aged children obtained from a national, cross-sectional survey conducted between November 2011 and February 2012. More than 5,000 children in 92 schools across Côte d′Ivoire participated. Bayesian geostatistical multinomial models were developed to assess infection risk, including S. haematobium–S. mansoni co-infection. The predicted risk of schistosomiasis was utilized to estimate the number of children that need preventive chemotherapy with praziquantel according to World Health Organization guidelines. Principal Findings We estimated that 8.9% of school-aged children in Côte d′Ivoire are affected by schistosomiasis; 5.3% with S. haematobium and 3.8% with S. mansoni. Approximately 2 million annualized praziquantel treatments would be required for preventive chemotherapy at health districts level. The distinct spatial patterns of S. haematobium and S. mansoni imply that co-infection is of little importance across the country. Conclusions/Significance We provide a comprehensive analysis of the spatial distribution of schistosomiasis risk among school-aged children in Côte d′Ivoire and a strong empirical basis for a rational targeting of control interventions. PMID:25522007

  20. Distribution of Schistosomiasis and Soil Transmitted Helminthiasis in Zimbabwe: Towards a National Plan of Action for Control and Elimination

    PubMed Central

    Midzi, Nicholas; Mduluza, Takafira; Chimbari, Moses J.; Tshuma, Clement; Charimari, Lincoln; Mhlanga, Gibson; Manangazira, Portia; Munyati, Shungu M.; Phiri, Isaac; Mutambu, Susan L.; Midzi, Stanley S.; Ncube, Anastancia; Muranzi, Lawrence P.; Rusakaniko, Simbarashe; Mutapi, Francisca

    2014-01-01

    Background Schistosomiasis and STH are among the list of neglected tropical diseases considered for control by the WHO. Although both diseases are endemic in Zimbabwe, no nationwide control interventions have been implemented. For this reason in 2009 the Zimbabwe Ministry of Health and Child Care included the two diseases in the 2009–2013 National Health Strategy highlighting the importance of understanding the distribution and burden of the diseases as a prerequisite for elimination interventions. It is against this background that a national survey was conducted. Methodology A countrywide cross-sectional survey was carried out in 280 primary schools in 68 districts between September 2010 and August 2011. Schistosoma haematobium was diagnosed using the urine filtration technique. Schistosoma mansoni and STH (hookworms, Trichuris trichiura, Ascaris lumbricoides) were diagnosed using both the Kato Katz and formol ether concentration techniques. Main findings Schistosomiasis was more prevalent country-wide (22.7%) than STH (5.5%). The prevalence of S. haematobium was 18.0% while that of S. mansoni was 7.2%. Hookworms were the most common STH with a prevalence of 3.2% followed by A. lumbricoides and T. trichiura with prevalence of 2.5% and 0.1%, respectively. The prevalence of heavy infection intensity as defined by WHO for any schistosome species was 5.8% (range 0%–18.3% in districts). Only light to moderate infection intensities were observed for STH species. The distribution of schistosomiasis and STH varied significantly between provinces, districts and schools (p<0.001). Overall, the prevalence of co-infection with schistosomiasis and STH was 1.5%. The actual co-endemicity of schistosomiasis and STH was observed in 43 (63.2%) of the 68 districts screened. Conclusion and recommendations This study provided comprehensive baseline data on the distribution of schistosomiasis and STH that formed the basis for initiating a national control and elimination programme

  1. Risk analysis for occurrences of schistosomiasis in the coastal area of Porto de Galinhas, Pernambuco, Brazil

    PubMed Central

    2014-01-01

    Background Manson’s schistosomiasis continues to be a severe public health problem in Brazil, where thousands of people live under the risk of contracting this parasitosis. In the Northeast of Brazil, schistosomiasis has expanded from rural areas to the coast of Pernambuco State, where the intermediate host is Biomphalaria glabrata snails. This study aims at presenting situational analyses on schistosomiasis at the coastal locality of Porto de Galinhas, Pernambuco, Brazil, by determining the risk factors relating to its occurrence from the epidemiological and spatial perspectives. Methods In order to gather prevalence data, a parasitological census surveys were conducted in 2010 in the light of the Kato-Katz technique. Furthermore, malacological surveys were also conducted in the same years so as to define the density and infection rates of the intermediate host. Lastly, socioeconomic-behavioral survey was also conducted to determine the odds ratio for infection by Schistosoma mansoni. Based on these data, spatial analyses were done, resulting in maps of the risk of disease transmission. To predict the risk of schistosomiasis occurrence, a multivariate logistic regression was performed using R 2.13 software. Results Based on prevalence, malacological and socioeconomic-behavioural surveys, it was identified a prevalence of 15.7% in the investigated population (2,757 individuals). Due to the malacological survey, 36 breeding sites were identified, of which 11 were classified as foci of schistosomiasis transmission since they pointed out snails which were infected by Schistosoma mansoni. Overall, 11,012 snails (Biomphalaria glabrata) were collected. The multivariate regression model identified six explanatory variables of environmental, socioeconomic and demographic nature. Spatial sweep analysis by means of the Bernoulli method identified one statistically significant cluster in Salinas (RR = 2.2; p-value < 0.000), the district with the highest occurrence

  2. Schistosoma mansoni Sirtuins: Characterization and Potential as Chemotherapeutic Targets

    PubMed Central

    Lancelot, Julien; Caby, Stéphanie; Dubois-Abdesselem, Florence; Vanderstraete, Mathieu; Trolet, Jacques; Oliveira, Guilherme; Bracher, Franz; Jung, Manfred; Pierce, Raymond J.

    2013-01-01

    Background The chemotherapy of schistosomiasis currently depends on the use of a single drug, praziquantel. In order to develop novel chemotherapeutic agents we are investigating enzymes involved in the epigenetic modification of chromatin. Sirtuins are NAD+ dependent lysine deacetylases that are involved in a wide variety of cellular processes including histone deacetylation, and have been demonstrated to be therapeutic targets in various pathologies, including cancer. Methodology, Principal Findings In order to determine whether Schistosoma mansoni sirtuins are potential therapeutic targets we first identified and characterized their protein sequences. Five sirtuins (SmSirt) are encoded in the S. mansoni genome and phylogenetic analysis showed that they are orthologues of mammalian Sirt1, Sirt2, Sirt5, Sirt6 and Sirt7. Both SmSirt1 and SmSirt7 have large insertion in the catalytic domain compared to their mammalian orthologues. SmSirt5 is the only mitochondrial sirtuin encoded in the parasite genome (orthologues of Sirt3 and Sirt4 are absent) and transcripts corresponding to at least five splicing isoforms were identified. All five sirtuins are expressed throughout the parasite life-cycle, but with distinct patterns of expression. Sirtuin inhibitors were used to treat both schistosomula and adult worms maintained in culture. Three inhibitors in particular, Sirtinol, Salermide and MS3 induced apoptosis and death of schistosomula, the separation of adult worm pairs, and a reduction in egg laying. Moreover, Salermide treatment led to a marked disruption of the morphology of ovaries and testes. Transcriptional knockdown of SmSirt1 by RNA interference in adult worms led to morphological changes in the ovaries characterized by a marked increase in mature oocytes, reiterating the effects of sirtuin inhibitors and suggesting that SmSirt1 is their principal target. Conclusion, Significance Our data demonstrate the potential of schistosome sirtuins as therapeutic targets

  3. Characterization of the phytochelatin synthase of Schistosoma mansoni.

    PubMed

    Ray, Debalina; Williams, David L

    2011-05-01

    Treatment for schistosomiasis, which is responsible for more than 280,000 deaths annually, depends exclusively on the use of praziquantel. Millions of people are treated annually with praziquantel and drug resistant parasites are likely to evolve. In order to identify novel drug targets the Schistosoma mansoni sequence databases were queried for proteins involved in glutathione metabolism. One potential target identified was phytochelatin synthase (PCS). Phytochelatins are oligopeptides synthesized enzymatically from glutathione by PCS that sequester toxic heavy metals in many organisms. However, humans do not have a PCS gene and do not synthesize phytochelatins. In this study we have characterized the PCS of S. mansoni (SmPCS). The conserved catalytic triad of cysteine-histidine-aspartate found in PCS proteins and cysteine proteases is also found in SmPCS, as are several cysteine residues thought to be involved in heavy metal binding and enzyme activation. The SmPCS open reading frame is considerably extended at both the N- and C-termini compared to PCS from other organisms. Multiple PCS transcripts are produced from the single encoded gene by alternative splicing, resulting in both mitochondrial and cytoplasmic protein variants. Expression of SmPCS in yeast increased cadmium tolerance from less than 50 µM to more than 1,000 µM. We confirmed the function of SmPCS by identifying PCs in yeast cell extracts using HPLC-mass spectrometry. SmPCS was found to be expressed in all mammalian stages of worm development investigated. Increases in SmPCS expression were seen in ex vivo worms cultured in the presence of iron, copper, cadmium, or zinc. Collectively, these results indicate that SmPCS plays an important role in schistosome response to heavy metals and that PCS is a potential drug target for schistosomiasis treatment. This is the first characterization of a PCS from a parasitic organism. PMID:21629724

  4. Characterization of the Phytochelatin Synthase of Schistosoma mansoni

    PubMed Central

    Ray, Debalina; Williams, David L.

    2011-01-01

    Treatment for schistosomiasis, which is responsible for more than 280,000 deaths annually, depends exclusively on the use of praziquantel. Millions of people are treated annually with praziquantel and drug resistant parasites are likely to evolve. In order to identify novel drug targets the Schistosoma mansoni sequence databases were queried for proteins involved in glutathione metabolism. One potential target identified was phytochelatin synthase (PCS). Phytochelatins are oligopeptides synthesized enzymatically from glutathione by PCS that sequester toxic heavy metals in many organisms. However, humans do not have a PCS gene and do not synthesize phytochelatins. In this study we have characterized the PCS of S. mansoni (SmPCS). The conserved catalytic triad of cysteine-histidine-aspartate found in PCS proteins and cysteine proteases is also found in SmPCS, as are several cysteine residues thought to be involved in heavy metal binding and enzyme activation. The SmPCS open reading frame is considerably extended at both the N- and C-termini compared to PCS from other organisms. Multiple PCS transcripts are produced from the single encoded gene by alternative splicing, resulting in both mitochondrial and cytoplasmic protein variants. Expression of SmPCS in yeast increased cadmium tolerance from less than 50 µM to more than 1,000 µM. We confirmed the function of SmPCS by identifying PCs in yeast cell extracts using HPLC-mass spectrometry. SmPCS was found to be expressed in all mammalian stages of worm development investigated. Increases in SmPCS expression were seen in ex vivo worms cultured in the presence of iron, copper, cadmium, or zinc. Collectively, these results indicate that SmPCS plays an important role in schistosome response to heavy metals and that PCS is a potential drug target for schistosomiasis treatment. This is the first characterization of a PCS from a parasitic organism. PMID:21629724

  5. Evaluation of Echinostoma liei worm, metacercaria and redia antigens for schistosomiasis control.

    PubMed

    Abdel-Monaem, G; Farid, A; Rabia, I; El-Amir, A

    2015-10-01

    While chemotherepeutic drugs, such as praziquantel, oxamniquine and metrifonate, are currently considered safe and effective drugs for schistosomiasis treatment, reinfection occurs frequently after drug treatment. Thus, a vaccine is sought to provide long-term treatment. Antigens from worm, metacercaria and redia of Echinostoma liei (E. liei) were purified using CNBr-activated Sepharose column, then used for immunization of mice prior to infection with Schistosomiasis mansoni. Worm burden, hepatic and intestinal eggs and oogram count was significantly reduced and that was reflected in normalization of liver architecture. This referred to a significant increase in the tested immunoglobulin level (IgM, IgG1 and IgG2). PMID:26115938

  6. Diagnostic and prognostic value of cell free circulating Schistosoma mansoni DNA: an experimental study.

    PubMed

    Eraky, Maysa Ahmad; Aly, Nagwa Shaban Mohamed

    2016-09-01

    Searching for a more sensitive and accurate marker for schistosomiasis diagnosis and treatment follow up is a potential necessity. Hereby, we evaluated usefulness of circulating free DNA as a marker for schistosomiasis diagnosis, assessing drug efficacy and monitoring the control interventions impact using SYBR green real-time PCR. A batch of mice were infected by 90 ± 10 Schistosoma mansoni cercariae. Starting from the 2nd day post infection (p.i.), groups of 2 or 3 mice were sacrificed every 3 days until 30 days p.i. The remaining animals were treated by a single dose of 400 mg/kg mefloquine and sacrificed in group at 5, 10, 21 days post treatment (35, 40, 51 days p.i.). Using SYBR green real time qPCR, pooled sera DNA were extracted and amplified. The results showed that, circulating free S. mansoni DNA was detected from the 2nd day post infection (p.i.) onwards with gradual decrease in the cycle threshold value Ct which indicates the gradual elevation of the DNA level (Log quantity was 2.6-3.1 IU/ml), As the infection progressed, DNA quantity was increased(Log quantity was 6.29 IU/ml). Initial increase of circulating free DNA was observed 10 days post treatment (40 days p.i.) (Log quantity was 7.38 IU/ml). That was followed by a progressive decrease in DNA level by the end of 21st day, post treatment (51 p.i.) (Log quantity 4.35 IU/ml). In conclusion, circulating free S. mansoni DNA is a reliable marker in the diagnosis of schistosomiasis and for assessing drug efficacy and monitoring the impact of control interventions. PMID:27605830

  7. Schistosomiasis transmission and environmental change: a spatio-temporal analysis in Porto de Galinhas, Pernambuco - Brazil

    PubMed Central

    2012-01-01

    Background In Brazil, schistosomiasis mansoni infection is an endemic disease that mainly affects the country’s rural populations who carry out domestic and social activities in rivers and water accumulations that provide shelter for the snails of the disease. The process of rural migration to urban centers and the disorderly occupation of natural environments by these populations from endemic areas have favored expansion of schistosomiasis to locations that had been considered to be disease-free. Based on environmental changes that have occurred in consequent to an occupation and urbanization process in the locality of Porto de Galinhas, the present study sought to identify the relationship between those chances, measure by remote-sensing techniques, and establish a new endemic area for schistosomiasis on the coast of Pernambuco State - Brazil. Methods To gather prevalence data, two parasitological census surveys were conducted (2000 and 2010) using the Kato-Katz technique. Two malacological surveys were also conducted in the same years in order to define the density and infection rate of the intermediate host. Based on these data, spatial analyses were done, resulting in maps of the risk of disease transmission. To ascertain the environmental changes that have occurred at the locality, images from the QuickBird satellite were analyzed, thus resulting in land use maps. Results Over this 10-year period, the foci of schistosomiasis became more concentrated in the Salinas district. This area was considered to be at the greatest risk of schistosomiasis transmission and had the highest prevalence rates over this period. The study illustrated that this was the area most affected by the environmental changes resulting from the disorderly urbanization process, which gave rise to unsanitary environments that favored the establishment and maintenance of foci of schistosomiasis transmission, thereby consolidating the process of expansion and endemization of this

  8. Molluscicides in schistosomiasis control

    PubMed Central

    McCullough, F. S.; Gayral, Ph.; Duncan, J.; Christie, J. D.

    1980-01-01

    Although mollusciciding can be a cost-effective method of controlling schistosomiasis transmission, only one organic molluscicide, niclosamide, is now being produced commercially, and only a few compounds are at present being tested in the laboratory. In future, improved cost-effective use of molluscicides will require more precise knowledge of schistosomiasis transmission patterns in each endemic area and improved application techniques. In snail control studies using controlled-release formulations only the organotins, especially tributyltin oxide (TBTO), have given satisfactory long-term results. However, large-scale field trials of organotin formulations have not been implemented and their use cannot be recommended as their chronic toxicity in mammals has not yet been determined. The development of molluscicides of indigenous plant origin deserves support. Endod, derived from the berries of the climbing plant Phytolacca dodecandra, is the most extensively tested plant molluscicide, but data on its chronic toxicity to non-target organisms are lacking. The mode of action of molluscicides has not been extensively studied, though knowledge of the properties required of molluscicidal molecules has contributed to the discovery and development of niclosamide and nicotinanilide. In general, molluscicides probably cause stress on the water balance system, which in gastropods in thought to be under neurosecretory control. PMID:6975179

  9. Immunological characterization of a chimeric form of Schistosoma mansoni aquaporin in the murine model.

    PubMed

    Figueiredo, Barbara Castro Pimentel; De Assis, Natan Raimundo Gonçalves; De Morais, Suellen Batistoni; Martins, Vicente Paulo; Ricci, Natasha Delaqua; Bicalho, Rodrigo Marques; Pinheiro, Carina Da Silva; Oliveira, Sergio Costa

    2014-09-01

    Aquaporin (SmAQP) is the most abundant transmembrane protein in the tegument of Schistosoma mansoni. This protein is expressed in all developmental stages and seems to be essential in parasite survival since it plays a crucial role in osmoregulation, nutrient transport and drug uptake. In this study, we utilized the murine model to evaluate whether this protein was able to induce protection against challenge infection with S. mansoni cercariae. A chimeric (c) SmAQP was formulated with Freund's adjuvant for vaccination trial and evaluation of the host's immune response was performed. Our results demonstrated that immunization with cSmAQP induced the production of high levels of specific anti-cSmAQP IgG antibodies and a Th1/Th17 type of immune response characterized by IFN-γ, TNF-α and IL-17 cytokines. However, vaccination of mice with cSmAQP failed to reduce S. mansoni worm burden and liver pathology. Finally, we were unable to detect humoral immune response anti-cSmAQP in the sera of S. mansoni-infected human patients. Our results lead us to believe that SmAQP, as formulated in this study, may not be a good target in the search for an anti-schistosomiasis vaccine. PMID:24786243

  10. Challenges in predicting the effects of climate change on Schistosoma mansoni and Schistosoma haematobium transmission potential.

    PubMed

    McCreesh, Nicky; Booth, Mark

    2013-11-01

    Climate change will inevitably influence both the distribution of Schistosoma mansoni and Schistosoma haematobium and the incidence of schistosomiasis in areas where it is currently endemic, and impact on the feasibility of schistosomiasis control and elimination goals. There are several limitations of current models of climate and schistosome transmission, and substantial gaps in empirical data that impair model development. In this review we consider how temperature, precipitation, heat waves, drought, and flooding could impact on snail and schistosome population dynamics. We discuss how widely used degree day models of schistosome development may not be accurate at lower temperatures, and highlight the need for further research to improve our understanding of the relationship between air and water temperature and schistosome and snail development. PMID:24064438

  11. Serological Screening of the Schistosoma mansoni Adult Worm Proteome

    PubMed Central

    Ludolf, Fernanda; Patrocínio, Paola R.; Corrêa-Oliveira, Rodrigo; Gazzinelli, Andréa; Falcone, Franco H.; Teixeira-Ferreira, André; Perales, Jonas; Oliveira, Guilherme C.; Silva-Pereira, Rosiane A.

    2014-01-01

    Background New interventions tools are a priority for schistosomiasis control and elimination, as the disease is still highly prevalent. The identification of proteins associated with active infection and protective immune response may constitute the basis for the development of a successful vaccine and could also indicate new diagnostic candidates. In this context, post-genomic technologies have been progressing, resulting in a more rational discovery of new biomarkers of resistance and antigens for diagnosis. Methodology/Principal Findings Two-dimensional electrophoresed Schistosoma mansoni adult worm protein extracts were probed with pooled sera of infected and non-infected (naturally resistant) individuals from a S. mansoni endemic area. A total of 47 different immunoreactive proteins were identified by mass spectrometry. Although the different pooled sera shared most of the immunoreactive protein spots, nine protein spots reacted exclusively with the serum pool of infected individuals, which correspond to annexin, major egg antigen, troponin T, filamin, disulphide-isomerase ER-60 precursor, actin and reticulocalbin. One protein spot, corresponding to eukaryotic translation elongation factor, reacted exclusively with the pooled sera of non-infected individuals living in the endemic area. Western blotting of two selected recombinant proteins, major egg antigen and hemoglobinase, showed a similar recognition pattern of that of the native protein. Concluding/Significance Using a serological proteome analysis, a group of antigens related to the different infection status of the endemic area residents was identified and may be related to susceptibility or resistance to infection. PMID:24651847

  12. AN INITIAL INDICATION OF PREDISPOSING RISK OF SCHISTOSOMA MANSONI INFECTION FOR HEPATOCELLULAR CARCINOMA.

    PubMed

    Sabry, Abd El Hamid A; El-Aal, Amany A Abd; Mahmoud, Naglaa Saad; Nabil, Yossra; Aziz, Inas Z Abdel

    2015-08-01

    Estimated 500,000 - 1 million cases of hepatocellular carcinoma (HCC) are reported to occur yearly worldwide, with a mean annual incidence of around 3 - 4% of global population. HCC is rapidly fatal in most patients; that makes its incidence and mortality rates almost equal. In the last 5-10 years there were many alarming reports of sharply increased incidence of HCC. In Egypt, HCC reported to account for about 4.7% of chronic liver disease (CLD) patients, which has tremendous impact on socio-economic development in the country. Available data suggests indirect evidence of an association between Schistosoma mansoni and hepatocellular carcinoma, possibly through potentiation of hepatitis infections. The present study was conducted case control analysis of 60 HCC patients. Chronic schistosomiasis cases were confirmed by finding Anti-Schistosoma mansoni antibodies IgG by ELISA. Hepatitis C viral infection was proved by detection of viral load by quantitative Real time PCR. Among the study group 56.6% (34/60) were dweller in rural in Al-Fayoum governorate. Within hepatocellular carcinoma cases 26.7% (16/60) and 33.3% (20/60) suffered mono chronic schistosomiasis and mono hepatitis C (HCV) infections respectively, with no statistically significant differences (p=0.37), indicating comparable risk value of both infections in predisposing directly to HCC. Additionally; frequency of HCC patients with assumed potentiated HCV infection by chronic Schistosoma mansoni 6.7% (4/60) were statistically significant (p<0.05) less among total HCC patients included in this study, when compared to HCC patients preceded by either pure chronic schistosomiasis 26.7% (16/60) or pure HCV infection 33.3% (20/60). Our present study is one of few, addressing the possibility of direct relation between S. mansoni & hepatic carcinoma, concluding an initial indication of equal risk value of both human chronic S. mansoni infection and hepatitis C viral infections in precipitating hepatocellular

  13. Development of a schistosomiasis vaccine.

    PubMed

    Molehin, Adebayo J; Rojo, Juan U; Siddiqui, Sabrina Z; Gray, Sean A; Carter, Darrick; Siddiqui, Afzal A

    2016-05-01

    Schistosomiasis is a neglected tropical disease (NTD) of public health importance. Despite decades of implementation of mass praziquantel therapy programs and other control measures, schistosomiasis has not been contained and continues to spread to new geographic areas. A schistosomiasis vaccine could play an important role as part of a multifaceted control approach. With regards to vaccine development, many biological bottlenecks still exist: the lack of reliable surrogates of protection in humans; immune interactions in co-infections with other diseases in endemic areas; the potential risk of IgE responses to antigens in endemic populations; and paucity of appropriate vaccine efficacy studies in nonhuman primate models. Research is also needed on the role of modern adjuvants targeting specific parts of the innate immune system to tailor a potent and protective immune response for lead schistosome vaccine candidates with the long-term aim to achieve curative worm reduction. This review summarizes the current status of schistosomiasis vaccine development. PMID:26651503

  14. Protein kinase A signalling in Schistosoma mansoni cercariae and schistosomules.

    PubMed

    Hirst, Natasha L; Lawton, Scott P; Walker, Anthony J

    2016-06-01

    Cyclic AMP (cAMP)-dependent protein kinase/protein kinase A regulates multiple processes in eukaryotes by phosphorylating diverse cellular substrates, including metabolic and signalling enzymes, ion channels and transcription factors. Here we provide insight into protein kinase A signalling in cercariae and 24h in vitro cultured somules of the blood parasite, Schistosoma mansoni, which causes human intestinal schistosomiasis. Functional mapping of activated protein kinase A using anti-phospho protein kinase A antibodies and confocal laser scanning microscopy revealed activated protein kinase A in the central and peripheral nervous system, oral-tip sensory papillae, oesophagus and excretory system of intact cercariae. Cultured 24h somules, which biologically represent the skin-resident stage of the parasite, exhibited similar activation patterns in oesophageal and nerve tissues but also displayed striking activation at the tegument and activation in a region resembling the germinal 'stem' cell cluster. The adenylyl cyclase activator, forskolin, stimulated somule protein kinase A activation and produced a hyperkinesia phenotype. The biogenic amines, serotonin and dopamine known to be present in skin also induced protein kinase A activation in somules, whereas neuropeptide Y or [Leu(31),Pro(34)]-neuropeptide Y attenuated protein kinase A activation. However, neuropeptide Y did not block the forskolin-induced somule hyperkinesia. Bioinformatic investigation of potential protein associations revealed 193 medium confidence and 59 high confidence protein kinase A interacting partners in S. mansoni, many of which possess putative protein kinase A phosphorylation sites. These data provide valuable insight into the intricacies of protein kinase A signalling in S. mansoni and a framework for further physiological investigations into the roles of protein kinase A in schistosomes, particularly in the context of interactions between the parasite and the host. PMID:26777870

  15. Oral immunization of mice against Schistosoma mansoni using drinking water from trays containing Biomphalaria alexandrina infected with Schistosoma mansoni.

    PubMed

    Noureldin, M S

    1999-01-01

    Water collected from trays containing Biomphalaria alexandrina infected with Schistosoma mansoni at the time of cercariae shedding (SmISW) and trays containing clean, non-infected, B. alexandrina (NISW) and underground water (UW), were filtered used as a drinking water for 3 groups of albino mice males. After two months, blood samples were collected from the 3 groups and serum was tested for anti-cercarial IgG, then mice were infected with 150 S. mansoni cercariae. Eight weeks after infection, mice were perfused and adult S. mansoni worms were counted. Anti-cercarial IgG was positive in 23 (82.1%) out of the 28 samples collected from mice drinking SmISW and only in 2 (9.5%) out of the 21 samples collected from mice drinking NISW, while all samples collected from mice drinking UW were negative for anti-cercarial IgG (X2=45.897; P<0.001). Worm load was significantly lower in the group of mice drinking SmISW than mice drinking NISW (P=0.032) and mice drinking UW (P=0.02). In mice drinking SmISW, adult worm count showed significant negative correlation with anti-cercarial IgG concentration (Kendall's taub =-0.325 and P=0.018). The results indicate that antigens present in drinking water stimulate a level of immunity against schistosomiasis, (inhabitants of endemic areas) resulting in a lower intensity and severity of infection. Also, it may reduce the specificity of serological tests used for diagnosis of Schistosoma infection, based on antibody determination. PMID:12561896

  16. Schistosomicidal activity and docking of Schistosoma mansoni ATPDase 1 with licoflavone B isolated from Glycyrrhiza inflata (Fabaceae).

    PubMed

    Aleixo de Carvalho, Lara Soares; Geraldo, Reinaldo Barros; de Moraes, Josué; Silva Pinto, Pedro Luiz; de Faria Pinto, Priscila; Pereira, Olavo dos Santos; Da Silva Filho, Ademar A

    2015-12-01

    Schistosomiasis is one of the world's major public health problems, and its treatment is widely dependent on praziquantel (PZQ), the only available drug. Schistosoma mansoni ATP diphosphohydrolases are ecto-enzymes localized on the external tegumental surface of S. mansoni and considered an important target for action of new drugs. In this work, the in vitro schistosomicidal activity of the crude extract of Glycyrrhiza inflata roots (GI) and its isolated compounds echinatin, licoflavone A and licoflavone B were evaluated against S. mansoni adult worms. Results showed that GI (200 μg/mL) was active against adult schistosomes, causing 100% mortality after 24 h of incubation. Chromatographic fractionation of GI led to isolation of echinatin, licoflavone A and licoflavone B. Licoflavone B (25-100 μM) caused 100% mortality, tegumental alterations, and reduction of oviposition and motor activity of all adult worms, without affecting mammalian Vero cells. Confocal laser scanning microscopy showed tegumental morphological alterations and changes on the numbers of tubercles of S. mansoni worms in a dose-dependent manner after incubation with licoflavone B. Licoflavone B also showed high S. mansoni ATPase (IC50 of 23.78 μM) and ADPase (IC50 of 31.50 μM) inhibitory activities. Docking studies predicted different interactions between licoflavone B and S. mansoni ATPDase 1, corroborating with the in vitro inhibitory activity. This report demonstrated the first evidence for the schistosomicidal activity of licoflavone B and suggests that its mechanism of action involve the inhibition of S. mansoni ATP diphosphohydrolases. PMID:26454044

  17. Detection of Schistosoma mansoni and Schistosoma haematobium by Real-Time PCR with High Resolution Melting Analysis

    PubMed Central

    Sady, Hany; Al-Mekhlafi, Hesham M.; Ngui, Romano; Atroosh, Wahib M.; Al-Delaimy, Ahmed K.; Nasr, Nabil A.; Dawaki, Salwa; Abdulsalam, Awatif M.; Ithoi, Init; Lim, Yvonne A. L.; Chua, Kek Heng; Surin, Johari

    2015-01-01

    The present study describes a real-time PCR approach with high resolution melting-curve (HRM) assay developed for the detection and differentiation of Schistosoma mansoni and S. haematobium in fecal and urine samples collected from rural Yemen. The samples were screened by microscopy and PCR for the Schistosoma species infection. A pair of degenerate primers were designed targeting partial regions in the cytochrome oxidase subunit I (cox1) gene of S. mansoni and S. haematobium using real-time PCR-HRM assay. The overall prevalence of schistosomiasis was 31.8%; 23.8% of the participants were infected with S. haematobium and 9.3% were infected with S. mansoni. With regards to the intensity of infections, 22.1% and 77.9% of S. haematobium infections were of heavy and light intensities, respectively. Likewise, 8.1%, 40.5% and 51.4% of S. mansoni infections were of heavy, moderate and light intensities, respectively. The melting points were distinctive for S. mansoni and S. haematobium, categorized by peaks of 76.49 ± 0.25 °C and 75.43 ± 0.26 °C, respectively. HRM analysis showed high detection capability through the amplification of Schistosoma DNA with as low as 0.0001 ng/µL. Significant negative correlations were reported between the real-time PCR-HRM cycle threshold (Ct) values and microscopic egg counts for both S. mansoni in stool and S. haematobium in urine (p < 0.01). In conclusion, this closed-tube HRM protocol provides a potentially powerful screening molecular tool for the detection of S. mansoni and S. haematobium. It is a simple, rapid, accurate, and cost-effective method. Hence, this method is a good alternative approach to probe-based PCR assays. PMID:26193254

  18. Detection of Schistosoma mansoni and Schistosoma haematobium by Real-Time PCR with High Resolution Melting Analysis.

    PubMed

    Sady, Hany; Al-Mekhlafi, Hesham M; Ngui, Romano; Atroosh, Wahib M; Al-Delaimy, Ahmed K; Nasr, Nabil A; Dawaki, Salwa; Abdulsalam, Awatif M; Ithoi, Init; Lim, Yvonne A L; Chua, Kek Heng; Surin, Johari

    2015-01-01

    The present study describes a real-time PCR approach with high resolution melting-curve (HRM) assay developed for the detection and differentiation of Schistosoma mansoni and S. haematobium in fecal and urine samples collected from rural Yemen. The samples were screened by microscopy and PCR for the Schistosoma species infection. A pair of degenerate primers were designed targeting partial regions in the cytochrome oxidase subunit I (cox1) gene of S. mansoni and S. haematobium using real-time PCR-HRM assay. The overall prevalence of schistosomiasis was 31.8%; 23.8% of the participants were infected with S. haematobium and 9.3% were infected with S. mansoni. With regards to the intensity of infections, 22.1% and 77.9% of S. haematobium infections were of heavy and light intensities, respectively. Likewise, 8.1%, 40.5% and 51.4% of S. mansoni infections were of heavy, moderate and light intensities, respectively. The melting points were distinctive for S. mansoni and S. haematobium, categorized by peaks of 76.49 ± 0.25 °C and 75.43 ± 0.26 °C, respectively. HRM analysis showed high detection capability through the amplification of Schistosoma DNA with as low as 0.0001 ng/µL. Significant negative correlations were reported between the real-time PCR-HRM cycle threshold (Ct) values and microscopic egg counts for both S. mansoni in stool and S. haematobium in urine (p < 0.01). In conclusion, this closed-tube HRM protocol provides a potentially powerful screening molecular tool for the detection of S. mansoni and S. haematobium. It is a simple, rapid, accurate, and cost-effective method. Hence, this method is a good alternative approach to probe-based PCR assays. PMID:26193254

  19. Changes in human schistosomiasis levels after the construction of two large hydroelectric dams in central Côte d'Ivoire.

    PubMed

    N'Goran, E K; Diabate, S; Utzinger, J; Sellin, B

    1997-01-01

    The construction of large dams has been shown to increase the prevalence and intensity of human schistosomiasis. However, until now no study had been carried out to assess the impact of such a project in Côte d'Ivoire. For Kossou and Taabo, two large dams which became operational in the 1970s, baseline data are available on schistosomiasis prevalence in the surrounding area before dam construction, so that the changes in schistosomiasis levels can be assessed. We re-evaluated the prevalence of Schistosoma haematobium and S. mansoni in November 1992, by analysing 548 urine and 255 stool samples, respectively, from schoolchildren from five villages around each lake. A marked increase in the overall prevalence of S. haematobium was observed, from 14% to 53% around Lake Kossou and from 0 to 73% around Lake Taabo. Baseline data for S. mansoni are only available for Lake Taabo, where a prevalence of 3% was found in 1979 and where the prevalence in 1992 was still low at 2%. The construction of these two large dams therefore led to little change in S. mansoni prevalence but to a significant increase in that of S. haematobium. PMID:9509626

  20. Schistosomiasis japonicum diagnosed on liver biopsy in a patient with hepatitis B co-infection: a case report

    PubMed Central

    2014-01-01

    Introduction Chronic hepatitis B virus and schistosomiasis are independently associated with significant mortality and morbidity worldwide. Despite much geographic overlap between these conditions and no reason why co-infection should not exist, we present what is, to the best of our knowledge, the first published report of a proven histological diagnosis of hepatic Schistosomiasis japonicum and chronic hepatitis B co-infection. A single case of hepatitis B and hepatic Schistosomiasis mansoni diagnosed by liver biopsy has previously been reported in the literature. Case presentation A 38-year-old Chinese man with known chronic hepatitis B virus infection presented with malaise, nausea and headache. Blood tests revealed increased transaminases and serology in keeping with hepatitis B virus e-antigen seroconversion. A liver biopsy was performed because some investigations, particularly transient elastography, suggested cirrhosis. Two schistosome ova were seen on liver histology, identified as S. japonicum, probably acquired in China as a youth. His peripheral eosinophil count was normal, schistosomal serology and stool microscopy for ova, cysts and parasites were negative. Conclusion Hepatic schistosomiasis co-infection should be considered in patients with hepatitis B virus infection who are from countries endemic for schistosomiasis. Screening for schistosomiasis using a peripheral eosinophil count, schistosomal serology and stool microscopy may be negative despite infection, therefore presumptive treatment could be considered. Transient elastography should not be used to assess liver fibrosis during acute flares of viral hepatitis because readings are falsely elevated. The impact of hepatic schistosomiasis on the sensitivity and specificity of transient elastography measurement for the assessment of hepatitis B is as yet unknown. PMID:24521427

  1. Temperature data from satellite imagery and the distribution of schistosomiasis in Egypt.

    PubMed

    Malone, J B; Huh, O K; Fehler, D P; Wilson, P A; Wilensky, D E; Holmes, R A; Elmagdoub, A I

    1994-06-01

    Polar orbiting environmental satellites operated by the National Oceanographic and Atmospheric Administration acquire daytime and nighttime thermal infrared measurements of the earth's surface around the world at a spatial resolution of 1.1 km. Day-night pairs of this imagery from the Advanced Very High Resolution Radiometer (AVHRR) were processed to produce temperature maximum, temperature minimum, and diurnal temperature difference (dT) maps of the lower Nile River valley. Nile delta subsets of the dT maps for August 16, 1990 and February 14, 1991 were analyzed in detail. Values of dT at specific locations were derived using the median of 5 x 5 pixels centered on the latitude and longitude of 41 survey sites listed in 1935, 1983, and 1990 schistosomiasis surveys of the Nile Delta. A Spearman correlation coefficient matrix revealed an inverse relationship between site dT values for August 16, 1990 and February 14, 1991 and prevalence of Schistosoma mansoni in the 1935 and 1983 surveys. For S. haematobium, a positive association of site dT values and prevalence was seen for 1935 only. A significant association was observed between 1935 S. mansoni prevalence and that observed in 1983 and 1990; S. haematobium prevalence in 1935 was not correlated with the later surveys. The results suggest that AVHRR thermal difference maps reflect regional hydrologic conditions that can be used as a predictor of environmental risk of schistosomiasis for control program management. PMID:8024064

  2. Reconstructing Colonization Dynamics of the Human Parasite Schistosoma mansoni following Anthropogenic Environmental Changes in Northwest Senegal

    PubMed Central

    Van den Broeck, Frederik; Maes, Gregory E.; Larmuseau, Maarten H. D.; Rollinson, David; Sy, Ibrahima; Faye, Djibril; Volckaert, Filip A. M.; Polman, Katja; Huyse, Tine

    2015-01-01

    Background Anthropogenic environmental changes may lead to ecosystem destabilization and the unintentional colonization of new habitats by parasite populations. A remarkable example is the outbreak of intestinal schistosomiasis in Northwest Senegal following the construction of two dams in the ‘80s. While many studies have investigated the epidemiological, immunological and geographical patterns of Schistosoma mansoni infections in this region, little is known about its colonization history. Methodology/Principal Findings Parasites were collected at several time points after the disease outbreak and genotyped using a 420 bp fragment of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1) and nine nuclear DNA microsatellite markers. Phylogeographic and population genetic analyses revealed the presence of (i) many genetically different haplotypes at the non-recombining mitochondrial marker and (ii) one homogenous S. mansoni genetic group at the recombining microsatellite markers. These results suggest that the S. mansoni population in Northwest Senegal was triggered by intraspecific hybridization (i.e. admixture) between parasites that were introduced from different regions. This would comply with the extensive immigration of infected seasonal agricultural workers from neighboring regions in Senegal, Mauritania and Mali. The spatial and temporal stability of the established S. mansoni population suggests a swift local adaptation of the parasite to the local intermediate snail host Biomphalaria pfeifferi at the onset of the epidemic. Conclusions/Significance Our results show that S. mansoni parasites are very successful in colonizing new areas without significant loss of genetic diversity. Maintaining high levels of diversity guarantees the adaptive potential of these parasites to cope with selective pressures such as drug treatment, which might complicate efforts to control the disease. PMID:26275049

  3. Still hope for schistosomiasis vaccine

    PubMed Central

    Ricciardi, Alessandra; Ndao, Momar

    2015-01-01

    Schistosomiasis is a parasitic disease caused by helminths belonging to the Schistosoma genus. Approximately 700 million people are at risk of infection and 200 million people are currently infected. Schistosomiasis is the most important helminth infection, and treatment relies solely on the drug praziquantel. Worries of praziquantel resistance as well as high disease burden are only some of the justifications which support the development of a vaccine against schistosomiasis. To date, only 2 schistosome vaccines have made it into clinical trials: Sh28GST (Bilhvax) and Sm14. However, there are several vaccine candidates, such as TSP-2, sm-p8, and Sm-Cathepsin B, which are generating promising results in pre-clinical studies. Schistosomiasis vaccine development has been an uphill battle, and there are still several hurdles to overcome in the future. Fortunately, the research groups involved in the research for vaccine development have not abandoned their work. Furthermore, in the last few years, schistosomiasis has garnered some additional attention on a global scale due to its significant impact on public health. PMID:26176659

  4. Epigenetic modulation, stress and plasticity in susceptibility of the snail host, Biomphalaria glabrata, to Schistosoma mansoni infection.

    PubMed

    Knight, Matty; Ittiprasert, Wannaporn; Arican-Goktas, Halime D; Bridger, Joanna M

    2016-06-01

    Blood flukes are the causative agent of schistosomiasis - a major neglected tropical disease that remains endemic in numerous countries of the tropics and sub-tropics. During the past decade, a concerted effort has been made to control the spread of schistosomiasis, using a drug intervention program aimed at curtailing transmission. These efforts notwithstanding, schistosomiasis has re-emerged in southern Europe, raising concerns that global warming could contribute to the spread of this disease to higher latitude countries where transmission presently does not take place. Vaccines against schistosomiasis are not currently available and reducing transmission by drug intervention programs alone does not prevent reinfection in treated populations. These challenges have spurred awareness that new interventions to control schistosomiasis are needed, especially since the World Health Organization hopes to eradicate the disease by 2025. For one of the major species of human schistosomes, Schistosoma mansoni, the causative agent of hepatointestinal schistosomiasis in Africa and the Western Hemisphere, freshwater snails of the genus Biomphalaria serve as the obligate intermediate host of this parasite. To determine mechanisms that underlie parasitism by S. mansoni of Biomphalaria glabrata, which might be manipulated to block the development of intramolluscan larval stages of the parasite, we focused effort on the impact of schistosome infection on the epigenome of the snail. Results to date reveal a complex relationship, manifested by the ability of the schistosome to manipulate the snail genome, including the expression of specific genes. Notably, the parasite subverts the stress response of the host to ensure productive parasitism. Indeed, in isolates of B. glabrata native to central and South America, susceptible to infection with S. mansoni, the heat shock protein 70 (Bg-HSP70) gene of this snail is rapidly relocated in the nucleus and transcribed to express HSP70

  5. Cellular and humoral immune responses to recombinant Smp17.7 Schistosoma mansoni antigen.

    PubMed

    Al-Sherbiny, Maged M; Galal, Iman F; Karim, Amr M; Ashour, Ameen A; Saad, Abdel-Hakim M

    2003-12-01

    To determine the immunological responses to S. mansoni antigen rSmp17.7, a total of 184 subjects, 174 patients from a schistosomiasis endemic area, and 10 controls were used. Proliferation, cytokine profile in culture supernatants from antigen-stimulated peripheral blood mononuclear cells and specific IgG1, IgG3, IgG4, IgA, IgM & IgE levels were assessed. The highest stimulation index to rSmp17.7 was detected in S. mansoni patients. The evaluation of the cytokine profile [IL-2, IL-4 & IFN-gamma] in response to this antigen showed a significant increase as demonstrated by ELISA. Specifically, IFN-gamma and IL-2 were significantly detected by flow cytometry. IgG1 and IgM were the only Igs which showed a significant increase. These results highlight the importance of rSmp17.7 as a candidate vaccine for schistosomiasis. The results pave the way to understand the mechanism of schistosome-vaccine efficacy. PMID:14708863

  6. Enhanced protective efficacy of a chimeric form of the schistosomiasis vaccine antigen Sm-TSP-2.

    PubMed

    Pearson, Mark S; Pickering, Darren A; McSorley, Henry J; Bethony, Jeffrey M; Tribolet, Leon; Dougall, Annette M; Hotez, Peter J; Loukas, Alex

    2012-01-01

    The large extracellular loop of the Schistosoma mansoni tetraspanin, Sm-TSP-2, when fused to a thioredoxin partner and formulated with Freund's adjuvants, has been shown to be an efficacious vaccine against murine schistosomiasis. Moreover, Sm-TSP-2 is uniquely recognised by IgG(1) and IgG(3) from putatively resistant individuals resident in S. mansoni endemic areas in Brazil. In the present study, we expressed Sm-TSP-2 at high yield and in soluble form in E. coli without the need for a solubility enhancing fusion partner. We also expressed in E. coli a chimera called Sm-TSP-2/5B, which consisted of Sm-TSP-2 fused to the immunogenic 5B region of the hookworm aspartic protease and vaccine antigen, Na-APR-1. Sm-TSP-2 formulated with alum/CpG showed significant reductions in adult worm and liver egg burdens in two separate murine schistosomiasis challenge studies. Sm-TSP-2/5B afforded significantly greater protection than Sm-TSP-2 alone when both antigens were formulated with alum/CpG. The enhanced protection obtained with the chimeric fusion protein was associated with increased production of anti-Sm-TSP-2 antibodies and IL-4, IL-10 and IFN-γ from spleen cells of vaccinated animals. Sera from 666 individuals from Brazil who were infected with S. mansoni were screened for potentially deleterious IgE responses to Sm-TSP-2. Anti-Sm-TSP-2 IgE to this protein was not detected (also shown previously for Na-APR-1), suggesting that the chimeric antigen Sm-TSP-2/5B could be used to safely and effectively vaccinate people in areas where schistosomes and hookworms are endemic. PMID:22428079

  7. Geographic information systems as a tool for control program management for schistosomiasis in Egypt.

    PubMed

    Abdel-Rahman, M S; El-Bahy, M M; Malone, J B; Thompson, R A; El Bahy, N M

    2001-04-27

    During a 4-year study a geographic information system (GIS) risk model was constructed for predicting the relative risk of schistosomiasis in Kafr El-Sheikh governorate, Egypt. A 1-year 1990-1991 time series on diurnal temperature difference (dT) prepared from the advanced very high resolution radiometer (AVHRR) sensor on the NOAA-11 satellite was used to develop a regional risk model for the Nile delta based on thermal-hydrological domains. A May 15, 1990 Landsat TM scene (path 177, Row 38) was used to develop a local 'village-scale' environmental risk model based on higher resolution satellite sensor data (30 m picture element size at earth surface). Four of ten classes derived from a tasseled cap (Tcap) transformation of the Landsat TM scene were shown to be significantly related to a 5-year Schistosoma mansoni prevalence database from the Ministry of Health. A risk model was developed based on dT and the proportional area of the four Tcap classes in 5 km(2) buffer zones centered on rural health unit (RHU) reporting units. Available historical data on S. mansoni and its snail host Biomphalaria alexandrina, as well as recent field collected data were gathered and incorporated as separate themes. Model validation was done using data collected on snail population bionomics-infection rates, water quality, underground water table and cercariometry at 13 hydrologically representative sites. The role of soil type, water table and water quality was studied at 79 of 154 rural health unit sites. The model permitted retrieval of relevant data by RHU point location. For the first time in Egypt, the Kafr El-Sheikh GIS schistosoma prediction model can support MOH efforts to make more accurate control program decisions based on environmental predilection sites of endemic Schistosomiasis mansoni. PMID:11378141

  8. Knowledge attitudes and practices of grade three primary schoolchildren in relation to schistosomiasis, soil transmitted helminthiasis and malaria in Zimbabwe

    PubMed Central

    2011-01-01

    Background Helminth infection rates in grade three children are used as proxy indicators of community infection status and to guide treatment strategies in endemic areas. However knowledge, attitudes and practices (KAP) of this target age group (8-10 years) in relation to schistosomiasis, soil transmitted helminthiasis (STHs) and malaria is not known at a time when integrated plasmodium - helminth control strategies are being advocated. This study sought to assess KAP of grade 3 children in relation to schistosomiasis, STHs and malaria in order to establish an effective school based health education for disease transmission control. Methods Grade 3 children (n = 172) attending four randomly selected primary schools (one in rural and 3 in the commercial farming areas) in Zimbabwe were interviewed using a pre-tested interviewer administered questionnaire. The urine filtration technique was used to determine S. haematobium infection status. Infection with S. mansoni and STHs was determined using a combination of results from the Kato Katz and formol ether concentration techniques. P. falciparum was diagnosed by examination of Giemsa stained thick blood smears. Results It was observed that 32.0%, 19.2% and 4.1% of the respondents had correct knowledge about the causes of schistosomiasis, malaria and STHs, respectively, whilst 22.1%, 19.2% and 5.8% knew correct measures to control schistosomiasis, malaria and STHs. Sixty-two percent and 44.8% did not use soap to wash hands after toilet and before eating food respectively, whilst 33.1% never wore shoes. There were no functional water points and soap for hand washing after toilet at all schools. There was a high prevalence distribution of all parasites investigated in this study at Msapa primary school - S. haematobium (77.8%), S. mansoni (33.3%) hookworms (29.6%) and P. falciparum (48.1%). Reports that participant had suffered from schistosomiasis and malaria before were significant predictors of these diseases (p = 0

  9. Synergy of Omeprazole and Praziquantel In Vitro Treatment against Schistosoma mansoni Adult Worms

    PubMed Central

    Anderson, Leticia; Venancio, Thiago M.; Nakaya, Helder I.; Miyasato, Patrícia A.; Rofatto, Henrique K.; Zerlotini, Adhemar; Nakano, Eliana; Oliveira, Guilherme; Verjovski-Almeida, Sergio

    2015-01-01

    Background Treatment and morbidity control of schistosomiasis relies on a single drug, praziquantel (PZQ), and the selection of resistant worms under repeated treatment is a concern. Therefore, there is a pressing need to understand the molecular effects of PZQ on schistosomes and to investigate alternative or synergistic drugs against schistosomiasis. Methodology We used a custom-designed Schistosoma mansoni expression microarray to explore the effects of sublethal doses of PZQ on large-scale gene expression of adult paired males and females and unpaired mature females. We also assessed the efficacy of PZQ, omeprazole (OMP) or their combination against S. mansoni adult worms with a survival in vitro assay. Principal Findings We identified sets of genes that were affected by PZQ in paired and unpaired mature females, however with opposite gene expression patterns (up-regulated in paired and down-regulated in unpaired mature females), indicating that PZQ effects are heavily influenced by the mating status. We also identified genes that were similarly affected by PZQ in males and females. Functional analyses of gene interaction networks were performed with parasite genes that were differentially expressed upon PZQ treatment, searching for proteins encoded by these genes whose human homologs are targets of different drugs used for other diseases. Based on these results, OMP, a widely prescribed proton pump inhibitor known to target the ATP1A2 gene product, was chosen and tested. Sublethal doses of PZQ combined with OMP significantly increased worm mortality in vitro when compared with PZQ or OMP alone, thus evidencing a synergistic effect. Conclusions Functional analysis of gene interaction networks is an important approach that can point to possible novel synergistic drug candidates. We demonstrated the potential of this strategy by showing that PZQ in combination with OMP displayed increased efficiency against S. mansoni adult worms in vitro when compared with

  10. Why the radiation-attenuated cercarial immunization studies failed to guide the road for an effective schistosomiasis vaccine: A review.

    PubMed

    El Ridi, Rashika; Tallima, Hatem

    2015-05-01

    Schistosomiasis is a debilitating parasitic disease caused by platyhelminthes of the genus Schistosoma, notably Schistosoma mansoni, Schistosoma haematobium, and Schistosoma japonicum. Pioneer researchers used radiation-attenuated (RA) schistosome larvae to immunize laboratory rodent and non-human primate hosts. Significant and reproducible reduction in challenge worm burden varying from 30% to 90% was achieved, providing a sound proof that vaccination against this infection is feasible. Extensive histopathological, tissue mincing and incubation, autoradiographic tracking, parasitological, and immunological studies led to defining conditions and settings for achieving optimal protection and delineating the resistance underlying mechanisms. The present review aims to summarize these findings and draw the lessons that should have guided the development of an effective schistosomiasis vaccine. PMID:26257924

  11. Quantitative evaluation of integrated schistosomiasis control: the example of passive case finding in Ghana.

    PubMed

    de Vlas, Sake J; Danso-Appiah, Anthony; van der Werf, Marieke J; Bosompem, Kwabena M; Habbema, J Dik F

    2004-06-01

    Passive case finding based on adequate diagnosis and treatment of symptomatic individuals with praziquantel by the health care facilities is a minimum requirement for integrated schistosomiasis control. Two field studies were conducted in Ghana to obtain quantifications about the steps in this process: (1) a study of health-seeking behaviour through interview of individuals with reported schistosomiasis-related symptoms; (2) a study of the performance of the Ghanaian health system with regard to schistosomiasis case management by presenting clinical scenarios to health workers and collecting information about availability of praziquantel. It appeared that cases of blood in urine (the most typical symptom of Schistosoma haematobium) and blood in stool (the most typical symptom of S. mansoni) have a very small probability of receiving praziquantel (4.4% and 1.4%, respectively) from health facilities. Programmes aimed at making the drug available at all levels of the health care delivery system and encouraging health-seeking behaviour through health education are not likely to increase these probabilities beyond 30%. This is because many cases with blood in urine do not consider it serious enough to seek health care, and blood in stool usually requires (imperfect) diagnostic testing and referral. We therefore conclude that additional control activities, especially for high-risk groups, will remain necessary. PMID:15189470

  12. Role of adult worm antigen-specific immunoglobulin E in acquired immunity to Schistosoma mansoni infection in baboons.

    PubMed

    Nyindo, M; Kariuki, T M; Mola, P W; Farah, I O; Elson, L; Blanton, R E; King, C L

    1999-02-01

    Allergic-type immune responses, particularly immunoglobulin E (IgE), correlate with protective immunity in human schistosomiasis. To better understand the mechanisms of parasite elimination we examined the immune correlates of protection in baboons (Papio cynocephalus anubis), which are natural hosts for Schistosoma mansoni and also develop allergic-type immunity with infection. In one experiment, animals were exposed to a single infection (1,000 cercariae) or were exposed multiple times (100 cercariae per week for 10 weeks) and subsequently were cured with praziquantel prior to challenge with 1, 000 cercariae. Singly and multiply infected animals mounted 59 and 80% reductions in worm burden, respectively (P < 0.01). In a second experiment, animals were inoculated with S. mansoni ova and recombinant human interleukin 12 (IL-12). This produced a 37 to 39% reduction in adult worm burden after challenge (P < 0.05). Parasite-specific IgG, IgE, IgM, and peripheral blood cytokine production were evaluated. The only immune correlate of protection in both experiments was levels of soluble adult worm antigen (SWAP)-specific IgE in serum at the time of challenge infection and/or 6 weeks later. Baboons repeatedly infected with cercariae or immunized with ova and IL-12 developed two- to sixfold-greater levels of SWAP-specific IgE in serum than did controls, and this correlated with reductions in worm burden (r2, -0.40 to -0.64; P, <0. 01). Thus, in baboons and unlike mice, adult worm-specific IgE is uniquely associated with acquired immunity to S. mansoni infection. This similar association of parasite-specific IgE and protection among primates infected with schistosomiasis, along with similar pathology, anatomy, and genetic make-up, indicates that baboons provide an excellent permissive experimental model for better understanding the mechanisms of innate and acquired immunity to schistosomiasis in humans. PMID:9916070

  13. Towards an Understanding of the Function of the Phytochelatin Synthase of Schistosoma mansoni

    PubMed Central

    Rigouin, Coraline; Nylin, Elyse; Cogswell, Alexis A.; Schaumlöffel, Dirk; Dobritzsch, Dirk; Williams, David L.

    2013-01-01

    Phytochelatin synthase (PCS) is a protease-like enzyme that catalyzes the production of metal chelating peptides, the phytochelatins, from glutathione (GSH). In plants, algae, and fungi phytochelatin production is important for metal tolerance and detoxification. PCS proteins also function in xenobiotic metabolism by processing GSH S-conjugates. The aim of the present study is to elucidate the role of PCS in the parasitic worm Schistosoma mansoni. Recombinant S. mansoni PCS proteins expressed in bacteria could both synthesize phytochelatins and hydrolyze various GSH S-conjugates. We found that both the N-truncated protein and the N- and C-terminal truncated form of the enzyme (corresponding to only the catalytic domain) work through a thiol-dependant and, notably, metal-independent mechanism for both transpeptidase (phytochelatin synthesis) and peptidase (hydrolysis of GSH S-conjugates) activities. PCS transcript abundance was increased by metals and xenobiotics in cultured adult worms. In addition, these treatments were found to increase transcript abundance of other enzymes involved in GSH metabolism. Highest levels of PCS transcripts were identified in the esophageal gland of adult worms. Taken together, these results suggest that S. mansoni PCS participates in both metal homoeostasis and xenobiotic metabolism rather than metal detoxification as previously suggested and that the enzyme may be part of a global stress response in the worm. Because humans do not have PCS, this enzyme is of particular interest as a drug target for schistosomiasis. PMID:23383357

  14. Comparison of Schistosoma mansoni Soluble Cercarial Antigens and Soluble Egg Antigens for Serodiagnosing Schistosome Infections

    PubMed Central

    Doenhoff, Mike; Aitken, Cara; Bailey, Wendi; Ji, Minjun; Dawson, Emily; Gilis, Henk; Spence, Grant; Alexander, Claire; van Gool, Tom

    2012-01-01

    A Schistosoma mansoni cercarial antigen preparation (cercarial transformation fluid – SmCTF) was evaluated for detection of anti-schistosome antibodies in human sera in 4 collaborating laboratories. The performance of SmCTF was compared with that of S. mansoni egg antigens (SmSEA) in an indirect enzyme-immunoassay (ELISA) antigen assay, the latter being used routinely in 3 of the 4 participating laboratories to diagnose S. mansoni and S. haematobium infections. In the fourth laboratory the performance of SmCTF was compared with that of S. japonicum egg antigens (SjSEA) in ELISA for detection of anti-S. japonicum antibodies. In all 4 laboratories the results given by SmCTF in ELISA were very similar to those given by the antigen preparation routinely used in the respective laboratory to detect anti-schistosome antibodies in human infection sera. In so far as the ELISA results from SmCTF are thus so little different from those given by schistosome egg antigens and also cheaper to produce, the former is a potentially useful new diagnostic aid for schistosomiasis. PMID:23029577

  15. Activation-induced apoptosis in peripheral blood mononuclear cells during hepatosplenic Schistosoma mansoni infections.

    PubMed

    Ghoneim, H M; Demian, S R; Heshmat, M G; Ismail, N S; El-Sayed, Laila H

    2008-01-01

    It is well established that programmed cell death (apoptosis) is an important regulator of host responses during infection with a variety of intra- and extra-cellular pathogens. The present work aimed at assessment of in vitro spontaneous and phytohemagglutinin (PHA)-induced apoptosis in mononuclear cells isolated from patients with hepatosplenic form of S. mansoni infections. Cell death data were correlated to the degree of lymphoproliferative responses to PHA as well as to the serum anti-schistosomal antibody titers. A markedly significant increase in PHA-induced apoptosis in lymphocytes isolated from S. mansoni-infected patients was seen when compared to the corresponding healthy controls. However, a slight difference was recorded between the two studied groups regarding the spontaneous apoptosis. This was accompanied with a significant impairment of in vitro PHA-induced lymphoproliferation of T cells from S. mansoni patients. Data of the present study supports the hypothesis that activation-induced cell death (AICD) is a potentially contributing factor in T helper (Th) cell regulation during chronic stages of schistosomiasis, which represents a critically determinant factor in the host-parasite interaction and might influence the destiny of parasitic infections either towards establishment of chronic infection or towards host death. PMID:20306689

  16. Schistosomiasis collection at NHM (SCAN)

    PubMed Central

    2012-01-01

    Background The Natural History Museum (NHM) is developing a repository for schistosomiasis-related material, the Schistosomiasis Collection at NHM (SCAN) as part of its existing Wolfson Wellcome Biomedical Laboratory (WWBL). This is timely because a major research and evaluation effort to understand control and move towards elimination of schistosomiasis in Africa has been initiated by the Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), resulting in the collection of many important biological samples, including larval schistosomes and snails. SCAN will collaborate with a number of research groups and control teams and the repository will acquire samples relevant to both immediate and future research interest. The samples collected through ongoing research and field activities, WWBL’s existing collections, and other acquisitions will be maintained over the long term and made available to the global research community for approved research purposes. Goals include: · Consolidation of the existing NHM schistosome and snail collections and transfer of specimens into suitable long-term storage systems for DNA retrieval, · Long-term and stable storage of specimens collected as part of on going field programmes initially in Africa especially relating to the SCORE research programmes, · Provision of access to snail and schistosome collections for approved research activities. PMID:22943137

  17. Efficacy and Safety of Arachidonic Acid for Treatment of School-Age Children in Schistosoma mansoni High-Endemicity Regions

    PubMed Central

    Barakat, Rashida; Abou El-Ela, Nadia E.; Sharaf, Soraya; El Sagheer, Ola; Selim, Sahar; Tallima, Hatem; Bruins, Maaike J.; Hadley, Kevin B.; El Ridi, Rashika

    2015-01-01

    Arachidonic acid (ARA), an omega-6 fatty acid, is a potent schistosomicide that displayed significant and safe therapeutic effects in Schistosoma mansoni-infected schoolchildren in S. mansoni low-prevalence regions. We here report on ARA efficacy and safety in treatment of schoolchildren in S. mansoni high-endemicity areas of Kafr El Sheikh, Egypt. The study was registered with ClinicalTrials.gov (NCT02144389). In total, 268 schoolchildren with light, moderate, or heavy S. mansoni infection were assigned to three study arms of 87, 91, and 90 children and received a single dose of 40 mg/kg praziquantel (PZQ), ARA (10 mg/kg per day for 15 days), or PZQ combined with ARA, respectively. The children were examined before and after treatment for stool parasite egg counts and blood biochemical, hematological, and immunological parameters. ARA, like PZQ, induced moderate cure rates (50% and 60%, respectively) in schoolchildren with light infection and modest cure rates (21% and 20%, respectively) in schoolchildren with high infection. PZQ and ARA combined elicited 83% and 78% cure rates in children with light and heavy infection, respectively. Biochemical and immunological profiles were either unchanged or ameliorated after ARA therapy. Combination of PZQ and ARA might be useful for treatment of children with schistosomiasis in high-endemicity regions. PMID:25624403

  18. Risk Factors and Spatial Distribution of Schistosoma mansoni Infection among Primary School Children in Mbita District, Western Kenya

    PubMed Central

    Nagi, Sachiyo; Chadeka, Evans A.; Sunahara, Toshihiko; Mutungi, Faith; Justin, Yombo K. Dan; Kaneko, Satoshi; Ichinose, Yoshio; Matsumoto, Sohkichi; Njenga, Sammy M.; Hashizume, Masahiro; Shimada, Masaaki; Hamano, Shinjiro

    2014-01-01

    Background An increasing risk of Schistosoma mansoni infection has been observed around Lake Victoria, western Kenya since the 1970s. Understanding local transmission dynamics of schistosomiasis is crucial in curtailing increased risk of infection. Methodology/Principal Findings We carried out a cross sectional study on a population of 310 children from eight primary schools. Overall, a total of 238 (76.8%) children were infected with S. mansoni, while seven (2.3%) had S. haematobium. The prevalence of hookworm, Trichuris trichiura and Ascaris lumbricoides were 6.1%, 5.2% and 2.3%, respectively. Plasmodium falciparum was the only malaria parasite detected (12.0%). High local population density within a 1 km radius around houses was identified as a major independent risk factor of S. mansoni infection. A spatial cluster of high infection risk was detected around the Mbita causeway following adjustment for population density and other potential risk factors. Conclusions/Significance Population density was shown to be a major factor fuelling schistosome infection while individual socio-economic factors appeared not to affect the infection risk. The high-risk cluster around the Mbita causeway may be explained by the construction of an artificial pathway that may cause increased numbers of S. mansoni host snails through obstruction of the waterway. This construction may have, therefore, a significant negative impact on the health of the local population, especially school-aged children who frequently come in contact with lake water. PMID:25058653

  19. Schistosomiasis Prevalence and Intensity of Infection in Latin America and the Caribbean Countries, 1942-2014: A Systematic Review in the Context of a Regional Elimination Goal

    PubMed Central

    2016-01-01

    Background In 2012 the World Health Assembly adopted resolution WHA65.21 on elimination of schistosomiasis, calling for increased investment in schistosomiasis control and support for countries to initiate elimination programs. This study aims to analyze prevalence and intensity of Schistosoma mansoni infection in children in Latin America and the Caribbean countries and territories (LAC), at the second administrative level or lower. Methodology A systematic review of schistosomiasis prevalence and intensity of infection was conducted by searching at PubMed, LILACS and EMBASE. Experts on the topic were informally consulted and institutional web pages were reviewed (PAHO/WHO, Ministries of Health). Only SCH infection among children was registered because it can be a ‘proxi-indicator’ of recent transmission by the time the study is conducted. Principal Findings One hundred thirty two full-text articles met the inclusion criteria and provided 1,242 prevalence and 199 intensity of infection data points. Most of them were from Brazil (69.7%). Only Brazil published studies after 2001, showing several 'hot spots' with high prevalence. Brazil, Venezuela, Suriname and Saint Lucia need to update the epidemiological status of schistosomiasis to re-design their national programs and target the elimination of Schistosoma mansoni transmission by 2020. In Antigua and Barbuda, Dominican Republic, Guadeloupe, Martinique, Montserrat and Puerto Rico schistosomiasis transmission may be interrupted. However the compilation of an elimination dossier and follow-up surveys, per WHO recommendations, are needed to verify that status. Hence, the burden of subtle SCH chronic infection may be still present and even high in countries that may have eliminated transmission. Heterogeneity in the methodologies used for monitoring and evaluating the progress of the schistosomiasis programs was found, making cross-national and chronological comparisons difficult. Conclusions There is a need for

  20. Susceptibility and compatibility of Biomphalaria tenagophila from the Río de la Plata basin with Schistosoma mansoni from Brazil.

    PubMed

    Borda, Carlos Edgardo; Rea, María Josefa F

    2010-07-01

    Schistosomiasis has expanded to southern parts of Brazil. Between 2005-2007 the dispersion and the proliferation of Biomphalaria tenagophila was verified in the province of Corrientes near the Brazilian border. In order to study the possibility that schistosomiasis might spread into the basins of the Paraná and Uruguay Rivers, 440 B. tenagophila collected from 10 populations groups were experimentally exposed to infection with Schistosoma mansoni of the SJ2 strain. Snails from five localities were susceptible. Frandsen's index (TCP/100) shows that those snails from Mirungá (11%), Aguacerito (2%) and Curupicay (2%) were Class I and not very compatible. Meanwhile, snails from Copra (6%) and Pay-Ubre (22%), in the Paraná River basin, were Class II and poorly compatible. PMID:20721498

  1. Schistosoma mansoni-Related Hepatosplenic Morbidity in Adult Population on Kome Island, Sengerema District, Tanzania

    PubMed Central

    Kaatano, Godfrey M.; Min, Duk-Young; Siza, Julius E.; Yong, Tai-Soon; Chai, Jong-Yil; Ko, Yunsuk; Chang, Su-Young; Changalucha, John M.; Eom, Keeseon S.; Rim, Han-Jong

    2015-01-01

    Schistosomiasis is one of the important neglected tropical diseases (NTDs) in Tanzania, particularly in Lake Victoria zone. This baseline survey was a part of the main study of integrated control of schistosomiasis and soil-transmitted helminths (STHs) aimed at describing morbidity patterns due to intestinal schistosomiasis among adults living on Kome Island, Sengerema District, Tanzania. Total 388 adults from Kome Islands (about 50 people from each village) aged between 12 and 85 years, were examined by abdominal ultrasound according to the Niamey protocol. Liver image patterns (LIPs) A and B were considered normal, and C-F as distinct periportal fibrosis (PPF). The overall prevalence of PPF was 42.2%; much higher in males than in females (47.0% in male vs 34.4% in females, P=0.007). Abnormal increase of segmental branch wall thickness (SBWT) and dilated portal vein diameter (PVD) were also more common in males than in females. Hepatosplenomegaly was frequently encountered; 68.1% had left liver lobe hepatomegaly and 55.2% had splenomegaly. Schistosoma mansoni-related morbidity is quite high among adults in this community justifying the implementation of integrated control strategies through mass drug administration, improved water supply (pumped wells), and health education that had already started in the study area. PMID:26537033

  2. Therapeutic effect of mefloquine on Schistosoma mansoni in experimental infection in mice.

    PubMed

    Abou-Shady, Omaima Mohammed; Mohammed, Soheir Sayed; Attia, Samar Sayed; Yusuf, Hebat-Allah Salah; Helmy, Dina Omar

    2016-06-01

    Schistosomiasis is one of the most prevalent parasitic infections worldwide. Praziquantel is the drug of choice for treatment of schistosomiasis for its high efficacy. The present work was carried out on 160 mice to evaluate the therapeutic effect of mefloquine on experimental schistosomiasis mansoni. Mice were classified into 3 groups; group I (20 infected non-treated mice), group II included 60 infected mice which were further divided into group IIm (20 mice treated with 400 mg/kg mefloquine), group IIp (20 mice treated with 1,000 mg/kg/2 days praziquantel) and group IIpm (20 mice treated with 200 mg/kg mefloquine and 500 mg/kg praziquantel), group III included 80 non-infected mice subdivided into group IIIn (20 non-treated mice), group IIIm (20 mice treated with 400 mg/kg mefloquine), group IIIp (20 mice treated with 1,000 mg/kg/2 days praziquantel), group IIIpm (20 mice treated with 200 mg mefloquine and 500 mg praziquantel). Mefloquine significantly reduced worm burden, tissue egg load, number of liver granulomas and increased the percent of dead ova within granulomas. Combination of mefloquine and praziquantel gave better curative effects than praziquantel or mefloquine given alone. PMID:27413290

  3. Schistosoma mansoni-Related Hepatosplenic Morbidity in Adult Population on Kome Island, Sengerema District, Tanzania.

    PubMed

    Kaatano, Godfrey M; Min, Duk-Young; Siza, Julius E; Yong, Tai-Soon; Chai, Jong-Yil; Ko, Yunsuk; Chang, Su-Young; Changalucha, John M; Eom, Keeseon S; Rim, Han-Jong

    2015-10-01

    Schistosomiasis is one of the important neglected tropical diseases (NTDs) in Tanzania, particularly in Lake Victoria zone. This baseline survey was a part of the main study of integrated control of schistosomiasis and soil-transmitted helminths (STHs) aimed at describing morbidity patterns due to intestinal schistosomiasis among adults living on Kome Island, Sengerema District, Tanzania. Total 388 adults from Kome Islands (about 50 people from each village) aged between 12 and 85 years, were examined by abdominal ultrasound according to the Niamey protocol. Liver image patterns (LIPs) A and B were considered normal, and C-F as distinct periportal fibrosis (PPF). The overall prevalence of PPF was 42.2%; much higher in males than in females (47.0% in male vs 34.4% in females, P=0.007). Abnormal increase of segmental branch wall thickness (SBWT) and dilated portal vein diameter (PVD) were also more common in males than in females. Hepatosplenomegaly was frequently encountered; 68.1% had left liver lobe hepatomegaly and 55.2% had splenomegaly. Schistosoma mansoni-related morbidity is quite high among adults in this community justifying the implementation of integrated control strategies through mass drug administration, improved water supply (pumped wells), and health education that had already started in the study area. PMID:26537033

  4. New Insights into the Molecular Epidemiology and Population Genetics of Schistosoma mansoni in Ugandan Pre-school Children and Mothers

    PubMed Central

    Betson, Martha; Sousa-Figueiredo, Jose C.; Kabatereine, Narcis B.; Stothard, J. Russell

    2013-01-01

    Significant numbers of pre-school children are infected with Schistosoma mansoni in sub-Saharan Africa and are likely to play a role in parasite transmission. However, they are currently excluded from control programmes. Molecular phylogenetic studies have provided insights into the evolutionary origins and transmission dynamics of S. mansoni, but there has been no research into schistosome molecular epidemiology in pre-school children. Here, we investigated the genetic diversity and population structure of S. mansoni in pre-school children and mothers living in lakeshore communities in Uganda and monitored for changes over time after praziquantel treatment. Parasites were sampled from children (<6 years) and mothers enrolled in the longitudinal Schistosomiasis Mothers and Infants Study at baseline and at 6-, 12- and 18-month follow-up surveys. 1347 parasites from 35 mothers and 45 children were genotyped by direct sequencing of the cytochrome c oxidase (cox1) gene. The cox1 region was highly diverse with over 230 unique sequences identified. Parasite populations were genetically differentiated between lakes and non-synonymous mutations were more diverse at Lake Victoria than Lake Albert. Surprisingly, parasite populations sampled from children showed a similar genetic diversity to those sampled from mothers, pointing towards a non-linear relationship between duration of exposure and accumulation of parasite diversity. The genetic diversity six months after praziquantel treatment was similar to pre-treatment diversity. Our results confirm the substantial genetic diversity of S. mansoni in East Africa and provide significant insights into transmission dynamics within young children and mothers, important information for schistosomiasis control programmes. PMID:24349589

  5. Schistosoma mansoni Infection Impairs Antimalaria Treatment and Immune Responses of Rhesus Macaques Infected with Mosquito-Borne Plasmodium coatneyi

    PubMed Central

    Semenya, Amma A.; Sullivan, JoAnn S.; Barnwell, John W.

    2012-01-01

    Malaria and schistosomiasis are the world's two most important parasitic infections in terms of distribution, morbidity, and mortality. In areas where Plasmodium and Schistosoma species are both endemic, coinfections are commonplace. Mouse models demonstrate that schistosomiasis worsens a malaria infection; however, just as mice and humans differ greatly, the murine-infecting Plasmodium species differ as much from those that infect humans. Research into human coinfections (Schistosoma haematobium-Plasmodium falciparum versus Schistosoma mansoni-P. falciparum) has produced conflicting results. The rhesus macaque model provides a helpful tool for understanding the role of S. mansoni on malaria parasitemia and antimalarial immune responses using Plasmodium coatneyi, a malaria species that closely resembles P. falciparum infection in humans. Eight rhesus macaques were exposed to S. mansoni cercariae. Eight weeks later, these animals plus 8 additional macaques were exposed to malaria either through bites of infected mosquitos or intravenous inoculation. When malaria infection was initiated from mosquito bites, coinfected animals displayed increased malaria parasitemia, decreased hematocrit levels, and suppressed malaria-specific antibody responses compared to those of malaria infection alone. However, macaques infected by intravenous inoculation with erythrocytic-stage parasites did not display these same differences in parasitemia, hematocrit, or antibody responses between the two groups. Use of the macaque model provides information that begins to unravel differences in pathological and immunological outcomes observed between humans with P. falciparum that are coinfected with S. mansoni or S. haematobium. Our results suggest that migration of malaria parasites through livers harboring schistosome eggs may alter host immune responses and infection outcomes. PMID:22907811

  6. The role of the immunological background of mice in the genetic variability of Schistosoma mansoni as detected by random amplification of polymorphic DNA.

    PubMed

    Cossa-Moiane, I L; Mendes, T; Ferreira, T M; Mauricio, I; Calado, M; Afonso, A; Belo, S

    2015-11-01

    Schistosomiasis is a parasitic disease caused by flatworms of the genus Schistosoma. Among the Schistosoma species known to infect humans, S. mansoni is the most frequent cause of intestinal schistosomiasis in sub-Saharan Africa and South America: the World Health Organization estimates that about 200,000 deaths per year result from schistosomiasis in sub-Saharan Africa alone. The Schistosoma life cycle requires two different hosts: a snail as intermediate host and a mammal as definitive host. People become infected when they come into contact with water contaminated with free-living larvae (e.g. when swimming, fishing, washing). Although S. mansoni has mechanisms for escaping the host immune system, only a minority of infecting larvae develop into adults, suggesting that strain selection occurs at the host level. To test this hypothesis, we compared the Belo Horizonte (BH) strain of S. mansoni recovered from definitive hosts with different immunological backgrounds using random amplification of polymorphic DNA-polymerase chain reaction (RAPD-PCR). Schistosoma mansoni DNA profiles of worms obtained from wild-type (CD1 and C57BL/6J) and mutant (Jα18- / - and TGFβRIIdn) mice were analysed. Four primers produced polymorphic profiles, which can therefore potentially be used as reference biomarkers. All male worms were genetically distinct from females isolated from the same host, with female worms showing more specific fragments than males. Of the four host-derived schistosome populations, female and male adults recovered from TGFβRIIdn mice showed RAPD-PCR profiles that were most similar to each other. Altogether, these data indicate that host immunological backgrounds can influence the genetic diversity of parasite populations. PMID:24991919

  7. Molecular characterization of serine protease inhibitor isoform 3, SmSPI, from Schistosoma mansoni.

    PubMed

    Pakchotanon, Pattarakul; Molee, Patamaporn; Nuamtanong, Supaporn; Limpanont, Yanin; Chusongsang, Phiraphol; Limsomboon, Jareemate; Chusongsang, Yupa; Maneewatchararangsri, Santi; Chaisri, Urai; Adisakwattana, Poom

    2016-08-01

    Serine protease inhibitors, known as serpins, are pleiotropic regulators of endogenous and exogenous proteases, and molecule transporters. They have been documented in animals, plants, fungi, bacteria, and viruses; here, we characterize a serpin from the trematode platyhelminth Schistosoma mansoni. At least eight serpins have been found in the genome of S. mansoni, but only two have characterized molecular properties and functions. Here, the function of S. mansoni serpin isoform 3 (SmSPI) was analyzed, using both computational and molecular biological approaches. Phylogenetic analysis showed that SmSPI was closely related to Schistosoma haematobium serpin and Schistosoma japonicum serpin B10. Structure determined in silico confirmed that SmSPI belonged to the serpin superfamily, containing nine α-helices, three β-sheets, and a reactive central loop. SmSPI was highly expressed in schistosomules, predominantly in the head gland, and in adult male and female with intensive accumulation on the spines, which suggests that it may have a role in facilitating intradermal and intravenous survival. Recombinant SmSPI was overexpressed in Escherichia coli; the recombinant protein was of the same size (46 kDa) as the native protein. Immunological analysis suggested that mice infected with S. mansoni responded to rSmSPI at 8 weeks postinfection (wpi) but not earlier. The inhibitory activity of rSmSPI was specific to chymotrypsin but not trypsin, neutrophil elastase, and porcine pancreatic elastase. Elucidating the biological and physiological functions of SmSPI as well as other serpins will lead to further understanding of host-parasite interaction machinery that may provide novel strategies to prevent and control schistosomiasis in the future. PMID:27083187

  8. Kinetics of interleukin-6 production after experimental infection of mice with Schistosoma mansoni.

    PubMed Central

    Khalil, R M; Hültner, L; Mailhammer, R; Luz, A; Moeller, J; Mohamed, A A; Omran, S; Dörmer, P

    1996-01-01

    It has been reported that interleukin-6 (IL-6) is expressed in cells of acute inflammatory granulomas experimentally induced in mice by eggs of Schistosoma mansoni. Moreover, in vitro IL-6 was shown to enhance the cytotoxic activity of human platelets against larvae of S. mansoni. To elucidate further a proposed biological significance of this cytokine during the course of schistosomiasis, we studied the kinetics of IL-6 production and concomitantly performed a histopathological analysis of the livers in BALB/c mice subcutaneously infected with S. mansoni cercariae. Over a period of 24 weeks postinfection (p.i.) we monitored serum IL-6 levels, IL-6 production in vitro by pokeweed mitogen (PWM)-stimulated spleen cells as well as IL-6 mRNA expression in livers, spleens and kidneys. We found significantly elevated IL-6 levels in PWM-stimulated spleen cell-conditioned media (SCM) at weeks 6 to 20 p.i., peaking at week 10 p.i. In contrast, serum IL-6 concentrations started to rise not before week 8 but remained significantly elevated above normal control values until week 24 p.i. The time pattern of enhanced IL-6 mRNA expression detected in spleens and livers, but not in kidneys, as well as the rises of IL-6 in SCM and with a delay of 2 weeks in serum samples correlated with the onset of the egg-induced inflammatory reactions as well as the incidence and the number of the granulomas observed histopathologically in the livers of infected mice. Our data emphasize both a local and a systemic role of IL-6 in the host immune response following infection of mice with S. mansoni. Images Figure 3 PMID:8943723

  9. Epidemiology of Schistosomiasis among Villagers of the New Halfa Agricultural Scheme, Sudan

    PubMed Central

    AFIFI, Azzam; AHMED, Abdel-Aziz A.; SULIEMAN, Yassir; PENGSAKUL, Theerakamol

    2016-01-01

    Background: Schistosomiasis is one of the major communicable diseases of public health and socioeconomic importance in developing countries. This study assessed the situation of schistosomiasis among villagers of the New Halfa Agricultural Scheme, Sudan. Methods: An epidemiological survey was carried out in three randomly selected residential sites: Village 19, Village 26 and Talat shagrat Camp, from October to December 2013. Feces and urine samples were collected from 2433 individual (1195 male and 1238 female) and examined for schistosomiasis infection. The prevalence and intensity of infection were calculated according to study sites and participants’ sex and age-group. Results: There was no infection with Schistosoma haematobium among the examined individuals, while the overall prevalence of S. mansoni infection was 27.4% and the mean intensity among those infected was 261.1 eggs per gram (epg). A high prevalence and intensity of infection was found among the residents of Talat shagrat Camp, followed by the other two villages. The prevalence of infection among males was 41.4%, and among females was 13.9%. On the other hand, the intensity of infection among females was 293.4 epg and among males 187.6 epg. A high prevalence of infection was found in the age-groups 11–20 years and > 50 years. High intensity of infection was present in the age-groups 31–40 years and > 50 years. Conclusion: The finding of the study shows the need for an integrated control program against schistosomiasis. Mass treatment, provision of adequate clean-water supply and combating the intermediate snail host are suggested. PMID:27095977

  10. Silymarin Reduces Profibrogenic Cytokines and Reverses Hepatic Fibrosis in Chronic Murine Schistosomiasis

    PubMed Central

    Mata-Santos, Hílton Antônio; Dutra, Fabianno Ferreira; Rocha, Carolina Carneiro; Lino, Fabiana Gonçalves; Xavier, Fabiola Ramos; Chinalia, Leandro Andrade; Hossy, Bryan Hudson; Castelo-Branco, Morgana Teixeira Lima; Teodoro, Anderson Junger; Paiva, Claudia N.

    2014-01-01

    In chronic schistosomiasis, hepatic fibrosis is linked to the portal hypertension that causes morbidity in Schistosoma mansoni infection. Silymarin (SIL) is a hepatoprotective and antioxidant medicament largely prescribed against liver diseases that has previously been shown to prevent fibrosis during acute murine schistosomiasis. Here we employed silymarin to try to reverse established hepatic fibrosis in chronic schistosomiasis. Silymarin or vehicle was administered to BALB/c mice every 48 h, starting on the 40th (80 days of treatment), 70th (50 days), or 110th (10 days) day postinfection (dpi). All mice were sacrificed and analyzed at 120 dpi. Treatment with silymarin reduced liver weight and granuloma sizes, reduced the increase in alanine aminotransferase and aspartate aminotransferase levels, and reduced the established hepatic fibrosis (assessed by hydroxyproline contents and picrosirius staining). Treatment with silymarin also reduced the levels of interleukin-13 (IL-13) in serum and increased the gamma interferon (IFN-γ)/IL-13 ratio. There was a linear correlation between IL-13 levels in serum and hydroxyproline hepatic content in both infected untreated and SIL-treated mice, with decreased IL-13 levels corresponding to decreased hydroxyproline hepatic contents. Treatment with either SIL or N-acetylcysteine reduced both proliferation of fibroblast cell lines and basal/IL-13-induced production of collagen I, indicating that besides inhibiting IL-13 production during infection, SIL antioxidant properties most likely contribute to inhibition of collagen production downstream of IL-13. These results show that silymarin interferes with fibrogenic cytokines, reduces established fibrosis, and inhibits downstream effects of IL-13 on fibrogenesis, indicating the drug as a safe and cheap treatment to liver fibrotic disease in schistosomiasis. PMID:24449779

  11. Genital Schistosomiasis in European Women

    PubMed Central

    Catteau, Xavier; Fakhri, Anass; Albert, Valérie; Doukoure, Brahima; Noël, Jean-Christophe

    2011-01-01

    Female genital schistosomiasis (FGS) is an isolated chronic form of schistosomiasis. Although most infections occur in residents of endemic areas, it has been clearly documented that brief freshwater exposure is sufficient to establish infection; thus, travellers may also be infected. The clinical manifestations of FGS are nonspecific, and lesions may mimic any neoplastic or infectious process in the female genital tract. It is important to take a careful history and physical examination, making sure to consider travel history in endemic areas. The diagnosis is confirmed by microscopy with egg identification or by serology. The standard of care for treatment is a single dose of oral praziquantel which avoids complications and substantial morbidity. Herein, we report a rare and original case of FGS in a European woman. PMID:21776398

  12. Schistosomiasis-associated pulmonary hypertension

    PubMed Central

    Mocumbi, Ana Olga H.; Kim, Nick H.; Mandel, Jess

    2014-01-01

    Abstract Schistosomiasis, a parasite-borne disease, is highly prevalent in Africa and Asia; it is estimated that close to 20 million people worldwide have a severe form of the disease. The chronic form can affect the gastrointestinal system and lead to hepatosplenic disease, and it may cause cardiopulmonary complications, including pulmonary hypertension. The exact pathogenesis of schistosomiasis-associated pulmonary hypertension (Sch-PH) remains unclear, although several mechanisms, including parasitic arterial embolization, pulmonary arteriopathy, and portopulmonary hypertension–like pathophysiology, have been suggested. The immunopathology of the disease is also unclear, although there are similarities with the immunology of idiopathic pulmonary arterial hypertension (PAH). Finally, the treatment of Sch-PH has not been well studied. There is some evidence on treating the underlying infection, with unclear effect on Sch-PH, and advanced PAH therapies are now being suggested, but more studies are needed to confirm their efficacy. PMID:25610596

  13. Schistosomiasis in pre-school-age children and their mothers in Chikhwawa district, Malawi with notes on characterization of schistosomes and snails

    PubMed Central

    2014-01-01

    Background To complement ongoing schistosomiasis control within national control programmes (NCPs) that administer praziquantel to school-age children, assessing the risk and extent of schistosomiasis in pre-school-age children (PSAC) is important. Methods In June 2012, schistosomiasis in Chikhwawa district, Malawi was assessed across 12 villages examining pre-school-age children (PSAC) and their mothers by serological and parasitological diagnosis, as supplemented with urine-antigen and questionnaire-interview methods. Urinary tract morbidity was inferred by haematuria and albuminuria assays. Results In total, 49.5% (CI95 42.6-56.4) of 208 PSAC and 94.5% (CI95 90.9-98.1) of 165 mothers were seropositive for schistosomiasis, in 2 villages seroprevalence exceeded 75% in PSAC. Egg-patent urogenital and intestinal schistosomiasis was observed; 17.7% (CI95 12.4-23.2) of PSAC and 45.1% (CI95 37.4-52.8) of mothers having active schistosomiasis by parasitological and urine-antigen testing combined. PSAC often had extensive daily water contact and many (~25%) had haematuria and albuminuria. As eggs with an atypical morphology of Schistosoma haematobium were observed, a general selection of schistosome eggs was characterized by DNA barcoding, finding Group I S. haematobium and Group IV and V S. mansoni. Malacological surveys encountered several populations of Bulinus globosus but failed to find Biomphalaria. Conclusions Both PSAC and their mothers appear to be at significant risk of schistosomiasis and should be considered for treatment within the NCP of Malawi. PMID:24690282

  14. Schistosomiasis in Travelers and Expatriates.

    PubMed

    Jelinek; Nothdurft; Löscher

    1996-09-01

    Background: Several outbreaks of schistosomiasis among travelers, expatriates, and military serviceman have been reported in recent years. Methods: The travel histories and anamnestic and clinical features of 62 patients with schistosomiasis, who presented to a German outpatient clinic specializing in infectious and tropical diseases, were investigated to identify risk factors that could lead to infection in travelers and expatriates. Results: All patients remembered incidents that led to a likely exposure to cercariae of Schistosoma sp. Fifty nine patients (95%) acquired infection in Africa, two (3%) in South America, and one each (2% each) in Iraq and the Mekong River, respectively. The highest proportion of infection (45%) was imported from West Africa. Patients returning from West Africa reported either contact with tributaries of the Niger (including freshwater pools in the Dogon country, Mali) or with waters of the Volta River, notably Lake Volta and/or its delta. Six patients (10%) acquired infection in little-visited areas such as Central Africa and the Congo Basin. East Africa (especially Lake Victoria) and Lake Malawi contributed 14 patients (22%) to our study group; a further nine patients (14%) became infected after contact with waters of the Zambezi River. Conclusions: The most sensitive method for detection of possible infection with schistosomiasis appeared to be a combination of thorough travel history and serologic testing by indirect hemagglutination (IHA), immunofluorescence antibody test (IFAT), and enzyme-linked immunosorbent assay (ELISA). Most infections were acquired by travelers on lengthy and adventurous journeys or by expatriates venturing outside their normal areas of activity. Most patients knew that they had traveled in an area endemic for schistosomiasis, but were uninformed about behavioral risks they had taken in specific settings. PMID:9815445

  15. Hepatocellular Carcinoma Related to Schistosoma mansoni Infection: Case Series and Literature Review

    PubMed Central

    Toda, Karla Sawada; Kikuchi, Luciana; Chagas, Aline Lopes; Tanigawa, Ryan Yukimatsu; Paranaguá-Vezozzo, Denise Cerqueira; Pfiffer, Túlio; Rocha, Manoel de Souza; Alves, Venâncio Avancini Ferreira; Carrilho, Flair José

    2015-01-01

    Background and Aims: Schistosomiasis is a major chronic disease of humans in endemic regions, and infected individuals may develop a spectrum of pathology, including hepatic fibrosis, hepatosplenomegaly, and portal hypertension. Hepatocellular carcinoma (HCC) is considered the fifth most common cancer in the world, and there is limited and controversial evidence suggesting that Schistosoma mansoni infection may be a possible risk factor for HCC. The aim of this study was to report a case series of patients with HCC and S. mansoni infection and to conduct a literature review on the topic. Methods: From January 2002 to January 2015, an institutional database was screened retrospectively to identify patients with HCC and S. mansoni infection at a single center in the Department of Gastroenterology of University of São Paulo School of Medicine and Hospital das Clínicas, Brazil. Results: Seven cases were included. The mean age of patients was 62.1±10.3 years; six (85.7%) were male and one (14.3%) was female. All cases had positive epidemiology, coming from endemic areas of S. mansoni infection in Brazil, and four (57.1%) had previous complications (upper gastrointestinal bleeding) related to portal hypertension or surgery intervention (splenectomy) performed more than 10 years before the HCC diagnosis. Nontumoral portal vein thrombosis was identified in five (71.4%) patients. All patients had negative serology for HCV, and four (57.1%) had positivity of HBVcore antibodies without evidence of viral replication. According to BCLC staging, one (14.3%) patient was BCLC A and received TACE instead of RFA because HCC size was >30 mm; three (42.8%) BCLC B patients received sorafenib instead of local regional treatment due to the presence of nontumoral TPV. During follow-up, all patients developed tumoral progression and died. Conclusions: It remains unclear if S. mansoni infection alone has carcinogenic potential. The available literature indicates that S. Mansoni, in the

  16. Sources and Distribution of Surface Water Fecal Contamination and Prevalence of Schistosomiasis in a Brazilian Village

    PubMed Central

    Ponce-Terashima, Rafael; Koskey, Amber M.; Reis, Mitermayer G.; McLellan, Sandra L.; Blanton, Ronald E.

    2014-01-01

    Background The relationship between poor sanitation and the parasitic infection schistosomiasis is well-known, but still rarely investigated directly and quantitatively. In a Brazilian village we correlated the spatial concentration of human fecal contamination of its main river and the prevalence of schistosomiasis. Methods We validated three bacterial markers of contamination in this population by high throughput sequencing of the 16S rRNA gene and qPCR of feces from local residents. The qPCR of genetic markers from the 16S rRNA gene of Bacteroides-Prevotella group, Bacteroides HF8 cluster, and Lachnospiraceae Lachno2 cluster as well as sequencing was performed on georeferenced samples of river water. Ninety-six percent of residents were examined for schistosomiasis. Findings Sequence of 16S rRNA DNA from stool samples validated the relative human specificity of the HF8 and Lachno 2 fecal indicators compared to animals. The concentration of fecal contamination increased markedly along the river as it passed an increasing proportion of the population on its way downstream as did the sequence reads from bacterial families associated with human feces. Lachnospiraceae provided the most robust signal of human fecal contamination. The prevalence of schistosomiasis likewise increased downstream. Using a linear regression model, a significant correlation was demonstrated between the prevalence of S. mansoni infection and local concentration of human fecal contamination based on the Lachnospiraceae Lachno2 cluster (r2 0.53) as compared to the correlation with the general fecal marker E. coli (r2 0.28). Interpretation Fecal contamination in rivers has a downstream cumulative effect. The transmission of schistosomiasis correlates with very local factors probably resulting from the distribution of human fecal contamination, the limited movement of snails, and the frequency of water contact near the home. In endemic regions, the combined use of human associated bacterial

  17. Sustaining the Control of Schistosoma mansoni in Western Côte d'Ivoire: Baseline Findings Before the Implementation of a Randomized Trial.

    PubMed

    Assaré, Rufin K; Hürlimann, Eveline; Ouattara, Mamadou; N'Guessan, Nicaise A; Tian-Bi, Yves-Nathan T; Yapi, Ahoua; Yao, Patrick K; Coulibaly, Jean T; Knopp, Stefanie; N'Goran, Eliézer K; Utzinger, Jürg

    2016-02-01

    We report baseline findings before the implementation of a 4-year intervention trial designed to assess the impact of three different school-based treatment schedules with praziquantel to sustain the control of intestinal schistosomiasis. The baseline survey was conducted in 75 schools of western Côte d'Ivoire previously identified with moderate Schistosoma mansoni endemicity (prevalence: 10-24% in children aged 13-14 years). Three stool samples collected over consecutive days were subjected to duplicate Kato-Katz thick smears each. A questionnaire was administered to collect village-specific information that is relevant for schistosomiasis transmission. Overall, 4,953 first graders (aged 5-8 years) and 7,011 school children (aged 9-12 years) had complete parasitologic data. The overall prevalence of S. mansoni was 5.4% among first graders and 22.1% in 9- to 12-year-old children. Open defecation was practiced in all villages. The current baseline findings will be important to better understand the dynamics of S. mansoni prevalence and intensity over the course of this trial that might be governed by village characteristics and specific treatment interventions. PMID:26598571

  18. Predictive Value of School-Aged Children's Schistosomiasis Prevalence and Egg Intensity for Other Age Groups in Western Kenya.

    PubMed

    Mwinzi, Pauline N M; Muchiri, Geoffrey; Wiegand, Ryan E; Omedo, Martin; Abudho, Bernard; Karanja, Diana M S; Montgomery, Susan P; Secor, W Evan

    2015-12-01

    World Health Organization recommendations for the timing and target population for mass drug administration (MDA) for schistosomiasis are based on the prevalence of infection in school children within a given community. In a large study comparing MDA approaches for Schistosoma mansoni control, we evaluated whether prevalence of infection and egg burdens in 9- to 12-year-old students reflected infection levels in young children and adults in the same community. Cross-sectional surveys of preadolescents (9-12 years old) were compared with those of first year students (5-8 years old) in 225 villages and adults (20-55 years old) in 150 villages along the Kenyan shores of Lake Victoria. Village schistosomiasis prevalence and intensity levels in preadolescents strongly correlated (P < 0.0001) with prevalence and infection intensity for other age groups in the community. Our findings suggest that S. mansoni prevalence and intensity among 9- to 12-year-olds are valid for community sampling purposes in mapping for MDAs. PMID:26416108

  19. Circulating antigen tests and urine reagent strips for diagnosis of active schistosomiasis in endemic areas

    PubMed Central

    Ochodo, Eleanor A; Gopalakrishna, Gowri; Spek, Bea; Reitsma, Johannes B; van Lieshout, Lisette; Polman, Katja; Lamberton, Poppy; Bossuyt, Patrick Mm; Leeflang, Mariska Mg

    2015-01-01

    Background Point-of-care (POC) tests for diagnosing schistosomiasis include tests based on circulating antigen detection and urine reagent strip tests. If they had sufficient diagnostic accuracy they could replace conventional microscopy as they provide a quicker answer and are easier to use. Objectives To summarise the diagnostic accuracy of: a) urine reagent strip tests in detecting active Schistosoma haematobium infection, with microscopy as the reference standard; and b) circulating antigen tests for detecting active Schistosoma infection in geographical regions endemic for Schistosoma mansoni or S. haematobium or both, with microscopy as the reference standard. Search methods We searched the electronic databases MEDLINE, EMBASE, BIOSIS, MEDION, and Health Technology Assessment (HTA) without language restriction up to 30 June 2014. Selection criteria We included studies that used microscopy as the reference standard: for S. haematobium, microscopy of urine prepared by filtration, centrifugation, or sedimentation methods; and for S. mansoni, microscopy of stool by Kato-Katz thick smear. We included studies on participants residing in endemic areas only. Data collection and analysis Two review authors independently extracted data, assessed quality of the data using QUADAS-2, and performed meta-analysis where appropriate. Using the variability of test thresholds, we used the hierarchical summary receiver operating characteristic (HSROC) model for all eligible tests (except the circulating cathodic antigen (CCA) POC for S. mansoni, where the bivariate random-effects model was more appropriate). We investigated heterogeneity, and carried out indirect comparisons where data were sufficient. Results for sensitivity and specificity are presented as percentages with 95% confidence intervals (CI). Main results We included 90 studies; 88 from field settings in Africa. The median S. haematobium infection prevalence was 41% (range 1% to 89%) and 36% for S. mansoni (range 8

  20. Schistosoma mansoni induces in the Kenyan baboon a novel intestinal pathology that is manifestly modulated by an irradiated cercarial vaccine.

    PubMed

    Farah, I O; Nyindo, M

    1996-08-01

    Light and scanning electron microscopic study of intestines of 5 baboons (Papio anubis) in a state of acute schistosomiasis mansoni after exposure to 800 cercariae was made. In addition to overt granulomatous inflammation in the mucosa of the colon and ileum, more subtle microscopic lesions consisting of smooth muscle hypertrophy and villous atrophy were present. The intensity and distribution of these lesions were less marked in 5 baboons previously vaccinated with 40,000 30-krad-attenuated cercariae and presenting a 39% mean protection level measured as a percent reduction in adult worms recovered from mesenteric vasculature at perfusion. No similar lesions were observed in 2 normal uninfected and nonvaccinated baboons. These results are comparable to what has been reported in mice infected by Schistosoma mansoni. The data indicate that villous atrophy, hypertrophy of muscularis mucosa, nd goblet cell hyperplasia are important pathological changes to be included in the evaluation of the efficacy of schistosomiasis vaccines in the baboon model, together with the routine adult worm recovery from mesenteric blood vessels and the overt liver and bowel pathology. PMID:8691367

  1. Cross-species protection: Schistosoma mansoni Sm-p80 vaccine confers protection against Schistosoma haematobium in hamsters and baboons.

    PubMed

    Karmakar, Souvik; Zhang, Weidong; Ahmad, Gul; Torben, Workineh; Alam, Mayeen U; Le, Loc; Damian, Raymond T; Wolf, Roman F; White, Gary L; Carey, David W; Carter, Darrick; Reed, Steven G; Siddiqui, Afzal A

    2014-03-01

    The ability of the Schistosoma mansoni antigen, Sm-p80, to provide cross-species protection against Schistosoma haematobium challenge was evaluated in hamster and baboon models. Pronounced reduction in worm burden (48%) and in tissue egg load (64%) was observed in hamsters vaccinated with recombinant Sm-p80 admixed with glucopyranosyl lipid adjuvant-stable emulsion (GLA-SE). Similarly, in baboons, the Sm-p80/GLA-SE vaccine produced a 25% reduction in S. haematobium adult worms and decreased the egg load in the urinary bladder by 64%. A 40% and 53% reduction in fecal and urine egg output, respectively, was observed in vaccinated baboons. A balanced pro-inflammatory (Th17 and Th1) and Th2 type of response was generated after vaccination and appears indicative of augmented prophylactic efficacy. These data on cross-species protection coupled with the prophylactic, therapeutic and antifecundity efficacy against the homologous parasite, S. mansoni, reinforces Sm-p80 as a promising vaccine candidate. It is currently being prepared for GMP-compliant manufacture and for further pre-clinical development leading to human clinical trials. These results solidify the expectation that the Sm-p80 vaccine will provide relief for both the intestinal and the urinary schistosomiasis and thus will be greatly beneficial in reducing the overall burden of schistosomiasis. PMID:24397898

  2. A Huge Thrombosed Pulmonary Artery Aneurysm without Pulmonary Hypertension in a Patient with Hepatosplenic Schistosomiasis

    PubMed Central

    Abo-Salem, Elsayed S.; Ramadan, Mahmoud M.

    2015-01-01

    Patient: Male, 55 Final Diagnosis: Thrombosed pulmonary artery aneurysm Symptoms: Cough productive • fever • shortness of breath Medication: — Clinical Procedure: Pericardiocentesis Specialty: Cardiology Objective: Rare disease Background: We herein report a case of huge pulmonary artery aneurysm in a 55-year-old male farmer from the Nile delta (Lower-Egypt), mostly due to infestation with Schistosoma mansoni, which is the parasite causing hepatosplenic schistosomiasis. Case Report: This male patient was admitted with a month-long history of progressive shortness of breath, 2-month history of fever, and a cough with mucoid sputum for 10 days. On examination, he had normal temperature and blood pressure, but he had tachypnea, tachycardia, and congested neck veins. Electrocardiography showed multifocal atrial tachycardia and right bundle branch block. Conclusions: The present case is unique in that it shows the presence of a huge pulmonary artery aneurysm despite the absence of pulmonary hypertension. PMID:25746428

  3. Schistosomiasis in school-age children in Burkina Faso after a decade of preventive chemotherapy

    PubMed Central

    Ouedraogo, Hamado; Drabo, François; Zongo, Dramane; Bagayan, Mohamed; Bamba, Issouf; Pima, Tiba; Yago-Wienne, Fanny; Toubali, Emily

    2016-01-01

    Abstract Objective To assess the impact of a decade of biennial mass administration of praziquantel on schistosomiasis in school-age children in Burkina Faso. Methods In 2013, in a national assessment based on 22 sentinel sites, 3514 school children aged 7–11 years were checked for Schistosoma haematobium and Schistosoma mansoni infection by the examination of urine and stool samples, respectively. We analysed the observed prevalence and intensity of infections and compared these with the relevant results of earlier surveys in Burkina Faso. Findings S. haematobium was detected in 287/3514 school children (adjusted prevalence: 8.76%, range across sentinel sites: 0.0–56.3%; median: 2.5%). The prevalence of S. haematobium infection was higher in the children from the Centre-Est, Est and Sahel regions than in those from Burkina Faso’s other eight regions with sentinel sites (P < 0.001). The adjusted arithmetic mean intensity of S. haematobium infection, among all children, was 6.0 eggs per 10 ml urine. Less than 1% of the children in six regions had heavy S. haematobium infections – i.e. at least 50 eggs per 10 ml urine – but such infections were detected in 8.75% (28/320) and 11.56% (37/320) of the children from the Centre-Est and Sahel regions, respectively. Schistosoma mansoni was only detected in two regions and 43 children – i.e. 1 (0.31%) of the 320 from Centre-Sud and 42 (8.75%) of the 480 from Hauts Bassins. Conclusion By mass use of preventive chemotherapy, Burkina Faso may have eliminated schistosomiasis as a public health problem in eight regions and controlled schistosome-related morbidity in another three regions. PMID:26769995

  4. Garlic attenuates histological and histochemical alterations in livers of Schistosoma mansoni infected mice.

    PubMed

    Mahmoud, Y I; Riad, N H; Taha, H

    2016-08-01

    Interest in screening for new anti-schistosomal agents is growing because of increased concerns about resistance to and safety of praziquantel. We investigated the anti-schistosomal action of prophylactic and therapeutic doses of garlic on the histological and histochemical alterations caused by Schistosoma mansoni infection. Livers of infected mice were characterized by granulomas, periportal inflammation and fibrosis, hepatocyte vacuolation, fatty degeneration and necrosis, and hypertrophy and pigmentation of Kupffer cells. Significant depletion of carbohydrates and increased lipid vacuoles also were observed. All garlic regimens caused suppression of granuloma formation and amelioration of histological and histochemical changes; the continuous treatment protocol produced the best results. Garlic appears to be a safe and economical anti-schistosomal adjuvant for attenuating the pathogenicity of schistosomiasis. PMID:27045197

  5. Do intestinal parasites interfere with the seroepidemiologic surveillance of Schistosoma mansoni infection?

    PubMed Central

    Alarcón de Noya, B.; Colmenares, C.; Losada, S.; Fermin, Z.; Masroua, G.; Ruiz, L.; Soto, L.; Noya, O.

    1996-01-01

    In view of the known cross-reactivity of sera from patients with intestinal parasites to some Schistosoma mansoni antigens, field work was conducted in an area of Venezuela non-endemic for schistosomiasis using the routine immunoenzymatic assay (ELISA) with soluble egg antigen (SEA). False positive reactions represented 15.3% of the total population as determined by SEA-ELISA. SEA-immunoblotting of the false positive sera indicated that protein fractions of 91 and 80 kDa appear to be responsible for cross-reactivity. Sera from hookworm infected individuals produced a higher frequency and intensity of cross-reaction than other sera. SEA-fractions of 105, 54, 46, 42, 32, 25 and 15 kDa were the most specific. Images Fig. 2 PMID:8666077

  6. Determination and control of schistosomiasis.

    PubMed

    Barbosa, F S

    1995-01-01

    The subject of this conference reflects the scientific community's interest in seeking to understand the complex causal web whose various social, economic, and biological components interact in the production and reproduction of schistosomiasis and its control in relation to community participation. From the onset, the author stresses the impossibility of dealing separately with community participation, as if social components were just one more "weapon" in the arsenal for schistosomiasis control. This study begins with a brief historical review of the 71 years of control activities with this endemic disease, stressing the enormous efforts and huge expenditures in this field vis-à-vis the limited results, despite the extraordinary technological development of specific, classical control inputs such as new treatment drugs and molluscicides. The article then discusses the various strategies used in control programs, emphasizing ideological consistencies and contradictions. Interactions at the macro and micro levels are discussed, as are the determinants and risk factors involved in producing the disease's endemicity. Unequal occupation of space leaves the segregated portion of the population exposed to extremely favorable conditions for transmission of the disease. This raises the issue of how to control an endemic disease which is so closely linked to the way of life imposed on the population. The study challenges the classical control model and suggests an alternative model now undergoing medium-term investigation in the States of Espirito Santo, and Pernambuco, Brazil. The author concludes that we do not need new strategies, but a new control model, contrary to the prevailing classical model in both concept and practice. From the conceptual point of view, the new model mentioned above is different from others in that schistosomiasis control is seen from a social perspective stressing the population's accumulated knowledge in addition to the building of shared

  7. Integrated community-directed intervention for schistosomiasis and soil transmitted helminths in western Kenya – a pilot study

    PubMed Central

    2012-01-01

    Background Schistosome and soil-transmitted helminth (STH) infections are recognized as major global public health problems, causing severe and subtle morbidity, including significant educational and nutritional effects in children. Although effective and safe drugs are available, ensuring access to these drugs by all those at risk of schistosomiasis and STHs is still a challenge. Community-directed intervention (CDI) has been used successfully for mass distribution of drugs for other diseases such as onchocerciasis and lymphatic filariasis. A national control programme is yet to be instituted in Kenya and evidence for cost-effective strategies for reaching most affected communities is needed. This study evaluated the effectiveness and feasibility of the CDI strategy in the control of schistosomiasis and STHs, in East Uyoma location, Rarieda district, a community of western Kenya that is highly endemic for both infections. Results Pre-treatment prevalence of S. mansoni averaged 17.4% (range 5-43%) in the entire location. Treatment coverage in different villages ranged from 54.19 to 96.6% by community drug distributor (CDD) records. Assessment from a household survey showed coverage of 52.3 -91.9% while the proportion of homesteads (home compounds) covered ranged from 54.9-98.5%. Six months after one round of drug distribution, the prevalence levels of S. mansoni, hookworm and Trichuris trichura infections were reduced by 33.2%, 69.4% and 42.6% respectively. Conclusions This study shows that CDI is an accepted and effective strategy in the mass treatment of schistosomiasis and STH infections in resource constrained communities in Kenya and may be useful in similar communities elsewhere. A controlled trial comparing CDI and school based mass drug administration to demonstarte their relative advantages is ongoing. PMID:22937890

  8. LOW PREVALENCE OF INTESTINAL SCHISTOSOMIASIS AMONG FISHERFOLK LIVING ALONG THE RIVER NILE IN NORTH-WESTERN UGANDA: A BIOSOCIAL INVESTIGATION.

    PubMed

    Pearson, Georgina

    2016-09-01

    Mass drug administration has been less successful as a technique for controlling intestinal schistosomiasis (S. mansoni) than anticipated. In Uganda, the mass distribution of praziquantel has been provided to populations at risk of infection since the early 2000s, but prevalence mostly remains high. This is the case, for example, at locations in north-western and south-eastern Uganda. However, there is a remarkable exception. Among Madi fishing populations and their immediate neighbours, living close to the border with South Sudan, the rate of infection has dropped dramatically. A parasitological survey carried out at twelve fishing sites in 2013 identified only three cases of S. mansoni among 383 adults tested. This article asks: why is the prevalence of S. mansoni so low among fisherfolk in northern Uganda? Taking a biosocial approach, it suggests that the mass distribution of drugs, free of charge, has had an impact. However, the low prevalence of infection cannot be attributed to this alone. Other important factors may also have contributed to the decline in infection. These include changing fishing livelihoods, local attitudes to public health interventions, access to water and sanitation facilities, hygiene practices and the use of anti-malarial treatments. Above all, the article highlights the importance of investigating both social and biological dimensions of infection simultaneously, and of recognizing the local complexities of sustainably treating this debilitating parasitic disease. PMID:27428067

  9. A Latent Markov Modelling Approach to the Evaluation of Circulating Cathodic Antigen Strips for Schistosomiasis Diagnosis Pre- and Post-Praziquantel Treatment in Uganda

    PubMed Central

    Koukounari, Artemis; Donnelly, Christl A.; Moustaki, Irini; Tukahebwa, Edridah M.; Kabatereine, Narcis B.; Wilson, Shona; Webster, Joanne P.; Deelder, André M.; Vennervald, Birgitte J.; van Dam, Govert J.

    2013-01-01

    Regular treatment with praziquantel (PZQ) is the strategy for human schistosomiasis control aiming to prevent morbidity in later life. With the recent resolution on schistosomiasis elimination by the 65th World Health Assembly, appropriate diagnostic tools to inform interventions are keys to their success. We present a discrete Markov chains modelling framework that deals with the longitudinal study design and the measurement error in the diagnostic methods under study. A longitudinal detailed dataset from Uganda, in which one or two doses of PZQ treatment were provided, was analyzed through Latent Markov Models (LMMs). The aim was to evaluate the diagnostic accuracy of Circulating Cathodic Antigen (CCA) and of double Kato-Katz (KK) faecal slides over three consecutive days for Schistosoma mansoni infection simultaneously by age group at baseline and at two follow-up times post treatment. Diagnostic test sensitivities and specificities and the true underlying infection prevalence over time as well as the probabilities of transitions between infected and uninfected states are provided. The estimated transition probability matrices provide parsimonious yet important insights into the re-infection and cure rates in the two age groups. We show that the CCA diagnostic performance remained constant after PZQ treatment and that this test was overall more sensitive but less specific than single-day double KK for the diagnosis of S. mansoni infection. The probability of clearing infection from baseline to 9 weeks was higher among those who received two PZQ doses compared to one PZQ dose for both age groups, with much higher re-infection rates among children compared to adolescents and adults. We recommend LMMs as a useful methodology for monitoring and evaluation and treatment decision research as well as CCA for mapping surveys of S. mansoni infection, although additional diagnostic tools should be incorporated in schistosomiasis elimination programs. PMID:24367250

  10. Achievements of schistosomiasis control in China.

    PubMed

    Yuan, Hongchang; Jiang, Qingwu; Zhao, Genming; He, Na

    2002-01-01

    The control of schistosomiasis has been spectacularly successful in terms of controlling endemicity and severity of the disease during the last 50 years. It can be categorized into two stages. From 1955 through 1980, the transmission-control strategy had been widely and successfully carried out. By the end of 1980, the epidemic of schistosomiasis was successfully circumscribed in certain core regions including areas at the middle and low reaches of the Yangtze River and some mountainous areas in Sichuan and Yunnan provinces, where control of schistosomiasis had been demonstrated to be very difficult to be sustained. Therefore, since 1980, schistosomiasis control in China has been modified to employ a stepwise strategy, based on which morbidity control has been given priorities and if possible transmission control has been pursued. However, since snail-ridden areas remain unchanged so far, reinfections occur frequently. This necessitates a maintenance phase to consolidate the achievements in the control of schistosomiasis. In the mean time, we are challenged with some environmental, social and economical changes in terms of controlling schistosomiasis. Successfully controlling schistosomiasis in China is still a long-term task but will be achieved without doubt along with the economic development and the promotion of living and cultural standard of people. PMID:12426618

  11. A catecholamine transporter from the human parasite Schistosoma mansoni with low affinity for psychostimulants

    PubMed Central

    Larsen, Mads B.; Fontana, Andréia C. K.; Magalhães, Lizandra G.; Rodrigues, Vanderlei; Mortensen, Ole V.

    2011-01-01

    The trematode Schistosoma mansoni is the primary cause of schistosomiasis, a devastating neglected tropical disease that affects 200 million individuals. Identifying novel therapeutic targets for the treatment of schistosomiasis is therefore of great public interest. The catecholamines norepinephrine (NE) and dopamine (DA) are essential for the survival of the parasite as they cause muscular relaxation and a lengthening in the parasite and thereby control movement. Here we characterize a novel dopamine/norepinephrine transporter (SmDAT) gene transcript, from Schistosoma mansoni. The SmDAT is expressed in the adult form and in the sporocyst form (infected snails) of the parasite, and also in the egg and miracidium stage. It is absent in the cercaria stage but curiously a transcript missing the exon encoding transmembrane domain 8 was identified in this stage. Heterologous expression of the cDNA in mammalian cells resulted in saturable, dopamine transport activity with an apparent affinity for dopamine comparable to that of the human dopamine transporter. Efflux experiments reveal notably higher substrate selectivity compared with its mammalian counterparts as amphetamine is a much less potent efflux elicitor against SmDAT compared to the human DAT. Pharmacological characterization of the SmDAT revealed that most human DAT inhibitors including psychostimulants such as cocaine were significantly less potent in inhibiting SmDAT. Like DATs from other simpler organisms the pharmacology for SmDAT was more similar to the human norepinephrine transporter. We were not able to identify other dopamine transporting carriers within the completed parasite genome and we hypothesize that the SmDAT is the only catecholamine transporter in the parasite and could be responsible for not only clearing DA but also NE. PMID:21251927

  12. The Schistosoma mansoni Cytochrome P450 (CYP3050A1) Is Essential for Worm Survival and Egg Development

    PubMed Central

    Ziniel, Peter D.; Karumudi, Bhargava; Barnard, Andrew H.; Fisher, Ethan M. S.; Thatcher, Gregory R. J.; Podust, Larissa M.; Williams, David L.

    2015-01-01

    Schistosomiasis affects millions of people in developing countries and is responsible for more than 200,000 deaths annually. Because of toxicity and limited spectrum of activity of alternatives, there is effectively only one drug, praziquantel, available for its treatment. Recent data suggest that drug resistance could soon be a problem. There is therefore the need to identify new drug targets and develop drugs for the treatment of schistosomiasis. Analysis of the Schistosoma mansoni genome sequence for proteins involved in detoxification processes found that it encodes a single cytochrome P450 (CYP450) gene. Here we report that the 1452 bp open reading frame has a characteristic heme-binding region in its catalytic domain with a conserved heme ligating cysteine, a hydrophobic leader sequence present as the membrane interacting region, and overall structural conservation. The highest sequence identity to human CYP450s is 22%. Double stranded RNA (dsRNA) silencing of S. mansoni (Sm)CYP450 in schistosomula results in worm death. Treating larval or adult worms with antifungal azole CYP450 inhibitors results in worm death at low micromolar concentrations. In addition, combinations of SmCYP450-specific dsRNA and miconazole show additive schistosomicidal effects supporting the hypothesis that SmCYP450 is the target of miconazole. Treatment of developing S. mansoni eggs with miconazole results in a dose dependent arrest in embryonic development. Our results indicate that SmCYP450 is essential for worm survival and egg development and validates it as a novel drug target. Preliminary structure-activity relationship suggests that the 1-(2,4-dichlorophenyl)-2-(1H-imidazol-1-yl)ethan-1-ol moiety of miconazole is necessary for activity and that miconazole activity and selectivity could be improved by rational drug design. PMID:26713732

  13. Cross-immunoreactivity between anti-potato apyrase antibodies and mammalian ATP diphosphohydrolases: potential use of the vegetal protein in experimental schistosomiasis.

    PubMed

    Faria-Pinto, P; Meirelles, M N L; Lenzi, H L; Mota, E M; Penido, M L O; Coelho, P M Z; Vasconcelos, E G

    2006-09-01

    We have previously showed that Schistosoma mansoni ATP-diphosphohydrolase and Solanum tuberosum potato apyrase share epitopes and the vegetable protein has immunostimulatory properties. Here, it was verified the in situ cross-immunoreactivity between mice NTPDases and anti-potato apyrase antibodies produced in rabbits, using confocal microscopy. Liver samples were taken from Swiss Webster mouse 8 weeks after infection with S. mansoni cercariae, and anti-potato apyrase and TRITC-conjugated anti-rabbit IgG antibody were tested on cryostat sections. The results showed that S. mansoni egg ATP diphosphohydrolase isoforms, developed by anti-potato apyrase, are expressed in miracidial and egg structures, and not in granulomatous cells and hepatic structures (hepatocytes, bile ducts, and blood vessels). Therefore, purified potato apyrase when inoculated in rabbit generates polyclonal sera containing anti-apyrase antibodies that are capable of recognizing specifically S. mansoni ATP diphosphohydrolase epitopes, but not proteins from mammalian tissues, suggesting that autoantibodies are not induced during potato apyrase immunization. A phylogenetic tree obtained for the NTPDase family showed that potato apyrase had lower homology with mammalian NTPDases 1-4, 7, and 8. Further analysis of potato apyrase epitopes could implement their potential use in schistosomiasis experimental models. PMID:17308798

  14. Discovery and Characterization of Novel Anti-schistosomal Properties of the Anti-anginal Drug, Perhexiline and Its Impact on Schistosoma mansoni Male and Female Reproductive Systems

    PubMed Central

    Perlas, Emerald; Bolasco, Giulia; Nibbio, Martina; Monteagudo, Edith; Bresciani, Alberto; Ruberti, Giovina

    2016-01-01

    Background Schistosomiasis, one of the world’s greatest human neglected tropical diseases, is caused by parasitic trematodes of the genus Schistosoma. A unique feature of schistosome biology is that the induction of sexual maturation as well as the maintenance of the differentiation status of female reproductive organs and egg production, necessary for both disease transmission and pathogenesis, are strictly dependent on the male. The treatment and most control initiatives of schistosomiasis rely today on the long-term application of a single drug, praziquantel (PZQ), mostly by campaigns of mass drug administration. PZQ, while very active on adult parasites, has much lower activity against juvenile worms. Monotherapy also favors the selection of drug resistance and, therefore, new drugs are urgently needed. Methods and Findings Following the screening of a small compound library with an ATP-based luminescent assay on Schistosoma mansoni schistosomula, we here report the identification and characterization of novel antischistosomal properties of the anti-anginal drug perhexiline maleate (PHX). By phenotypic worm survival assays and confocal microscopy studies we show that PHX, in vitro, has a marked lethal effect on all S. mansoni parasite life stages (newly transformed schistosomula, juvenile and adult worms) of the definitive host. We further demonstrate that sub-lethal doses of PHX significantly impair egg production and lipid depletion within the vitellarium of adult female worms. Moreover, we highlighted tegumental damage in adult male worms and remarkable reproductive system alterations in both female and male adult parasites. The in vivo study in S. mansoni-patent mice showed a notable variability of worm burdens in the individual experiments, with an overall minimal schistosomicidal effect upon PHX treatment. The short PHX half-life in mice, together with its very high rodent plasma proteins binding could be the cause of the modest efficacy of PHX in the

  15. Polymerase chain reaction for the amplification of the 121-bp repetitive sequence of Schistosoma mansoni: a highly sensitive potential diagnostic tool for areas of low endemicity.

    PubMed

    Ferrer, E; Pérez, F; Bello, I; Bolívar, A; Lares, M; Osorio, A; León, L; Amarista, M; Incani, R N

    2015-11-01

    Schistosomiasis is a disease caused by parasitic flatworms of the genus Schistosoma, whose diagnosis has limitations, such as the low sensitivity and specificity of parasitological and immunological methods, respectively. In the present study an alternative molecular technique requiring previous standardization was carried out using the polymerase chain reaction (PCR) for the amplification of a 121-bp highly repetitive sequence for Schistosoma mansoni. DNA was extracted from eggs of S. mansoni by salting out. Different conditions were standardized for the PCR technique, including the concentration of reagents and the DNA template, annealing temperature and number of cycles, followed by the determination of the analytical sensitivity and specificity of the technique. Furthermore, the standardized PCR technique was employed in DNA extracted, using Chelex®100, from samples of sera of patients with an immunodiagnosis of schistosomiasis. The optimal conditions for the PCR were 2.5 mm MgCl2, 150 mm deoxynucleoside triphosphates (dNTPs), 0.4 μm primers, 0.75 U DNA polymerase, using 35 cycles and an annealing temperature of 63°C. The analytical sensitivity of the PCR was 10 attograms of DNA and the specificity was 100%. The DNA sequence was successfully detected in the sera of two patients, demonstrating schistosomiasis transmission, although low, in the community studied. The standardized PCR technique, using smaller amounts of reagents than in the original protocol, is highly sensitive and specific for the detection of DNA from S. mansoni and could be an important tool for diagnosis in areas of low endemicity. PMID:25141275

  16. Serum albumin and α-1 acid glycoprotein impede the killing of Schistosoma mansoni by the tyrosine kinase inhibitor Imatinib.

    PubMed

    Beckmann, Svenja; Long, Thavy; Scheld, Christina; Geyer, Rudolf; Caffrey, Conor R; Grevelding, Christoph G

    2014-12-01

    In the search for new drugs and drug targets to treat the flatworm disease schistosomiasis, protein kinases (PKs) have come under particular scrutiny because of their essential roles in developmental and physiological processes in schistosome parasites. In this context the application of the anti-cancer Abl tyrosine kinase (TK) inhibitor Imatinib (Gleevec/Glivec; STI-571) to adult Schistosoma mansoni in vitro has indicated negative effects on diverse physiological processes including survival. Motivated by these in vitro findings, we performed in vivo experiments in rodent models of S. mansoni infection. Unexpectedly, Imatinib had no effect on worm burden or egg-production. We found that the blood components serum albumin (SA) and alpha-1 acid glycoprotein (AGP or orosomucoid) negated Imatinib's deleterious effects on adult S. mansoni and schistosomula (post-infective larvae) in vitro. This negative effect was partially reversed by erythromycin. AGP synthesis can increase as a consequence of inflammatory processes or infection; in addition upon infection AGP levels are 6-8 times higher in mice compared to humans. Therefore, mice and probably other rodents are poor infection models for measuring the effects of Imatinib in vivo. Accordingly, we suggest the routine evaluation of the ability of AGP and SA to block in vitro anti-schistosomal effects of small molecules like Imatinib prior to laborious and expensive animal experiments. PMID:25516839

  17. Protein Kinase C and Extracellular Signal-Regulated Kinase Regulate Movement, Attachment, Pairing and Egg Release in Schistosoma mansoni

    PubMed Central

    Ressurreição, Margarida; De Saram, Paulu; Kirk, Ruth S.; Rollinson, David; Emery, Aidan M.; Page, Nigel M.; Davies, Angela J.; Walker, Anthony J.

    2014-01-01

    Protein kinases C (PKCs) and extracellular signal-regulated kinases (ERKs) are evolutionary conserved cell signalling enzymes that coordinate cell function. Here we have employed biochemical approaches using ‘smart’ antibodies and functional screening to unravel the importance of these enzymes to Schistosoma mansoni physiology. Various PKC and ERK isotypes were detected, and were differentially phosphorylated (activated) throughout the various S. mansoni life stages, suggesting isotype-specific roles and differences in signalling complexity during parasite development. Functional kinase mapping in adult worms revealed that activated PKC and ERK were particularly associated with the adult male tegument, musculature and oesophagus and occasionally with the oesophageal gland; other structures possessing detectable activated PKC and/or ERK included the Mehlis' gland, ootype, lumen of the vitellaria, seminal receptacle and excretory ducts. Pharmacological modulation of PKC and ERK activity in adult worms using GF109203X, U0126, or PMA, resulted in significant physiological disturbance commensurate with these proteins occupying a central position in signalling pathways associated with schistosome muscular activity, neuromuscular coordination, reproductive function, attachment and pairing. Increased activation of ERK and PKC was also detected in worms following praziquantel treatment, with increased signalling associated with the tegument and excretory system and activated ERK localizing to previously unseen structures, including the cephalic ganglia. These findings support roles for PKC and ERK in S. mansoni homeostasis, and identify these kinase groups as potential targets for chemotherapeutic treatments against human schistosomiasis, a neglected tropical disease of enormous public health significance. PMID:24921927

  18. Serum albumin and α-1 acid glycoprotein impede the killing of Schistosoma mansoni by the tyrosine kinase inhibitor Imatinib

    PubMed Central

    Beckmann, Svenja; Long, Thavy; Scheld, Christina; Geyer, Rudolf; Caffrey, Conor R.; Grevelding, Christoph G.

    2014-01-01

    In the search for new drugs and drug targets to treat the flatworm disease schistosomiasis, protein kinases (PKs) have come under particular scrutiny because of their essential roles in developmental and physiological processes in schistosome parasites. In this context the application of the anti-cancer Abl tyrosine kinase (TK) inhibitor Imatinib (Gleevec/Glivec; STI-571) to adult Schistosoma mansoni in vitro has indicated negative effects on diverse physiological processes including survival. Motivated by these in vitro findings, we performed in vivo experiments in rodent models of S. mansoni infection. Unexpectedly, Imatinib had no effect on worm burden or egg-production. We found that the blood components serum albumin (SA) and alpha-1 acid glycoprotein (AGP or orosomucoid) negated Imatinib’s deleterious effects on adult S. mansoni and schistosomula (post-infective larvae) in vitro. This negative effect was partially reversed by erythromycin. AGP synthesis can increase as a consequence of inflammatory processes or infection; in addition upon infection AGP levels are 6–8 times higher in mice compared to humans. Therefore, mice and probably other rodents are poor infection models for measuring the effects of Imatinib in vivo. Accordingly, we suggest the routine evaluation of the ability of AGP and SA to block in vitro anti-schistosomal effects of small molecules like Imatinib prior to laborious and expensive animal experiments. PMID:25516839

  19. Asymptomatic schistosomiasis in a young Sudanese refugee.

    PubMed

    Benson, Jill

    2007-04-01

    In 2004-2005, approximately 13,000 refugees settled in Australia, 70% of them from Africa. Schistosomiasis is one of the many illnesses endemic in Africa and approximately 40% of refugees have been found to be infected by this parasite. It has the potential to cause serious morbidity and mortality in those who are infected and after malaria is the second most prevalent tropical disease worldwide. Australia is not known to have an appropriate snail vector and so schistosomiasis is unlikely to be a public health problem. This article presents a case that demonstrates one of the sequelae of schistosomiasis - pipe stem cirrhosis - with associated splenomegaly and oesophageal varices. PMID:17392939

  20. Repeated praziquantel treatments remodel the genetic and spatial landscape of schistosomiasis risk and transmission.

    PubMed

    Barbosa, Lúcio M; Reis, Eliana A; Dos Santos, Cláudio R A; Costa, Jackson M; Carmo, Theomira M; Aminu, Peace T; Pitanga, Thassila N; Ponce-Terashima, Rafael; Blank, Walter A; Silva, Luciano K; Reis, Mitermayer G; Blanton, Ronald E

    2016-05-01

    Repeated treatments with praziquantel reduce schistosomiasis prevalence and morbidity, but transmission persists and populations often recover within a few years. To identify factors associated with persistence, we surveyed and treated all identified Schistosoma mansoni infections in two rural Brazilian communities (Jenipapo and Volta do Rio) in 2009, 2012 and 2013. Eggs were collected from all infected individuals and genotyped with 11 microsatellite markers to evaluate parasite differentiation and diversity. After successive rounds of community-wide treatment, prevalence decreased from 45% to 24% then 16%. Intensity of infection decreased by 57% over this period, and the number of eggs transmitted to the environment decreased by 92%. During all time periods the majority of eggs were excreted by those >15years of age. The incidence was 23% in 2012 and 15% in 2013, consistent with a decrease in transmission. There was little immigration or gene flow over a distance of 6km. On reinfection, infrapopulations were moderately differentiated indicating that pretreatment multilocus genotypes were not fully reacquired. The effective population size responded to census population decline more rapidly than differentiation. Reinfection was concentrated in the downstream portion of Jenipapo, consistent with the observed increased human fecal contamination. At this scale and in this area S. mansoni infections exist on a fragmented landscape with a highly focal pattern of transmission that may facilitate future elimination. PMID:26953255

  1. In vivo T cell depletion regulates resistance and morbidity in murine schistosomiasis

    SciTech Connect

    Phillips, S.M.; Linette, G.P.; Doughty, B.L.; Byram, J.E.; Von Lichtenberg, F.

    1987-08-01

    These studies assessed the roles of subpopulations of T lymphocytes in inducing and modulating resistance to schistosomiasis and thereby influencing subsequent morbidity. C57BL/6 mice were depleted in vivo of Lyt-1+, Lyt-2+, and L3T4+ cells by the daily administration of monoclonal antibodies. The development of protective immunity, induced by exposure to irradiated Schistosoma mansoni cercariae as expressed in depleted animals, was compared to that demonstrated in undepleted, normal, and congenitally athymic C57BL/6 mice. The development of morbidity was determined by spleen weight, portal pressure and reticuloendothelial system activity. The results indicated that depletion of specific subpopulations of T lymphocytes minimally affected the primary development of parasites; however, depletion strongly influenced the development of resistance to the parasite and subsequent morbidity due to infection. Depletion of T lymphocytes by anti-Lyt-1+ or anti-L3T4+ antibody decreased the development of resistance, antibody and delayed-type hypersensitivity directed against schistosome antigens. Morbidity due to disease was increased. Depletion of Lyt-2+ cells produced opposite changes with augmented resistance and reduced morbidity. Congenitally athymic mice developed minimal resistance and morbidity. Moreover, resistance was inversely related to the morbidity shown by a given animal. These studies indicate that the development of protective immunity to S. mansoni cercariae is regulated by discrete subpopulations of T lymphocytes. The feasibility of decreasing morbidity by increasing specific immunologically mediated resistance is suggested.

  2. Idiotypic sensitization in utero of children born to mothers with schistosomiasis or Chagas' disease.

    PubMed Central

    Eloi-Santos, S M; Novato-Silva, E; Maselli, V M; Gazzinelli, G; Colley, D G; Correa-Oliveira, R

    1989-01-01

    Cord blood mononuclear cells (CBMC) of neonates born of mothers with Chagas' disease or schistosomiasis exhibited strong proliferative responses against idiotypes expressed on antibodies with specificity for Trypanosoma cruzi or Schistosoma mansoni antigens, respectively. These immunoaffinity-purified preparations were stimulatory if they were prepared from pools of patients' sera or from the mother's own serum, taken early during her pregnancy. These CBMC did not respond to normal immunoglobulin, and CBMC of neonates born of uninfected mothers did not respond to antibodies against either T. cruzi or S. mansoni, or normal immunoglobulin preparations. We propose that in utero exposure of a fetus to some idiotypes expressed on placentally transferred antibodies induces anti-Id T lymphocyte sensitization, which we detect as a proliferative response by CBMC exposed to immunoaffinity-purified antibodies expressing the relevant idiotypes. This is the first experimental evidence that children born of mothers with chronic infections undergo natural in utero idiotypic manipulations and are born possessing cellular anti-Id reactivity. PMID:2503542

  3. Urogenital Schistosomiasis in Women of Reproductive Age in Tanzania's Lake Victoria Region

    PubMed Central

    Downs, Jennifer A.; Mguta, Charles; Kaatano, Godfrey M.; Mitchell, Katrina B.; Bang, Heejung; Simplice, Harusha; Kalluvya, Samuel E.; Changalucha, John M.; Johnson, Warren D.; Fitzgerald, Daniel W.

    2011-01-01

    We conducted a community-based study of 457 women aged 18–50 years living in eight rural villages in northwest Tanzania. The prevalence of female urogenital schistosomiasis (FUS) was 5% overall but ranged from 0% to 11%. FUS was associated with human immunodeficiency virus (HIV) infection (odds ratio [OR] = 4.0, 95% confidence interval [CI] = 1.2–13.5) and younger age (OR = 5.5 and 95% CI = 1.2–26.3 for ages < 25 years and OR = 8.2 and 95% CI = 1.7–38.4 for ages 25–29 years compared with age > 35 years). Overall HIV prevalence was 5.9% but was 17% among women with FUS. We observed significant geographical clustering of schistosomiasis: northern villages near Lake Victoria had more Schistosoma mansoni infections (P < 0.0001), and southern villages farther from the lake had more S. haematobium (P = 0.002). Our data support the postulate that FUS may be a risk factor for HIV infection and may contribute to the extremely high rates of HIV among young women in sub-Saharan Africa. PMID:21363971

  4. Increased expression of NTPDases 2 and 3 in mesenteric endothelial cells during schistosomiasis favors leukocyte adhesion through P2Y1 receptors.

    PubMed

    Oliveira, Suellen Darc Santos; Oliveira, Nathália F; Meyer-Fernandes, José R; Savio, Luiz Eduardo Baggio; Ornelas, Flavia G I; Ferreira, Zulma S; Coutinho-Silva, Robson; Silva, Claudia Lucia Martins

    2016-07-01

    Schistosomiasis is caused by an intravascular parasite and linked to phenotypic changes in endothelial cells that favor inflammation. Endothelial cells express P2Y1 receptors (P2Y1R), and their activation by ADP favors leukocyte adhesion to the endothelial monolayer. We aimed to evaluate the influence of schistosomiasis upon endothelial purinergic signaling-mediated leukocyte adhesion. Mesenteric endothelial cells and mononuclear cells from control and Schistosoma mansoni-infected mice were used in co-culture. P2Y1R levels were similar in both groups. Basal leukocyte adhesion was higher in the infected than in the control group; leukocyte adhesion increased after treatment with the P2Y1R agonist 2-MeSATP in both groups, though it only marginally increased in the infected group. Pre-incubation with the selective P2Y1R antagonist MRS2179 (0.3μM) prevented the agonist effect. However, in the infected group it also reduced the basal leukocyte adhesion, suggesting endothelial cell pre-activation. The endothelial expressions of NTPDases 2 and 3 were significantly increased in the infected group, increasing extracellular ATP hydrolysis and ADP formation by endothelial cells. Therefore, mesenteric endothelial cells are primed by schistosomiasis to a pro-inflammatory phenotype characterized by an increased expression of NTPDases 2 and 3, favoring ADP accumulation and mononuclear cell adhesion, possibly contributing to mesenteric inflammation and schistosomiasis morbidity. PMID:26924460

  5. Role of antibody dependent cell mediated cytotoxicity (ADCC) in Sm-p80-mediated protection against Schistosoma mansoni

    PubMed Central

    Torben, Workineh; Ahmad, Gul; Zhang, Weidong; Nash, Stewart; Le, Loc; Karmakar, Souvik; Siddiqui, Afzal A.

    2012-01-01

    Schistosomiasis is a major health problem in the developing world and for international travelers to the endemic countries. Existing strategies to control schistosomiasis have had limited successes so far. The addition of an effective vaccine in existing control measures would be greatly beneficial in reducing the impact of the disease. In this regard, Sm-p80 mediated protection against intestinal schistosomiasis caused by Schistosoma mansoni has been observed to be promising in two animal models of infection and disease. In this study, the role of antibody dependent cell mediated cytotoxcity (ADCC) was deciphered in Sm-p80-mediated protection especially in the elimination of lung stage schistosomula. This was achieved using lung lavage cells and lung cells that were isolated from mice immunized with and without Sm-p80 formulated in a recombinant vaccine formulation. Significant differences were observed in cytotoxicity assays using immune sera with the lung lavage cells which showed 51% more killing of schistosomula and elevated levels of nitric oxide in the supernatants were detected compared to controls. PMID:23000221

  6. QSAR-Driven Discovery of Novel Chemical Scaffolds Active against Schistosoma mansoni.

    PubMed

    Melo-Filho, Cleber C; Dantas, Rafael F; Braga, Rodolpho C; Neves, Bruno J; Senger, Mario R; Valente, Walter C G; Rezende-Neto, João M; Chaves, Willian T; Muratov, Eugene N; Paveley, Ross A; Furnham, Nicholas; Kamentsky, Lee; Carpenter, Anne E; Silva-Junior, Floriano P; Andrade, Carolina H

    2016-07-25

    Schistosomiasis is a neglected tropical disease that affects millions of people worldwide. Thioredoxin glutathione reductase of Schistosoma mansoni (SmTGR) is a validated drug target that plays a crucial role in the redox homeostasis of the parasite. We report the discovery of new chemical scaffolds against S. mansoni using a combi-QSAR approach followed by virtual screening of a commercial database and confirmation of top ranking compounds by in vitro experimental evaluation with automated imaging of schistosomula and adult worms. We constructed 2D and 3D quantitative structure-activity relationship (QSAR) models using a series of oxadiazoles-2-oxides reported in the literature as SmTGR inhibitors and combined the best models in a consensus QSAR model. This model was used for a virtual screening of Hit2Lead set of ChemBridge database and allowed the identification of ten new potential SmTGR inhibitors. Further experimental testing on both shistosomula and adult worms showed that 4-nitro-3,5-bis(1-nitro-1H-pyrazol-4-yl)-1H-pyrazole (LabMol-17) and 3-nitro-4-{[(4-nitro-1,2,5-oxadiazol-3-yl)oxy]methyl}-1,2,5-oxadiazole (LabMol-19), two compounds representing new chemical scaffolds, have high activity in both systems. These compounds will be the subjects for additional testing and, if necessary, modification to serve as new schistosomicidal agents. PMID:27253773

  7. Structural parameters, molecular properties, and biological evaluation of some terpenes targeting Schistosoma mansoni parasite.

    PubMed

    Mafud, Ana C; Silva, Marcos P N; Monteiro, Daniela C; Oliveira, Maria F; Resende, João G; Coelho, Mayara L; de Sousa, Damião P; Mendonça, Ronaldo Z; Pinto, Pedro L S; Freitas, Rivelilson M; Mascarenhas, Yvonne P; de Moraes, Josué

    2016-01-25

    The use of natural products has a long tradition in medicine, and they have proven to be an important source of lead compounds in the development of new drugs. Among the natural compounds, terpenoids present broad-spectrum activity against infective agents such as viruses, bacteria, fungi, protozoan and helminth parasites. In this study, we report a biological screening of 38 chemically characterized terpenes from different classes, which have a hydroxyl group connected by hydrophobic chain or an acceptor site, against the blood fluke Schistosoma mansoni, the parasite responsible for schistosomiasis mansoni. In vitro bioassays revealed that 3,7-dimethyl-1-octanol (dihydrocitronellol) (10) was the most active terpene (IC50 values of 13-52 μM) and, thus, we investigated its antischistosomal activity in greater detail. Confocal laser scanning microscopy revealed that compound 10 induced severe tegumental damage in adult schistosomes and a correlation between viability and tegumental changes was observed. Furthermore, we compared all the inactive compounds with dihydrocitronellol structurally by using shape and charge modeling. Lipophilicity (miLogP) and other molecular properties (e.g. molecular polar surface area, molecular electrostatic potential) were also calculated. From the 38 terpenes studied, compound 10 is the one with the greatest flexibility, with a sufficient apolar region by which it may interact in a hydrophobic active site. In conclusion, the integration of biological and chemical analysis indicates the potential of the terpene dihydrocitronellol as an antiparasitic agent. PMID:26697994

  8. Schistosomiasis therapeutics: whats in the pipeline?

    PubMed

    Trainor-Moss, Santiago; Mutapi, Francisca

    2016-02-01

    Schistosomiasis is a debilitating neglected tropical disease caused by schistosome worms. Global efforts to control schistosomiasis rely predominantly on mass drug administration of the drug praziquantel to populations at risk of infection. We review the history of schistosome drug development and the current position of schistosome drug research. We conclude that with no additional candidates currently in the anti-schistosome drug clinical trial pipeline, a practical and necessary approach is to optimise the health benefits from praziquantel. We offer suggestions of where and how this can be achieved. We also highlight knowledge gaps in the utility of praziquantel particularly in the treatment of chronic schistosomiasis, which includes fibrosis, organomegaly and cervical lesions associated with female genital schistosomiasis. PMID:26508363

  9. The prolonged use of niclosamide as a molluscicide for the control of Schistosoma mansoni.

    PubMed

    Coura-Filho, P; Mendes, N M; de Souza, C P; Pereira, J P

    1992-01-01

    Applications of niclosamide at three-monthly intervals were undertaken for 14 years in foci of Biomphalaria glabrata in the water sources of Peri-Peri (Capim Branco, MG). All the residents of the area were submitted to an annual fecal examination (Kato/Katz) and those individuals eliminating Schistosoma mansoni eggs were treated with oxamniquine. A malacological survey was undertaken at three-monthly intervals by means of ten scoops with a perforated ladle each ten metres along the two banks of the ditches and streams of the region. Where snails were found, molluscicide was applied by means of dripping or aspersion using a 3 ppm aqueous suspension of niclosamide. Initially, a mean of 14.3% of snails in the region were found to be eliminating cercariae. Following the first four applications of molluscicide, this was reduced to 0.0% and maintained at about 1.5% throughout the program. Thus, there was a continued possibility of schistosomiasis transmission in the area and it was observed that the population of snails reestablished itself within three months of molluscicide application. The results obtained in this study do not encourage the continual use of niclosamide as the only method of control of schistosomiasis. PMID:1342106

  10. Cost analysis of tests for the detection of Schistosoma mansoni infection in children in western Kenya.

    PubMed

    Worrell, Caitlin M; Bartoces, Monina; Karanja, Diana M S; Ochola, Elizabeth A; Matete, Daniel O; Mwinzi, Pauline N M; Montgomery, Susan P; Secor, W Evan

    2015-06-01

    Financial resources tend to be limited in schistosomiasis endemic areas, forcing program managers to balance financial and scientific considerations when selecting detection assays. Therefore, we compared the costs of using single stool Kato-Katz, triplicate stool Kato-Katz, and point-of-contact circulating cathodic antigen (POC-CCA) assays for the detection of Schistosoma mansoni infection. Economic and financial costs were estimated from the viewpoint of a schistosomiasis control program using the ingredients approach. Costs related to specimen collection, sample processing and analysis, and treatment delivery were considered. Analysis inputs and assumptions were tested using one-way and two-way sensitivity analysis. The total per-person cost of performing the single Kato-Katz, triplicate Kato-Katz, and POC-CCA was US$6.89, US$17.54, and US$7.26, respectively. Major cost drivers included labor, transportation, and supplies. In addition, we provide a costing tool to guide program managers in evaluating detection costs in specific settings, as costs may vary temporally and spatially. PMID:25870422

  11. The Role of Efflux Pumps in Schistosoma mansoni Praziquantel Resistant Phenotype

    PubMed Central

    Armada, Ana; Belo, Silvana; Carrilho, Emanuel; Viveiros, Miguel; Afonso, Ana

    2015-01-01

    Background Schistosomiasis is a neglected disease caused by a trematode of the genus Schistosoma that is second only to malaria in public health significance in Africa, South America, and Asia. Praziquantel (PZQ) is the drug of choice to treat this disease due to its high cure rates and no significant side effects. However, in the last years increasingly cases of tolerance to PZQ have been reported, which has caused growing concerns regarding the emergency of resistance to this drug. Methodology/Principal Findings Here we describe the selection of a parasitic strain that has a stable resistance phenotype to PZQ. It has been reported that drug resistance in helminths might involve efflux pumps such as members of ATP-binding cassette transport proteins, including P-glycoprotein and multidrug resistance-associated protein families. Here we evaluate the role of efflux pumps in Schistosoma mansoni resistance to PZQ, by comparing the efflux pumps activity in susceptible and resistant strains. The evaluation of the efflux activity was performed by an ethidium bromide accumulation assay in presence and absence of Verapamil. The role of efflux pumps in resistance to PZQ was further investigated comparing the response of susceptible and resistant parasites in the absence and presence of different doses of Verapamil, in an ex vivo assay, and these results were further reinforced through the comparison of the expression levels of SmMDR2 RNA by RT-PCR. Conclusions/Significance This work strongly suggests the involvement of Pgp-like transporters SMDR2 in Praziquantel drug resistance in S. mansoni. Low doses of Verapamil successfully reverted drug resistance. Our results might give an indication that a combination therapy with PZQ and natural or synthetic Pgp modulators can be an effective strategy for the treatment of confirmed cases of resistance to PZQ in S. mansoni. PMID:26445012

  12. Identification of Candidate Serum Biomarkers for Schistosoma mansoni Infected Mice Using Multiple Proteomic Platforms

    PubMed Central

    Kardoush, Manal I.

    2016-01-01

    Background Schistosomiasis is an important helminth infection of humans. There are few reliable diagnostic biomarkers for early infection, for recurrent infection or to document successful treatment. In this study, we compared serum protein profiles in uninfected and infected mice to identify disease stage-specific biomarkers. Methods Serum collected from CD1 mice infected with 50–200 Schistosoma mansoni cercariae were analyzed before infection and at 3, 6 and 12 weeks post-infection using three mass spectrometric (MS) platforms. Results Using SELDI-TOF MS, 66 discriminating m/z peaks were detected between S. mansoni infected mice and healthy controls. Used in various combinations, these peaks could 1) reliably diagnose early-stage disease, 2) distinguish between acute and chronic infection and 3) diagnose S. mansoni infection regardless the parasite burden. The most important contributors to these diagnostic algorithms were peaks at 3.7, 13 and 46 kDa. Employing sample fractionation and differential gel electrophoresis, we analyzed gel slices either by MALDI-TOF MS or Velos Orbitrap MS. The former yielded eight differentially-expressed host proteins in the serum at different disease stages including transferrin and alpha 1- antitrypsin. The latter suggested the presence of a surprising number of parasite-origin proteins in the serum during both the acute (n = 200) and chronic (n = 105) stages. The Orbitrap platform also identified many differentially-expressed host-origin serum proteins during the acute and chronic stages (296 and 220 respectively). The presence of one of the schistosome proteins, glutathione S transferase (GST: 25 KDa), was confirmed by Western Blot. This study provides proof-of-principle for an approach that can yield a large number of novel candidate biomarkers for Schistosoma infection. PMID:27138990

  13. Schistosomiasis elimination by 2020 or 2030?

    PubMed

    Fenwick, Alan; Jourdan, Peter

    2016-06-01

    Schistosomiasis has been a public health burden in a number of countries across the globe for centuries and probably beyond. The World Health Organization and partners are currently preparing to move towards elimination of this disease. However, given the historical challenges and barriers to ridding areas of this water-borne parasite infection, we question whether the current targets for eliminating schistosomiasis as a global health problem can be achieved. PMID:26907938

  14. Reduction of Urogenital Schistosomiasis with an Integrated Control Project in Sudan

    PubMed Central

    Lee, Young-Ha; Jeong, Hoo Gn; Kong, Woo Hyun; Lee, Soon-Hyung; Cho, Han-Ik; Nam, Hae-Sung; Ismail, Hassan Ahmed Hassan Ahmed; Alla, Gibril Nouman Abd; Oh, Chung Hyeon; Hong, Sung-Tae

    2015-01-01

    Purpose Schistosomiasis remains a major public health concern in Sudan, particularly Schistosoma haematobium infection. This study presents the disease-reduction outcomes of an integrated control program for schistosomiasis in Al Jabalain locality of White Nile State, Sudan from 2009 through 2011. Methods The total population of the project sites was 482,902, and the major target group for intervention among them was 78,615 primary school students. For the cross-sectional study of the prevalence, urine and stool specimens were examined using the urine sedimentation method and the Kato cellophane thick smear method, respectively. To assess the impacts of health education for students and a drinking water supply facility at Al Hidaib village, questionnaire survey was done. Results The overall prevalence for S. haematobium and S. mansoni at baseline was 28.5% and 0.4%, respectively. At follow-up survey after 6–9 months post-treatment, the prevalence of S. haematobium infection was reduced to 13.5% (95% CI = 0.331–0.462). A higher reduction in prevalence was observed among girls, those with moderately infected status (around 20%), and residents in rural areas, than among boys, those with high prevalence (>40%), and residents in urban areas. After health education, increased awareness about schistosomiasis was checked by questionnaire survey. Also, a drinking water facility was constructed at Al Hidaib village, where infection rate was reduced more compared to that in a neighboring village within the same unit. However, we found no significant change in the prevalence of S. mansoni infection between baseline and follow-up survey (95% CI = 0.933–6.891). Conclusions At the end of the project, the prevalence of S. haematobium infection was reduced by more than 50% in comparison with the baseline rate. Approximately 200,000 subjects had received either praziquantel therapy, health education, or supply of clean water. To consolidate the achievements of this

  15. Large-scale determinants of intestinal schistosomiasis and intermediate host snail distribution across Africa: does climate matter?

    PubMed

    Stensgaard, Anna-Sofie; Utzinger, Jürg; Vounatsou, Penelope; Hürlimann, Eveline; Schur, Nadine; Saarnak, Christopher F L; Simoonga, Christopher; Mubita, Patricia; Kabatereine, Narcis B; Tchuem Tchuenté, Louis-Albert; Rahbek, Carsten; Kristensen, Thomas K

    2013-11-01

    The geographical ranges of most species, including many infectious disease agents and their vectors and intermediate hosts, are assumed to be constrained by climatic tolerances, mainly temperature. It has been suggested that global warming will cause an expansion of the areas potentially suitable for infectious disease transmission. However, the transmission of infectious diseases is governed by a myriad of ecological, economic, evolutionary and social factors. Hence, a deeper understanding of the total disease system (pathogens, vectors and hosts) and its drivers is important for predicting responses to climate change. Here, we combine a growing degree day model for Schistosoma mansoni with species distribution models for the intermediate host snail (Biomphalaria spp.) to investigate large-scale environmental determinants of the distribution of the African S. mansoni-Biomphalaria system and potential impacts of climatic changes. Snail species distribution models included several combinations of climatic and habitat-related predictors; the latter divided into "natural" and "human-impacted" habitat variables to measure anthropogenic influence. The predictive performance of the combined snail-parasite model was evaluated against a comprehensive compilation of historical S. mansoni parasitological survey records, and then examined for two climate change scenarios of increasing severity for 2080. Future projections indicate that while the potential S. mansoni transmission area expands, the snail ranges are more likely to contract and/or move into cooler areas in the south and east. Importantly, we also note that even though climate per se matters, the impact of humans on habitat play a crucial role in determining the distribution of the intermediate host snails in Africa. Thus, a future contraction in the geographical range size of the intermediate host snails caused by climatic changes does not necessarily translate into a decrease or zero-sum change in human

  16. Regular treatments of praziquantel do not impact on the genetic make-up of Schistosoma mansoni in Northern Senegal.

    PubMed

    Huyse, T; Van den Broeck, F; Jombart, T; Webster, B L; Diaw, O; Volckaert, F A M; Balloux, F; Rollinson, D; Polman, K

    2013-08-01

    The Senegal River Basin (SRB) experienced a major epidemic of intestinal schistosomiasis in the early nineties, after the construction of a dam for irrigation purposes. Exceptionally low cure rates following praziquantel (PZQ) treatment at the onset of the epidemic raised concerns about PZQ resistant strains of Schistosoma mansoni, although they could also be attributed to the intense transmission at that time. A field study in the same region more than 15 years later found cure rates for S. mansoni still to be low, whereas Schistosomahaematobium responded well to treatment. We collected S. mansoni miracidia from children at base-line prior to treatment, six months after two PZQ treatments and two years after the start of the study when they had received a total of five PZQ treatments. In total, 434 miracidia from 12 children were successfully genotyped with at least six out of nine DNA microsatellite loci. We found no significant differences in the genetic diversity of, and genetic differentiation between parasite populations before and after repeated treatment, suggesting that PZQ treatment does not have an impact on the neutral evolution of the parasite. This is in stark contrast with a similar study in Tanzania where a significant decrease in genetic diversity was observed in S. mansoni miracidia after a single round of PZQ treatment. We argue that PZQ resistance might play a role in our study area, although rapid re-infection cannot be excluded. It is important to monitor this situation carefully and conduct larger field studies with short-term follow-up after treatment. Since PZQ is the only general schistosomicide available, the possibility of PZQ resistance is of great concern both for disease control and for curative use in clinical practice. PMID:23684792

  17. [Ecological civilization and schistosomiasis control in Yujiang County].

    PubMed

    Ai, Dong-Yun; Liu, Bu-Yun

    2012-02-01

    This article describes the main approach of ecological civilization construction and great changes and achievements in the original schistosomiasis endemic areas, Yujiang County, Jiangxi Province. Ecological civilization is an important part of schistosomiasis control work. PMID:22590876

  18. Evaluation of the CCA Immuno-Chromatographic Test to Diagnose Schistosoma mansoni in Minas Gerais State, Brazil

    PubMed Central

    Silveira, Alda Maria Soares; Costa, Emanuele Gama Dutra; Ray, Debalina; Suzuki, Brian M.; Hsieh, Michael H.; Fraga, Lucia Alves de Oliveira; Caffrey, Conor R.

    2016-01-01

    Background The Kato-Katz (KK) stool smear is the standard test for the diagnosis of Schistosoma mansoni infection, but suffers from low sensitivity when infections intensities are moderate to low. Thus, misdiagnosed individuals remain untreated and contribute to the disease transmission, thereby forestalling public health efforts to move from a modality of disease control to one of elimination. As an alternative, the urine-based diagnosis of schistosomiasis mansoni via the circulating cathodic antigen immuno-chromatographic test (CCA-ICT) has been extensively evaluated in Africa with the conclusion that it may replace the KK test in areas where prevalences are moderate or high. Methods and Findings The objective was to measure the performance of the CCA-ICT in a sample study population composed of residents from non-endemic and endemic areas for schistosomiasis mansoni in two municipalities of Minas Gerais state, Brazil. Volunteers (130) were classified into three infection status groups based on duplicate Kato-Katz thick smears from one stool sample (2KK test): 41 negative individuals from non-endemic areas, 41 negative individuals from endemic areas and 48 infected individuals from endemic areas. Infection status was also determined by the CCA-ICT and infection exposure by antibody ELISA (enzyme-linked immunosorbent assay) to S. mansoni soluble egg antigen (SEA) and soluble (adult) worm antigen preparation (SWAP). Sensitivity and specificity were influenced by whether the trace score visually adjudicated in the CCA-ICT was characterized as positive or negative for S. mansoni infection. An analysis of a two-graph receiver operating characteristic was performed to change the cutoff point. When the trace score was interpreted as a positive rather than as a negative result, the specificity decreased from 97.6% to 78.0% whereas sensitivity increased from 68.7% to 85.4%. A significantly positive correlation between the CCA-ICT scores and egg counts was identified (r

  19. Schistosomiasis

    MedlinePlus

    ... can get a schistosoma infection through contact with contaminated water. This parasite swims freely in open bodies ... disease is known to exist Been exposed to contaminated or possibly contaminated bodies of water

  20. Schistosomiasis

    MedlinePlus

    ... to its preferred body part, depending on its species. These areas include the: Bladder Rectum Intestines Liver ... Symptoms vary with the species of worm and the phase of ... cause fever, chills, swollen lymph nodes, and swollen liver and ...

  1. A Novel Toll-Like Receptor (TLR) Influences Compatibility between the Gastropod Biomphalaria glabrata, and the Digenean Trematode Schistosoma mansoni

    PubMed Central

    Pila, Emmanuel A.; Tarrabain, Mahmoud; Kabore, Alethe L.; Hanington, Patrick C.

    2016-01-01

    Schistosomiasis, a devastating disease caused by parasitic flatworms of the genus Schistosoma, affects over 260 million people worldwide especially in tropical and sub-tropical regions. Schistosomes must undergo their larval development within specific species of snail intermediate hosts, a trait that is shared among almost all digenean trematodes. This unique and long-standing host-parasite relationship presents an opportunity to study both the importance of conserved immunological features in novel immunological roles, as well as new immunological adaptations that have arisen to combat a very specific type of immunological challenge. While it is well supported that the snail immune response is important for protecting against schistosome infection, very few specific snail immune factors have been identified and even fewer have been functionally characterized. Here, we provide the first functional report of a snail Toll-like receptor, which we demonstrate as playing an important role in the cellular immune response of the snail Biomphalaria glabrata following challenge with Schistosoma mansoni. This TLR (BgTLR) was identified as part of a peptide screen of snail immune cell surface proteins that differed in abundance between B. glabrata snails that differ in their compatibility phenotype to challenge by S. mansoni. The S. mansoni-resistant strain of B. glabrata (BS-90) displayed higher levels of BgTLR compared to the susceptible (M-line) strain. Transcript expression of BgTLR was found to be very responsive in BS-90 snails when challenged with S. mansoni, increasing 27 fold relative to β-actin (non-immune control gene); whereas expression in susceptible M-line snails was not significantly increased. Knockdown of BgTLR in BS-90 snails via targeted siRNA oligonucleotides was confirmed using a specific anti-BgTLR antibody and resulted in a significant alteration of the resistant phenotype, yielding patent infections in 43% of the normally resistant snails, which

  2. A Novel Toll-Like Receptor (TLR) Influences Compatibility between the Gastropod Biomphalaria glabrata, and the Digenean Trematode Schistosoma mansoni.

    PubMed

    Pila, Emmanuel A; Tarrabain, Mahmoud; Kabore, Alethe L; Hanington, Patrick C

    2016-03-01

    Schistosomiasis, a devastating disease caused by parasitic flatworms of the genus Schistosoma, affects over 260 million people worldwide especially in tropical and sub-tropical regions. Schistosomes must undergo their larval development within specific species of snail intermediate hosts, a trait that is shared among almost all digenean trematodes. This unique and long-standing host-parasite relationship presents an opportunity to study both the importance of conserved immunological features in novel immunological roles, as well as new immunological adaptations that have arisen to combat a very specific type of immunological challenge. While it is well supported that the snail immune response is important for protecting against schistosome infection, very few specific snail immune factors have been identified and even fewer have been functionally characterized. Here, we provide the first functional report of a snail Toll-like receptor, which we demonstrate as playing an important role in the cellular immune response of the snail Biomphalaria glabrata following challenge with Schistosoma mansoni. This TLR (BgTLR) was identified as part of a peptide screen of snail immune cell surface proteins that differed in abundance between B. glabrata snails that differ in their compatibility phenotype to challenge by S. mansoni. The S. mansoni-resistant strain of B. glabrata (BS-90) displayed higher levels of BgTLR compared to the susceptible (M-line) strain. Transcript expression of BgTLR was found to be very responsive in BS-90 snails when challenged with S. mansoni, increasing 27 fold relative to β-actin (non-immune control gene); whereas expression in susceptible M-line snails was not significantly increased. Knockdown of BgTLR in BS-90 snails via targeted siRNA oligonucleotides was confirmed using a specific anti-BgTLR antibody and resulted in a significant alteration of the resistant phenotype, yielding patent infections in 43% of the normally resistant snails, which

  3. Activity of Praziquantel Enantiomers and Main Metabolites against Schistosoma mansoni

    PubMed Central

    Meister, Isabel; Ingram-Sieber, Katrin; Cowan, Noemi; Todd, Matthew; Robertson, Murray N.; Meli, Claudia; Patra, Malay; Gasser, Gilles

    2014-01-01

    A racemic mixture of R and S enantiomers of praziquantel (PZQ) is currently the treatment of choice for schistosomiasis. Though the S enantiomer and the metabolites are presumed to contribute only a little to the activity of the drug, in-depth side-by-side studies are lacking. The aim of this study was to investigate the in vitro activities of PZQ and its main metabolites, namely, R- and S-cis- and R- and S-trans-4′-hydroxypraziquantel, against adult worms and newly transformed schistosomula (NTS). Additionally, we explored the in vivo activity and hepatic shift (i.e., the migration of the worms to the liver) produced by each PZQ enantiomer in mice. Fifty percent inhibitory concentrations of R-PZQ, S-PZQ, and R-trans- and R-cis-4′-hydroxypraziquantel of 0.02, 5.85, 4.08, and 2.42 μg/ml, respectively, for adult S. mansoni were determined in vitro. S-trans- and S-cis-4′-hydroxypraziquantel were not active at 100 μg/ml. These results are consistent with microcalorimetry data and studies with NTS. In vivo, single 400-mg/kg oral doses of R-PZQ and S-PZQ achieved worm burden reductions of 100 and 19%, respectively. Moreover, worms treated in vivo with S-PZQ displayed an only transient hepatic shift and returned to the mesenteric veins within 24 h. Our data confirm that R-PZQ is the main effector molecule, while S-PZQ and the metabolites do not play a significant role in the antischistosomal properties of PZQ. PMID:24982093

  4. Human immune responses to Schistosoma mansoni vaccine candidate antigens.

    PubMed

    Ribeiro de Jesus, A; Araújo, I; Bacellar, O; Magalhães, A; Pearce, E; Harn, D; Strand, M; Carvalho, E M

    2000-05-01

    To determine the naturally occurring immunological responses to the Schistosoma mansoni antigens paramyosin, IrV-5, Sm-23 (MAP-3), and triose phosphate isomerase (MAP-4), a total of 119 subjects from an area of endemicity for schistosomiasis, including "resistant" subjects (n = 17) were evaluated. Specific immunoglobulin G1 (IgG1), IgG2, IgG3, IgG4, and IgA levels for each of the antigens and the cytokine profile in culture supernatants from antigen-stimulated peripheral blood mononuclear cells (PBMC) were determined. Although all the subjects had a high degree of contaminated water exposure, their infection levels were variable (0 to 1,128 eggs/g of stool). There were direct correlations between infection levels and levels of SWAP- and paramyosin-specific IgG1 and IgG4 (P < 0.05). However, an inverse correlation between infection levels and specific IgG2 to IrV-5 (P < 0.01) was observed. The evaluation of the cytokine profile (interleukin 5 [IL-5], IL-10, gamma interferon [IFN-gamma], and tumor necrosis factor alpha) in response to these antigens showed inverse correlations between the degree of infection and IFN-gamma levels in PBMC supernatants stimulated with paramyosin (P < 0.05) and IrV-5 (P < 0.01). Additionally, inverse correlations between the degree of infection and IL-5 levels in MAP-3- and MAP-4-stimulated PBMC supernatants (P < 0.01) were found. Logistic regression analysis was performed to adjust the results of cytokine profile by age. IL-5 production in MAP-3-stimulated PBMC supernatants was associated with lower infection levels (odds ratio = 11.2 [95% confidence interval, 2.7 to 45.8]). PMID:10768975

  5. Adult somatic stem cells in the human parasite, Schistosoma mansoni

    PubMed Central

    Collins, James J.; Wang, Bo; Lambrus, Bramwell G.; Tharp, Marla; Iyer, Harini; Newmark, Phillip A.

    2013-01-01

    Summary Schistosomiasis is among the most prevalent human parasitic diseases, affecting more than 200 million people worldwide1. The etiological agents of this disease are trematode flatworms (Schistosoma) that live and lay eggs within the vasculature of the host. These eggs lodge in host tissues, causing inflammatory responses that are the primary cause of morbidity. Because these parasites can live and reproduce within human hosts for decades2, elucidating the mechanisms that promote their longevity is of fundamental importance. Although adult pluripotent stem cells, called neoblasts, drive long-term homeostatic tissue maintenance in long-lived free-living flatworms3,4 (e.g., planarians), and neoblast-like cells have been described in some parasitic tapeworms5, little is known about whether similar cell types exist in any trematode species. Here, we describe a population of neoblast-like cells in the trematode Schistosoma mansoni. These cells resemble planarian neoblasts morphologically and share their ability to proliferate and differentiate into derivatives of multiple germ layers. Capitalizing on available genomic resources6,7 and RNAseq-based gene expression profiling, we find that these schistosome neoblast-like cells express a fibroblast growth factor receptor ortholog. Using RNA interference we demonstrate that this gene is required for the maintenance of these neoblast-like cells. Our observations suggest that adaptation of developmental strategies shared by free-living ancestors to modern-day schistosomes likely contributed to the success of these animals as long-lived obligate parasites. We expect that future studies deciphering the function of these neoblast-like cells will have important implications for understanding the biology of these devastating parasites. PMID:23426263

  6. Schistosomiasis transmission and control in China.

    PubMed

    Zou, Lan; Ruan, Shigui

    2015-03-01

    In the last 60 years, great progress has been made in controlling and preventing schistosomiasis in China. However, due to the ecosystem changes caused by the construction of the Three Gorges Dams and the South-north Water Conversion Project, the effects of climate change, the scarcity of a highly sensitive surveillance and response system, schistosomiasis is still considered as a major public health problem and is listed among the top infectious diseases in the country prioritized for control and elimination. Based on the epidemiological pattern of schistosomiasis and ecological characteristics of the vector snail, endemic areas of schistosomiasis in China were categorized into three types: (i) plain region with waterway networks, (ii) mountainous and hilly regions, and (iii) marshland and lake regions. China aims to reach the criteria of transmission control threshold of less than 1% in the lake and marshland provinces and reach transmission interruption threshold in hilly provinces of Sichuan and Yunnan by the end of 2015. The purpose of this article is to use the deterministic model proposed in our earlier study in (Chen et al., 2010) to simulate the schistosomiasis infection data from other lake and marshland provinces, including Hunan, Jiangxi and Anhui. Our simulations demonstrate that the model can reasonably mimic the schistosomiasis infection data from these lake and marshland provinces. Thus, similar control and prevention measures can be designed and proposed for these provinces. We will also try to use the model to simulate the schistosomiasis infection data from Sichuan and Yunnan provinces in the mountainous and hilly regions where cattle farming is not as popular and important as in the lake and marshland provinces and find out that different control and prevention strategies are required. PMID:25559046

  7. Effect of different stages of Schistosoma mansoni infection on the parasite burden and immune response to Strongyloides venezuelensis in co-infected mice.

    PubMed

    de Rezende, Michelle Carvalho; Araújo, Emília Souza; Moreira, João Marcelo Peixoto; Rodrigues, Vanessa Fernandes; Rodrigues, Jailza Lima; Pereira, Cíntia A de Jesus; Negrão-Corrêa, Deborah

    2015-12-01

    Multiple schistosome and soil-transmitted nematode infections are frequently reported in human populations living in tropical areas of developing countries. In addition to exposure factors, the host immune response plays an important role in helminth control and morbidity in hosts with multiple infections; however, these aspects are difficult to evaluate in human populations. In the current study, female Swiss mice were simultaneously co-infected with Strongyloides venezuelensis and Schistosoma mansoni or infected with St. venezuelensis at 2, 4, or 14 weeks after Sc. mansoni infection. The simultaneously infected mice showed a similar parasite burden for St. venezuelensis compared with mono-infected mice. In contrast, there was a significant reduction of St. venezuelensis burden (primarily during the migration of the larvae) in mice that were previously infected with Sc. mansoni at the acute or chronic phase. Independent of the stage of Sc. mansoni infection, the St. venezuelensis co-infection was capable of inducing IL-4 production in the small intestine, increasing the IgE concentration in the serum and increasing eosinophilia in the lungs and intestine. This result suggests that the nematode infection stimulates local type 2 immune responses independently of the schistosomiasis stage. Moreover, previous Sc. mansoni infection stimulated early granulocyte infiltration in the lungs and trematode-specific IgM and IgG1 production that recognized antigens from St. venezuelensis infective larvae; these immune responses would act in the early control of St. venezuelensis larvae. Our data suggest that the effect of multiple helminth infections on host susceptibility and morbidity largely depends on the species of parasite and the immune response. PMID:26350380

  8. Sexual Preferences in Nutrient Utilization Regulate Oxygen Consumption and Reactive Oxygen Species Generation in Schistosoma mansoni: Potential Implications for Parasite Redox Biology

    PubMed Central

    Oliveira, Matheus P.; Correa Soares, Juliana B. R.; Oliveira, Marcus F.

    2016-01-01

    Schistosoma mansoni, one of the causative agents of human schistosomiasis, has a unique antioxidant network that is key to parasite survival and a valuable chemotherapeutic target. The ability to detoxify and tolerate reactive oxygen species increases along S. mansoni development in the vertebrate host, suggesting that adult parasites are more exposed to redox challenges than young stages. Indeed, adult parasites are exposed to multiple redox insults generated from blood digestion, activated immune cells, and, potentially, from their own parasitic aerobic metabolism. However, it remains unknown how reactive oxygen species are produced by S. mansoni metabolism, as well as their biological effects on adult worms. Here, we assessed the contribution of nutrients and parasite gender to oxygen utilization pathways, and reactive oxygen species generation in whole unpaired adult S. mansoni worms. We also determined the susceptibilities of both parasite sexes to a pro-oxidant challenge. We observed that glutamine and serum importantly contribute to both respiratory and non-respiratory oxygen utilization in adult worms, but with different proportions among parasite sexes. Analyses of oxygen utilization pathways revealed that respiratory rates were high in male worms, which contrast with high non-respiratory rates in females, regardless nutritional sources. Interestingly, mitochondrial complex I-III activity was higher than complex IV specifically in females. We also observed sexual preferences in substrate utilization to sustain hydrogen peroxide production towards glucose in females, and glutamine in male worms. Despite strikingly high oxidant levels and hydrogen peroxide production rates, female worms were more resistant to a pro-oxidant challenge than male parasites. The data presented here indicate that sexual preferences in nutrient metabolism in adult S. mansoni worms regulate oxygen utilization and reactive oxygen species production, which may differently contribute

  9. Sexual Preferences in Nutrient Utilization Regulate Oxygen Consumption and Reactive Oxygen Species Generation in Schistosoma mansoni: Potential Implications for Parasite Redox Biology.

    PubMed

    Oliveira, Matheus P; Correa Soares, Juliana B R; Oliveira, Marcus F

    2016-01-01

    Schistosoma mansoni, one of the causative agents of human schistosomiasis, has a unique antioxidant network that is key to parasite survival and a valuable chemotherapeutic target. The ability to detoxify and tolerate reactive oxygen species increases along S. mansoni development in the vertebrate host, suggesting that adult parasites are more exposed to redox challenges than young stages. Indeed, adult parasites are exposed to multiple redox insults generated from blood digestion, activated immune cells, and, potentially, from their own parasitic aerobic metabolism. However, it remains unknown how reactive oxygen species are produced by S. mansoni metabolism, as well as their biological effects on adult worms. Here, we assessed the contribution of nutrients and parasite gender to oxygen utilization pathways, and reactive oxygen species generation in whole unpaired adult S. mansoni worms. We also determined the susceptibilities of both parasite sexes to a pro-oxidant challenge. We observed that glutamine and serum importantly contribute to both respiratory and non-respiratory oxygen utilization in adult worms, but with different proportions among parasite sexes. Analyses of oxygen utilization pathways revealed that respiratory rates were high in male worms, which contrast with high non-respiratory rates in females, regardless nutritional sources. Interestingly, mitochondrial complex I-III activity was higher than complex IV specifically in females. We also observed sexual preferences in substrate utilization to sustain hydrogen peroxide production towards glucose in females, and glutamine in male worms. Despite strikingly high oxidant levels and hydrogen peroxide production rates, female worms were more resistant to a pro-oxidant challenge than male parasites. The data presented here indicate that sexual preferences in nutrient metabolism in adult S. mansoni worms regulate oxygen utilization and reactive oxygen species production, which may differently contribute

  10. Prevalence of Schistosomes and Soil-Transmitted Helminths and Morbidity Associated with Schistosomiasis among Adult Population in Lake Victoria Basin, Tanzania

    PubMed Central

    Siza, Julius E.; Kaatano, Godfrey M.; Chai, Jong-Yil; Eom, Keeseon S.; Rim, Han-Jong; Yong, Tai-Soon; Min, Duk-Young; Chang, Su Young; Ko, Yunsuk; Changalucha, John M.

    2015-01-01

    The objective of this study was to carry out a community survey on schistosomiais and soil-transmitted helminth (STH) infections in order to suggest feasible and effective intervention strategies in Lake Victoria basin, Tanzania. A total of 37 communities selected from 23 districts of the 4 regions in the Lake Victoria basin of Tanzania were involved in the study. From each of the selected locality, 50 adult community members, 25 males and 25 females, were recruited for the study. Each study participant was requested to submit stool and urine specimens. From each stool specimen, duplicate Kato-Katz thick smears were prepared and microscopically examined for Schistosoma mansoni and STH eggs. Urine specimens were processed by the filtration technique and microscopically examined for Schistosoma haematobium eggs. Ultrasound examination for morbidity due to schistosomiasis was performed. Mass treatment was done using praziquantel and albendazole for schistosome and STHs infections, respectively. Out of 1,606 adults who provided stool specimens, 199 (12.4%) were positive for S. mansoni, 349 (21.7%) for hookworms, 133 (8.3%) for Ascaris lumbricoides, and 33 (2.0%) for Trichuris trichiura. Out of 1,400 participants who provided urine specimens, 25 (1.8%) were positive for S. haematobium eggs. Because of the co-endemicity of these afflictions and their impact on vulnerable population groups, the helminthiasis could be simultaneously treated with 2 drugs, praziquantel for schistosomiasis and albendazole for STHs. PMID:26537031

  11. Prevalence of Schistosomes and Soil-Transmitted Helminths and Morbidity Associated with Schistosomiasis among Adult Population in Lake Victoria Basin, Tanzania.

    PubMed

    Siza, Julius E; Kaatano, Godfrey M; Chai, Jong-Yil; Eom, Keeseon S; Rim, Han-Jong; Yong, Tai-Soon; Min, Duk-Young; Chang, Su Young; Ko, Yunsuk; Changalucha, John M

    2015-10-01

    The objective of this study was to carry out a community survey on schistosomiais and soil-transmitted helminth (STH) infections in order to suggest feasible and effective intervention strategies in Lake Victoria basin, Tanzania. A total of 37 communities selected from 23 districts of the 4 regions in the Lake Victoria basin of Tanzania were involved in the study. From each of the selected locality, 50 adult community members, 25 males and 25 females, were recruited for the study. Each study participant was requested to submit stool and urine specimens. From each stool specimen, duplicate Kato-Katz thick smears were prepared and microscopically examined for Schistosoma mansoni and STH eggs. Urine specimens were processed by the filtration technique and microscopically examined for Schistosoma haematobium eggs. Ultrasound examination for morbidity due to schistosomiasis was performed. Mass treatment was done using praziquantel and albendazole for schistosome and STHs infections, respectively. Out of 1,606 adults who provided stool specimens, 199 (12.4%) were positive for S. mansoni, 349 (21.7%) for hookworms, 133 (8.3%) for Ascaris lumbricoides, and 33 (2.0%) for Trichuris trichiura. Out of 1,400 participants who provided urine specimens, 25 (1.8%) were positive for S. haematobium eggs. Because of the co-endemicity of these afflictions and their impact on vulnerable population groups, the helminthiasis could be simultaneously treated with 2 drugs, praziquantel for schistosomiasis and albendazole for STHs. PMID:26537031

  12. Validation of a Point-of-Care Circulating Cathodic Antigen Urine Cassette Test for Schistosoma mansoni Diagnosis in the Sahel, and Potential Cross-Reaction in Pregnancy.

    PubMed

    Greter, Helena; Krauth, Stefanie J; Ngandolo, Bongo N R; Alfaroukh, Idriss O; Zinsstag, Jakob; Utzinger, Jürg

    2016-02-01

    On the shores of Lake Chad, schistosomiasis among mobile pastoralists was investigated in a field laboratory. Point-of-care circulating cathodic antigen (POC-CCA) cassette test, reagent strip, and filtration were conducted on urine samples. Fresh stool samples were subjected to the Kato-Katz technique, and fixed samples were examined with an ether-concentration method at a reference laboratory. POC-CCA urine cassette tests revealed a Schistosoma mansoni prevalence of 6.9%, compared with only 0.5% by stool microscopy. Three pregnant women with otherwise negative urine and stool testing had positive POC-CCA. This observation raises concern of cross-reactivity in pregnancy. Hence, two pregnant women in Switzerland with no history of schistosomiasis were subjected to POC-CCA and one tested positive. Our data suggest that POC-CCA can be performed under extreme Sahelian conditions (e.g., temperatures > 40°C), and it is more sensitive than stool microscopy for S. mansoni diagnosis. However, potential cross-reactivity in pregnancy needs further investigation. PMID:26556831

  13. Prevalence and Morbidity Data on Schistosoma mansoni Infection in Two Rural Areas of Jequitinhonha and Rio Doce Valleys in Minas Gerais, Brazil

    PubMed Central

    Conceição, Maria José; Carlôto, Aline Eduardo; de Melo, Eric Vinaud; da Silva, Iran Mendonça; Coura, José Rodrigues

    2013-01-01

    Objective. This study aimed to compare the prevalence and morbidity data on Schistosoma mansoni infection in two rural areas: the Jequitinhonha valley (area 1) and the Rio Doce valley (area 2) in the state of Minas Gerais, Brazil, covering the period from 2007 to 2010. Material and Methods. The parasitological stool tests were based on the quantitative method of Kato modified by Katz et al. Three clinical forms were considered: type I—schistosomiasis infection, type II—hepatointestinal form, and type III—hepatosplenic form. Results. The prevalence of infection among inhabitants of area 1 was 22.9%, with 2.1% presenting the hepatosplenic form and two cases of schistosomal myeloradiculopathy. The infection prevalence rate in area 2 was 20.2%, with 3.3% presenting the hepatosplenic form. Conclusion and Recommendation. There was no difference in the prevalence and in the morbidity of Schistosoma mansoni infection between the two areas, but it was predominant in young men with a low intensity of infection. The cases of schistosomal myeloradiculopathy in area 1 can be highlighted: these emphasize that schistosomiasis should not be neglected in Brazil. The lack of infection control in both areas may be related to the poor sanitation system, the absence of previous treatment, and the reinfection process. PMID:27335859

  14. Recent situation of schistosomiasis in Indonesia.

    PubMed

    Izhar, Ali; Sinaga, R M; Sudomo, M; Wardiyo, N D

    2002-05-01

    Schistosomiasis in Indonesia is limited to two very isolated areas, the Napu and Lindu valleys, in the province of Central Sulawesi. The disease was initially found in 1937 in the village of Tomado. In 1940, a study on schistosomiasis in the Lake Lindu area was initiated and an infection rate of 56% among the people in the three villages of Anca, Tomado and Langko was found. Before a comprehensive control programme was initiated, the infection rate among the population of approximately 4000 people in the Napu valley was very high, e.g. 72% in the village of Winowanga. In 1982, more coordinated and intensive schistosomiasis control measures in the Napu and Lindu valleys were initiated. The average infection rate after control measures were greatly decreased-in Napu valley it was 1.83%, while in Lindu valley it was 0.46%, in 1999. The control approaches can be described over five phases, from 1982 to 1986, up to 1998 to present. In 1998, an agreement between the Government of Indonesia and the Asian Development Bank was signed to develop the schistosomiasis endemic areas of Central Sulawesi into a better socio-economic condition. The objectives of the project are not only to control schistosomiasis, but mainly to protect the National Park which is located between the Lindu and Napu valleys. It is an integrated project named 'Central Sulawesi Integrated Area Development and Conservation Project' and many relevant sectors have been involved in the implementation of this project for the development of the area, including control of schistosomiasis. The implementation of the integrated project started in 1999. PMID:12020902

  15. Potential of Sentinel Satellites for Schistosomiasis Monitoring

    NASA Astrophysics Data System (ADS)

    Li, C.-R.; Tang, L.-L.; Niu, H.-B.; Zhou, X.-N.; Liu, Z.-Y.; Ma, L.-L.; Zhou, Y.-S.

    2012-04-01

    Schistosomiasis is a parasitic disease that menaces human health. In terms of impact this disease is second only to malaria as the most devastating parasitic disease. Oncomelania hupensis is the unique intermediate host of Schistosoma, and hence monitoring and controlling of the number of oncomelania is key to reduce the risk of schistosomiasis transmission. Remote sensing technology can real-timely access the large-scale environmental factors related to oncomelania breeding and reproduction, such as temperature, moisture, vegetation, soil, and rainfall, and can also provide the efficient information to determine the location, area, and spread tendency of oncomelania. Many studies show that the correlation coefficient between oncomelania densities and remote sensing environmental factors depends largely on suitable and high quality remote sensing data used in retrieve environmental factors. Research achievements on retrieving environmental factors (which are related to the living, multiplying and transmission of oncomelania) by multi-source remote data are shown firstly, including: (a) Vegetation information (e.g., Modified Soil-Adjusted Vegetation Index, Normalized Difference Moisture Index, Fractional Vegetation Cover) extracted from optical remote sensing data, such as Landsat TM, HJ-1A/HSI image; (b) Surface temperature retrieval from Thermal Infrared (TIR) and passive-microwave remote sensing data; (c) Water region, soil moisture, forest height retrieval from synthetic aperture radar data, such as Envisat SAR, DLR's ESAR image. Base on which, the requirements of environmental factor accuracy for schistosomiasis monitoring will be analyzed and summarized. Our work on applying remote sensing technique to schistosomiasis monitoring is then presented. The fuzzy information theory is employed to analyze the sensitivity and feasibility relation between oncomelania densities and environmental factors. Then a mechanism model of predicting oncomelania distribution and

  16. School-based and community-based actions for scaling-up diagnosis and treatment of schistosomiasis toward its elimination in an endemic area of Brazil.

    PubMed

    Favre, Tereza C; Pereira, Ana Paula B; Beck, Lilian C N H; Galvão, Aline F; Pieri, Otávio S

    2015-09-01

    This study evaluated a school-based and a community-based scheme for diagnosis, treatment and follow-up of schistosomiasis mansoni among school-aged children in views of resolution CD49.R19 of the Pan American Health Organization toward the elimination of schistosomiasis as a public health problem in the Americas and subsequent commitments endorsed by the Brazilian government. The school-aged population from a representative municipality of the endemic area of Northeastern Brazil was randomly allocated to either school-based or community-based scheme. The two schemes were compared with regard to coverage of diagnosis by the Kato-Katz method (KK) at baseline, treatment of the positives for Schistosoma mansoni with praziquantel, treatment of the positives for soil-transmitted helminthes (STH) with mebendazole, as well as follow-up of treatment efficacy and reinfection assessed respectively at four and 12 months after treatment. Nutritional status of the positives for S. mansoni was assessed at baseline and re-assessed at 12 months after treatment. Coverage of diagnosis and treatment was satisfactory (>75%) in both schemes. Diagnosis coverage at baseline and at 12 months was significantly higher in the community scheme, whereas treatment coverage did not differ significantly between the two schemes either at baseline or at 12 months. The number of children covered per day was significantly higher in the schools than in the community at baseline but not at follow-up, when daily coverage was higher in the community. With regard to S. mansoni, overall treatment efficacy rate at four months was 90.8%, and reinfection rate at 12 months was 21.6%. For STH, overall treatment efficacy was 45.4% and reinfection, 32.8%. The nutritional status of the positives for S. mansoni at baseline did not change significantly at 12 months post-treatment. Actions targeted at this particularly vulnerable high-risk group should combine school-based and community-based interventions as well as

  17. Differential Anti-Glycan Antibody Responses in Schistosoma mansoni-Infected Children and Adults Studied by Shotgun Glycan Microarray

    PubMed Central

    van Diepen, Angela; Smit, Cornelis H.; van Egmond, Loes; Kabatereine, Narcis B.; Pinot de Moira, Angela; Dunne, David W.; Hokke, Cornelis H.

    2012-01-01

    Background Schistosomiasis (bilharzia) is a chronic and potentially deadly parasitic disease that affects millions of people in (sub)tropical areas. An important partial immunity to Schistosoma infections does develop in disease endemic areas, but this takes many years of exposure and maturation of the immune system. Therefore, children are far more susceptible to re-infection after treatment than older children and adults. This age-dependent immunity or susceptibility to re-infection has been shown to be associated with specific antibody and T cell responses. Many antibodies generated during Schistosoma infection are directed against the numerous glycans expressed by Schistosoma. The nature of glycan epitopes recognized by antibodies in natural schistosomiasis infection serum is largely unknown. Methodology/Principal Findings The binding of serum antibodies to glycans can be analyzed efficiently and quantitatively using glycan microarray approaches. Very small amounts of a large number of glycans are presented on a solid surface allowing binding properties of various glycan binding proteins to be tested. We have generated a so-called shotgun glycan microarray containing natural N-glycan and lipid-glycan fractions derived from 4 different life stages of S. mansoni and applied this array to the analysis of IgG and IgM antibodies in sera from children and adults living in an endemic area. This resulted in the identification of differential glycan recognition profiles characteristic for the two different age groups, possibly reflecting differences in age or differences in length of exposure or infection. Conclusions/Significance Using the shotgun glycan microarray approach to study antibody response profiles against schistosome-derived glycan elements, we have defined groups of infected individuals as well as glycan element clusters to which antibody responses are directed in S. mansoni infections. These findings are significant for further exploration of Schistosoma

  18. Two allelic isoforms of the serotonin transporter from Schistosoma mansoni display electrogenic transport and high selectivity for serotonin

    PubMed Central

    Fontana, Andréia C. K.; Sonders, Mark S.; Pereira-Junior, Olavo S.; Knight, Matty; Javitch, Jonathan A.; Rodrigues, Vanderlei; Amara, Susan G.; Mortensen, Ole V.

    2009-01-01

    The human blood fluke Schistosoma mansoni is the primary cause of schistosomiasis, a debilitating disease that affects 200 million individuals in over 70 countries. The biogenic amine serotonin is essential for the survival of the parasite and serotonergic proteins are potential novel drug targets for treating schistosomiasis. Here we characterize two novel serotonin transporter gene transcripts, SmSERT-A and SmSERT-B, from Schistosoma mansoni. Southern blot analysis shows that the two mRNAs are the products of different alleles of a single SmSERT gene locus. The two SmSERT forms differ in three amino acid positions near the N-terminus of the protein. Both SmSERTs are expressed in the adult form and in the sporocyst form (infected snails) of the parasite, but are absent from all other stages of the parasite’s complex life cycle. Heterologous expression of the two cDNAs in mammalian cells resulted in saturable, sodium-dependent serotonin transport activity with an apparent affinity for serotonin comparable to that of the human serotonin transporter. Although the two SmSERTs are pharmacologically indistinguishable from each other, efflux experiments reveal notably higher substrate selectivity for serotonin compared with their mammalian counterparts. Several well-established substrates for human SERT including (±)MDMA, S-(+)amphetamine, RU 24969, and m-CPP are not transported by SmSERTs, underscoring the higher selectivity of the schistosomal isoforms. Voltage clamp recordings of SmSERT substrate-elicited currents confirm the substrate selectivity observed in efflux experiments and suggest that it may be possible to exploit the electrogenic nature of SmSERT to screen for compounds that target the parasite in vivo. PMID:19549517

  19. Field evaluation of a new antibody-based diagnostic for Schistosoma haematobium and S. mansoni at the point-of-care in northeast Zimbabwe

    PubMed Central

    2014-01-01

    Background Rapid diagnostic tests (RDTs) for use at the point-of-care (POC) are likely to become increasingly useful as large-scale control programmes for schistosomiasis get underway. Given the low sensitivity of the reference standard egg count methods in detecting light infections, more sensitive tests will be required to monitor efforts aimed at eliminating schistosomiasis as advocated by the World Health Assembly Resolution 65.21 passed in 2012. Methods A recently developed RDT incorporating Schistosoma mansoni cercarial transformation fluid (SmCTF) for detection of anti-schistosome antibodies in human blood was here evaluated in children (mean age: 7.65 years; age range: 1-12 years) carrying light S. mansoni and S. haematobium infections in a schistosome-endemic area of Zimbabwe by comparison to standard parasitological techniques (i.e. the Kato-Katz faecal smear and urine filtration). Enzyme-linked immunosorbent assays (ELISAs) incorporating S. haematobium antigen preparations were also employed for additional comparison. Results The sensitivity of the SmCTF-RDT compared to standard parasitological methods was 100% while the specificity was 39.5%. It was found that the sera from RDT “false-positive” children showed significantly higher antibody titres in IgM-cercarial antigen preparation (CAP) and IgM-soluble egg antigen (SEA) ELISA assays than children identified by parasitology as “true-negatives”. Conclusions Although further evaluations are necessary using more accurate reference standard tests, these results indicate that the RDT could be a useful tool for the rapid prevalence-mapping of both S. mansoni and S. haematobium in schistosome-endemic areas. It is affordable, user-friendly and allows for diagnosis of both schistosome species at the POC. PMID:24666689

  20. Study of the snail intermediate hosts for Schistosoma mansoni on Itamaracá Island in northeast Brazil: spatial displacement of Biomphalaria glabrata by Biomphalaria straminea.

    PubMed

    Barbosa, Constança S; Barbosa, Verônica S; Nascimento, Wheverton C; Pieri, Otavio S; Araújo, Karina C G M

    2014-05-01

    In 2012 a malacological survey of the breeding sites of Biomphalaria glabrata and B. straminea , the two intermediate host snails of Schistosoma mansoni , was carried out on Itamaraca Island in Pernambuco, Brazil. This study has now been extended by studying the competition between the two species. Snails were collected and dissected to identify the species and tests were performed to verify S. mansoni infection. Student's t test was used to compare the proportion between the two species and their breeding sites and a parasitological survey was conducted among local residents, using the Kato-Katz method. The spatial distribution of the two snail species was determined using TerraView, while a snail density map was constructed by Kernel estimate. The survey identified two breeding sites for B. glabrata with 17 specimens and 19 breeding sites for B. straminea with 459 snails, all of them negative for S. mansoni infection. The statistical analysis revealed that the proportion of the numbers of specimens and breeding sites of B. straminea (37.84 ± 9.01) were significantly greater than those of B. glabrata (8.50 ± 6.50). Parasitological examinations from 41 residents diagnosed two cases of schistosomiasis with parasite loads of 60 and 84 eggs per 1 g of stool, respectively. This indiction of a competitive process between the two snail species requires monitoring of schistosomiasis in the resident and travelling human populations occupying this environment, which could potentially result in social and economic changes on the island risking its attraction as a centre for eco-tourism. PMID:24893012

  1. Fecal Occult Blood and Fecal Calprotectin as Point-of-Care Markers of Intestinal Morbidity in Ugandan Children with Schistosoma mansoni Infection

    PubMed Central

    Bustinduy, Amaya L.; Sousa-Figueiredo, José C.; Adriko, Moses; Betson, Martha; Fenwick, Alan; Kabatereine, Narcis; Stothard, J. Russell

    2013-01-01

    Background Calprotectin is a calcium-binding cytoplasmic protein found in neutrophils and increasingly used as a marker of bowel inflammation. Fecal occult blood (FOB) is also a dependable indicator of bowel morbidity. The objective of our study was to determine the applicability of these tests as surrogate markers of Schistosoma mansoni intestinal morbidity before and after treatment with praziquantel (PZQ). Methods 216 children (ages 3–9 years old) from Buliisa District in Lake Albert, Uganda were examined and treated with PZQ at baseline in October 2012 with 211 of them re-examined 24 days later for S. mansoni and other soil transmitted helminths (STH). POC calprotectin and FOB assays were performed at both time points on a subset of children. Associations between the test results and infection were analysed by logistic regression. Results Fecal calprotectin concentrations of 150–300 µg/g were associated with S. mansoni egg patent infection both at baseline and follow up (OR: 12.5 P = 0.05; OR: 6.8 P = 0.02). FOB had a very strong association with baseline anemia (OR: 9.2 P = 0.03) and medium and high egg intensity schistosomiasis at follow up (OR: 6.6 P = 0.03; OR: 51.3 P = 0.003). Both tests were strongly associated with heavy intensity S. mansoni infections. There was a significant decrease in FOB and calprotectin test positivity after PZQ treatment in those children who had egg patent schistosomiasis at baseline. Conclusions Both FOB and calprotectin rapid assays were found to correlate positively and strongly with egg patent S. mansoni infection with a positive ameloriation response after PZQ treatment indicative of short term reversion of morbidity. Both tests were appropriate for use in the field with excellent operational performance and reliability. Due to its lower-cost which makes its scale-up of use affordable, FOB could be immediately adopted as a monitoring tool for PC campaigns for efficacy evaluation before and after

  2. Synthesis of a sugar-based thiosemicarbazone series and structure-activity relationship versus the parasite cysteine proteases rhodesain, cruzain, and Schistosoma mansoni cathepsin B1.

    PubMed

    Fonseca, Nayara Cristina; da Cruz, Luana Faria; da Silva Villela, Filipe; do Nascimento Pereira, Glaécia Aparecida; de Siqueira-Neto, Jair Lage; Kellar, Danielle; Suzuki, Brian M; Ray, Debalina; de Souza, Thiago Belarmino; Alves, Ricardo José; Sales Júnior, Policarpo Ademar; Romanha, Alvaro José; Murta, Silvane Maria Fonseca; McKerrow, James H; Caffrey, Conor R; de Oliveira, Renata Barbosa; Ferreira, Rafaela Salgado

    2015-05-01

    The pressing need for better drugs against Chagas disease, African sleeping sickness, and schistosomiasis motivates the search for inhibitors of cruzain, rhodesain, and Schistosoma mansoni CB1 (SmCB1), the major cysteine proteases from Trypanosoma cruzi, Trypanosoma brucei, and S. mansoni, respectively. Thiosemicarbazones and heterocyclic analogues have been shown to be both antitrypanocidal and inhibitory against parasite cysteine proteases. A series of compounds was synthesized and evaluated against cruzain, rhodesain, and SmCB1 through biochemical assays to determine their potency and structure-activity relationships (SAR). This approach led to the discovery of 6 rhodesain, 4 cruzain, and 5 SmCB1 inhibitors with 50% inhibitory concentrations (IC50s) of ≤ 10 μM. Among the compounds tested, the thiosemicarbazone derivative of peracetylated galactoside (compound 4i) was discovered to be a potent rhodesain inhibitor (IC50 = 1.2 ± 1.0 μM). The impact of a range of modifications was determined; removal of thiosemicarbazone or its replacement by semicarbazone resulted in virtually inactive compounds, and modifications in the sugar also diminished potency. Compounds were also evaluated in vitro against the parasites T. cruzi, T. brucei, and S. mansoni, revealing active compounds among this series. PMID:25712353

  3. Synthesis of a Sugar-Based Thiosemicarbazone Series and Structure-Activity Relationship versus the Parasite Cysteine Proteases Rhodesain, Cruzain, and Schistosoma mansoni Cathepsin B1

    PubMed Central

    Fonseca, Nayara Cristina; da Cruz, Luana Faria; da Silva Villela, Filipe; do Nascimento Pereira, Glaécia Aparecida; de Siqueira-Neto, Jair Lage; Kellar, Danielle; Suzuki, Brian M.; Ray, Debalina; de Souza, Thiago Belarmino; Alves, Ricardo José; Júnior, Policarpo Ademar Sales; Romanha, Alvaro José; Murta, Silvane Maria Fonseca; McKerrow, James H.; Caffrey, Conor R.; de Oliveira, Renata Barbosa

    2015-01-01

    The pressing need for better drugs against Chagas disease, African sleeping sickness, and schistosomiasis motivates the search for inhibitors of cruzain, rhodesain, and Schistosoma mansoni CB1 (SmCB1), the major cysteine proteases from Trypanosoma cruzi, Trypanosoma brucei, and S. mansoni, respectively. Thiosemicarbazones and heterocyclic analogues have been shown to be both antitrypanocidal and inhibitory against parasite cysteine proteases. A series of compounds was synthesized and evaluated against cruzain, rhodesain, and SmCB1 through biochemical assays to determine their potency and structure-activity relationships (SAR). This approach led to the discovery of 6 rhodesain, 4 cruzain, and 5 SmCB1 inhibitors with 50% inhibitory concentrations (IC50s) of ≤10 μM. Among the compounds tested, the thiosemicarbazone derivative of peracetylated galactoside (compound 4i) was discovered to be a potent rhodesain inhibitor (IC50 = 1.2 ± 1.0 μM). The impact of a range of modifications was determined; removal of thiosemicarbazone or its replacement by semicarbazone resulted in virtually inactive compounds, and modifications in the sugar also diminished potency. Compounds were also evaluated in vitro against the parasites T. cruzi, T. brucei, and S. mansoni, revealing active compounds among this series. PMID:25712353

  4. Molecular evidence supports an african affinity of the neotropical freshwater gastropod, Biomphalaria glabrata, say 1818, an intermediate host for Schistosoma mansoni.

    PubMed

    Campbell, G; Jones, C S; Lockyer, A E; Hughes, S; Brown, D; Noble, L R; Rollinson, D

    2000-12-01

    Freshwater snails of the genus Biomphalaria, Preston 1910, are the most important and widely distributed intermediate hosts of Schistosoma mansoni, the blood fluke responsible for human intestinal schistosomiasis, in Africa and the Neotropics. S. mansoni is thought to have been imported repeatedly into the Americas during the last 500 years with the African slave trade. Surprisingly considering that the New and Old World separated 95-106 million years (Myr) ago, the disease rapidly became established due to the presence of endemic susceptible hosts. Reconstructing the phylogenetic relationships within Biomphalaria may provide insights into the successful intercontinental spread of S. mansoni. Parsimony and distance analyses of mitochondrial and nuclear sequences show African taxa to be monophyletic and Neotropical species paraphyletic, with Biomphalaria glabrata forming a separate clade from other Neotropical Biomphalaria, and ancestral to the African taxa. A west to east trans-Atlantic dispersal of a B. glabrata-like taxon, possibly as recently as the Plio-Pleistocene (1.8-3.6 Myr ago) according to a general mitochondrial clock, would fit these observations. Vicariance or an African origin for B. glabrata followed by multiple introductions to South America over the past 500 years with the African slave trade seem unlikely explanations. Knowledge of the phylogenetic relationships among important intermediate host species may prove useful in furthering control measures which exploit genetic differences in susceptibility to parasites, and in elucidating the evolution of schistosome resistance. PMID:11133023

  5. Monoclonal antibody-based dipstick assay: a reliable field applicable technique for diagnosis of Schistosoma mansoni infection using human serum and urine samples.

    PubMed

    Demerdash, Zeinab; Mohamed, Salwa; Hendawy, Mohamed; Rabia, Ibrahim; Attia, Mohy; Shaker, Zeinab; Diab, Tarek M

    2013-02-01

    A field applicable diagnostic technique, the dipstick assay, was evaluated for its sensitivity and specificity in diagnosing human Schistosoma mansoni infection. A monoclonal antibody (mAb) against S. mansoni adult worm tegumental antigen (AWTA) was employed in dipstick and sandwich ELISA for detection of circulating schistosome antigen (CSA) in both serum and urine samples. Based on clinical and parasitological examinations, 60 S. mansoni-infected patients, 30 patients infected with parasites other than schistosomiasis, and 30 uninfected healthy individuals were selected. The sensitivity and specificity of dipstick assay in urine samples were 86.7% and 90.0%, respectively, compared to 90.0% sensitivity and 91.7% specificity of sandwich ELISA. In serum samples, the sensitivity and specificity were 88.3% and 91.7% for dipstick assay vs. 91.7% and 95.0% for sandwich ELISA, respectively. The diagnostic efficacy of dipstick assay in urine and serum samples was 88.3% and 90.0%, while it was 90.8% and 93.3% for sandwich ELISA, respectively. The diagnostic indices of dipstick assay and ELISA either in serum or in urine were statistically comparable (P>0.05). In conclusion, the dipstick assay offers an alternative simple, rapid, non-invasive technique in detecting CSA or complement to stool examinations especially in field studies. PMID:23467705

  6. Schistosomiasis: The World's Number One Health Problem

    ERIC Educational Resources Information Center

    Mallon, Elizabeth J.

    1977-01-01

    Provides an informative discussion of the disease called schistosomiasis. The discussion covers environmental factors contributing to the disease, its symptoms, the disease organism and its vectors, and treatment of the disease. The author points out the need for water and soil pollution control in disease prone areas. (MR)

  7. Evaluation of the immune response and protective efficacy of Schistosoma mansoni Cathepsin B in mice using CpG dinucleotides as adjuvant.

    PubMed

    Ricciardi, Alessandra; Dalton, John P; Ndao, Momar

    2015-01-01

    Schistosomiasis is the most important human helminth infection due to its impact on public health. Worldwide, schistosomiasis is estimated to infect at least 200 million individuals while 700 million are at risk. The clinical manifestations are chronic and significantly decrease an individual's quality of life. Infected individuals suffer from long-term organ pathologies including fibrosis which eventually leads to organ failure. The development of a vaccine against this parasitic disease would contribute to a long-lasting decrease in disease spectrum and transmission. Our group has chosen to target Schistosoma mansoni Cathepsin B as a prospective vaccine candidate. The recombinant protein was tested in the presence of synthetic oligodeoxynucleotides containing unmethylated CpG dinucleotides, which are Toll-like receptor 9 agonists known to stimulate a Th1 response. This formulation conferred a 59% decrease in worm burden as well as a reduction in egg burden. Hepatic egg burden and intestinal egg burden were decreased by 56% and 54% respectively. Immunizations with the formulation elicited robust production of Sm-Cathepsin B specific antibodies, both IgG1 and IgG2c but with the latter predominating. Furthermore, splenocytes isolated from the immunized animals, compared to control animals, had increased secretion levels of key Th1 cytokines, IFN-γ and TNF-α, as well as the chemokine CCL5 when stimulated with recombinant Sm-Cathepsin B. These results highlight the potential of Sm-Cathepsin B/CpG as a vaccine candidate against schistosomiasis. PMID:25448114

  8. Effect of Chemotherapy with Praziquantel on the Production of Cytokines and Morbidity Associated with Schistosomiasis Mansoni▿

    PubMed Central

    Martins-Leite, P.; Gazzinelli, G.; Alves-Oliveira, L. F.; Gazzinelli, A.; Malaquias, L. C. C.; Correa-Oliveira, R.; Teixeira-Carvalho, A.; Silveira, A. M. S.

    2008-01-01

    The objective of the present study was to test the hypothesis that treatment of schistosomiasis mansoni with praziquantel can alter significantly the immune response of patients and generate a reversal of the level of fibrosis. Peripheral blood mononuclear cell (PBMC) samples were collected from, and abdominal ultrasound examinations conducted on, volunteers infected with Schistosoma mansoni and living in an area where the disease is endemic, both prior to and one year after treatment with praziquantel. Subjects were classified into groups according to the level of pathology (i.e., absent, incipient, moderate, or severe fibrosis). PBMCs were stimulated with schistosome soluble egg antigens (SEA), and the levels of production of the cytokines gamma interferon (IFN-γ), tumor necrosis factor alpha, transforming growth factor β, and interleukin-4 (IL-4), IL-10, and IL-13 were determined. The chemotherapy was effective in reducing morbidity, particularly for individuals presenting with severe fibrosis. When levels of cytokine production in posttreatment PBMC cultures stimulated by SEA were categorized as low or high, significant differences in the distribution of IL-13 levels between groups presenting with or not presenting with fibrosis were established. Comparison of pre- and posttreatment SEA-induced cytokine levels in individuals who had experienced no change in the grade of fibrosis following chemotherapy revealed that the level of IFN-γ decreased in subjects with fibrosis whereas that of IL-10 decreased in individuals with and without fibrosis. The data suggest that chemotherapy is effective in reducing the morbidity of the disease and that the level of IL-13 may be a useful indicator of the persistence of fibrosis following treatment. PMID:18519730

  9. Rural tourism as risk factor for the transmission of schistosomiasis in Minas Gerais, Brazil.

    PubMed

    Enk, Martin J; Caldeira, Roberta L; Carvalho, Omar S; Schall, Virginia T

    2004-01-01

    Recently, the booming rural tourism in endemic areas of the state of Minas Gerais was identified as a contributing factor in the dissemination of the infection with Schistosoma mansoni. This article presents data from six holiday resorts in a rural district approximately 100 km distant from Belo Horizonte, MG, Brazil, where a possibly new and until now unperceived way of transmission was observed. The infection takes place in swimming pools and little ponds, which are offered to tourists and the local population for fishing and leisure activities. The health authorities of the district reported cases of schistosomiasis among the local population after visiting these sites. As individuals of the non-immune middle class parts of the society of big urban centers also frequent these resorts, infection of these persons cannot be excluded. A malacological survey revealed the presence of molluscs of the species Biomphalaria glabrata and Biomphalaria straminea at the resorts. The snails (B. glabrata) of one resort tested positive for S. mansoni. In order to resolve this complex problem a multidisciplinary approach including health education, sanitation measures, assistance to the local health services, and evolvement of the local political authorities, the local community, the tourism association, and the owners of the leisure resorts is necessary. This evidence emphasizes the urgent need for a participative strategic plan to develop the local tourism in an organized and well-administered way. Only so this important source of income for the region can be ensured on the long term without disseminating the disease and putting the health of the visitors at risk. PMID:15486645

  10. Immunocapture of circulating Schistosoma mansoni cathepsin B antigen (Sm31) by anti-Sm31 polyclonal antibodies.

    PubMed

    González, Amelia Y; Sulbarán, Guidenn S; Ballen, Diana E; Cesari, Italo M

    2016-06-01

    Adult Schistosoma mansoni parasites have the capacity to degrade ingested host hemoglobin and other host plasma proteins by using a series of gut proteolytic enzymes, including cathepsin B; this enzyme is released to the host intravascular environment during regurgitations of adult worms. Cathepsin B becomes thus a circulating parasite component that has been shown to be specifically recognized as the Sm31 antigen by antibodies present in most S. mansoni infected patients. Taking advantage of this immunological property, we attempted here to immunocapture Sm31 from sera of infected patients using specific polyclonal rabbit antibodies raised against a highly enriched preparation of Sm31 and detect its intrinsic proteolytic activity using a previously described solid-phase procedure called Cysteine Protease Immuno Assay (CPIA). To produce highly specific anti-Sm31/cathepsin B antibodies, cathepsin B (Sm31 or SmCB) was enriched more than 3000-folds from an adult worm preparation using a series of conventional biochemical steps including ion exchange and affinity chromatography. Anti-cathepsin B antibodies were generated by immunizing rabbits with the enriched cathepsin B fraction; these antibodies recognized a band of Mr.~31 kDa in Western-blot (WB) analysis of this fraction and were able to capture, in a modified CPIA procedure, Sm31/SmCB present in sera from infected Venezuelan patients living in low endemic areas for schistosomiasis. CPIA showed 100% sensitivity and 100% specificity; representing a new diagnostic tool to detect circulating Sm31 antigen in actual infections. PMID:26709076

  11. High prevalence of Schistosoma mansoni in six health areas of - Kasansa health zone, Democratic Republic of the Congo: short report.

    PubMed

    Linsuke, Sylvie; Nundu, Sabin; Mupoyi, Sylvain; Mukele, Rodin; Mukunda, Faustin; Kabongo, Madeleine Mbuyi; Inocêncio da Luz, Raquel; Van Geertruyden, Jean-Pierre; Van Sprundel, Marc; Boelaert, Marleen; Polman, Katja; Lutumba, Pascal

    2014-12-01

    School-aged children suffer the most from schistosomiasis infection in sub Saharan Africa due to poverty and limited sanitary conditions. Mapping of disease burden is recommended and there is a need of updating prevalence data which is as old as 20 years in the Democratic Republic of Congo. An epidemiological and parasitological study was carried out in 2011 in the health zone of Kasansa. Six health areas (HA) were included in the study. In each health area, one primary school was selected. School-aged children were screened for S. mansoni infection using parallel Kato-Katz and direct microscopy techniques. A total of 335 school-aged children were screened. The average prevalence was 82.7% and ranged between 59.5-94.9%. Four of the six HAs had a prevalence level over 91%. Of all infected children, about half 112 (43.2%) had light parasite density. These results demonstrate that Schistosoma mansoni infection is a bigger problem than anticipated and there is an urgent need to implement effective control measures. PMID:25521351

  12. New Approaches with Different Types of Circulating Cathodic Antigen for the Diagnosis of Patients with Low Schistosoma mansoni Load

    PubMed Central

    Grenfell, Rafaella; Harn, Donald A.; Tundup, Smanla; Da'dara, Akram; Siqueira, Liliane; Coelho, Paulo Marcos Zech

    2013-01-01

    Background Schistosomiasis mansoni is a debilitating and sometimes fatal disease. Accurate diagnosis plays a key role in patient management and infection control. However, currently available parasitological methods are laborious and lack sensitivity. The selection of target antigen candidates has turned out to be a promising tool for the development of more sensitive diagnostic methods. In our previous investigations, the use of crude antigens led to false-positive results. Recently, focus has been given to highly purified Schistosoma mansoni antigens, especially to circulating antigens. Method Thus, our main goal was to test different types of circulating cathodic antigen glycoprotein (CCA), as “crude antigen,” the protein chain of recombinant CCA and two individual peptides. These schistosome proteins/peptides were tested in a new diagnostic method employing immunomagnetic separation based on the improvement of antigen–antibody binding. Principal Findings Use of recombinant CCA as a diagnostic antigen allowed us to develop a diagnostic assay with high sensitivity and specificity with no false-negative results. Interestingly, the “crude antigen” worked as a good marker for control of cure after praziquantel treatment. Conclusions/Significance Our new diagnostic method was superior to enzyme-linked immunosorbent assay in diagnosing low endemicity patients. PMID:23469295

  13. Pilot-scale production and characterization of paramyosin, a vaccine candidate for schistosomiasis japonica.

    PubMed

    Jiz, Mario; Wu, Hai-Wei; Meng, Rui; Pond-Tor, Sunthorn; Reynolds, Mindy; Friedman, Jennifer F; Olveda, Remigio; Acosta, Luz; Kurtis, Jonathan D

    2008-07-01

    Despite effective chemotherapy, schistosomiasis remains a major public health problem in the developing world, with at least 200 million active infections resulting in significant morbidity. Rapid reinfection after treatment, accompanied by extensive residual morbidity, mandates alternative control strategies, including vaccine development. Paramyosin, a myofibrillar protein found only in invertebrates, has been widely studied as a vaccine candidate for both Schistosoma mansoni and Schistosoma japonicum. Recently, we demonstrated that Th2-biased immune responses to paramyosin are associated with resistance to reinfection with S. japonicum in humans; however, challenges in the pilot-scale production of schistosome paramyosin have hampered further studies of this promising vaccine candidate. Here we report a method for the pilot-scale expression and purification of recombinant S. japonicum paramyosin (rSj97). rSj97 was extracted from Escherichia coli inclusion bodies and purified with sequential anion-exchange, hydroxyapatite, and size exclusion chromatography. The purified rSj97 was >95% pure as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis and was free of significant endotoxin contamination. We demonstrate that, like native paramyosin, rSj97 adopts an alpha-helical coiled-coil tertiary structure and binds immunoglobulin and collagen. Naïve mice infected with S. japonicum produce anti-rSj97 immunoglobulin G (IgG) antibodies as early as 4 weeks postinfection, while sera collected from S. japonicum-infected individuals contain anti-rSj97 IgE antibodies. Our method for pilot-scale production of recombinant full-length paramyosin will facilitate preclinical evaluation of paramyosin as a vaccine for schistosomiasis. PMID:18426875

  14. Distribution and abundance of schistosomiasis and fascioliasis host snails along the Mara River in Kenya and Tanzania

    PubMed Central

    Dida, Gabriel O.; Gelder, Frank B.; Anyona, Douglas N.; Matano, Ally-Said; Abuom, Paul O.; Adoka, Samson O.; Ouma, Collins; Kanangire, Canisius K.; Owuor, Phillip O.; Ofulla, Ayub V. O.

    2014-01-01

    We purposively selected 39 sampling sites along the Mara River and its two perennial tributaries of Amala and Nyangores and sampled snails. In addition, water physicochemical parameters (temperature, turbidity, dissolved oxygen, conductivity, alkalinity, salinity and pH) were taken to establish their influence on the snail abundance and habitat preference. Out of the 39 sites sampled, 10 (25.6%) had snails. The snail species encountered included Biomphalaria pfeifferi Krauss – the intermediate host of Schistosoma mansoni Sambon, Bulinus africanus – the intermediate host of Schistosoma haematobium, and Lymnaea natalensis Krauss – the intermediate host of both Fasciola gigantica and F. hepatica Cobbold. Ceratophallus spp., a non-vector snail was also encountered. Most (61.0%) of the snails were encountered in streamside pools. Schistosomiasis-transmitting host snails, B. pfeifferi and B. africanus, were fewer than fascioliasis-transmitting Lymnaea species. All the four different snail species were found to be attached to different aquatic weeds, with B. pfeifferi accounting for over half (61.1%) of the snails attached to the sedge, followed by B. africanus and Lymnaea spp., accounting for 22.2 and 16.7%, respectively. Ceratophallus spp. were non-existent in sedge. The results from this preliminary study show that snails intermediate hosts of schistosomiasis and fascioliasis exists in different habitats, in few areas along the Mara River, though their densities are still low to have any noticeable impacts on disease transmission in case they are infected. The mere presence of the vector snails in these focal regions calls for their immediate control and institution of proper regulations, management, and education among the locals that can help curtail the spread of the snails and also schistosomiasis and fascioliasis within the Mara River basin. PMID:25405008

  15. In Vitro and In Vivo Activities of Arachidonic Acid against Schistosoma mansoni and Schistosoma haematobium▿

    PubMed Central

    El Ridi, Rashika; Aboueldahab, Marwa; Tallima, Hatem; Salah, Mohamed; Mahana, Noha; Fawzi, Samia; Mohamed, Shadia H.; Fahmy, Omar M.

    2010-01-01

    The development of arachidonic acid (ARA) for treatment of schistosomiasis is an entirely novel approach based on a breakthrough discovery in schistosome biology revealing that activation of parasite tegument-bound neutral sphingomyelinase (nSMase) by unsaturated fatty acids, such as ARA, induces exposure of parasite surface membrane antigens to antibody binding and eventual attrition of developing schistosomula and adult worms. Here, we demonstrate that 5 mM ARA leads to irreversible killing of ex vivo 1-, 3-, 4-, 5-, and 6-week-old Schistosoma mansoni and 9-, 10-, and 12-week-old Schistosoma haematobium worms within 3 to 4 h, depending on the parasite age, even when the worms were maintained in up to 50% fetal calf serum. ARA-mediated worm attrition was prevented by nSMase inhibitors, such as CaCl2 and GW4869. Scanning and transmission electron microscopy revealed that ARA-mediated worm killing was associated with spine destruction, membrane blebbing, and disorganization of the apical membrane structure. ARA-mediated S. mansoni and S. haematobium worm attrition was reproduced in vivo in a series of 6 independent experiments using BALB/c or C57BL/6 mice, indicating that ARA in a pure form (Sigma) or included in infant formula (Nestle) consistently led to 40 to 80% decrease in the total worm burden. Arachidonic acid is already marketed for human use in the United States and Canada for proper development of newborns and muscle growth of athletes; thus, ARA has potential as a safe and cost-effective addition to antischistosomal therapy. PMID:20479203

  16. Morphological Characteristics of Schistosoma mansoni PZQ-Resistant and -Susceptible Strains Are Different in Presence of Praziquantel

    PubMed Central

    Pinto-Almeida, António; Mendes, Tiago; de Oliveira, Rosimeire Nunes; Corrêa, Sheila de Andrade Penteado; Allegretti, Silmara Marques; Belo, Silvana; Tomás, Ana; Anibal, Fernanda de Freitas; Carrilho, Emanuel; Afonso, Ana

    2016-01-01

    Schistosomiasis is one of the most common human parasitic diseases whose socioeconomic impact is only surpassed by malaria. Praziquantel (PZQ) is the only drug commercially available for the treatment of all schistosome species causing disease in humans. However, there has been stronger evidences of PZQ-resistance on Schistosoma mansoni and thus it is very important to study the phenotypic characteristics associated with it. The aim of this study was to evaluate morphological alterations in S. mansoni PZQ-resistant adult worms and eggs, by comparing a PZQ- resistant strain obtained under PZQ drug pressure with a PZQ-susceptible strain. For this, scanning electronic microscopy was used to assess tegumental responsiveness of both strains under PZQ exposure, and optical microscopy allowed the monitoring of worms and eggs in the presence of the drug. Those assays showed that PZQ-susceptible worms exposed to the drug had more severe tegumental damages than the resistant one, which had only minor alterations. Moreover, contrary to what occurred in the susceptible strain, resistant worms were viable after PZQ exposure and gradually regaining full motility after removal of the drug. Eggs from resistant strain parasites are considerably smaller than those from susceptible strain. Our results suggest that there might be a difference in the tegument composition of the resistant strain and that worms are less responsive to PZQ. Changes observed in egg morphology might imply alterations in the biology of schistosomes associated to PZQ-resistance, which could impact on transmission and pathology of the disease. Moreover, we propose a hypothetical scenario where there is a different egg tropism of the S. mansoni resistant strain. This study is the first comparing two strains that only differ in their resistance characteristics, which makes it a relevant step in the search for resistance determinants. PMID:27199925

  17. Morphological Characteristics of Schistosoma mansoni PZQ-Resistant and -Susceptible Strains Are Different in Presence of Praziquantel.

    PubMed

    Pinto-Almeida, António; Mendes, Tiago; de Oliveira, Rosimeire Nunes; Corrêa, Sheila de Andrade Penteado; Allegretti, Silmara Marques; Belo, Silvana; Tomás, Ana; Anibal, Fernanda de Freitas; Carrilho, Emanuel; Afonso, Ana

    2016-01-01

    Schistosomiasis is one of the most common human parasitic diseases whose socioeconomic impact is only surpassed by malaria. Praziquantel (PZQ) is the only drug commercially available for the treatment of all schistosome species causing disease in humans. However, there has been stronger evidences of PZQ-resistance on Schistosoma mansoni and thus it is very important to study the phenotypic characteristics associated with it. The aim of this study was to evaluate morphological alterations in S. mansoni PZQ-resistant adult worms and eggs, by comparing a PZQ- resistant strain obtained under PZQ drug pressure with a PZQ-susceptible strain. For this, scanning electronic microscopy was used to assess tegumental responsiveness of both strains under PZQ exposure, and optical microscopy allowed the monitoring of worms and eggs in the presence of the drug. Those assays showed that PZQ-susceptible worms exposed to the drug had more severe tegumental damages than the resistant one, which had only minor alterations. Moreover, contrary to what occurred in the susceptible strain, resistant worms were viable after PZQ exposure and gradually regaining full motility after removal of the drug. Eggs from resistant strain parasites are considerably smaller than those from susceptible strain. Our results suggest that there might be a difference in the tegument composition of the resistant strain and that worms are less responsive to PZQ. Changes observed in egg morphology might imply alterations in the biology of schistosomes associated to PZQ-resistance, which could impact on transmission and pathology of the disease. Moreover, we propose a hypothetical scenario where there is a different egg tropism of the S. mansoni resistant strain. This study is the first comparing two strains that only differ in their resistance characteristics, which makes it a relevant step in the search for resistance determinants. PMID:27199925

  18. Immunization with recombinantly expressed glycan antigens from Schistosoma mansoni induces glycan-specific antibodies against the parasite

    PubMed Central

    Prasanphanich, Nina Salinger; Luyai, Anthony E; Song, Xuezheng; Heimburg-Molinaro, Jamie; Mandalasi, Msano; Mickum, Megan; Smith, David F; Nyame, A Kwame; Cummings, Richard D

    2014-01-01

    Schistosomiasis caused by infection with parasitic helminths of Schistosoma spp. is a major global health problem due to inadequate treatment and lack of a vaccine. The immune response to schistosomes includes glycan antigens, which could be valuable diagnostic markers and vaccine targets. However, no precedent exists for how to design vaccines targeting eukaryotic glycoconjugates. The di- and tri-saccharide motifs LacdiNAc (GalNAcβ1,4GlcNAc; LDN) and fucosylated LacdiNAc (GalNAcβ1,4(Fucα1-3)GlcNAc; LDNF) are the basis for several important schistosome glycan antigens. They occur in monomeric form or as repeating units (poly-LDNF) and as part of a variety of different glycoconjugates. Because chemical synthesis and conjugation of such antigens is exceedingly difficult, we sought to develop a recombinant expression system for parasite glycans. We hypothesized that presentation of parasite glycans on the cell surface would induce glycan-specific antibodies. We generated Chinese hamster ovary (CHO) Lec8 cell lines expressing poly-LDN (L8-GT) and poly-LDNF (L8-GTFT) abundantly on their membrane glycoproteins. Sera from Schistosoma mansoni-infected mice were highly cross-reactive with the cells and with cell-surface N-glycans. Immunizing mice with L8-GT and L8-GTFT cells induced glycan-specific antibodies. The L8-GTFT cells induced a sustained booster response, with antibodies that bound to S. mansoni lysates and recapitulated the exquisite specificity of the anti-parasite response for particular presentations of LDNF antigen. In summary, this recombinant expression system promotes successful generation of antibodies to the glycans of S. mansoni, and it can be adapted to study the role of glycan antigens and anti-glycan immune responses in many other infections and pathologies. PMID:24727440

  19. An epidemiological study of Schistosoma haematobium and S. mansoni infection in thirty-five rural Egyptian villages.

    PubMed

    Miller, F; Hussein, M; Mancy, K H; Hilbert, M S; Monto, A S; Barakat, R M

    1981-12-01

    Probability samples of individuals from 35 village communities in the rural Egyptian Nile Valley were examined for the presence of schistosome ova by sedimentation of urine and by the MIFC technique for stools. In all there were 12,933 persons selected of which 11,337 provided specimens for examination from a total population of 66,768 persons divided among three governorates: 37% in North Central Delta, 31% in Upper-Middle Egypt and 32% in the Upper Egypt. After controlling the differences attributed to sampling methods, 30% of the villagers from Kafr El Sheikh, were found positive for S. haematobium and 20% for S. mansoni. The prevalence of schistosomiasis in the Kafr El Sheikh villages was 42%. South of the Nile Delta in the Beni Suef villages, 27% were found positive for S. haematobium and less than 1% positive for S. mansoni. In Aswan, prevalence was associated with the type and location of the village. Prevalence was low (4%) in villages located on high barren ground, but elevated (25%) in a village built within cropped and irrigated land. S. mansoni cases were also in the Aswan villagers; however, local acquisition of this infection was not substantiated. The specific age-sex distributions for both schistosomes species were characteristic with a notable difference in the male-female infection ratio that increased from north to south. The source of domestic water supply and prevalence of infection were consistently associated. These results were compared to past findings in order to provide a frame of reference to aid in the development of future surveillance and investigations. PMID:7342382

  20. Quantitative High-Throughput Screen Identifies Inhibitors of the Schistosoma mansoni Redox Cascade

    PubMed Central

    Simeonov, Anton; Jadhav, Ajit; Sayed, Ahmed A.; Wang, Yuhong; Nelson, Michael E.; Thomas, Craig J.; Inglese, James; Williams, David L.; Austin, Christopher P.

    2008-01-01

    Schistosomiasis is a tropical disease associated with high morbidity and mortality, currently affecting over 200 million people worldwide. Praziquantel is the only drug used to treat the disease, and with its increased use the probability of developing drug resistance has grown significantly. The Schistosoma parasites can survive for up to decades in the human host due in part to a unique set of antioxidant enzymes that continuously degrade the reactive oxygen species produced by the host's innate immune response. Two principal components of this defense system have been recently identified in S. mansoni as thioredoxin/glutathione reductase (TGR) and peroxiredoxin (Prx) and as such these enzymes present attractive new targets for anti-schistosomiasis drug development. Inhibition of TGR/Prx activity was screened in a dual-enzyme format with reducing equivalents being transferred from NADPH to glutathione via a TGR-catalyzed reaction and then to hydrogen peroxide via a Prx-catalyzed step. A fully automated quantitative high-throughput (qHTS) experiment was performed against a collection of 71,028 compounds tested as 7- to 15-point concentration series at 5 µL reaction volume in 1536-well plate format. In order to generate a robust data set and to minimize the effect of compound autofluorescence, apparent reaction rates derived from a kinetic read were utilized instead of end-point measurements. Actives identified from the screen, along with previously untested analogues, were subjected to confirmatory experiments using the screening assay and subsequently against the individual targets in secondary assays. Several novel active series were identified which inhibited TGR at a range of potencies, with IC50s ranging from micromolar to the assay response limit (∼25 nM). This is, to our knowledge, the first report of a large-scale HTS to identify lead compounds for a helminthic disease, and provides a paradigm that can be used to jump-start development of novel

  1. Anthelmintic Activity In Vivo of Epiisopiloturine against Juvenile and Adult Worms of Schistosoma mansoni

    PubMed Central

    Guimarães, Maria A.; de Oliveira, Rosimeire N.; Véras, Leiz M. C.; Lima, David F.; Campelo, Yuri D. M.; Campos, Stefano Augusto; Kuckelhaus, Selma A. S.; Pinto, Pedro L. S.; Eaton, Peter; Mafud, Ana C.; Mascarenhas, Yvonne P.; Allegretti, Silmara M.; de Moraes, Josué; Lolić, Aleksandar; Verbić, Tatjana; Leite, José Roberto S. A.

    2015-01-01

    Schistosomiasis is a serious disease currently estimated to affect more that 207 million people worldwide. Due to the intensive use of praziquantel, there is increasing concern about the development of drug-resistant strains. Therefore, it is necessary to search for and investigate new potential schistosomicidal compounds. This work reports the in vivo effect of the alkaloid epiisopiloturine (EPI) against adults and juvenile worms of Schistosoma mansoni. EPI was first purified its thermal behavior and theoretical solubility parameters charaterised. In the experiment, mice were treated with EPI over the 21 days post-infection with the doses of 40 and 200 mg/kg, and 45 days post-infection with single doses of 40, 100 and 300 mg/kg. The treatment with EPI at 40 mg/kg was more effective in adult worms when compared with doses of 100 and 300 mg/kg. The treatment with 40 mg/kg in adult worms reduced parasite burden significantly, lead to reduction in hepatosplenomegaly, reduced the egg burden in faeces, and decreased granuloma diameter. Scanning electron microscopy revealed morphological changes to the parasite tegument after treatment, including the loss of important features. Additionally, the in vivo treatment against juvenile with 40 mg/kg showed a reduction of the total worm burden of 50.2%. Histopathological studies were performed on liver, spleen, lung, kidney and brain and EPI was shown to have a DL50 of 8000 mg/kg. Therefore EPI shows potential to be used in schistosomiasis treatment. This is the first time that schistosomicidal in vivo activity of EPI has been reported. PMID:25816129

  2. Assessment of toxicity of Moringa oleifera flower extract to Biomphalaria glabrata, Schistosoma mansoni and Artemia salina.

    PubMed

    Rocha-Filho, Cláudio A A; Albuquerque, Lidiane P; Silva, Luanna R S; Silva, Patrícia C B; Coelho, Luana C B B; Navarro, Daniela M A F; Albuquerque, Monica C P A; Melo, Ana Maria M A; Napoleão, Thiago H; Pontual, Emmanuel V; Paiva, Patrícia M G

    2015-08-01

    This study reports the effect of an aqueous extract from Moringa oleifera Lam. flowers on Biomphalaria glabrata embryos and adults and on Schistosoma mansoni adult worms. The extract contains tannins, saponins, flavones, flavonols, xanthones, and trypsin inhibitor activity. The toxicity of the extract on Artemia salina larvae was also investigated to determine the safety of its use for schistosomiasis control. After incubation for 24h, the flower extract significantly (p<0.05) delayed the development of B. glabrata embryos and promoted mortality of adult snails (LC50: 2.37±0.5mgmL(-1)). Furthermore, treatment with the extract disrupted the development of embryos generated by snails, with most of them remaining in the blastula stage while control embryos were already in the gastrula stage. Flower extract killed A. salina larvae with a LC50 value (0.2±0.015mgmL(-1)) lower than that determined for snails. A small reduction (17%) in molluscicidal activity was detected when flower extract (2.37mgmL(-1)) was exposed to tropical environmental conditions (UVI index ranging from 1 to 14, temperature from 25 to 30°C, and 65% relative humidity). Toxicity to A. salina was also reduced (LC50 value of 0.28±0.01mgmL(-1)). In conclusion, M. oleifera flower extract had deleterious effects on B. glabrata adults and embryos. However, unrestricted use to control schistosomiasis should be avoided due to the toxicity of this extract on A. salina. PMID:25867917

  3. Drugs for treating urinary schistosomiasis

    PubMed Central

    Kramer, Christine V; Zhang, Fan; Sinclair, David; Olliaro, Piero L

    2014-01-01

    Background Urinary schistosomiasis is caused by an intravascular infection with parasitic Schistosoma haematobium worms. The adult worms typically migrate to the venous plexus of the human bladder and excrete eggs which the infected person passes in their urine. Chronic infection can cause substantial morbidity and long-term complications as the eggs become trapped in human tissues causing inflammation and fibrosis. We summarised evidence of drugs active against the infection. This is new edition of a review first published in 1997. Objectives To evaluate the efficacy and safety of drugs for treating urinary schistosomiasis. Search methods We searched the Cochrane Infectious Diseases Group Specialized Register, MEDLINE, CENTRAL, EMBASE and LILACS and reference lists of articles up to 23 May 2014. Selection criteria Randomized controlled trials (RCTs) of antischistosomal drugs and drug combinations compared to placebo, no intervention, or each other. Data collection and analysis Two researchers independently screened the records, extracted the data and assessed risk of bias. The primary efficacy outcomes were parasitological failure (defined as the continued presence of S. haematobium eggs in the urine at time points greater than one month after treatment), and percent reduction of egg counts from baseline. We presented dichotomous data as risk ratios (RR), and continuous data as mean difference (MD), alongside their 95% confidence intervals (CIs). Where appropriate we combined trials in meta analyses or tables. We assessed the quality of evidence using the GRADE approach. Main results We included 30 RCTs enrolling 8165 participants in this review. Twenty-four trials were conducted in children in sub-Saharan Africa, and 21 trials were over 20 years old. Many studies were assessed as being at unclear risk of bias due to inadequate descriptions of study methods. Praziquantel On average, a single 40 mg/kg dose of praziquantel reduced the proportion of people still

  4. Preliminary crystallographic studies of a Schistosoma mansoni antigen (Sm21.7) dynein light-chain (DLC) domain

    PubMed Central

    Costa, M. A. F.; Rodrigues, F. T. G.; Chagas, B. C. A.; Rezende, C. M. F.; Goes, A. M.; Nagem, R. A. P.

    2014-01-01

    Schistosomiasis is an inflammatory chronic disease that represents a major health problem in tropical and subtropical countries. The drug of choice for treatment, praziquantel, is effective in killing adult worms but fails to kill immature forms and prevent reinfection. One prominent antigen candidate for an anti-schistosomiasis vaccine is the protein Sm21.7 (184 amino-acid residues) from Schistosoma mansoni, a tegumental protein capable of reducing the worm burden in a murine immunization model. In the present work, the Sm21.7 gene was cloned and expressed in Escherichia coli and the full-length protein was purified to homogeneity. Crystals of recombinant Sm21.7 suitable for X-ray diffraction were obtained using PEG monomethyl ether 2000 as a precipitant. X-ray diffraction images of a native crystal (at 2.05 Å resolution) and a quick-cryosoaked NaI derivative (at 1.95 Å resolution) were collected on the W01B-MX2 beamline at the Laboratório Nacional de Luz Síncrotron (LNLS, Brazilian Synchrotron Light Laboratory/MCT). Both crystals belonged to the hexagonal space group P6122, with similar unit-cell parameters a = b = 108.5, c = 55.8 Å. SIRAS-derived phases were used to generate the first electron-density map, from which a partial three-dimensional model of Sm21.7 (from Gln89 to Asn184) was automatically constructed. Anaysis of dissolved crystals by SDS–PAGE confirmed that the protein was cleaved in the crystallization drop and only the Sm21.7 C-terminal domain was crystallized. The structure of the Sm21.7 C-terminal domain will help in the localization of the epitopes responsible for its protective immune responses, constituting important progress in the development of an anti-schistosomiasis vaccine. PMID:24915098

  5. Dot-ELISA in diagnosis of schistosomiasis.

    PubMed

    Madwar, M A; Hassan, M M

    1989-12-01

    One microliter of S. mansoni egg antigen was dotted directly on the nitrocellulose paper sheet acting as the adsorbent surface (9 dots/paper). The sera of 25 Egyptian patients and 15 healthy persons (2 microliters of each) were dotted over the antigen dots, then 2 ml of each of the blocking, washing, HRP-conjugated IgG and DAB adding procedures, were added over the nitrocellulose paper in the petri-dish at room temperature. An intact brown circle (by naked-eye) indicates a positive in Dot-ELISA. There is an insignificant dot colour intensities in different clinical stages of S. mansoni infected Egyptians whereas, a direct relation was obtained between egg count and the colour intensity of the dots. The test had 100% sensitivity and 86% specificity thus it appears to be useful for both laboratory and field studies. PMID:2794577

  6. Schistosoma mansoni Egg, Adult Male and Female Comparative Gene Expression Analysis and Identification of Novel Genes by RNA-Seq

    PubMed Central

    Anderson, Letícia; Amaral, Murilo S.; Beckedorff, Felipe; Silva, Lucas F.; Dazzani, Bianca; Oliveira, Katia C.; Almeida, Giulliana T.; Gomes, Monete R.; Pires, David S.; Setubal, João C.; DeMarco, Ricardo; Verjovski-Almeida, Sergio

    2015-01-01

    Background Schistosomiasis is one of the most prevalent parasitic diseases worldwide and is a public health problem. Schistosoma mansoni is the most widespread species responsible for schistosomiasis in the Americas, Middle East and Africa. Adult female worms (mated to males) release eggs in the hepatic portal vasculature and are the principal cause of morbidity. Comparative separate transcriptomes of female and male adult worms were previously assessed with using microarrays and Serial Analysis of Gene Expression (SAGE), thus limiting the possibility of finding novel genes. Moreover, the egg transcriptome was analyzed only once with limited bacterially cloned cDNA libraries. Methodology/Principal findings To compare the gene expression of S. mansoni eggs, females, and males, we performed RNA-Seq on these three parasite forms using 454/Roche technology and reconstructed the transcriptome using Trinity de novo assembly. The resulting contigs were mapped to the genome and were cross-referenced with predicted Smp genes and H3K4me3 ChIP-Seq public data. For the first time, we obtained separate, unbiased gene expression profiles for S. mansoni eggs and female and male adult worms, identifying enriched biological processes and specific enriched functions for each of the three parasite forms. Transcripts with no match to predicted genes were analyzed for their protein-coding potential and the presence of an encoded conserved protein domain. A set of 232 novel protein-coding genes with putative functions related to reproduction, metabolism, and cell biogenesis was detected, which contributes to the understanding of parasite biology. Conclusions/Significance Large-scale RNA-Seq analysis using de novo assembly associated with genome-wide information for histone marks in the vicinity of gene models constitutes a new approach to transcriptome analysis that has not yet been explored in schistosomes. Importantly, all data have been consolidated into a UCSC Genome Browser search

  7. The Diterpenoid 7-Keto-Sempervirol, Derived from Lycium chinense, Displays Anthelmintic Activity against both Schistosoma mansoni and Fasciola hepatica

    PubMed Central

    Edwards, Jennifer; Brown, Martha; Peak, Emily; Bartholomew, Barbara; Nash, Robert J.; Hoffmann, Karl F.

    2015-01-01

    Background Two platyhelminths of biomedical and commercial significance are Schistosoma mansoni (blood fluke) and Fasciola hepatica (liver fluke). These related trematodes are responsible for the chronic neglected tropical diseases schistosomiasis and fascioliasis, respectively. As no vaccine is currently available for anti-flukicidal immunoprophylaxis, current treatment is mediated by mono-chemical chemotherapy in the form of mass drug administration (MDA) (praziquantel for schistosomiasis) or drenching (triclabendazole for fascioliasis) programmes. This overreliance on single chemotherapeutic classes has dramatically limited the number of novel chemical entities entering anthelmintic drug discovery pipelines, raising significant concerns for the future of sustainable blood and liver fluke control. Methodology/ Principle Findings Here we demonstrate that 7-keto-sempervirol, a diterpenoid isolated from Lycium chinense, has dual anthelmintic activity against related S. mansoni and F. hepatica trematodes. Using a microtiter plate-based helminth fluorescent bioassay (HFB), this activity is specific (Therapeutic index = 4.2, when compared to HepG2 cell lines) and moderately potent (LD50 = 19.1 μM) against S. mansoni schistosomula cultured in vitro. This anti-schistosomula effect translates into activity against both adult male and female schistosomes cultured in vitro where 7-keto-sempervirol negatively affects motility/behaviour, surface architecture (inducing tegumental holes, tubercle swelling and spine loss/shortening), oviposition rates and egg morphology. As assessed by the HFB and microscopic phenotypic scoring matrices, 7-keto-sempervirol also effectively kills in vitro cultured F. hepatica newly excysted juveniles (NEJs, LD50 = 17.7 μM). Scanning electron microscopy (SEM) evaluation of adult F. hepatica liver flukes co-cultured in vitro with 7-keto-sempervirol additionally demonstrates phenotypic abnormalities including breaches in tegumental integrity and

  8. Workshop report: Schistosomiasis vaccine clinical development and product characteristics.

    PubMed

    Mo, Annie X; Colley, Daniel G

    2016-02-17

    A schistosomiasis vaccine meeting was organized to evaluate the utility of a vaccine in public health programs, to discuss clinical development paths, and to define basic product characteristics for desirable vaccines to be used in the context of schistosomiasis control and elimination programs. It was concluded that clinical evaluation of a schistosomiasis vaccine is feasible with appropriate trial design and tools. Some basic Preferred Product Characteristics (PPC) for a human schistosomiasis vaccine and for a veterinary vaccine for bovine use were also proposed. PMID:26721329

  9. Variations in helminth faecal egg counts in Kato-Katz thick smears and their implications in assessing infection status with Schistosoma mansoni.

    PubMed

    Berhe, Nega; Medhin, Girmay; Erko, Birhanu; Smith, Tara; Gedamu, Selamawitt; Bereded, Dereje; Moore, Rashida; Habte, Endashaw; Redda, Abraham; Gebre-Michael, Teshome; Gundersen, Svein Gunnar

    2004-01-01

    Examination of stool specimens by Kato-Katz (K-K) thick smears is the standard method recommended by the WHO for field diagnosis of intestinal schistosomiasis. However, there is increasing concern that this technique has low diagnostic sensitivity. In 326 study subjects, we compared the diagnostic yield of examining one, three or five Kato-Katz thick smears prepared from one stool specimen using 41.7 mg templates. In a subset of 169 subjects who had no demonstrable Schistosoma mansoni eggs in their first three Kato-Katz thick smears, we assessed the comparative advantage of examining an additional three Kato-Katz thick smears from another stool specimen, taken four weeks later, to that of cumulative yield obtained by examining all five Kato-Katz thick smears derived from the first stool specimen. For all helminth infections, single Kato-Katz thick smear-based prevalence estimates were significantly lower than those obtained from triplet or quintet Kato-Katz thick smears. Prevalence of S. mansoni infection based on single, triplet and quintet Kato-Katz thick smears from one stool specimen were 31.3%, 45.7% and 52.1%, respectively. Prevalence estimate of S. mansoni based on quintet Kato-Katz thick smears from the first day stool specimens was not different from cumulative estimate obtained with two triplet Kato-Katz thick smears from two stool specimens, 52.1% and 52.8%, respectively. In conclusion, either examination of quintet Kato-Katz thick smears from one stool specimen using 41.7 mg template or initial triplet Kato-Katz thick smears from one stool specimen, and if these are negative, followed by examination of additional triplet Kato-Katz thick smears from subsequent day stool specimen can adequately assess individuals for infection status with S. mansoni. PMID:15533288

  10. Cercarial transformation and in vitro cultivation of Schistosoma mansoni schistosomules.

    PubMed

    Milligan, John N; Jolly, Emmitt R

    2011-01-01

    Schistosome parasites are the causative agents of schistosomiasis, a chronically debilitating disease that affects over 200 million people globally and ranks second to malaria among parasitic diseases in terms of public health and socio-economic impact (1-4). Schistosome parasites are trematode worms with a complex life cycle interchanging between a parasitic life in molluscan and mammalian hosts with intervening free-swimming stages. Briefly, free-swimming cercariae infect a mammalian host by penetrating the skin with the aid of secreted proteases, during which time the cercariae lose their tails, transforming into schistosomules. The schistosomules must now evade the host immune system, develop a gut for digestion of red blood cells, and migrate though the lungs and portal circulation en route to their final destination in the hepatic portal system and eventually the mesenteric veins (for S. mansoni) where male and female worms pair and mate, producing hundreds of eggs daily. Some of the eggs are excreted from the body into fresh water, where the eggs hatch into free-swimming miracidia (5-10). The miracidia infect specific snail species and transform into mother and daughter sporocysts, which in turn, produce infective cercariae, completing the life cycle. Unfortunately, the entire schistosome life cycle cannot be cultured in vitro, but infective cercariae can be transformed into schistosomules, and the schistosomules can be cultured for weeks for the analysis of schistosome development in vitro or microarray analysis. In this protocol, we provide a visual description of cercarial transformation and in vitro culturing of schistosomules. We shed infectious cercariae from the snail host Biomphalaria glabrata and manually transform them into schistosomules by detaching their tails using an emulsifying double-ended needle. The in vitro cercarial transformation and schistosomules culture techniques described avoid the use of a mammalian host, which simplifies

  11. Environmental, genetic and immunological factors in human resistance to Schistosoma mansoni.

    PubMed

    Dessein, A J; Couissinier, P; Demeure, C; Rihet, P; Kohlstaedt, S; Carneiro-Carvalho, D; Ouattara, M; Goudot-Crozel, V; Dessein, H; Bourgois, A

    1992-08-01

    The design of programs for the control of endemies requires the knowledge of the principal factors that determine parasite transmission and infection levels in exposed populations. In the studies summarized in this article, the role of environmental and host specific factors in the infection by S. mansoni have been evaluated. It is shown that a limited number of factors actually influences infection intensity: water contacts, age, and sex were shown to account for 20 to 25% of infection variance, while 35 to 40% of it was accounted for by the effect of a major codominant gene. A remarkable fact is the important weighting (around 55% of the variance) of factors (the major gene and age) that influence human capacities of resistance. This observation strongly supports control measures aimed at increasing human resistance, such as vaccination. The effect of age on the development of resistance has now been observed in several studies on S. mansoni or S. haematobium. It is, therefore, a constant finding in schistosomiasis infections that resistance develops extremely slowly requiring a long period of exposure to the parasite and repeated infections. These studies provide strong incentives to increase efforts in the evaluation of the immune response of subjects living in endemic areas. Such evaluations are necessary to define vaccine and vaccination programs, and they are also urgently needed to evaluate the effects of chemotherapy on the development of immunity in children and adolescents, as well as on the persistence of protective immunity in adults. Immunological studies begin to provide a clearer picture of the role of acquired immunity in human protection against S. mansoni. It is increasingly clear that the slow development of resistance in children, as well as its alteration in certain age groups, are related to the maturation of parasite specific immunity and its alteration by specific immune factors. Thus, the development of resistance is associated with the

  12. Schistosoma haematobium hotspots in south Nyanza, western Kenya: prevalence, distribution and co-endemicity with Schistosoma mansoni and soil-transmitted helminths

    PubMed Central

    2014-01-01

    Background Schistosomiasis studies in western Kenya have mainly focused on the intestinal form, with evidence of urinary schistosomiasis remaining anecdotal. Detailed disease mapping has been carried out predominantly along the shores of Lake Victoria, but there is a paucity of information on intestinal and urinary schistosomiasis in inland sites. Methods This cross-sectional survey of 3,487 children aged 7–18 years from 95 schools in south Nyanza, western Kenya determined the prevalence, infection intensity, and geographical distribution of Schistosoma haematobium, evaluating its co-endemicity with Schistosoma mansoni and soil-transmitted helminths (STHs). Helminth eggs were analyzed from single urine (for S. haematobium) and stool (for S. mansoni and STHs) samples by centrifugation and Kato-Katz, respectively. Hematuria was used as a proxy indicator for S. haematobium. Schools and water bodies (ponds, water-points, streams, dams and rivers) were mapped using Geographical Information System and prevalence maps obtained using ArcView GIS Software. Results S. haematobium infections with an overall prevalence of 9.3% (95% CI = 8.4-10.2%) were mostly prevalent in Rachuonyo, 22.4% (95% CI = 19.2-25.9% and 19.7 eggs/10 ml) and Migori, 10.7% (95% CI = 9.2-12.3% and 29.5 eggs/10 ml) districts, particularly around Kayuka pond and Ongoche river respectively. Overall infections correlated with hematuria (r = 0.9, P < 0.0001) and were more likely in boys (P < 0.0001, OR = 0.624). S. mansoni infections with an overall prevalence of 13% (95% CI =11.9-14.1%) were majorly confined along the shores of Lake Victoria. STH infections were homogenously distributed with A. lumbricoides occurring in 5.4% (95% CI = 4.7-6.3%) and T. trichiura in 2.8% (95% CI = 2.3-3.4%) of the children. Although S. mansoni infections were more co-endemic with S. haematobium, only A. lumbricoides infections were positively associated with S. haematobium (P = 0

  13. [Urinary schistosomiasis: remarks on a case].

    PubMed

    Scarlata, F; Giordano, S; Romano, A; Marasa, L; Lipani, G; Infurnari, L; Titone, L

    2005-12-01

    Urinary tract schistosomiasis is a parasitic disease caused by S. haematobium with a wide range of clinical manifestations related to the mucosal and submucosal granulomatous lesions of the bladder. It affects about 80 million people in Africa, Middle-East and India, while in Italy it is rarely seen among immigrants from endemic areas and returning travellers. The authors describe a case occurred in a 26 years old man, recently emigrated from a rural area of Ghana. He had the symptoms of a haemorrhagic cystitis. Cystoscopy and biopsy showed granulomatous lesions of bladder with calcified eggs. Microscopic examination of urine was positive for Schistosoma haematobium eggs. The therapy with Praziquantel (40 mg/Kg una tantum) was effective. The authors emphasized the risk of introduction of schistosomiasis in some regions of our country, in consideration of the presence of the intermediate host as well as of an appropriate climate. PMID:16388282

  14. T-Helper 17 Cells Are Associated With Pathology in Human Schistosomiasis

    PubMed Central

    Mbow, Moustapha; Larkin, Bridget M.; Meurs, Lynn; Wammes, Linda J.; de Jong, Sanne E.; Labuda, Lucja A.; Camara, Makhtar; Smits, Hermelijn H.; Polman, Katja; Dieye, Tandakha N.; Mboup, Souleymane; Stadecker, Miguel J.; Yazdanbakhsh, Maria

    2013-01-01

    Background. Schistosome infections are often clinically silent, but some individuals develop severe pathological reactions. In several disease processes, T-helper 17 (Th17) cells have been linked to tissue injuries, while regulatory T cells (Tregs) are thought to downmodulate inflammatory reactions. We assessed whether bladder pathology in human Schistosoma haematobium infection is related to the balance of Th17 cells and Tregs. We used a murine model of Schistosoma mansoni infection to further investigate whether the peripheral profiles reflected ongoing events in tissues. Methods. We characterized T-helper cell subsets in the peripheral blood of children residing in a S. haematobium–endemic area and in the peripheral blood, spleen, and hepatic granulomas of S. mansoni–infected high-pathology CBA mice and low-pathology C57BL/6 mice. Results. S. haematobium–infected children with bladder pathology had a significantly higher percentage of Th17 cells than those without pathology. Moreover, the Th17/Treg ratios were significantly higher in infected children with pathology, compared with infected children without pathology. Percentages of interleukin 17–producing cells were significantly higher in spleen and granulomas of CBA mice, compared with C57BL/6 mice. This difference was also reflected in the peripheral blood. Conclusions. This is the first study to indicate that Th17 cells may be involved in the pathogenesis of human schistosomiasis. PMID:23087431

  15. Studies on the molluscicidal activity of Agave angustifolia and Pittosporum tobira on schistosomiasis transmitting snails.

    PubMed

    Ibrahim, Abdalla M; Abdel-Gawad, Mahfouz M; El-Nahas, Hanan A; Osman, Nadia S

    2015-04-01

    In the search for new molluscicidal plants for controlling the snail vectors of schistosomiasis, laboratory evaluation was made to assess the molluscicidal activity of Agave angustifolia and Pittosporum tobira plants against Biomphalaria alexandrina snails. Results indicated that both plants have promising molluscicidal activity as the LC90 of the dry powder of both plants was 120 ppm. Both plants showed marked cercaricidal and miracidicidal potencies against S. mansoni larvae. The LC90 of both plants (120 ppm) killed most B. alexandrina eggs within 24 h of exposure. The sub-lethal concentrations of both plants markedly suppressed the survival rate of B. alexandrina snails and the mortality increased with increasing the concentrations and the exposure period up to 10 successive weeks. The accumulative toxic effect of these concentrations was continuous during the recovery period. Also, the reproductive rates of exposed snails were greatly affected even through the recovery period. This depression in reproductive ability of snails was accompanied by histological damage in the hermaphrodite glands of exposed snails. Meanwhile, the growth of snails was estimated weekly and it showed great inhibition in exposed snails comparing with the control ones. PMID:26012228

  16. Autotransplant of spleen tissue in children with schistosomiasis: evaluation of splenic function after splenosis.

    PubMed

    Brandt, C T; Maciel, D T; Caneca, O A; Castro, C M; Araújo, L B

    2001-01-01

    Autotransplantation of spleen tissue has been done, in the past ten years, in children with schistosomiasis mansoni with bleeding varices. The purposes of this investigation were: (1) to study the morphology and function of the remnant spleen tissue; (2) to quantify the production of tuftsin; and (3) to assess the immune response to pneumococcal vaccine of these patients. Twenty three children, who underwent splenectomy and autologous implantation of spleen tissue into the greater omentum were included in this investigation. The average postoperative follow-up is five years. Splenosis was proved by colloid liver-spleen scans. Search for Howell-Jolly bodies assessed the filtration function. Tuftsin and the titer of pneumococcal antibodies were quantified by ELISA. Splenosis was evident in all children; however, it was insufficient in two. Howell-Jolly bodies were found only in these two patients. The mean tuftsin serum concentration (335.0 +/- 29.8 ng/ml) was inside the normal range. The immune response to pneumococcal vaccination was adequate in 15 patients; intermediate in four; and inadequate in four. From the results the following conclusions can be drawn: splenosis was efficient in maintaining the filtration splenic function in more than 90% and produced tuftsin inside the range of normality. It also provided the immunologic splenic response to pneumococcal vaccination in 65% of the patients of this series. PMID:11586436

  17. [Epidemiology of human schistosomiasis in Mauritania. The right bank of the Senegal River as model].

    PubMed

    Ouldabdallahi, M; Ouldbezeid, M; Diop, C; Dem, E; Lassana, K

    2010-12-01

    A study was performed to determine the transmission and prevalence of human schistosomiasis in the Mauritanian side of the Senegal River basin. Parasitological investigations by Kato-Katz and urine filtration conducted on 1,259 school children indicated a mean prevalence of S. haematobium--29.0%, 25.9% and 34.3%, respectively, in the children of the lower, middle and high valley. Only the school children of the lower delta valley were infected by S. mansoni with a mean prevalence rate of 21.5%. The malacological investigations carried out in the water points of each visited village highlighted the presence of B. pfeifferi, B. senegalensis, B. globosus, B. umbilicatus, B. truncatus and B. forskalii. The last three species are announced for the first time in the Mauritanian side of the Senegal River. The laboratory snail infection experiments indicate that B. senegalensis and B. globosus are the most important intermediate hosts for S. haematobium in the Mauritanian side of the Senegal River basin. However, an incompatibility between the oasis strains of S. haematobium and the snails of the lower valley was noted. In the middle valley and high valley, the infection of the school children takes place during the rainy season, because of the creation of the temporary water points, in the lower valley; the transmission seems to be continuous. PMID:20686878

  18. Schistosomiasis and the social patterning of infection.

    PubMed

    Huang, Y; Manderson, L

    1992-08-01

    Social, cultural, behavioural and economic factors interact with local environmental and ecological factors to produce extraordinary variation in the epidemiology of schistosomiasis, including with respect to prevalence and intensity of infection and the potential for control. This article reviews the literature on schistosomiasis infection, primarily derived from African studies, to identify its major social themes. Research has demonstrated a strong link between economic development strategies, where irrigation has been introduced to boost agricultural production, and the increased transmission of infection. Water-contact studies have provided the fullest and most detailed descriptions of social risk factors, and have isolated age, sex, religion and occupation as primary risk factors. However, fuller explorations of the social and cultural context of infection have yet to be undertaken. The social context of water-related behaviour and patterns of water use within communities and households, the intersection of social and economic activities, and the significance that people give to these activities, remains poorly explored, and although research papers concerned with community-based interventions refer to poor community understanding of the cause, prevention and treatment of the disease, this domain has also received little scholarly attention. Finally, economic studies have focused primarily on working capacity, and extrapolated these findings to generalize about the impact that this might have on productivity, but have yet to address either household or community costs of schistosomiasis infection. PMID:1359746

  19. Water-based interventions for schistosomiasis control

    PubMed Central

    Evan Secor, William

    2014-01-01

    Mass drug administration with praziquantel is the mainstay of programs for the control of schistosomiasis morbidity. However, there is a growing recognition that treatment alone will not be sufficient for eventually effecting elimination and that additional measures will be required to interrupt transmission. In the absence of a safe and an effective vaccine for human schistosomiasis, the strategies to reduce infection levels will necessarily involve some interventions that affect the water-related stages of the schistosome life cycle: by reducing exposure to infectious water, by moderating availability of the intermediate snail host, or by decreasing contamination of water with egg-containing excreta. While much research on the importance of water on schistosomiasis has been performed, advances in these areas have perhaps languished with the ready availability of a cost-effective treatment. As some endemic areas near a shift to an elimination goal, a better understanding of water-based interventions that can be used alone or in concert with treatment will be needed. Reinvigoration of laboratory, field, and human behavioral aspects of this research now will ensure that the appropriate strategies are available by the time their implementation becomes necessary. PMID:25175875

  20. Identification of Antigenic Glycans from Schistosoma mansoni by Using a Shotgun Egg Glycan Microarray.

    PubMed

    Mickum, Megan L; Prasanphanich, Nina Salinger; Song, Xuezheng; Dorabawila, Nelum; Mandalasi, Msano; Lasanajak, Yi; Luyai, Anthony; Secor, W Evan; Wilkins, Patricia P; Van Die, Irma; Smith, David F; Nyame, A Kwame; Cummings, Richard D; Rivera-Marrero, Carlos A

    2016-05-01

    Infection of mammals by the parasitic helminth Schistosoma mansoni induces antibodies to glycan antigens in worms and eggs, but the differential nature of the immune response among infected mammals is poorly understood. To better define these responses, we used a shotgun glycomics approach in which N-glycans from schistosome egg glycoproteins were prepared, derivatized, separated, and used to generate an egg shotgun glycan microarray. This array was interrogated with sera from infected mice, rhesus monkeys, and humans and with glycan-binding proteins and antibodies to gather information about the structures of antigenic glycans, which also were analyzed by mass spectrometry. A major glycan antigen targeted by IgG from different infected species is the FLDNF epitope [Fucα3GalNAcβ4(Fucα3)GlcNAc-R], which is also recognized by the IgG monoclonal antibody F2D2. The FLDNF antigen is expressed by all life stages of the parasite in mammalian hosts, and F2D2 can kill schistosomula in vitro in a complement-dependent manner. Different antisera also recognized other glycan determinants, including core β-xylose and highly fucosylated glycans. Thus, the natural shotgun glycan microarray of schistosome eggs is useful in identifying antigenic glycans and in developing new anti-glycan reagents that may have diagnostic applications and contribute to developing new vaccines against schistosomiasis. PMID:26883596

  1. The extracellular release of Schistosoma mansoni HMGB1 nuclear protein is mediated by acetylation

    SciTech Connect

    Coutinho Carneiro, Vitor; Moraes Maciel, Renata de; Caetano de Abreu da Silva, Isabel; Furtado Madeira da Costa, Rodrigo; Neto Paiva, Claudia; Torres Bozza, Marcelo; Rosado Fantappie, Marcelo

    2009-12-25

    Schistosoma mansoni HMGB1 (SmHMGB1) was revealed to be a substrate for the parasite histone acetyltransferases SmGCN5 and SmCBP1. We found that full-length SmHMGB1, as well as its HMG-box B (but not HMG-box A) were acetylated in vitro by SmGCN5 and SmCBP1. However, SmCBP1 was able to acetylate both substrates more efficiently than SmGCN5. Interestingly, the removal of the C-terminal acidic tail of SmHMGB1 (SmHMGB1{Delta}C) resulted in increased acetylation of the protein. We showed by mammalian cell transfection assays that SmHMGB1 and SmHMGB1{Delta}C were transported from the nucleus to the cytoplasm after sodium butyrate (NaB) treatment. Importantly, after NaB treatment, SmHMGB1 was also present outside the cell. Together, our data suggest that acetylation of SmHMGB1 plays a role in cellular trafficking, culminating with its secretion to the extracellular milieu. The possible role of SmHMGB1 acetylation in the pathogenesis of schistosomiasis is discussed.

  2. Schistosoma mansoni: vaccination of mice with 10-krad-irradiated, cryopreserved schistosomules

    SciTech Connect

    Lewis, F.A.; Stirewalt, M.A.; Leef, J.L.

    1984-06-01

    Protection against a Schistosoma mansoni cercarial challenge was evaluated in mice immunized with a vaccine composed of 10-krad-irradiated, cryopreserved schistosomules. The level of resistance induced in C57B1/6 or NMRI (CV) mice increased with the number of schistosomules injected. Up to 83% reduction in challenge worm burden was achieved when 5000 schistosomules were injected per mouse. Intramuscular injection of the vaccine was superior to subcutaneous. Multiple immunizations, up to 3 at 4-week intervals, did not increase the resistance induced by a single immunization. A high level of protection developed in as little as 2 weeks and was maintained through at least 12 weeks postimmunization. The vaccine irradiated with 10 krad from either a 60-cobalt or 137-cesium source induced equivalent levels of resistance, and no differences were found in the immunogenicity of vaccines comprised of organisms irradiated as cercariae or as 1- to 3-hr-old schistosomules. These findings are basic to the development of a cryopreserved, live vaccine against schistosomiasis of humans or domestic animals.

  3. Activity Profile of an FDA-Approved Compound Library against Schistosoma mansoni

    PubMed Central

    Panic, Gordana; Vargas, Mireille; Scandale, Ivan; Keiser, Jennifer

    2015-01-01

    Background As plans to expand mass drug treatment campaigns to fight schistosomiasis form, worries about reliance on praziquantel as the sole available treatment motivate the investigation for novel antischistosomal compounds. Drug repurposing might be an inexpensive and effective source of novel antischistosomal leads. Methodology 1600 FDA approved compounds were first assayed against Schistosoma mansoni schistosomula at a concentration of 10 µM. Active compounds identified from this screen were advanced to the adult worm screen at 33.33 µM, followed by hit characterization. Leads with complementary pharmacokinetic and toxicity profiles were then selected for in vivo studies. Principal Findings The in vitro screen identified 121 and 36 compounds active against the schistosomula and adult stage, respectively. Further, in vitro characterization and comparison with already available pharmacokinetic and toxicity data identified 11 in vivo candidates. Doramectin (10 mg/kg) and clofazimine (400 mg/kg) were found to be active in vivo with worm burden reductions of 60.1% and 82.7%, respectively. Conclusions/Significance The work presented here expands the knowledge of antischistosomal properties of already approved compounds and underscores variations observed between target-based and phenotypic approaches and among laboratories. The two in vivo-active drugs identified in this study, doramectin and clofazimine are widely available and present as novel drug classes as starting points for further investigation. PMID:26230921

  4. FASCIOLA HEPATICA AND SCHISTOSOMA MANSONI: IDENTIFICATION OF COMMON PROTEINS BY COMPARATIVE PROTEOMIC ANALYSIS

    PubMed Central

    Boukli, Nawal M.; Delgado, Bonnibel; Ricaurte, Martha; Espino, Ana M.

    2013-01-01

    It is not unusual to find common molecules among parasites of different species, genera, or phyla. When those molecules are antigenic, they may be used for developing drugs or vaccines that simultaneously target different species or genera of parasite. In the present study, we used a proteomic-based approach to identify proteins that are common to adult Fasciola hepatica and Schistosoma mansoni. Whole-worm extracts from each parasite were separated by 2-dimensional electrophoresis (2-DE), and digital images of both proteomes were superimposed using imaging software to identify proteins with identical isoelectric points and molecular weights. Protein identities were determined by mass spectrometry. Imaging and immunoblot analyses identified 28 immunoreactive proteins that are common to both parasites. Among these molecules are antioxidant proteins (thioredoxin and glutathione-S-transferase), glycolytic enzymes (glyceraldehyde 6-phosphate dehydrogenase and enolase), proteolytic enzymes (cathepsin-L and -D), inhibitors (Kunitz-type, Stefin-1), proteins with chaperone activity (heat shock protein 70 and fatty acid–binding protein), and structural proteins (calcium-binding protein, actin, and myosin). Some of the identified proteins could be used to develop drugs and vaccines against fascioliasis and schistosomiasis. PMID:21506812

  5. Excretion/secretion products from Schistosoma mansoni adults, eggs and schistosomula have unique peptidase specificity profiles.

    PubMed

    Dvořák, Jan; Fajtová, Pavla; Ulrychová, Lenka; Leontovyč, Adrian; Rojo-Arreola, Liliana; Suzuki, Brian M; Horn, Martin; Mareš, Michael; Craik, Charles S; Caffrey, Conor R; O'Donoghue, Anthony J

    2016-03-01

    Schistosomiasis is one of a number of chronic helminth diseases of poverty that severely impact personal and societal well-being and productivity. Peptidases (proteases) are vital to successful parasitism, and can modulate host physiology and immunology. Interference of peptidase action by specific drugs or vaccines can be therapeutically beneficial. To date, research on peptidases in the schistosome parasite has focused on either the functional characterization of individual peptidases or their annotation as part of global genome or transcriptome studies. We were interested in functionally characterizing the complexity of peptidase activity operating at the host-parasite interface, therefore the excretory-secretory products of key developmental stages of Schistosoma mansoni that parasitize the human were examined. Using class specific peptidase inhibitors in combination with a multiplex substrate profiling assay, a number of unique activities derived from endo- and exo-peptidases were revealed in the excretory-secretory products of schistosomula (larval migratory worms), adults and eggs. The data highlight the complexity of the functional degradome for each developmental stage of this parasite and facilitate further enquiry to establish peptidase identity, physiological and immunological function, and utility as drug or vaccine candidates. PMID:26409899

  6. Purine nucleoside phosphorylase from Schistosoma mansoni in complex with ribose-1-phosphate

    PubMed Central

    D’Muniz Pereira, Humberto; Oliva, Glaucius; Garratt, Richard Charles

    2011-01-01

    Schistosomes are blood flukes which cause schistosomiasis, a disease affecting approximately 200 million people worldwide. Along with several other important human parasites including trypanosomes and Plasmodium, schistosomes lack the de novo pathway for purine synthesis and depend exclusively on the salvage pathway for their purine requirements, making the latter an attractive target for drug development. Part of the pathway involves the conversion of inosine (or guanosine) into hypoxanthine (or guanine) together with ribose-1-phosphate (R1P) or vice versa. This inter-conversion is undertaken by the enzyme purine nucleoside phosphorylase (PNP) which has been used as the basis for the development of novel anti-malarials, conceptually validating this approach. It has been suggested that, during the reverse reaction, R1P binding to the enzyme would occur only as a consequence of conformational changes induced by hypoxanthine, thus making a binary PNP–R1P complex unlikely. Contradictory to this statement, a crystal structure of just such a binary complex involving the Schistosoma mansoni enzyme has been successfully obtained. The ligand shows an intricate hydrogen-bonding network in the phosphate and ribose binding sites and adds a further chapter to our knowledge which could be of value in the future development of selective inhibitors. PMID:21169694

  7. Newly Established Monoclonal Antibody Diagnostic Assays for Schistosoma mansoni Direct Detection in Areas of Low Endemicity

    PubMed Central

    Grenfell, Rafaella Fortini Queiroz; Coelho, Paulo Marcos Zech; Taboada, Diana; de Mattos, Ana Carolina Alves; Davis, Ruth; Harn, Donald A.

    2014-01-01

    Background Current available methods for diagnosis of schistosomiasis mansoni lack sufficient sensitivity, which results in underreporting of infectious in areas of low endemicity. Methodology/Principal Findings We developed three novel diagnostic methodologies for the direct detection of schistosome infection in serum samples. These three new methods were evaluated with positive patients from a low endemicity area in southeast Brazil. The basis of the assay was the production of monoclonal antibodies against the protein backbone of heavily glycosylated Circulating Cathodic Antigen (CCA). The antibodies were also selected for having no specificity to repeating poly-Lewis x units. Assays based on the detection CCA-protein should not encounter a limitation in sensitivity due to a biological background of this particular epitope. Three diagnostic methodologies were developed and validated, (i) Immunomagnetic Separation based on improved incubation steps of non-diluted serum, (ii) Direct Enzyme-linked Immunosorbent Assay and (iii) Fluorescent Microscopy Analysis as a qualitative assay. The two quantitative assays presented high sensitivity (94% and 92%, respectively) and specificity (100%), equivalent to the analysis of 3 stool samples and 16 slides by Kato-Katz, showing promising results on the determination of cure. Conclusions/Significance The Immunomagnetic Separation technique showed excellent correlation with parasite burden by Cohen coefficient. The qualitative method detected 47 positive individuals out of 50 with the analysis of 3 slides. This easy-to-do method was capable of discriminating positive from negative cases, even for patients with low parasite burden. PMID:24498191

  8. Schistosoma mansoni in a low-prevalence area in Brazil: the importance of additional methods for the diagnosis of hard-to-detect individual carriers by low-cost immunological assays

    PubMed Central

    Grenfell, Rafaella Fortini Queiroz; Martins, Watson; Enk, Martin; Almeida, Áureo; Siqueira, Liliane; Silva-Moraes, Vanessa; Oliveira, Edward; Carneiro, Nídia Francisca de Figueiredo; Coelho, Paulo Marcos Zech

    2013-01-01

    Schistosomiasis diagnosis is based on the detection of eggs in the faeces, which is laborious and lacks sensitivity, especially for patients with a low parasite burden. Immunological assays for specific antibody detection are available, but they usually demonstrate low sensitivity and/or specificity. In this study, two simple immunological assays were evaluated for the detection of soluble Schistosoma mansoni adult worm preparation (SWAP) and egg-specific IgGs. These studies have not yet been evaluated for patients with low parasite burdens. Residents of an endemic area in Brazil donated sera and faecal samples for our study. The patients were initially diagnosed by a rigorous Kato-Katz analysis of 18 thick smears from four different stool samples. The ELISA-SWAP was successful for human diagnosis with 90% sensitivity and specificity, confirming the Kato-Katz diagnosis with nearly perfect agreement, as seen by the Kappa index (0.85). Although the ELISA-soluble S. mansoni egg antigen was 85% sensitive, it exhibited low specificity (80%; Kappa index: 0.75) and was more susceptible to cross-reactivity. We believe that immunological assays should be used in conjunction with Kato-Katz analysis as a supplementary tool for the diagnosis of schistosomiasis for patients with low infection burdens, which are usually hard to detect. PMID:23778663

  9. [Evolution of schistosomiasis control and prevention strategies in hilly regions with schistosomiasis endemic in China].

    PubMed

    Lu, Long-ting; Zhu, Rong; Zhang, Li-juan; Zhong, Bo; Feng, Xi-guang; Xu, Xiao-lin; Guo, Jia-gang

    2013-10-01

    This article expatiates the epidemiological characteristics, the evolution process of control and prevention strategies and measures in hilly regions with schistosomiasis endemic, especially the research progress and obstacle factors existed in the implementation process of the comprehensive strategy focused on controlling infection source, aiming at providing references for the hilly regions to reach transmission interrupted standard. PMID:24490372

  10. Detection and quantification of circulating antigen in schistosomiasis by a monoclonal antibody. I. Specificity analysis of a monoclonal antibody with immunodiagnostic capacity.

    PubMed Central

    Nogueira-Queiroz, J A; Lutsch, C; Capron, M; Dessaint, J P; Capron, A

    1986-01-01

    Monoclonal antibodies were obtained after immunization of mice with Schistosoma mansoni excretory/secretory antigen, previously shown to contain the circulating cathodic (M) antigen. Among these, the 40:B1 monoclonal antibody proved to be specific for the schistosome genus and to detect only adult worm-derived antigens as shown both by immunoprecipitation and with a two-site immunoradiometric assay using the monoclonal as both the solid-phase and the labelled antibody. The two-site immunoradiometric assay allows a sensitive measurement (detection limit: 5 ng) of circulating schistosome antigen in blood and in urine from patients with schistosomiasis. The amount of circulating schistosome M antigen is correlated with schistosome egg excretion in stool. Images Fig. 2 PMID:3098474

  11. Schistosoma mansoni Infection in Preschool-Aged Children: Development of Immunoglobulin E and Immunoglobulin G4 Responses to Parasite Allergen-Like Proteins

    PubMed Central

    Pinot de Moira, Angela; Sousa-Figueiredo, Jose C.; Jones, Frances M.; Fitzsimmons, Colin M.; Betson, Martha; Kabatereine, Narcis B.; Stothard, J. Russell; Dunne, David W.

    2013-01-01

    Specific immunoglobulin E (IgE) responses are upregulated during chronic schistosome infection and during allergy. These responses are tightly regulated during schistosomiasis. We have previously shown that IgE regulation depends on the extent and length of exposure to individual parasite allergen-like proteins. Here we compare the development of IgE and immunoglobulin G4 (IgG4) responses to the differentially expressed allergen-like proteins SmTAL1 and SmTAL2 among preschool-aged children from 2 villages with different levels of Schistosoma mansoni transmission. We found a lack of SmTAL1 responsiveness among all children, but evidence for IgG4-dependent IgE-SmTAL2 desensitization in both villages, occurring earlier among children from the village where the level of transmission was greater. Findings provide insights into the development and regulation of allergic-type immune responses. PMID:23125445

  12. [Schistosomiasis and soil-transmitted helminthiasis among schoolchildren of Nikki and Pèrèrè, two northeastern towns of Benin].

    PubMed

    Ibikounlé, M; Gbédjissi, L G; Ogouyèmi-Hounto, A; Batcho, W; Kindé-Gazard, D; Massougbodji, A

    2014-08-01

    Infection with schistosomiasis and soil-transmitted helminthiasis are widespread in sub-Saharan Africa and the burden of disease associated with parasites is enormous. A study was performed to determine the transmission and prevalence of human schistosomiasis and soil-transmitted helminthiasis among school children of Nikki and Perere, two north eastern towns of Benin, bordering Republic of Nigeria. Parasitological investigations by urine filtration and Kato-Katz conducted on 1,344 school children indicated a mean prevalence of S. haematobium and S. mansoni 48.44% and 0%, respectively, in the children of Nikki area and 45.24% and 4.11% in Perere area. Only schoolchildren of Sonon locality were infected by S. mansoni with a mean prevalence rate of 36.24%. KatoKatz tests releaved five species of soil-transmitted helminths: Ankylostoma duodenale (8.16% and 6.73%), Ascaris lumbricoides (6.26% and 2.30%), Enterobius vermicularis (1.09% and 1.97%), Trichuris trichiura (1.97% and 1.90%) and Strongyloides stercoralis (2.04% and 0.99%), respectively, in the schoolchildren of Nikki and Perere areas. The malacological investigations carried out in the freshwater points of each visited locality highlighted the presence of four species of freshwater snails known as intermediate host of schistosome: Biomphalaria pfeifferi, Bulinus forskalii, B. globosus and B. truncatus.Two B. globosus and B. pfeifferi collected in Sonon locality were naturally infected by schistosome, indicated the importance of their two species of snail in schistosome transmission cycle. PMID:24595888

  13. Topical application of DEET for schistosomiasis

    PubMed Central

    Ramaswamy, Kalyanasundaram; He, Yi-Xun; Salafsky, Buz; Shibuya, Takeshi

    2009-01-01

    N, N-diethyl-m-toluamide (also known as DEET) is a broad-spectrum insect repellent that is used extensively against both human and animal pests, worldwide. Recent studies show that topical lipid formulations of DEET, such as LipoDEET, are highly effective in killing schistosome cercariae in the skin. Minimal systemic absorption, low manufacturing cost, and a wide range of activity against insects and schistosomes potentially makes compounds such as LipoDEET an excellent prophylactic agent against human and animal schistosomiasis in endemic areas, especially for travelers, until an effective vaccine is available. PMID:14642762

  14. Radiographic spectrum of rectocolonic calcification from schistosomiasis.

    PubMed

    Fataar, S; Bassiony, H; Hamed, M S; Ghoneim, I; Satyanath, S; Hebbar, H G; Elgindy, N N; Hanna, R M

    1984-05-01

    Rectocolonic calcification was detected radiographically in 17 sites in 14 patients undergoing excretory urography for the assessment of urinary schistosomiasis. The right colon was involved in 11 sites, the rectum in four, and the left colon in two. The pattern of calcification varied according to the degree of bowel distension. A laminar pattern was common to all sites and occurred when the rectum or colon was distended with air, feces, or barium. A laminar or irregular amorphous density was found in the empty colon, whereas the calcified, empty rectum had a corrugated pattern. Rectocolonic calcification is probably the most common radiographic manifestation of schistosomal infestation of the gastrointestinal tract. PMID:6609576

  15. Genome-Wide Scan and Test of Candidate Genes in the Snail Biomphalaria glabrata Reveal New Locus Influencing Resistance to Schistosoma mansoni

    PubMed Central

    Tennessen, Jacob A.; Bonner, Kaitlin M.; Bollmann, Stephanie R.; Johnstun, Joel A.; Yeh, Jan-Ying; Marine, Melanie; Tavalire, Hannah F.; Bayne, Christopher J.; Blouin, Michael S.

    2015-01-01

    Background New strategies to combat the global scourge of schistosomiasis may be revealed by increased understanding of the mechanisms by which the obligate snail host can resist the schistosome parasite. However, few molecular markers linked to resistance have been identified and characterized in snails. Methodology/Principal Findings Here we test six independent genetic loci for their influence on resistance to Schistosoma mansoni strain PR1 in the 13-16-R1 strain of the snail Biomphalaria glabrata. We first identify a genomic region, RADres, showing the highest differentiation between susceptible and resistant inbred lines among 1611 informative restriction-site associated DNA (RAD) markers, and show that it significantly influences resistance in an independent set of 439 outbred snails. The additive effect of each RADres resistance allele is 2-fold, similar to that of the previously identified resistance gene sod1. The data fit a model in which both loci contribute independently and additively to resistance, such that the odds of infection in homozygotes for the resistance alleles at both loci (13% infected) is 16-fold lower than the odds of infection in snails without any resistance alleles (70% infected). Genome-wide linkage disequilibrium is high, with both sod1 and RADres residing on haplotype blocks >2Mb, and with other markers in each block also showing significant effects on resistance; thus the causal genes within these blocks remain to be demonstrated. Other candidate loci had no effect on resistance, including the Guadeloupe Resistance Complex and three genes (aif, infPhox, and prx1) with immunological roles and expression patterns tied to resistance, which must therefore be trans-regulated. Conclusions/Significance The loci RADres and sod1 both have strong effects on resistance to S. mansoni. Future approaches to control schistosomiasis may benefit from further efforts to characterize and harness this natural genetic variation. PMID:26372103

  16. Systematic Review and Meta-analysis of the Impact of Chemical-Based Mollusciciding for Control of Schistosoma mansoni and S. haematobium Transmission

    PubMed Central

    King, Charles H.; Sutherland, Laura J.; Bertsch, David

    2015-01-01

    Background Programs for schistosomiasis control are advancing worldwide, with many benefits noted in terms of disease reduction. Yet risk of reinfection and recurrent disease remain, even in areas with high treatment coverage. In the search for means to better prevent new Schistosoma infections, attention has returned to an older strategy for transmission control, i.e., chemical mollusciciding, to suppress intermediate host snail species responsible for S. mansoni and S. haematobium transmission. The objective of this systematic review and meta-analysis was to summarize prior experience in molluscicide-based control of Bulinus and Biomphalaria spp. snails, and estimate its impact on local human Schistosoma infection. Methodology/Principal Findings The review was registered at inception with PROSPERO (CRD42013006869). Studies were identified by online database searches and hand searches of private archives. Eligible studies included published or unpublished mollusciciding field trials performed before January 2014 involving host snails for S. mansoni or S. haematobium, with a primary focus on the use of niclosamide. Among 63 included papers, there was large variability in terms of molluscicide dosing, and treatment intervals varied from 3–52 weeks depending on location, water source, and type of application. Among 35 studies reporting on prevalence, random effects meta-analysis indicated that, on average, odds of infection were reduced 77% (OR 0.23, CI95% 0.17, 0.31) during the course of mollusciciding, with increased impact if combined with drug therapy, and progressively greater impact over time. In 17 studies reporting local incidence, risk of new infection was reduced 64% (RR 0.36 CI95% 0.25, 0.5), but additional drug treatment did not appear to influence incidence effects. Conclusion/Significance While there are hurdles to implementing molluscicide control, its impact on local transmission is typically strong, albeit incomplete. Based on past experience

  17. Schistosoma mansoni: cercarial responses to irradiance changes

    SciTech Connect

    Saladin, K.S.

    1982-02-01

    Cercariae of Schistosoma mansoni alternate between active swimming and passive drifting. They began swimming in response to either an increase or decrease in irradiance experienced during the passive phase. The number of cercariae reacting to a shadow was proportional to the magnitude of the stimulus. The shadow response may be mediated by the cercaria's ciliary receptors. About half as many cercariae reacted to an irradiance increase as to an equivalent decrease. This report is the first quantitative study of photosensory stimulus-response relationships in schistosome cercariae.

  18. Praziquantel inhibits Schistosoma mansoni attachment in vitro.

    PubMed

    da-Silva, S P; Noel, F

    1990-01-01

    Male adult Schistosoma mansoni worms were placed in a glass dish containing Tyrode solution and observed for 15 min after addition of praziquantel (0.01 to 1 microM). Praziquantel promoted a concentration- and time-dependent inhibition of sucker-mediated attachment of the worm. Attachment inhibition was correlated with shortening of the parasite. We propose that the rapid and total inhibition of worm attachment observed in vitro with 1 microM praziquantel indicates that therapeutic concentrations of this drug should promote a rapid hepatic shift, in vivo, which may facilitate host tissue reaction. PMID:2101049

  19. Comparison of Schistosoma mansoni Prevalence and Intensity of Infection, as Determined by the Circulating Cathodic Antigen Urine Assay or by the Kato-Katz Fecal Assay: A Systematic Review.

    PubMed

    Kittur, Nupur; Castleman, Jennifer D; Campbell, Carl H; King, Charles H; Colley, Daniel G

    2016-03-01

    The relationship between results from Kato-Katz (KK) fecal microscopy and urine-based point-of-care circulating cathodic antigen (POC-CCA) assays for Schistosoma mansoni infection remains a critical issue. This systematic literature review of 25 published papers compares prevalence of S. mansoni infection by KK with that by the POC-CCA assay. Nineteen published studies met our inclusion criteria for data extraction and analysis. Above a prevalence of 50% by KK, KK and POC-CCA results yielded essentially the same prevalence. Below 50% prevalence by KK, the prevalence by the POC-CCA assay was between 1.5- and 6-fold higher and increased as prevalence by KK decreased. Five of nine publications met inclusion criteria for extractable data on intensity of S. mansoni infection by KK assay and visual band density using the POC-CCA assay. A clear positive relationship exists between intensity by the KK and POC-CCA assays. This systematic review indicates that below 50% prevalence, the POC-CCA assay is much more sensitive than the KK assay. However, the existing data are inadequate to precisely define the relationship between POC-CCA and KK at lower levels of KK prevalence. More studies directly comparing the two assays in low-prevalence areas are essential to inform decision-making by national schistosomiasis control programs. PMID:26755565

  20. Comparison of Schistosoma mansoni Prevalence and Intensity of Infection, as Determined by the Circulating Cathodic Antigen Urine Assay or by the Kato-Katz Fecal Assay: A Systematic Review

    PubMed Central

    Kittur, Nupur; Castleman, Jennifer D.; Campbell, Carl H.; King, Charles H.; Colley, Daniel G.

    2016-01-01

    The relationship between results from Kato-Katz (KK) fecal microscopy and urine-based point-of-care circulating cathodic antigen (POC-CCA) assays for Schistosoma mansoni infection remains a critical issue. This systematic literature review of 25 published papers compares prevalence of S. mansoni infection by KK with that by the POC-CCA assay. Nineteen published studies met our inclusion criteria for data extraction and analysis. Above a prevalence of 50% by KK, KK and POC-CCA results yielded essentially the same prevalence. Below 50% prevalence by KK, the prevalence by the POC-CCA assay was between 1.5- and 6-fold higher and increased as prevalence by KK decreased. Five of nine publications met inclusion criteria for extractable data on intensity of S. mansoni infection by KK assay and visual band density using the POC-CCA assay. A clear positive relationship exists between intensity by the KK and POC-CCA assays. This systematic review indicates that below 50% prevalence, the POC-CCA assay is much more sensitive than the KK assay. However, the existing data are inadequate to precisely define the relationship between POC-CCA and KK at lower levels of KK prevalence. More studies directly comparing the two assays in low-prevalence areas are essential to inform decision-making by national schistosomiasis control programs. PMID:26755565

  1. Examining the Relationship between Urogenital Schistosomiasis and HIV Infection

    PubMed Central

    Mbabazi, Pamela Sabina; Andan, Olivia; Fitzgerald, Daniel W.; Chitsulo, Lester; Engels, Dirk; Downs, Jennifer A.

    2011-01-01

    Background Urogenital schistosomiasis, caused by infection with Schistosoma haematobium, is widespread and causes substantial morbidity on the African continent. The infection has been suggested as an unrecognized risk factor for incident HIV infection. Current guidelines recommend preventive chemotherapy, using praziquantel as a public health tool, to avert morbidity due to schistosomiasis. In individuals of reproductive age, urogenital schistosomiasis remains highly prevalent and, likely, underdiagnosed. This comprehensive literature review was undertaken to examine the evidence for a cause-effect relationship between urogenital schistosomiasis and HIV/AIDS. The review aims to support discussions of urogenital schistosomiasis as a neglected yet urgent public health challenge. Methodology/Principal Findings We conducted a systematic search of the literature including online databases, clinical guidelines, and current medical textbooks. We describe plausible local and systemic mechanisms by which Schistosoma haematobium infection could increase the risk of HIV acquisition in both women and men. We also detail the effects of S. haematobium infection on the progression and transmissibility of HIV in co-infected individuals. We briefly summarize available evidence on the immunomodulatory effects of chronic schistosomiasis and the implications this might have for populations at high risk of both schistosomiasis and HIV. Conclusions/Significance Studies support the hypothesis that urogenital schistosomiasis in women and men constitutes a significant risk factor for HIV acquisition due both to local genital tract and global immunological effects. In those who become HIV-infected, schistosomal co-infection may accelerate HIV disease progression and facilitate viral transmission to sexual partners. Establishing effective prevention strategies using praziquantel, including better definition of treatment age, duration, and frequency of treatment for urogenital

  2. Schistosoma mansoni and Biomphalaria: past history and future trends.

    PubMed

    Morgan, J A; Dejong, R J; Snyder, S D; Mkoji, G M; Loker, E S

    2001-01-01

    Schistosoma mansoni is one of the most abundant infectious agents of humankind. Its widespread distribution is permitted by the broad geographic range of susceptible species of the freshwater snail genus Biomphalaria that serve as obligatory hosts for its larval stages. Molecular phylogenetic studies suggest that Schistosoma originated in Asia, and that a pulmonate-transmitted progenitor colonized Africa and gave rise to both terminal-spined and lateral-spined egg species groups, the latter containing S. mansoni. Schistosoma mansoni likely appeared only after the trans-Atlantic dispersal of Biomphalaria from the Neotropics to Africa, an event that, based on the present African fossil record, occurred only 2-5 million years ago. This parasite became abundant in tropical Africa and then entered the New World with the slave trade. It prospered in the Neotropics because a remarkably susceptible and productive host, B. glabrata, was widely distributed there. Indeed, a snail similar to B. glabrata may have given rise to the African species of Biomphalaria. Schistosoma mansoni has since spread into other Neotropical Biomphalaria species and mammalian hosts. The distribution of S. mansoni is in a state of flux. In Egypt, S. mansoni has nearly completely replaced S. haematobium in the Nile Delta, and has spread to other regions of the country. A susceptible host snail, B. straminea, has been introduced into Asia and there is evidence of S. mansoni transmission in Nepal. Dam and barrage construction has lead to an epidemic of S. mansoni in Senegal, and the parasite continues its spread in Brazil. Because of competition with introduced aquatic species and environmental changes, B. glabrata and consequently S. mansoni have become less abundant on the Caribbean islands. Control of S. mansoni using praziquantel and oxamniquine has reduced global prevalence but control is difficult to sustain, and S. mansoni can develop tolerance/resistance to praziquantel, raising concerns about

  3. [Effect of comprehensive control project on schistosomiasis in Nanjian county].

    PubMed

    Zuo, Ji-Mao; Wu, Jun-Sheng; Yang, Meng-Xian; Li, Dian; Jiao, Dian; Lian, Fu; Yang, Qing-Quan

    2011-04-01

    The comprehensive control project for schistosomiasis was implemented in Nanjian County from 2004 to 2008. After the implementation of the control project, the infection rates of population and livestock decreased by 94.39% and 83.29% in 2008, respectively, with both infection rates less than 1%, no acute schistosomiasis cases had been found since 2005. Snail areas decreased by 70.01%, no infected snails had been found since 2007. Through the implementation of the comprehensive control project, schistosomiasis had been effectively controlled in Nanjian County. PMID:22164604

  4. Evaluation of the effect of Sm28GST-derived peptides in murine hepatosplenic schistosomiasis: interest of the lipopeptidic form of the C-terminal peptide.

    PubMed

    Pancré, V; Wolowczuk, I; Bossus, M; Gras-Masse, H; Guerret, S; Delanoye, A; Capron, A; Auriault, C

    1994-11-01

    Among the synthetic peptides derived from the 28-kDa Schistosoma mansoni glutathione S-transferase (Sm28GST), immunization with the C-terminal peptide comprising amino acid residues 190-211 induced a reduction in splenomegaly, in the number of hepatic eggs and in hepatic fibrosis in mice infected by Schistosoma mansoni. The absence of antibodies specific for the Sm28GST or for the 190-211 peptide observed in our conditions of immunization with this peptide argued in favour of the involvement of cellular-dependent mechanisms in the reduction in hepatic pathology. This was confirmed by the passive transfer of 190-211 peptide-specific T-cell enriched spleen cells which reproduced the protective effect conferred by immunization with the 190-211 peptide. These 190-211 peptide-specific cells produced little IL4 and high levels of IFN-gamma, a potent inhibitor of collagen synthesis. Furthermore, the use of a lipopeptidic form of the 190-211 peptide significantly improved the reduction in hepatic pathology obtained with the uncoupled peptide and induced a durable protective response. These results provide encouraging information for the possible use of synthetic peptides in the immunoprophylaxis of Schistosomiasis. PMID:7969186

  5. A Microfiltration Device for Urogenital Schistosomiasis Diagnostics

    PubMed Central

    Xiao, Yuan; Lu, Yi; Hsieh, Michael; Liao, Joseph; Wong, Pak Kin

    2016-01-01

    Schistosomiasis is a parasitic disease affecting over 200 million people worldwide. This study reports the design and development of a microfiltration device for isolating schistosome eggs in urine for rapid diagnostics of urogenital schistosomiasis. The design of the device comprises a linear array of microfluidic traps to immobilize and separate schistosome eggs. Sequential loading of individual eggs is achieved autonomously by flow resistance, which facilitates observation and enumeration of samples with low-abundance targets. Computational fluid dynamics modeling and experimental characterization are performed to optimize the trapping performance. By optimizing the capture strategy, the trapping efficiency could be achieved at 100% with 300 μl/min and 83% with 3000 μl/min, and the filtration procedure could be finished within 10 min. The trapped eggs can be either recovered for downstream analysis or preserved in situ for whole-mount staining. On-chip phenotyping using confocal laser fluorescence microscopy identifies the microstructure of the trapped schistosome eggs. The device provides a novel microfluidic approach for trapping, counting and on-chip fluorescence characterization of urinal Schistosoma haematobium eggs for clinical and investigative application. PMID:27124499

  6. A Microfiltration Device for Urogenital Schistosomiasis Diagnostics.

    PubMed

    Xiao, Yuan; Lu, Yi; Hsieh, Michael; Liao, Joseph; Wong, Pak Kin

    2016-01-01

    Schistosomiasis is a parasitic disease affecting over 200 million people worldwide. This study reports the design and development of a microfiltration device for isolating schistosome eggs in urine for rapid diagnostics of urogenital schistosomiasis. The design of the device comprises a linear array of microfluidic traps to immobilize and separate schistosome eggs. Sequential loading of individual eggs is achieved autonomously by flow resistance, which facilitates observation and enumeration of samples with low-abundance targets. Computational fluid dynamics modeling and experimental characterization are performed to optimize the trapping performance. By optimizing the capture strategy, the trapping efficiency could be achieved at 100% with 300 μl/min and 83% with 3000 μl/min, and the filtration procedure could be finished within 10 min. The trapped eggs can be either recovered for downstream analysis or preserved in situ for whole-mount staining. On-chip phenotyping using confocal laser fluorescence microscopy identifies the microstructure of the trapped schistosome eggs. The device provides a novel microfluidic approach for trapping, counting and on-chip fluorescence characterization of urinal Schistosoma haematobium eggs for clinical and investigative application. PMID:27124499

  7. Progressive Cross-Reactivity in IgE Responses: an Explanation for the Slow Development of Human Immunity to Schistosomiasis?

    PubMed Central

    Jones, Frances M.; Pinot de Moira, Angela; Protasio, Anna V.; Khalife, Jamal; Dickinson, Harriet A.; Tukahebwa, Edridah M.; Dunne, David W.

    2012-01-01

    People in regions of Schistosoma mansoni endemicity slowly acquire immunity, but why this takes years to develop is still not clear. It has been associated with increases in parasite-specific IgE, induced, some investigators propose, to antigens exposed during the death of adult worms. These antigens include members of the tegumental-allergen-like protein family (TAL1 to TAL13). Previously, in a group of S. mansoni-infected Ugandan males, we showed that IgE responses to three TALs expressed in worms (TAL1, -3, and -5) became more prevalent with age. Now, in a subcohort we examined associations of these responses with resistance to reinfection and use the data to propose a mechanism for the slow development of immunity. IgE was measured 9 weeks posttreatment and at reinfection at 2 years (n = 144). An anti-TAL5 IgE (herein referred to as TAL5 IgE) response was associated with reduced reinfection even after adjusting for age using regression analysis (geometric mean odds ratio, 0.24; P = 0.016). TAL5 IgE responders were a subset of TAL3 IgE responders, themselves a subset of TAL1 responders. TAL3 IgE and TAL5 IgE were highly cross-reactive, with TAL3 the immunizing antigen and TAL5 the cross-reactive antigen. Transcriptional and translational studies show that TAL3 is most abundant in adult worms and that TAL5 is most abundant in infectious larvae. We propose that in chronic schistosomiasis, older individuals have repeatedly experienced IgE antigens exposed when adult worms die (e.g., TAL3) and that this leads to increasing cross-reactivity with antigens of invading larvae (e.g., TAL5). Progressive accumulation of worm/larvae cross-reactivity could explain the age-dependent immunity observed in areas of endemicity. PMID:23006852

  8. Localization of Tyrosine Hydroxylase-like Immunoreactivity in the Nervous Systems of Biomphalaria glabrata and Biomphalaria alexandrina, Intermediate Hosts for Schistosomiasis

    PubMed Central

    Vallejo, Deborah; Habib, Mohammed R.; Delgado, Nadia; Vaasjo, Lee O.; Croll, Roger P.; Miller, Mark W.

    2014-01-01

    Planorbid snails of the genus Biomphalaria are major intermediate hosts for the digenetic trematode parasite Schistosoma mansoni. Evidence suggests that levels of the neurotransmitter dopamine (DA) are reduced during the course of S. mansoni multiplication and transformation within the snail. This investigation used immunohistochemical methods to localize tyrosine hydroxylase (TH), the rate-limiting enzyme in the biosynthesis of catecholamines, in the nervous system of Biomphalaria. The two species examined, Biomphalaria glabrata and Biomphalaria alexandrina, are the major intermediate hosts for S. mansoni in sub-Saharan Africa, where more than 90% of global cases of human intestinal schistosomiasis occur. TH-like immunoreactive (THli) neurons were distributed throughout the central nervous system (CNS) and labeled fibers were present in all commissures, connectives, and nerves. Some asymmetries were observed, including a large distinctive neuron (LPeD1) in the pedal ganglion described previously in several pulmonates. The majority of TH-like immunoreactive neurons were detected in the peripheral nervous system (PNS), especially in lip and foot regions of the anterior integument. Independent observations supporting the dopaminergic phenotype of THli neurons included 1) block of LPeD1 synaptic signaling by the D2/3 antagonist sulpiride, and 2) the similar localization of aqueous aldehyde (FaGlu) induced fluorescence. The distribution of THli neurons indicates that, as in other gastropods, dopamine functions as a sensory neurotransmitter and in the regulation of feeding and reproductive behaviors in Biomphalaria. It is hypothesized that infection could stimulate transmitter release from dopaminergic sensory neurons and that dopaminergic signaling could contribute to modifications of both host and parasite behavior. PMID:24477836

  9. Evaluation of the protective immune response induced in mice by immunization with Schistosoma mansoni schistosomula tegument (Smteg) in association with CpG-ODN.

    PubMed

    Teixeira de Melo, Tatiane; Araujo, Juliano Michel; Campos de Sena, Isabela; Carvalho Alves, Clarice; Araujo, Neusa; Toscano Fonseca, Cristina

    2013-01-01

    In schistosomiasis, the current control strategy does not prevent reinfection, therefore, vaccine strategies are essential to combat the Schistosoma mansoni. The efficacy vaccine depends on parasite stage and effective adjuvant. We have recently demonstrated that S. mansoni schistosomula tegument (Smteg) is able to activate dendritic cells up regulate CD40 and CD86 molecules and induce a partial protection in mice (43-48%) when formulated with Freund's adjuvant. In this study we evaluated the ability of Smteg + alum or Smteg + alum + CpG-ODN to induce protection in mice. Our results demonstrate that Smteg + alum + CpG-ODN induced a partial reduction in worm burden (43.1%), reduction in the number of eggs eliminated in the feces. The protective response was associated with a predominant Th1 type of immune response, with increased production of specific IgG2c, IFN-γ and TNF-α, B cells proliferation and CD4 cells and macrophages activation. PMID:23099420

  10. The biotechnology-value chain: development of Sm14 as a schistosomiasis vaccine.

    PubMed

    Tendler, Miriam; Simpson, Andrew J G

    2008-01-01

    In the 1990s, WHO/TDR created a product development program and initiated collaborations with other major international donors to promote rapid vaccine development and other tools for the control of endemic diseases. This "push strategy" was chosen to achieve effective research projects fostering innovation in the context of rapid product development. In the field of vaccine development, the aim was to bring forth ways and means to immunize against the most important human parasite diseases. Although the malaria vaccine projects scored initial successes it has been difficult to move forward decidedly. With regard to schistosomiasis, more than 10 important antigens with strong potential as vaccines candidates emerged from the several 100 scientific projects supported by international donor agencies and national research programs over the last few decades. Among those still seriously pursued, the Fatty Acid-Binding Protein (FABP)-14 kDa Schistosoma mansoni (Sm14) antigen stands out, both due to its steady progress towards field trials and because it represents the sole vaccine candidate to emerge from an endemic country. Work has now progressed to the scale-up level and an industrial production process has successfully been put in place. The very special feature of Sm14 is its strong immunological reactivity with an antigen shared between two different important parasites, which give this vaccine candidate the potential to be used against more than one infection. It has been demonstrated that it has effect not only against S. mansoni in humans but also against Fasciola hepatica, a parasite that causes disease in cattle and sheep leading to annual losses over 3 $US billion to the food industry worldwide. The Sm14 patents, granted to Oswaldo Cruz Foundation (FIOCRUZ), a Brazilian scientific institution directly linked to the Brazilian Ministry of Health, have been licensed to a private company which has the intention to lead the Sm14 project to success, both in the

  11. Ultrasonographic Diagnosis of Schistosoma mansoni Eggs in Rectum

    PubMed Central

    Campos, Joao Batista; Toppa, Nivaldo Hartung; Wexner, Steven D.

    2016-01-01

    Schistosomiasis is a trematode infection endemic in more than 70 countries that affects an estimated 250 million people. We report the case of a 60-year-old healthy female referred for endoscopic ultrasound after rectal examination revealed granular lesions. Ultrasound revealed the presence of deep mucosal nodular lesions with calcified/hyperechoic inclusions. Histologic evaluation has confirmed the final diagnosis of chronic schistosomal colitis. In patients with nonspecific intestinal lesions without a suspected diagnosis of schistosomiasis, endoscopic ultrasound can be enlightening. Schistosomiasis is still an endemic infection in some parts of Brazil and other tropical regions, causing colorectal lesions with unspecific presentation. PMID:27579196

  12. Ultrasonographic Diagnosis of Schistosoma mansoni Eggs in Rectum.

    PubMed

    Rodrigues, Fabio G; Campos, Joao Batista; Toppa, Nivaldo Hartung; Wexner, Steven D; Dasilva, Giovanna

    2016-01-01

    Schistosomiasis is a trematode infection endemic in more than 70 countries that affects an estimated 250 million people. We report the case of a 60-year-old healthy female referred for endoscopic ultrasound after rectal examination revealed granular lesions. Ultrasound revealed the presence of deep mucosal nodular lesions with calcified/hyperechoic inclusions. Histologic evaluation has confirmed the final diagnosis of chronic schistosomal colitis. In patients with nonspecific intestinal lesions without a suspected diagnosis of schistosomiasis, endoscopic ultrasound can be enlightening. Schistosomiasis is still an endemic infection in some parts of Brazil and other tropical regions, causing colorectal lesions with unspecific presentation. PMID:27579196

  13. Potential schistosomiasis foci in China: a prospective study for schistosomiasis surveillance and response.

    PubMed

    Qian, Ying-Jun; Li, Shi-Zhu; Xu, Jing; Yang, Kun; Huang, Yi-Xin; Cao, Zhi-Guo; Miu, Feng; Dang, Hui; Zhang, Li-Juan; Zhang, Li; Wang, Qiang; Bergquist, Robert; Zhou, Xiao-Nong

    2015-01-01

    Schistosomiasis japonica was endemic in 12 provinces (including municipalities and autonomous regions) in the People's Republic of China (PR China). Despite the tremendous decrease of schistosomiasis incidence after almost 60 years of control, the distribution of snail-breeding sites has not been reduced significantly. In order to verify current transmission risks and identify the potential establishment of new foci of schistosomiasis driven by environmental changes, we conducted surveillance in selected risk areas of three provinces: Jiangsu, Anhui and Shandong from 2008 to 2010 in addition to routine snail surveillance. We investigated populations and possible reservoirs in sentinel sites and report that the total number of new acute cases did not diminish further in spite of ongoing control activities. In Anhui Province the local count compared to the national count was 43% (19/44) in 2008, 33% (25/75) in 2009 and 40% (17/42) in 2010. In all, 31.58 km(2) areas of snail breeding sites were newly detected nationwide through the year 2008-2010, of which the proportion of Anhui was 42% (5.03/11.98) in 2008, 95% (8.39/8.79) in 2009 and 79% (8.52/10.81) in 2010. Sentinel surveillance showed eight, nine and five confirmed cases of acute schistosomiasis in mobile populations (fishermen, migrant workers) in 2008, 2009 and 2010, respectively. All these cases were detected in Chaohu County, which must therefore be deemed an area at risk. We conclude that continuous surveillance with an emphasis on snails must be enhanced in potential risk areas in PR China. PMID:24012536

  14. Schistosoma mansoni PIII antigen modulates in vitro granuloma formation by regulating CD28, CTLA-4, and CD86 expression in humans.

    PubMed

    Zouain, C S; Falcão, P L; Goes, T S; Leite, M F; Goes, A M

    2004-02-15

    We investigated the in vitro responses of peripheral blood mononuclear cells (PBMC) from intestinal chronic schistosomiasis patients to PIII, a multivalent antigen prepared from Schistosoma mansoni adult worm. PIII decreased cellular proliferation and granulomatous reaction. Moreover, induced the reduction of IFN-gamma levels and increased IL-10 production. To better understand the mechanism through which the observed suppression occurs, the present study focused on the phenotypic pattern displayed by PBMC treated with PIII in an in vitro granuloma assay. Expression of the surface markers CD28, CTLA-4 and CD86 by lymphocytes and monocytes were analyzed by flow cytometry. Our results demonstrated a significant decrease of CD28+CD4+ and CD28+CD8+ T-cell percentage stimulated by PIII compared to its non-infected counterparts. This suppressive effect was related to a significant increase in the percentage of T-cells expressing CTLA-4. PIII also promoted a significant increase in the percentage of cells expressing CD86. Indeed, our results demonstrated that PIII was capable of modulating in vitro granuloma reaction, and this event was related to the balance of IL-10, IFN-gamma and CD28, CTLA-4, CD86 bringing new insight to the immunoregulation of granulomatous hypersensitivity in human schistosomiasis. PMID:15019278

  15. Analysis of two Schistosoma mansoni uridine phosphorylases isoforms suggests the emergence of a protein with a non-canonical function.

    PubMed

    da Silva Neto, Antônio Marinho; Torini de Souza, Juliana Roberta; Romanello, Larissa; Cassago, Alexandre; Serrão, Vitor Hugo Balasco; DeMarco, Ricardo; Brandão-Neto, José; Garratt, Richard Charles; Pereira, Humberto D'Muniz

    2016-06-01

    Reports of Schistosoma mansoni strains resistant to praziquantel, the only therapeutic strategy available for the treatment of schistosomiasis, have motivated the scientific community towards the search for new possible therapies. Biochemical characterization of the parasite's metabolism is an essential component for the rational development of new therapeutic alternatives. One of the so far uncharacterized enzymes is uridine phosphorylase (UP) (EC 2.4.2.3), for which the parasite genome presents two isoforms (SmUPa and SmUPb) that share 92% sequence identity. In this paper, we present crystal structures for SmUPa and SmUPb in their free states as well as bound to different ligands. This we have complemented by enzyme kinetic characterization and phylogenetic analyses. Both enzymes present an overall fold and active site structure similar to other known UPs. The kinetic analyses showed conclusively that SmUPa is a regular uridine phosphorylase but by contrast SmUPb presented no detectable activity. This is particularly noteworthy given the high level of sequence identity between the two isoforms and is probably the result of the significant differences observed for SmUPb in the vicinity of the active site itself, suggesting that it is not a UP at all. On the other hand, it was not possible to identify an alternative function for SmUPb, although our phylogenetic analyses and expression data suggest that SmUPb is still functional and plays a role in parasite metabolism. The unusual UPb isoform may open up new opportunities for understanding unique features of S. mansoni metabolism. PMID:26898674

  16. Protein and small non-coding RNA-enriched extracellular vesicles are released by the pathogenic blood fluke Schistosoma mansoni

    PubMed Central

    Nowacki, Fanny C.; Swain, Martin T.; Klychnikov, Oleg I.; Niazi, Umar; Ivens, Alasdair; Quintana, Juan F.; Hensbergen, Paul J.; Hokke, Cornelis H.; Buck, Amy H.; Hoffmann, Karl F.

    2015-01-01

    Background Penetration of skin, migration through tissues and establishment of long-lived intravascular partners require Schistosoma parasites to successfully manipulate definitive host defences. While previous studies of larval schistosomula have postulated a function for excreted/secreted (E/S) products in initiating these host-modulatory events, the role of extracellular vesicles (EVs) has yet to be considered. Here, using preparatory ultracentrifugation as well as methodologies to globally analyse both proteins and small non-coding RNAs (sncRNAs), we conducted the first characterization of Schistosoma mansoni schistosomula EVs and their potential host-regulatory cargos. Results Transmission electron microscopy analysis of EVs isolated from schistosomula in vitro cultures revealed the presence of numerous, 30–100 nm sized exosome-like vesicles. Proteomic analysis of these vesicles revealed a core set of 109 proteins, including homologs to those previously found enriched in other eukaryotic EVs, as well as hypothetical proteins of high abundance and currently unknown function. Characterization of E/S sncRNAs found within and outside of schistosomula EVs additionally identified the presence of potential gene-regulatory miRNAs (35 known and 170 potentially novel miRNAs) and tRNA-derived small RNAs (tsRNAs; nineteen 5′ tsRNAs and fourteen 3′ tsRNAs). Conclusions The identification of S. mansoni EVs and the combinatorial protein/sncRNA characterization of their cargo signifies that an important new participant in the complex biology underpinning schistosome/host interactions has now been discovered. Further work defining the role of these schistosomula EVs and the function/stability of intra- and extra-vesicular sncRNA components presents tremendous opportunities for developing novel schistosomiasis diagnostics or interventions. PMID:26443722

  17. 5-lipoxygenase pathway is essential for the control of granuloma extension induced by Schistosoma mansoni eggs in lung.

    PubMed

    Toffoli da Silva, Gabriel; Espíndola, Milena Sobral; Fontanari, Caroline; Rosada, Rogerio Silva; Faccioli, Lúcia Helena; Ramos, Simone Gusmão; Rodrigues, Vanderlei; Frantz, Fabiani Gai

    2016-08-01

    According to WHO, it is estimated that approximately 2 billion people are infected with intestinal helminths worldwide and the number of people who are cured of these diseases is relatively low, resulting in a large percentage of chronically infected individuals. Schistosomiasis is one of the most important parasitic diseases present in developing countries configuring it as a serious public health problem, directly related to poverty and social disadvantage. Once the parasite infection is established, Schistosoma mansoni eggs fall into the bloodstream and are trapped in the liver microcirculation where a strong granulomatous response and fibrosis formation occurs. In the experimental model, granulomas develop in the mouse lung after intravenous injection of purified eggs. Here we aim to understand how leukotrienes are involved in the granuloma formation. Leukotrienes are lipid mediators derived from arachidonic acid metabolites via 5-lipoxygenase (5LO) enzyme. They are potent proinflammatory agents and induce recruitment, cell activation, regulation of microbicidal activity of polymorphonuclear and mononuclear cells. In this study, 5LO deficient mice (5LO(-/-)) were inoculated with S. mansoni eggs for evaluation of immunopathological parameters involved in the induction of type 2 granulomas. We showed that in the absence of leukotrienes, the size of granulomas were decreased comparing to the wild type mice and the inflammatory compromised areas had a lower extension. In 5LO(-/-) mice granulomas presented extensive areas of fibrosis, detected by α-SMA expression along the lesions, indicating remodeling in attempt to reestablish the normal tissue. Also, comparing to WT mice we detected decrease of IL-4 and IL-13 and increase of TGF-β in the lung of 5LO(-/-), but these mice failed to produce protective IFN-γ and IL-12. These results evidenced 5-Lipoxygenase as an important pathway during lung injury due to Schistosoma-eggs injection. PMID:27262746

  18. Novel Non-Peptide Inhibitors against SmCL1 of Schistosoma mansoni: In Silico Elucidation, Implications and Evaluation via Knowledge Based Drug Discovery

    PubMed Central

    Zafar, Atif; Ahmad, Sabahuddin; Rizvi, Asim; Ahmad, Masood

    2015-01-01

    Schistosomiasis is a major endemic disease known for excessive mortality and morbidity in developing countries. Because praziquantel is the only drug available for its treatment, the risk of drug resistance emphasizes the need to discover new drugs for this disease. Cathepsin SmCL1 is the critical target for drug design due to its essential role in the digestion of host proteins for growth and development of Schistosoma mansoni. Inhibiting the function of SmCL1 could control the wide spread of infections caused by S. mansoni in humans. With this objective, a homology modeling approach was used to obtain theoretical three-dimensional (3D) structure of SmCL1. In order to find the potential inhibitors of SmCL1, a plethora of in silico techniques were employed to screen non-peptide inhibitors against SmCL1 via structure-based drug discovery protocol. Receiver operating characteristic (ROC) curve analysis and molecular dynamics (MD) simulation were performed on the results of docked protein-ligand complexes to identify top ranking molecules against the modelled 3D structure of SmCL1. MD simulation results suggest the phytochemical Simalikalactone-D as a potential lead against SmCL1, whose pharmacophore model may be useful for future screening of potential drug molecules. To conclude, this is the first report to discuss the virtual screening of non-peptide inhibitors against SmCL1 of S. mansoni, with significant therapeutic potential. Results presented herein provide a valuable contribution to identify the significant leads and further derivatize them to suitable drug candidates for antischistosomal therapy. PMID:25933436

  19. Diagnostic Accuracy and Applicability of a PCR System for the Detection of Schistosoma mansoni DNA in Human Urine Samples from an Endemic Area

    PubMed Central

    Enk, Martin Johannes; Oliveira e Silva, Guilherme; Rodrigues, Nilton Barnabé

    2012-01-01

    Schistosomiasis caused by Schistosoma mansoni, one of the most neglected human parasitoses in Latin America and Africa, is routinely confirmed by microscopic visualization of eggs in stool. The main limitation of this diagnostic approach is its lack of sensitivity in detecting individual low worm burdens and consequently data on infection rates in low transmission settings are little reliable. According to the scientific literature, PCR assays are characterized by high sensitivity and specificity in detecting parasite DNA in biological samples. A simple and cost effective extraction method for DNA of Schistosoma mansoni from urine samples in combination with a conventional PCR assay was developed and applied in an endemic area. This urine based PCR system was tested for diagnostic accuracy among a population of a small village in an endemic area, comparing it to a reference test composed of three different parasitological techniques. The diagnostic parameters revealed a sensitivity of 100%, a specificity of 91.20%, positive and negative predictive values of 86.25% and 100%, respectively, and a test accuracy of 94.33%. Further statistical analysis showed a k index of 0.8806, indicating an excellent agreement between the reference test and the PCR system. Data obtained from the mouse model indicate the infection can be detected one week after cercariae penetration, opening a new perspective for early detection and patient management during this stage of the disease. The data indicate that this innovative PCR system provides a simple to handle and robust diagnostic tool for the detection of S. mansoni DNA from urine samples and a promising approach to overcome the diagnostic obstacles in low transmission settings. Furthermore the principals of this molecular technique, based on the examination of human urine samples may be useful for the diagnosis of other neglected tropical diseases that can be detected by trans-renal DNA. PMID:22701733

  20. Diagnostic accuracy and applicability of a PCR system for the detection of Schistosoma mansoni DNA in human urine samples from an endemic area.

    PubMed

    Enk, Martin Johannes; Oliveira e Silva, Guilherme; Rodrigues, Nilton Barnabé

    2012-01-01

    Schistosomiasis caused by Schistosoma mansoni, one of the most neglected human parasitoses in Latin America and Africa, is routinely confirmed by microscopic visualization of eggs in stool. The main limitation of this diagnostic approach is its lack of sensitivity in detecting individual low worm burdens and consequently data on infection rates in low transmission settings are little reliable. According to the scientific literature, PCR assays are characterized by high sensitivity and specificity in detecting parasite DNA in biological samples. A simple and cost effective extraction method for DNA of Schistosoma mansoni from urine samples in combination with a conventional PCR assay was developed and applied in an endemic area. This urine based PCR system was tested for diagnostic accuracy among a population of a small village in an endemic area, comparing it to a reference test composed of three different parasitological techniques. The diagnostic parameters revealed a sensitivity of 100%, a specificity of 91.20%, positive and negative predictive values of 86.25% and 100%, respectively, and a test accuracy of 94.33%. Further statistical analysis showed a k index of 0.8806, indicating an excellent agreement between the reference test and the PCR system. Data obtained from the mouse model indicate the infection can be detected one week after cercariae penetration, opening a new perspective for early detection and patient management during this stage of the disease. The data indicate that this innovative PCR system provides a simple to handle and robust diagnostic tool for the detection of S. mansoni DNA from urine samples and a promising approach to overcome the diagnostic obstacles in low transmission settings. Furthermore the principals of this molecular technique, based on the examination of human urine samples may be useful for the diagnosis of other neglected tropical diseases that can be detected by trans-renal DNA. PMID:22701733

  1. The Relationship between Water, Sanitation and Schistosomiasis: A Systematic Review and Meta-analysis

    PubMed Central

    Grimes, Jack E. T.; Croll, David; Harrison, Wendy E.; Utzinger, Jürg; Freeman, Matthew C.; Templeton, Michael R.

    2014-01-01

    Background Access to “safe” water and “adequate” sanitation are emphasized as important measures for schistosomiasis control. Indeed, the schistosomes' lifecycles suggest that their transmission may be reduced through safe water and adequate sanitation. However, the evidence has not previously been compiled in a systematic review. Methodology We carried out a systematic review and meta-analysis of studies reporting schistosome infection rates in people who do or do not have access to safe water and adequate sanitation. PubMed, Web of Science, Embase, and the Cochrane Library were searched from inception to 31 December 2013, without restrictions on year of publication or language. Studies' titles and abstracts were screened by two independent assessors. Papers deemed of interest were read in full and appropriate studies included in the meta-analysis. Publication bias was assessed through the visual inspection of funnel plots and through Egger's test. Heterogeneity of datasets within the meta-analysis was quantified using Higgins' I2. Principal Findings Safe water supplies were associated with significantly lower odds of schistosomiasis (odds ratio (OR) = 0.53, 95% confidence interval (CI): 0.47–0.61). Adequate sanitation was associated with lower odds of Schistosoma mansoni, (OR = 0.59, 95% CI: 0.47–0.73) and Schistosoma haematobium (OR = 0.69, 95% CI: 0.57–0.84). Included studies were mainly cross-sectional and quality was largely poor. Conclusions/Significance Our systematic review and meta-analysis suggests that increasing access to safe water and adequate sanitation are important measures to reduce the odds of schistosome infection. However, most of the studies were observational and quality was poor. Hence, there is a pressing need for adequately powered cluster randomized trials comparing schistosome infection risk with access to safe water and adequate sanitation, more studies which rigorously define water and sanitation, and new

  2. Performance and Safety of Praziquantel for Treatment of Intestinal Schistosomiasis in Infants and Preschool Children

    PubMed Central

    Sousa-Figueiredo, José C.; Betson, Martha; Atuhaire, Aaron; Arinaitwe, Moses; Navaratnam, Annalan M. D.; Kabatereine, Narcis B.; Bickle, Quentin; Stothard, J. Russell

    2012-01-01

    Background In 2012 the WHO formally recognised that infants and preschool children are at significant risk of schistosomiasis and qualify for treatment with praziquantel (PZQ). Targeted surveys determining both the performance and safety of this drug are now needed in endemic areas. We have formally assessed parasitological cure and putative side-effects in a prospective cohort of Schistosoma mansoni-infected children (aged 5 months–7 years old) in lakeshore settings of Uganda. Methodology/Principal Findings From a total of 369 children found to be egg-patent for intestinal schistosomiasis, 305 were followed-up three to four weeks after PZQ treatment and infection status re-assessed. Separately, a previously tested side-effect questionnaire was employed before and 24 hours after PZQ treatment to assess incidence and amelioration of symptoms in young children and their mothers. While the overall observed parasitological cure was 56.4%, a significant difference was found between a sub-set of children who had a history of multiple PZQ treatments (between one and four in an 18 month period), where cure rate was 41.7%, and those who had never received treatment (cure rate was 77·6%). PZQ proved to be safe, with only mild reported side effects which cleared within a month after treatment. Prevalence of reported symptoms was significantly lower in children than in mothers, and fewer side-effects were reported upon subsequent rounds of PZQ treatment. Conclusion/Significance Our findings show that PZQ treatment of young children resulted in satisfactory cure rates, and marked reduction in egg-output, with only mild and transient reported side-effects. However, the cure rate is clearly lower in younger children and those with history of previous treatment. Cure rate, but not egg reduction rate, was also lower in children with heavier pre-intervention infection intensity. With chemotherapy now recommended as a long-term strategy for disease control in young children

  3. Mapping of Schistosomiasis and Soil-Transmitted Helminths in Namibia: The First Large-Scale Protocol to Formally Include Rapid Diagnostic Tests

    PubMed Central

    Sousa-Figueiredo, José Carlos; Stanton, Michelle C.; Katokele, Stark; Arinaitwe, Moses; Adriko, Moses; Balfour, Lexi; Reiff, Mark; Lancaster, Warren; Noden, Bruce H.; Bock, Ronnie; Stothard, J. Russell

    2015-01-01

    Background Namibia is now ready to begin mass drug administration of praziquantel and albendazole against schistosomiasis and soil-transmitted helminths, respectively. Although historical data identifies areas of transmission of these neglected tropical diseases (NTDs), there is a need to update epidemiological data. For this reason, Namibia adopted a new protocol for mapping of schistosomiasis and geohelminths, formally integrating rapid diagnostic tests (RDTs) for infections and morbidity. In this article, we explain the protocol in detail, and introduce the concept of ‘mapping resolution’, as well as present results and treatment recommendations for northern Namibia. Methods/Findings/Interpretation This new protocol allowed a large sample to be surveyed (N = 17 896 children from 299 schools) at relatively low cost (7 USD per person mapped) and very quickly (28 working days). All children were analysed by RDTs, but only a sub-sample was also diagnosed by light microscopy. Overall prevalence of schistosomiasis in the surveyed areas was 9.0%, highly associated with poorer access to potable water (OR = 1.5, P<0.001) and defective (OR = 1.2, P<0.001) or absent sanitation infrastructure (OR = 2.0, P<0.001). Overall prevalence of geohelminths, more particularly hookworm infection, was 12.2%, highly associated with presence of faecal occult blood (OR = 1.9, P<0.001). Prevalence maps were produced and hot spots identified to better guide the national programme in drug administration, as well as targeted improvements in water, sanitation and hygiene. The RDTs employed (circulating cathodic antigen and microhaematuria for Schistosoma mansoni and S. haematobium, respectively) performed well, with sensitivities above 80% and specificities above 95%. Conclusion/Significance This protocol is cost-effective and sensitive to budget limitations and the potential economic and logistical strains placed on the national Ministries of Health. Here we present a high resolution map

  4. Predation of schistosomiasis vector snails by ostracoda (crustacea)

    USGS Publications Warehouse

    Sohn, I.G.; Kornicker, L.S.

    1972-01-01

    An ostracod species of Cypretta is an effective predator in laboratory experiments on 1- to 3-day-old Biomphalaria glabrata, a vector snail of the blood fluke that causes the tropical and subtropical disease schistosomiasis.

  5. Combining process-based and correlative models improves predictions of climate change effects on Schistosoma mansoni transmission in eastern Africa.

    PubMed

    Stensgaard, Anna-Sofie; Booth, Mark; Nikulin, Grigory; McCreesh, Nicky

    2016-01-01

    Currently, two broad types of approach for predicting the impact of climate change on vector-borne diseases can be distinguished: i) empirical-statistical (correlative) approaches that use statistical models of relationships between vector and/or pathogen presence and environmental factors; and ii) process-based (mechanistic) approaches that seek to simulate detailed biological or epidemiological processes that explicitly describe system behavior. Both have advantages and disadvantages, but it is generally acknowledged that both approaches have value in assessing the response of species in general to climate change. Here, we combine a previously developed dynamic, agentbased model of the temperature-sensitive stages of the Schistosoma mansoni and intermediate host snail lifecycles, with a statistical model of snail habitat suitability for eastern Africa. Baseline model output compared to empirical prevalence data suggest that the combined model performs better than a temperature-driven model alone, and highlights the importance of including snail habitat suitability when modeling schistosomiasis risk. There was general agreement among models in predicting changes in risk, with 24-36% of the eastern Africa region predicted to experience an increase in risk of up-to 20% as a result of increasing temperatures over the next 50 years. Vice versa the models predicted a general decrease in risk in 30-37% of the study area. The snail habitat suitability models also suggest that anthropogenically altered habitat play a vital role for the current distribution of the intermediate snail host, and hence we stress the importance of accounting for land use changes in models of future changes in schistosomiasis risk. PMID:27063739

  6. Effectiveness of a Pre-treatment Snack on the Uptake of Mass Treatment for Schistosomiasis in Uganda: A Cluster Randomized Trial

    PubMed Central

    Muhumuza, Simon; Olsen, Annette; Katahoire, Anne; Kiragga, Agnes N.; Nuwaha, Fred

    2014-01-01

    Background School-based mass treatment with praziquantel is the cornerstone for schistosomiasis control in school-aged children. However, uptake of treatment among school-age children in Uganda is low in some areas. The objective of the study was to examine the effectiveness of a pre-treatment snack on uptake of mass treatment. Methods and Findings In a cluster randomized trial carried out in Jinja district, Uganda, 12 primary schools were randomized into two groups; one received education messages for schistosomiasis prevention for two months prior to mass treatment, while the other, in addition to the education messages, received a pre-treatment snack shortly before mass treatment. Four weeks after mass treatment, uptake of praziquantel was assessed among a random sample of 595 children in the snack schools and 689 children in the non-snack schools as the primary outcome. The occurrence of side effects and the prevalence and mean intensity of Schistosoma mansoni infection were determined as the secondary outcomes. Uptake of praziquantel was higher in the snack schools, 93.9% (95% CI 91.7%–95.7%), compared to that in the non-snack schools, 78.7% (95% CI 75.4%–81.7%) (p = 0.002). The occurrence of side effects was lower in the snack schools, 34.4% (95% CI 31.5%–39.8%), compared to that in the non-snack schools, 46.9% (95% CI 42.2%–50.7%) (p = 0.041). Prevalence and mean intensity of S. mansoni infection was lower in the snack schools, 1.3% (95% CI 0.6%–2.6%) and 38.3 eggs per gram of stool (epg) (95% CI 21.8–67.2), compared to that in the non-snack schools, 14.1% (95% CI 11.6%–16.9%) (p = 0.001) and 78.4 epg (95% CI 60.6–101.5) (p = 0.001), respectively. Conclusions Our results suggest that provision of a pre-treatment snack combined with education messages achieves a higher uptake compared to the education messages alone. The use a pre-treatment snack was associated with reduced side effects as well as decreased prevalence and

  7. Microarray analysis of gene expression induced by sexual contact in Schistosoma mansoni

    PubMed Central

    Waisberg, Michael; Lobo, Francisco P; Cerqueira, Gustavo C; Passos, Liana KJ; Carvalho, Omar S; Franco, Glória R; El-Sayed, Najib M

    2007-01-01

    Background The parasitic trematode Schistosoma mansoni is one of the major causative agents of Schistosomiasis, a disease that affects approximately 200 million people, mostly in developing countries. Since much of the pathology is associated with eggs laid by the female worm, understanding the mechanisms involved in oogenesis and sexual maturation is an important step towards the discovery of new targets for effective drug therapy. It is known that the adult female worm only develops fully in the presence of a male worm and that the rates of oviposition and maturation of eggs are significantly increased by mating. In order to study gene transcripts associated with sexual maturation and oviposition, we compared the gene expression profiles of sexually mature and immature parasites using DNA microarrays. Results For each experiment, three amplified RNA microarray hybridizations and their dye swaps were analyzed. Our results show that 265 transcripts are differentially expressed in adult females and 53 in adult males when mature and immature worms are compared. Of the genes differentially expressed, 55% are expressed at higher levels in paired females while the remaining 45% are more expressed in unpaired ones and 56.6% are expressed at higher levels in paired male worms while the remaining 43.4% are more expressed in immature parasites. Real-time RT-PCR analysis validated the microarray results. Several new maturation associated transcripts were identified. Genes that were up-regulated in single-sex females were mostly related to energy generation (i.e. carbohydrate and protein metabolism, generation of precursor metabolites and energy, cellular catabolism, and organelle organization and biogenesis) while genes that were down-regulated related to RNA metabolism, reactive oxygen species metabolism, electron transport, organelle organization and biogenesis and protein biosynthesis. Conclusion Our results confirm previous observations related to gene expression induced

  8. RNA Interference in Schistosoma mansoni Schistosomula: Selectivity, Sensitivity and Operation for Larger-Scale Screening

    PubMed Central

    Horn, Martin; Braschi, Simon; Sojka, Daniel; Ruelas, Debbie S.; Suzuki, Brian; Lim, Kee-Chong; Hopkins, Stephanie D.; McKerrow, James H.; Caffrey, Conor R.

    2010-01-01

    Background The possible emergence of resistance to the only available drug for schistosomiasis spurs drug discovery that has been recently incentivized by the availability of improved transcriptome and genome sequence information. Transient RNAi has emerged as a straightforward and important technique to interrogate that information through decreased or loss of gene function and identify potential drug targets. To date, RNAi studies in schistosome stages infecting humans have focused on single (or up to 3) genes of interest. Therefore, in the context of standardizing larger RNAi screens, data are limited on the extent of possible off-targeting effects, gene-to-gene variability in RNAi efficiency and the operational capabilities and limits of RNAi. Methodology/Principal Findings We investigated in vitro the sensitivity and selectivity of RNAi using double-stranded (ds)RNA (approximately 500 bp) designed to target 11 Schistosoma mansoni genes that are expressed in different tissues; the gut, tegument and otherwise. Among the genes investigated were 5 that had been previously predicted to be essential for parasite survival. We employed mechanically transformed schistosomula that are relevant to parasitism in humans, amenable to screen automation and easier to obtain in greater numbers than adult parasites. The operational parameters investigated included defined culture media for optimal parasite maintenance, transfection strategy, time- and dose- dependency of RNAi, and dosing limits. Of 7 defined culture media tested, Basch Medium 169 was optimal for parasite maintenance. RNAi was best achieved by co-incubating parasites and dsRNA (standardized to 30 µg/ml for 6 days); electroporation provided no added benefit. RNAi, including interference of more than one transcript, was selective to the gene target(s) within the pools of transcripts representative of each tissue. Concentrations of dsRNA above 90 µg/ml were directly toxic. RNAi efficiency was transcript

  9. Macrophages are required for host survival in experimental urogenital schistosomiasis

    PubMed Central

    Fu, Chi-Ling; Odegaard, Justin I.; Hsieh, Michael H.

    2015-01-01

    Urogenital schistosomiasis, Schistosoma haematobium worm infection, afflicts millions of people with egg-triggered, fibrotic bladder granulomata. Despite the significant global impact of urogenital schistosomiasis, the mechanisms of bladder granulomogenesis and fibrosis are ill defined due to the prior lack of tractable animal models. We combined a mouse model of urogenital schistosomiasis with macrophage-depleting liposomal clodronate (LC) to define how macrophages mediate bladder granulomogenesis and fibrosis. Mice were injected with eggs purified from infected hamsters or vehicle prepared from uninfected hamster tissues (xenoantigen and injection trauma control). Empty liposomes were controls for LC: 1) LC treatment resulted in fewer bladder egg granuloma-infiltrating macrophages, eosinophils, and T and B cells, lower bladder and serum levels of eotaxin, and higher bladder concentrations of IL-1α and chemokines (in a time-dependent fashion), confirming that macrophages orchestrate leukocyte infiltration of the egg-exposed bladder; 2) macrophage-depleted mice exhibited greater weight loss and bladder hemorrhage postegg injection; 3) early LC treatment postegg injection resulted in profound decreases in bladder fibrosis, suggesting differing roles for macrophages in fibrosis over time; and 4) LC treatment also led to egg dose-dependent mortality, indicating that macrophages prevent death from urogenital schistosomiasis. Thus, macrophages are a potential therapeutic target for preventing or treating the bladder sequelae of urogenital schistosomiasis.—Fu, C.-L., Odegaard, J. I., Hsieh, M. H. Macrophages are required for host survival in experimental urogenital schistosomiasis. PMID:25351984

  10. Enhancing collaboration between China and African countries for schistosomiasis control.

    PubMed

    Xu, Jing; Yu, Qing; Tchuenté, Louis-Albert Tchuem; Bergquist, Robert; Sacko, Moussa; Utzinger, Jürg; Lin, Dan-Dan; Yang, Kun; Zhang, Li-Juan; Wang, Qiang; Li, Shi-Zhu; Guo, Jia-Gang; Zhou, Xiao-Nong

    2016-03-01

    Schistosomiasis remains an important public health issue, with a large number of cases reported across sub-Saharan Africa, and parts of Asia and Latin America. China was once highly endemic, but has made substantial progress and is moving towards elimination of schistosomiasis. Meanwhile, despite long-term, repeated, school-based chemotherapy in many African countries, more than 90% of all schistosomiasis cases are concentrated in Africa, and hence, this continent constitutes the key challenge for schistosomiasis control. Opportunities and issues for international collaboration in the fight against schistosomiasis are outlined with a focus on China's experiences, including the role of public health authorities and intersectoral collaboration, use of new and effective snail control approaches and diagnostic tools adapted to the specific stage of control, as well as the strengthening of risk mapping and surveillance-response mechanisms. Training courses targeting African governmental officials and professionals, coupled with field visits of African scientists and control programme managers to China, and vice versa, are considered important for improved schistosomiasis control and elimination. The crucial question remains whether the Chinese experience can be translated and applied in African countries to improve the effectiveness of health interventions and scale-up. PMID:26851829

  11. Socioeconomic Studies of Schistosomiasis in Brazil: a Review

    PubMed Central

    Kloos, Helmut; Correa-Oliveira, Rodrigo; Quites, Humberto Ferreira; Souza, Márcia Christina; Gazzinelli, Andrea

    2009-01-01

    This review finds considerable evidence that socioeconomic status has significantly influenced the transmission, spread and treatment of schistosomiasis in Brazil. High infection rates persist among both the rural and urban poor. Rural living, poor housing and water supplies and low educational level were major factors in schistosomiasis occurrence among agricultural populations. In urban areas, prevailing living conditions in shantytowns and labor migrations from and periodic return movements to rural areas were predictive of schistosomiasis. The risk of the establishment of new transmission foci exists in both rural and urban areas, conferred by and affecting poorer people. Associations between schistosomiasis and socioeconomic parameters, persisting inequities in health services accessibility, prevailing health impacts of schistosomiasis, and the ongoing decentralization of health services point to opportunities and strategies for focused interventions aimed at promoting health-enhancing behavior and living conditions and improving access to health care. The authors call for multidisciplinary studies to better examine the complexities of the socioeconomic environment in relation to schistosomiasis and for economic programs to reduce prevailing socioeconomic inequalities. PMID:18694715

  12. Imatinib Treatment Causes Substantial Transcriptional Changes in Adult Schistosoma mansoni In Vitro Exhibiting Pleiotropic Effects

    PubMed Central

    Oliveira, Katia C.; Dissous, Colette; Cailliau, Katia; Marhöfer, Richard J.; Selzer, Paul M.; Verjovski-Almeida, Sergio; Grevelding, Christoph G.

    2014-01-01

    Background Schistosome parasites cause schistosomiasis, one of the most important infectious diseases worldwide. For decades Praziquantel (PZQ) is the only drug widely used for controlling schistosomiasis. The absence of a vaccine and fear of PZQ resistance have motivated the search for alternatives. Studies on protein kinases (PKs) demonstrated their importance for diverse physiological processes in schistosomes. Among others two Abl tyrosine kinases, SmAbl1 and SmAbl2, were identified in Schistosoma mansoni and shown to be transcribed in the gonads and the gastrodermis. SmAbl1 activity was blocked by Imatinib, a known Abl-TK inhibitor used in human cancer therapy (Gleevec/Glivec). Imatinib exhibited dramatic effects on the morphology and physiology of adult schistosomes in vitro causing the death of the parasites. Methodology/Principal Findings Here we show modeling data supporting the targeting of SmAbl1/2 by Imatinib. A biochemical assay confirmed that SmAbl2 activity is also inhibited by Imatinib. Microarray analyses and qRT-PCR experiments were done to unravel transcriptional processes influenced by Imatinib in adult schistosomes in vitro demonstrating a wide influence on worm physiology. Surface-, muscle-, gut and gonad-associated processes were affected as evidenced by the differential transcription of e.g. the gynecophoral canal protein gene GCP, paramyosin, titin, hemoglobinase, and cathepsins. Furthermore, transcript levels of VAL-7 and egg formation-associated genes such as tyrosinase 1, p14, and fs800-like were affected as well as those of signaling genes including a ribosomal protein S6 kinase and a glutamate receptor. Finally, a comparative in silico analysis of the obtained microarray data sets and previous data analyzing the effect of a TGFβR1 inhibitor on transcription provided first evidence for an association of TGFβ and Abl kinase signaling. Among others GCP and egg formation-associated genes were identified as common targets. Conclusions

  13. Evaluation of a Urine Pooling Strategy for the Rapid and Cost-Efficient Prevalence Classification of Schistosomiasis

    PubMed Central

    Coulibaly, Jean T.; Bendavid, Eran; N’Goran, Eliézer K.; Utzinger, Jürg; Keiser, Jennifer; Bogoch, Isaac I.; Andrews, Jason R.

    2016-01-01

    Background A key epidemiologic feature of schistosomiasis is its focal distribution, which has important implications for the spatial targeting of preventive chemotherapy programs. We evaluated the diagnostic accuracy of a urine pooling strategy using a point-of-care circulating cathodic antigen (POC-CCA) cassette test for detection of Schistosoma mansoni, and employed simulation modeling to test the classification accuracy and efficiency of this strategy in determining where preventive chemotherapy is needed in low-endemicity settings. Methodology We performed a cross-sectional study involving 114 children aged 6–15 years in six neighborhoods in Azaguié Ahoua, south Côte d’Ivoire to characterize the sensitivity and specificity of the POC-CCA cassette test with urine samples that were tested individually and in pools of 4, 8, and 12. We used a Bayesian latent class model to estimate test characteristics for individual POC-CCA and quadruplicate Kato-Katz thick smears on stool samples. We then developed a microsimulation model and used lot quality assurance sampling to test the performance, number of tests, and total cost per school for each pooled testing strategy to predict the binary need for school-based preventive chemotherapy using a 10% prevalence threshold for treatment. Principal Findings The sensitivity of the urine pooling strategy for S. mansoni diagnosis using pool sizes of 4, 8, and 12 was 85.9%, 79.5%, and 65.4%, respectively, when POC-CCA trace results were considered positive, and 61.5%, 47.4%, and 30.8% when POC-CCA trace results were considered negative. The modeled specificity ranged from 94.0–97.7% for the urine pooling strategies (when POC-CCA trace results were considered negative). The urine pooling strategy, regardless of the pool size, gave comparable and often superior classification performance to stool microscopy for the same number of tests. The urine pooling strategy with a pool size of 4 reduced the number of tests and total

  14. PARASITES AND POVERTY: THE CASE OF SCHISTOSOMIASIS

    PubMed Central

    King, Charles H.

    2009-01-01

    Simultaneous and sequential transmission of multiple parasites, and their resultant overlapping chronic infections, are facts of life in many underdeveloped rural areas. These represent significant but often poorly-measured health and economic burdens for affected populations. For example, the chronic inflammatory process associated with long-term schistosomiasis contributes to anaemia and undernutrition, which, in turn, can lead to growth stunting, poor school performance, poor work productivity, and continued poverty. To date, most national and international programs aimed at parasite control have not considered the varied economic and ecological factors underlying multi-parasite transmission, but some are beginning to provide a coordinated approach to control. In addition, interest is emerging in new studies for the re-evaluation and recalibration of the health burden of helminthic parasite infection. Their results should highlight the strong potential of integrated parasite control in efforts for poverty reduction. PMID:19962954

  15. Observer design for a schistosomiasis model.

    PubMed

    Diaby, Mouhamadou; Iggidr, Abderrahman; Sy, Mamadou

    2015-11-01

    This paper deals with the state estimation for a schistosomiasis infection dynamical model described by a continuous nonlinear system when only the infected human population is measured. The central idea is studied following two major angles. On the one hand, when all the parameters of the model are supposed to be well known, we construct a simple observer and a high-gain Luenberger observer based on a canonical controller form and conceived for the nonlinear dynamics where it is implemented. On the other hand, when the nonlinear uncertain continuous-time system is in a bounded-error context, we introduce a method for designing a guaranteed interval observer. Numerical simulations are included in order to test the behavior and the performance of the given observers. PMID:26334676

  16. Parasites and poverty: the case of schistosomiasis.

    PubMed

    King, Charles H

    2010-02-01

    Simultaneous and sequential transmission of multiple parasites, and their resultant overlapping chronic infections, are facts of life in many underdeveloped rural areas. These represent significant but often poorly measured health and economic burdens for affected populations. For example, the chronic inflammatory process associated with long-term schistosomiasis contributes to anaemia and undernutrition, which, in turn, can lead to growth stunting, poor school performance, poor work productivity, and continued poverty. To date, most national and international programs aimed at parasite control have not considered the varied economic and ecological factors underlying multi-parasite transmission, but some are beginning to provide a coordinated approach to control. In addition, interest is emerging in new studies for the re-evaluation and recalibration of the health burden of helminthic parasite infection. Their results should highlight the strong potential of integrated parasite control in efforts for poverty reduction. PMID:19962954

  17. Spinal Cord Schistosomiasis: Two Different Outcomes

    PubMed Central

    Alsomaili, Mohammed; Abulaban, Ahmad A.

    2016-01-01

    Spinal cord schistosomiasis is difficult to diagnose in nonendemic areas. We report the clinical profile of 2 young Saudi males who presented with myelopathy. The first patient arrived at our hospital relatively late, i.e. 3 months following the presentation of initial symptoms, and had received both pulse steroid therapy and a plasma exchange. Praziquantel was administered late and the patient did not recover. The second case presented early, i.e. within around 8 weeks of initial symptoms. This patient received praziquantel without any kind of steroid and had a complete recovery. We concluded that prompt recognition and early treatment with praziquantel is crucial for a better outcome. The role of steroids in these cases still needs to be proven. PMID:27293404

  18. Does granulocyte-colony stimulating factor administration induce damage or repair response in schistosomiasis?

    PubMed Central

    Ghanem, Lobna Y; Dahmen, Uta; Dirsch, Olaf; Nosseir, Mona MF; Mahmoud, Soheir S; Mansour, Wafaa AF

    2010-01-01

    AIM: To introduce Granulocyte-colony stimulating factor (G-CSF) as a new therapeutic modality for schistosomiasis through stem cell mobilization, immunomodulation or fibrosis remodeling. METHODS: In this study, a 5 d course of human recombinant G-CSF (100 μg/kg sc) was applied to Schistosoma mansoni-infected mice at different stages of disease (5 d before infection as well as 3, 5 and 7 wk post-infection). The animals were sacrificed at 10 d as well as 4, 6 and 8 wk post infection. Mice were examined for: (1) Total leukocyte count which is an accepted surrogate marker for the stem cell mobilization into the circulation; (2) Egg count in intestine and liver tissue to assess the parasitic load; and (3) Histopathological changes in Hx/E and Masson trichrome stained sections as well as collagen content in Sirius red-stained liver sections to determine the severity of liver fibrosis. RESULTS: Mice developed leukocytosis. The egg load and the number of granulomas were not affected by the G-CSF treatment but there was an obvious change in the composition of granulomas towards an increased cellularity. Moreover, fibrosis was significantly decreased in treated groups compared to untreated animals (collagen content either preinfection or at 3 and 5 wk post infection: 5.8 ± 0.5, 4.7 ± 0.5, 4.0 ± 0.7 vs 8.2 ± 0.9; P ≤ 0.01). CONCLUSION: Although G-CSF did not cause direct elimination of the parasite, it enhanced granulomatous reaction and reduced the fibrosis. Further investigation of the underlying mechanisms of these two actions is warranted. PMID:21191519

  19. Specific Schistosoma mansoni rat T cell clones. I. Generation and functional analysis in vitro and in vivo.

    PubMed

    Pestel, J; Dissous, C; Dessaint, J P; Louis, J; Engers, H; Capron, A

    1985-06-01

    In an attempt to determine the role of schistosome-specific T cells in the immune mechanisms developed during schistosomiasis, Schistosoma mansoni-specific T cells and clones were generated in vitro and some of their functions analyzed in vitro and in vivo in the fischer rat model. The data presented here can be summarized as follows: a) Lymph node cells (LNC) from rats primed with the excretory/secretory antigens-incubation products (IPSm) of adult worms proliferate in vitro only in response to the homologous schistosome antigens and not to unrelated antigens (Ag) such as ovalbumin (OVA) or Dipetalonema viteae and Fasciola hepatica parasite extracts. b) After in vitro restimulation of the primed LNC population with IPSm in the presence of antigen-presenting cells (APC) and maintenance in IL 2-containing medium, the frequency of IPSm-specific T cells is increased and the T cells can be restimulated only in the presence of APC possessing the same major histocompatibility complex (MHC) antigens. c) Following appropriate limiting dilution assays (LDA) (1 cell/well), 10 IPSm-specific T cell clones were obtained, and two of four maintained in culture were tested for their helper activity because they expressed only the W3/13+ W3/25+ surface phenotypes. d) The two highly proliferating IPSm-specific T cell clones (G5 and E23) exhibit an IPSm-dependent helper activity, as shown by the increase in IgG production by IPSm-primed B cells. e) IPSm-T cell clone (G5) as well as IPSm-T cell lines when injected in S. mansoni-infested rats can exert an in vivo helper activity, which is characterized by an accelerated production of IgG antibodies specific for the previously identified 30 to 40 kilodaltons (kd) schistosomula surface antigens (Ag). As recent studies have demonstrated that rat monoclonal antibodies recognize some incubation products of adult S. mansoni as well as one of the 30 to 40 kd schistosomula surface antigens, and taking into account the fact that the T cell

  20. A chemokinetic response in Schistosoma mansoni cercariae.

    PubMed

    Shiff, C J; Graczyk, T K

    1994-12-01

    Schistosoma mansoni cercariae have been shown to aggregate in the presence of glass slides treated with clear nail varnish and linoleic acid. In choice chambers cercariae move toward the stimulant, but this behavior is not seen when linoleic acid is omitted. After 30-45 min, the cercariae were concentrated near the end of the choice-chamber containing the linoleic acid slide. When the cercariae were added in the center of the choice chamber, they formed a diffuse cloud that dispersed slowly in both directions in the absence of linoleic acid. Cercariae aggregating in the vicinity of a stimulant surface are not immediately stimulated to commence penetration; this appears to be time and dose related. PMID:7799158

  1. In-silico analysis of Sirt2 from Schistosoma mansoni: structures, conformations, and interactions with inhibitors.

    PubMed

    Singh, Raghvendra; Singh, Swadha; Pandey, Paras Nath

    2016-05-01

    Sirtuins are NAD+-dependent lysine deacetylases member of the class III HDAC family. These are demonstrated to be therapeutic targets in parasitic diseases like schistosomiasis. Observations suggested that sirtuin enzyme is necessary for the functionality of fe/male reproductive system, due to which SmSirt2 is treated as a potential therapeutic target. There are no structural and molecular features of SmSirt2 have been reported yet. In this study, homology modeling has been used to determine the three-dimensional features of the SmSITRT2. Further, structure validation has been performed by energy minimization and Ramachandran plot. Validated structures are further subjected to molecular docking and virtual screening to find the best lead molecules for downstream analysis. Ten lead molecules were selected while comparing virtual screening of hSirt2 and SmSirt2 both. These leads are further compared with AKG2 which is known inhibitor of hSirt2 (-8.8 kcal/mol). Out of selected 10 leads, four of them (ZINC23995485 (-9.5 kcal/mol), ZINC53298162 (-9.4 kcal/mol), ZINC70927268 (-10.0 kcal/mol), ZINC89878705 (-11.2 kcal/mol)) have shown better interaction with SmSirt2, in which ZINC89878705 (-11.2 kcal/mol) shows a more compact packing as compared to AKG2 and rest of ligands. These molecules could be further subject to in vitro study and model of SmSirt2 has been proposed for further structure-based drug design projects concerning sirtuins from Schistosoma mansoni. PMID:26108803

  2. Evidence for Novel Pharmacological Sensitivities of Transient Receptor Potential (TRP) Channels in Schistosoma mansoni

    PubMed Central

    Bais, Swarna; Churgin, Matthew A.; Fang-Yen, Christopher; Greenberg, Robert M.

    2015-01-01

    Schistosomiasis, caused by parasitic flatworms of the genus Schistosoma, is a neglected tropical disease affecting hundreds of millions globally. Praziquantel (PZQ), the only drug currently available for treatment and control, is largely ineffective against juvenile worms, and reports of PZQ resistance lend added urgency to the need for development of new therapeutics. Ion channels, which underlie electrical excitability in cells, are validated targets for many current anthelmintics. Transient receptor potential (TRP) channels are a large family of non-selective cation channels. TRP channels play key roles in sensory transduction and other critical functions, yet the properties of these channels have remained essentially unexplored in parasitic helminths. TRP channels fall into several (7–8) subfamilies, including TRPA and TRPV. Though schistosomes contain genes predicted to encode representatives of most of the TRP channel subfamilies, they do not appear to have genes for any TRPV channels. Nonetheless, we find that the TRPV1-selective activators capsaicin and resiniferatoxin (RTX) induce dramatic hyperactivity in adult worms; capsaicin also increases motility in schistosomula. SB 366719, a highly-selective TRPV1 antagonist, blocks the capsaicin-induced hyperactivity in adults. Mammalian TRPA1 is not activated by capsaicin, yet knockdown of the single predicted TRPA1-like gene (SmTRPA) in S. mansoni effectively abolishes capsaicin-induced responses in adult worms, suggesting that SmTRPA is required for capsaicin sensitivity in these parasites. Based on these results, we hypothesize that some schistosome TRP channels have novel pharmacological sensitivities that can be targeted to disrupt normal parasite neuromuscular function. These results also have implications for understanding the phylogeny of metazoan TRP channels and may help identify novel targets for new or repurposed therapeutics. PMID:26655809

  3. Antischistosomal activity of ginger (Zingiber officinale) against Schistosoma mansoni harbored in C57 mice.

    PubMed

    Mostafa, Osama M S; Eid, Refaat A; Adly, Mohamed A

    2011-08-01

    The repeated chemotherapy of schistosomiasis has resulted in the emergence of drug-resistant schistosome strains. The development of such resistance has drawn the attention of many authors to alternative drugs. Many medicinal plants were studied to investigate their antischistosomal potency. The present work aimed to evaluate antischistosomal activity of crude aqueous extract of ginger against Schistosoma mansoni. Sixteen mice of C57 strain were exposed to 100 ± 10 cercariae per mouse by the tail immersion method; the mice were divided into two groups: untreated group and ginger-treated one. All mice were sacrificed at the end of 10th week post-infection. Worm recovery and egg counting in the hepatic tissues and faeces were determined. Surface topography of the recovered worms was studied by scanning electron microscopy. Histopathological examination of liver and intestine was done using routine histological procedures. The worm burden and the egg density in liver and faeces of mice treated with ginger were fewer than in non-treated ones. Scanning electron microscopical examination revealed that male worms recovered from mice treated with ginger lost their normal surface architecture, since its surface showed partial loss of tubercles' spines, extensive erosion in inter-tubercle tegumental regions and numerous small blebs around tubercles. Histopathological data indicated a reduction in the number and size of granulomatous inflammatory infiltrations in the liver and intestine of treated mice compared to non-treated mice. The results of the present work suggested that ginger has antischistosomal activities and provided a basis for subsequent experimental and clinical trials. PMID:21327992

  4. Evaluation of the Anti-Schistosoma mansoni Activity of Thiosemicarbazones and Thiazoles

    PubMed Central

    de Oliveira, Sheilla Andrade; de Oliveira Filho, Gevânio Bezerra; Moreira, Diogo Rodrigo Magalhaes; Gomes, Paulo André Teixeira; da Silva, Anekécia Lauro; de Barros, Andréia Ferreira; da Silva, Aline Caroline; dos Santos, Thiago André Ramos; Pereira, Valéria Rêgo Alves; Gonçalves, Gabriel Gazzoni Araújo; Brayner, Fábio André; Alves, Luiz Carlos; Wanderley, Almir Gonçalves; Leite, Ana Cristina Lima

    2014-01-01

    Schistosomiasis is a chronic and debilitating disease caused by a trematode of the genus Schistosoma and affects over 207 million people. Chemotherapy is the only immediate recourse for minimizing the prevalence of this disease and involves predominately the administration of a single drug, praziquantel (PZQ). Although PZQ has proven efficacy, there is a recognized need to develop new drugs as schistosomicides since studies have shown that repeated use of this drug in areas of endemicity may cause a temporary reduction in susceptibility in isolates of Schistosoma mansoni. Hydrazones, thiosemicarbazones, phthalimides, and thiazoles are thus regarded as privileged structures used for a broad spectrum of activities and are potential candidates for sources of new drug prototypes. The present study determined the in vitro schistosomicidal activity of 10 molecules containing these structures. During the assays, parameters such motility and mortality, oviposition, morphological changes in the tegument, cytotoxicity, and immunomodulatory activity caused by these compounds were evaluated. The results showed that compounds formed of thiazole and phthalimide led to higher mortality of worms, with a significant decline in motility, inhibition of pairing and oviposition, and a mortality rate of 100% starting from 144 h of exposure. These compounds also stimulated the production of nitric oxide and tumor necrosis factor alpha (TNF-α), thereby demonstrating the presence of immunomodulatory activity. The phthalyl thiazole LpQM-45 caused significant ultrastructural alterations, with destruction of the tegument in both male and female worms. According to the present study, phthalyl thiazole compounds possess antischistosomal activities and should form the basis for future experimental and clinical trials. PMID:24165185

  5. In vitro cellular and humoral responses to Schistosoma mansoni vaccine candidate antigens.

    PubMed

    Al-Sherbiny, Maged; Osman, Ahmed; Barakat, Rashida; El Morshedy, Hala; Bergquist, Robert; Olds, Richard

    2003-10-01

    Few studies comparing schistosomiasis vaccine candidate antigens between laboratories have been carried out and published. Generally, only the investigators who discovered the molecules have evaluated them in either experimental animal models or in human correlate studies. In an attempt to identify responses against specific antigens and investigate their association with resistance versus susceptibility to re-infection, we studied the serological reactions and the cytokine responses stimulated by a panel of 10 candidate vaccine molecules in 225 long-term residents of an area endemic for Schistosoma mansoni in Egypt. The panel consisted of four recombinant antigens (Sm62-Irv5, Sm37-G3PDH, Sm28-GST and Sm14-FABP), one full-length native protein (Sm97-paramyosin), two synthetic peptides (MAP3 and MAP4) and three unpublished antigens (PR52-filamin, PL45-phosphoglycerate kinase, PN18-cyclophilin). Two different study designs, one based on retrospective and the other on prospective parasitological data were applied in the evaluation of the immune responses. Using historical data collected over the previous 5 years, correlations between frequency of re-infection and antigen-specific immune responses were investigated. In the prospective arm of the study, the subjects were followed over time after treatment with praziquantel with periodic immunological tests and stool examinations. Thus, highly specific humoral and cellular immune reactions in response to the 10 antigens described above could be correlated, both prospectively and retrospectively, with detailed epidemiological data covering a 66-month period. The immune response profiles produced were unique to each antigen but no clear "winner" or "winners" were identified. However, markers for both resistance and susceptibility to re-infection were identified for each molecule indicating which types of responses to aim for in vaccination and which ones to avoid. The insights gained from this approach should be useful for

  6. Prolyl Oligopeptidase from the Blood Fluke Schistosoma mansoni: From Functional Analysis to Anti-schistosomal Inhibitors

    PubMed Central

    Fajtová, Pavla; Štefanić, Saša; Hradilek, Martin; Dvořák, Jan; Vondrášek, Jiří; Jílková, Adéla; Ulrychová, Lenka; McKerrow, James H.; Caffrey, Conor R.; Mareš, Michael; Horn, Martin

    2015-01-01

    Background Blood flukes of the genus Schistosoma cause schistosomiasis, a parasitic disease that infects over 240 million people worldwide, and for which there is a need to identify new targets for chemotherapeutic interventions. Our research is focused on Schistosoma mansoni prolyl oligopeptidase (SmPOP) from the serine peptidase family S9, which has not been investigated in detail in trematodes. Methodology/Principal Findings We demonstrate that SmPOP is expressed in adult worms and schistosomula in an enzymatically active form. By immunofluorescence microscopy, SmPOP is localized in the tegument and parenchyma of both developmental stages. Recombinant SmPOP was produced in Escherichia coli and its active site specificity investigated using synthetic substrate and inhibitor libraries, and by homology modeling. SmPOP is a true oligopeptidase that hydrolyzes peptide (but not protein) substrates with a strict specificity for Pro at P1. The inhibition profile is analogous to those for mammalian POPs. Both the recombinant enzyme and live worms cleave host vasoregulatory, proline-containing hormones such as angiotensin I and bradykinin. Finally, we designed nanomolar inhibitors of SmPOP that induce deleterious phenotypes in cultured schistosomes. Conclusions/Significance We provide the first localization and functional analysis of SmPOP together with chemical tools for measuring its activity. We briefly discuss the notion that SmPOP, operating at the host-parasite interface to cleave host bioactive peptides, may contribute to the survival of the parasite. If substantiated, SmPOP could be a new target for the development of anti-schistosomal drugs. PMID:26039195

  7. The efficacy of antihelminthic compound; Clorsulon against experimental Schistosoma mansoni infection.

    PubMed

    Mossallam, Shereen F; Ali, Safia M; El Zawawy, Lobna A; Said, Doaa E

    2007-04-01

    The efficacy of Clorsulon (CLS) against experimental schistosomiasis mansoni, using Praziquantel (PZQ) as a therapeutic control was evaluated. Swiss Albino mice were divided into infected non-treated control, PZQ-treated group given a single dose of 500 mg/kg four weeks post infection (PI), and infected mice treated with single, double, and triple doses of 5 mg/kg CLS per dose, one week apart starting from the 4th week PI. All animals were perfused for adults count. Parts of livers and intestines were examined for granulomata number and sizes. Pathological changes in hepatic parenchyma by H&E and Masson trichrome stains were also examined. Results revealed that a single treatment with PZQ caused a significant percentage reduction (%R) of worm load (92.68%), mean egg count in liver and intestine (91.20 & 94.01% respectively), and mean size of liver granulomata was reduced (92.06%). Regarding CLS, the worm burden was reduced proportionally with number of doses given; 87.80, 96.34 & 97.56% in single, double and triple exposures successively. Egg count in liver was decreased by 85.90, 97.01 & 96.23% respectively in treated mice. Number of intestinal granulomata was decreased by 85.28, 94.24 & 95.49% in a similar way. Size of hepatic granulomata was decreased by 89.02, 94.51 & 95.05% by 1, 2 & 3 doses consecutively. All parameters reflected non significant difference between 2 & 3 dose of CLS. The results were critically discussed. PMID:17580576

  8. Endoscopic characteristics and causes of misdiagnosis of intestinal schistosomiasis.

    PubMed

    Ye, Chuncui; Tan, Shiyun; Jiang, Lin; Li, Ming; Sun, Peng; Shen, Lei; Luo, Hesheng

    2013-10-01

    The aim of this study was to determine the clinical and endoscopic manifestations, and pathological characteristics of intestinal schistosomiasis in China, in order to raise awareness of intestinal schistosomiasis and prevent misdiagnosis and missed diagnosis. The retrospective analysis of clinical and endoscopic manifestations, and histopathological characteristics, were conducted for 96 patients with intestinal schistosomiasis. Among these patients, 21 lived in areas that were not infected with Schistosoma and 25 (26%) had no history of schistosome infection or contact with infected water. These patients were mainly hospitalized due to symptoms of diarrhea, mucus and bloody purulent stool. Sixteen cases were of the acute enteritis type, and colonoscopy results determined hyperaemic edema and dispersed small mucosal ulcers. The acute infection in patients was pathologically characterized by the deposition of intact ova with a large quantity of eosinocyte infiltration. Forty‑one cases were of the chronic enteritis type which predominantly manifested with yellow nodules and disorder of the vascular surfaces in the intestines. Thirty‑nine cases were diagnosed with mixed type enteritis, which demonstrated acute and chronic histopathological appearances. In addition, six cases of complicated colorectal cancer were observed. Of the 24 misdiagnosed patients, eight were misdiagnosed with ulcerative colitis, five with colorectal cancer, five with colorectal tuberculosis, four with chronic bacillary dysentery and two with irritable bowel syndrome. Intestinal schistosomiasis demonstrated no specific clinical or endoscopic manifestations and it was determined that patients with abdominal pain, diarrhea and mucous stool may be infected with intestinal schistosomiasis. Epidemiological investigations and colonoscopy combined with multi‑block and multi‑site biopsies may improve the diagnosis of intestinal schistosomiasis. In addition, it is necessary for intestinal

  9. In silico repositioning-chemogenomics strategy identifies new drugs with potential activity against multiple life stages of Schistosoma mansoni.

    PubMed

    Neves, Bruno J; Braga, Rodolpho C; Bezerra, José C B; Cravo, Pedro V L; Andrade, Carolina H

    2015-01-01

    Morbidity and mortality caused by schistosomiasis are serious public health problems in developing countries. Because praziquantel is the only drug in therapeutic use, the risk of drug resistance is a concern. In the search for new schistosomicidal drugs, we performed a target-based chemogenomics screen of a dataset of 2,114 proteins to identify drugs that are approved for clinical use in humans that may be active against multiple life stages of Schistosoma mansoni. Each of these proteins was treated as a potential drug target, and its amino acid sequence was used to interrogate three databases: Therapeutic Target Database (TTD), DrugBank and STITCH. Predicted drug-target interactions were refined using a combination of approaches, including pairwise alignment, conservation state of functional regions and chemical space analysis. To validate our strategy, several drugs previously shown to be active against Schistosoma species were correctly predicted, such as clonazepam, auranofin, nifedipine, and artesunate. We were also able to identify 115 drugs that have not yet been experimentally tested against schistosomes and that require further assessment. Some examples are aprindine, gentamicin, clotrimazole, tetrabenazine, griseofulvin, and cinnarizine. In conclusion, we have developed a systematic and focused computer-aided approach to propose approved drugs that may warrant testing and/or serve as lead compounds for the design of new drugs against schistosomes. PMID:25569258

  10. Factors associated with Schistosoma mansoni infection 5 years after selective treatment in a low endemic area in Brazil.

    PubMed

    Disch, Jolande; Katz, Naftale; Pereira e Silva, Yerkes; de Gouvêa Viana, Luciana; Andrade, Marcela Orsini; Rabello, Ana

    2002-02-01

    Five years after a single dose treatment, prevalence, intensity and morbidity of schistosomiasis mansoni were evaluated in Agua Branca, a low endemic community in the South East Brazil (cure rate 94%). At community level, prevalence showed a decrease from 38.9 to 24.5% and the intensity of infection dropped from 119.5 to 38.9 eggs per g of faeces (epg). However, after the exclusion of immigrants, newborn children and individuals that had left the area after the first evaluation, the prevalence among the treated and followed population was not significantly affected. Multivariate analysis showed that the 10-29 age group and water contact for agricultural purposes were independently associated with the presence of infection on post treatment evaluation [OR 3.9 and 5.09, respectively]. A previous treatment among subjects older than 15 years was inversely associated [OR 0.58]. The authors wish to draw attention to the fact that mobility may lead to a serious bias in evaluating the impact of the control programme. PMID:11801220

  11. In Silico Repositioning-Chemogenomics Strategy Identifies New Drugs with Potential Activity against Multiple Life Stages of Schistosoma mansoni

    PubMed Central

    Neves, Bruno J.; Braga, Rodolpho C.; Bezerra, José C. B.; Cravo, Pedro V. L.; Andrade, Carolina H.

    2015-01-01

    Morbidity and mortality caused by schistosomiasis are serious public health problems in developing countries. Because praziquantel is the only drug in therapeutic use, the risk of drug resistance is a concern. In the search for new schistosomicidal drugs, we performed a target-based chemogenomics screen of a dataset of 2,114 proteins to identify drugs that are approved for clinical use in humans that may be active against multiple life stages of Schistosoma mansoni. Each of these proteins was treated as a potential drug target, and its amino acid sequence was used to interrogate three databases: Therapeutic Target Database (TTD), DrugBank and STITCH. Predicted drug-target interactions were refined using a combination of approaches, including pairwise alignment, conservation state of functional regions and chemical space analysis. To validate our strategy, several drugs previously shown to be active against Schistosoma species were correctly predicted, such as clonazepam, auranofin, nifedipine, and artesunate. We were also able to identify 115 drugs that have not yet been experimentally tested against schistosomes and that require further assessment. Some examples are aprindine, gentamicin, clotrimazole, tetrabenazine, griseofulvin, and cinnarizine. In conclusion, we have developed a systematic and focused computer-aided approach to propose approved drugs that may warrant testing and/or serve as lead compounds for the design of new drugs against schistosomes. PMID:25569258

  12. Schistosoma mansoni: is acquired immunity induced by highly x-irradiated cercariae dependent on the size of the challenging dose

    SciTech Connect

    Hsue, S.Y.; Hsue, H.F.; Osborne, J.W.; Johnson, S.C.

    1982-04-01

    A high degree of immunity, as shown by a 91% reduction of the number of worms recovered was found in five groups of mice that were immunized five times with highly X-irradiated cercariae and then challenged with 10, 20, 50, 100, or 500 normal Schistosoma mansoni cercariae. The results indicated that there were no significant differences in worm reduction in immunized mice challenged with different numbers of cercariae; consequently the immunity induced by this immunization method did not appear to be challenge-dose-dependent. However, the results also showed that when immunized mice were challenged with 500, 100, 50, 20, and 10 cercariae, 0, 13, 26, 56, and 68%, respectively, of the experimental animals were free of worms. Thus, the percentage of worm-negative cases increased as the number of challenge cercariae decreased. When viewed in this manner, the acquired immunity may be considered challenge-dose-dependent as well. If this method of vaccination is used for schistosomiasis control, we may anticipate that in both hypo- and hyperendemic areas, the intensity of infection and the severity of the disease will be reduced owing to a reduction in worms burdens, and in hypoendemic areas, there will be a number of worm-free cases.

  13. Screening the Schistosoma mansoni transcriptome for genes differentially expressed in the schistosomulum stage in search for vaccine candidates.

    PubMed

    Farias, Leonardo P; Tararam, Cibele A; Miyasato, Patricia A; Nishiyama, Milton Y; Oliveira, Katia C; Kawano, Toshie; Verjovski-Almeida, Sergio; Leite, Luciana Cezar de Cerqueira

    2011-01-01

    Schistosomiasis affects more than 200 million people worldwide; another 600 million are at risk of infection. The schistosomulum stage is believed to be the target of protective immunity in the attenuated cercaria vaccine model. In an attempt to identify genes up-regulated in the schistosomulum stage in relation to cercaria, we explored the Schistosoma mansoni transcriptome by looking at the relative frequency of reads in EST libraries from both stages. The 400 genes potentially up-regulated in schistosomula were analyzed as to their Gene Ontology categorization, and we have focused on those encoding-predicted proteins with no similarity to proteins of other organisms, assuming they could be parasite-specific proteins important for survival in the host. Up-regulation in schistosomulum relative to cercaria was validated with real-time reverse transcription polymerase chain reaction (RT-PCR) for five out of nine selected genes (56%). We tested their protective potential in mice through immunization with DNA vaccines followed by a parasite challenge. Worm burden reductions of 16-17% were observed for one of them, indicating its protective potential. Our results demonstrate the value and caveats of using stage-associated frequency of ESTs as an indication of differential expression coupled to DNA vaccine screening in the identification of novel proteins to be further investigated as potential vaccine candidates. PMID:20852890

  14. The USAID/Government of Egypt's Schistosomiasis Research Project (SRP).

    PubMed

    El Khoby, T; Galal, N; Fenwick, A

    1998-03-01

    Schistosomiasis is the major public health problem in rural Egypt, with almost six million Egyptians infected as at mid-1996. In 1983, the prevalence of schistosomiasis in rural Egypt was greater than 50%, but a ten-year campaign of diagnosis and treatment has reduced the prevalence and intensity of infection. Parallel to this campaign, the government of the USA has funded a research project to examine all aspects of schistosomiasis with a view to improving the control strategy. As outlined here by Taha El Khoby, Nabil Galal and Alan Fenwick, after almost ten years, the project's achievements include: assisting WHO in its attempts to develop a vaccine against schistosomiasis, developing a suspension formulation of praziquantel suitable for young children, and establishing a unit to monitor reports of resistance to praziquantel. In addition, a large epidemiological study has established the extent of the problem in Egypt. Slow-release formulation of niclosamide, health education material for use on TV, dipstick diagnostic tests, and evaluation of ultrasound as a diagnostic tool have also been achieved. As the project closes, Egypt is left with an effective strategy for the control of schistosomiasis and several back-up tools for use in the event of development of resistance to praziquantel. The Ministry of Health and Population has the basis of a Geographical Information System (GIS) unit and the country has a trained and equipped scientific community capable of biomedical research, and almost 100 scientific papers published on their work. PMID:17040713

  15. Design of schistosomiasis ontology (IDOSCHISTO) extending the infectious disease ontology.

    PubMed

    Camara, Gaoussou; Despres, Sylvie; Djedidi, Rim; Lo, Moussa

    2013-01-01

    Epidemiological monitoring of the schistosomiasis' spreading brings together many practitioners working at different levels of granularity (biology, host individual, host population), who have different perspectives (biology, clinic and epidemiology) on the same phenomenon. Biological perspective deals with pathogens (e.g. life cycle) or physiopathology while clinical perspective deals with hosts (e.g. healthy or infected host, diagnosis, treatment, etc.). In an epidemiological perspective corresponding to the host population level of granularity, the schistosomiasis disease is characterized according to the way (causes, risk factors, etc.) it spreads in this population over space and time. In this paper we provide an ontological analysis and design for the Schistosomiasis domain knowledge and spreading dynamics. IDOSCHISTO - the schistosomiasis ontology - is designed as an extension of the Infectious Disease Ontology (IDO). This ontology aims at supporting the schistosomiasis monitoring process during a spreading crisis by enabling data integration, semantic interoperability, for collaborative work on one hand and for risk analysis and decision making on the other hand. PMID:23920598

  16. Multivariable Regression Analysis in Schistosoma mansoni-Infected Individuals in the Sudan Reveals Unique Immunoepidemiological Profiles in Uninfected, egg+ and Non-egg+ Infected Individuals

    PubMed Central

    Wiszniewsky, Anna; Ritter, Manuel; Goreish, Ibtisam A.; Atti El Mekki, Misk El Yemen A.; Arriens, Sandra; Pfarr, Kenneth; Fimmers, Rolf; Doenhoff, Mike; Hoerauf, Achim; Layland, Laura E.

    2016-01-01

    Background In the Sudan, Schistosoma mansoni infections are a major cause of morbidity in school-aged children and infection rates are associated with available clean water sources. During infection, immune responses pass through a Th1 followed by Th2 and Treg phases and patterns can relate to different stages of infection or immunity. Methodology This retrospective study evaluated immunoepidemiological aspects in 234 individuals (range 4–85 years old) from Kassala and Khartoum states in 2011. Systemic immune profiles (cytokines and immunoglobulins) and epidemiological parameters were surveyed in n = 110 persons presenting patent S. mansoni infections (egg+), n = 63 individuals positive for S. mansoni via PCR in sera but egg negative (SmPCR+) and n = 61 people who were infection-free (Sm uninf). Immunoepidemiological findings were further investigated using two binary multivariable regression analysis. Principal Findings Nearly all egg+ individuals had no access to latrines and over 90% obtained water via the canal stemming from the Atbara River. With regards to age, infection and an egg+ status was linked to young and adolescent groups. In terms of immunology, S. mansoni infection per se was strongly associated with increased SEA-specific IgG4 but not IgE levels. IL-6, IL-13 and IL-10 were significantly elevated in patently-infected individuals and positively correlated with egg load. In contrast, IL-2 and IL-1β were significantly lower in SmPCR+ individuals when compared to Sm uninf and egg+ groups which was further confirmed during multivariate regression analysis. Conclusions/Significance Schistosomiasis remains an important public health problem in the Sudan with a high number of patent individuals. In addition, SmPCR diagnostics revealed another cohort of infected individuals with a unique immunological profile and provides an avenue for future studies on non-patent infection states. Future studies should investigate the downstream signalling pathways

  17. Experimental schistosomiasis in primates in Tanzania

    PubMed Central

    Jordan, P.; von Lichtenberg, F.; Goatly, K. D.

    1967-01-01

    Laboratory infection of animals with Schistosoma haematobium is generally unsatisfactory as adult worms invariably inhabit the portal venous system rather than the vesical plexus as in man. However, it was thought that certain primates might prove more valuable for experimental studies of schistosomiasis than the usual laboratory animals. Baboons, Papio anubis, were therefore exposed to cercariae of S. haematobium and the pattern of egg excretion in stools and urine was followed quantitatively. Histological studies of various organs were made and it was found that although eggs were excreted in the faeces, they were also passed in the urine and that tissue changes in the bladder were similar to those found in human infections. It is suggested that the sequelae of S. haematobium infection found in man might develop in baboons and that the animal may be useful for studying their development in the laboratory. ImagesFIG. 3FIG. 8FIG. 11FIG. 4FIG. 10FIG. 9FIG. 6FIG. 7FIG. 5 PMID:4968348

  18. Schistosoma mansoni Annexin 2: molecular characterization and immunolocalization.

    PubMed

    Tararam, Cibele Aparecida; Farias, Leonardo Paiva; Wilson, R Alan; Leite, Luciana Cezar de Cerqueira

    2010-10-01

    We here describe the cloning and characterization of the Schistosoma mansoni Annexin 2, previously identified in the tegument by proteomic studies, and as an up-regulated gene in schistosomulum stage by microarray data. In silico analysis predicts a conserved core containing four repeat domains of Annexin (ANX) and a variable N-terminal region similar to that described for mammalian isoforms. Real-time RT-PCR and Western blot analysis determined that S. mansoni Annexin 2 is significantly up-regulated in the transition from free-living cercaria to schistosomulum and adult worm parasitic stages. Immunolocalization experiments and tegument membrane preparations confirmed Annexin 2 as a protein mainly localized in the tegument of schistosomula and adult worms. Furthermore, it binds to the tegument surface membranes in a calcium-dependent manner. These results suggest that S. mansoni Annexin 2 is closely associated to the tegument arrangement, being a potential target for immune intervention. PMID:20417203

  19. Epidemiology and control of human schistosomiasis in Tanzania

    PubMed Central

    2012-01-01

    In Tanzania, the first cases of schistosomiasis were reported in the early 19th century. Since then, various studies have reported prevalences of up to 100% in some areas. However, for many years, there have been no sustainable control programmes and systematic data from observational and control studies are very limited in the public domain. To cover that gap, the present article reviews the epidemiology, malacology, morbidity, and the milestones the country has made in efforts to control schistosomiasis and discusses future control approaches. The available evidence indicates that, both urinary and intestinal schistosomiasis are still highly endemic in Tanzania and cause significant morbidity.Mass drug administration using praziquantel, currently used as a key intervention measure, has not been successful in decreasing prevalence of infection. There is therefore an urgent need to revise the current approach for the successful control of the disease. Clearly, these need to be integrated control measures. PMID:23192005

  20. Nucleic acid detection in the diagnosis and prevention of schistosomiasis.

    PubMed

    He, Ping; Song, Lan-Gui; Xie, Hui; Liang, Jin-Yi; Yuan, Dong-Ya; Wu, Zhong-Dao; Lv, Zhi-Yue

    2016-01-01

    Schistosomiasis is an important zoonotic parasitic disease that causes serious harms to humans and animals. Surveillance and diagnosis play key roles in schistosomiasis control, however, current techniques for surveillance and diagnosis of the disease have limitations. As genome data for parasites are increasing, novel techniques for detection incorporating nucleotide sequences are receiving widespread attention. These sensitive, specific, and rapid detection methods are particularly important in the diagnosis of low-grade and early infections, and may prove to have clinical significance. This paper reviews the progress of nucleic acid detection in the diagnosis and prevention of schistosomiasis, including such aspects as the selection of target genes, and development and application of nucleic acid detection methods. PMID:27025210

  1. The Establishment and Function of Schistosomiasis Surveillance System Towards Elimination in The People's Republic of China.

    PubMed

    Zhang, L-J; Li, S-Z; Wen, L-Y; Lin, D-D; Abe, E M; Zhu, R; Du, Y; Lv, S; Xu, J; Webster, B L; Rollinson, D; Zhou, X-N

    2016-01-01

    Schistosoma japonicum is the main schistosome species in The People's Republic of China, causing intestinal schistosomiasis, a debilitating disease of public health importance. The People's Republic of China used to be heavily endemic with schistosomiasis, but great progress has been made through the vigorous efforts of the national control programmes in the last six decades. Presently, efforts are geared towards eliminating schistosomiasis from The People's Republic of China by the end of 2025 through effective schistosomiasis surveillance, an important component in the drive towards schistosomiasis elimination. Therefore, this article explicitly outlines the development and progress made in schistosomiasis surveillance since 1990 with a special focus on the new surveillance system in use. Although the surveillance system has steadily improved over the years, it is faced with many challenges. Hence, more efforts are needed to establish an effective and sensitive evaluation system for the national schistosomiasis elimination programme in The People's Republic of China. PMID:27137445

  2. Global Health: Urogenital Schistosomiasis in the Adolescent Girl.

    PubMed

    Richardson, Sharise T; Franklin, Ashley L; Rome, Ellen S; Simms-Cendan, Judith S

    2016-08-01

    Urogenital schistosomiasis affects millions of women in sub-Saharan Africa. Infection by the causative organism, Schistosoma hematobium, commonly occurs during childhood and adolescence and can lead to anemia from hematuria, inflammation on the cervix which can increase risk of HIV transmission, and pelvic infection leading to infertility. Fortunately treatment is not costly, but early diagnosis is important to reduce long-term morbidity. Our objective is to review the epidemiology, pathophysiology, and diagnosis of urogenital schistosomiasis as well as treatment to improve the reproductive health of girls where this infection is endemic. PMID:26173381

  3. Africa: Schistosomiasis in Africa and the Role of Environmental Education.

    ERIC Educational Resources Information Center

    Stapp, William B.

    1985-01-01

    Illustrates problems involved in controlling a public health disease (schistosomiasis) which is interwoven into a country's religious, economic, political, educational, and social systems. The strong relationship between the disease and development of irrigation systems is pointed out. A successful education and integrative program is described.…

  4. Local and International Implications of Schistosomiasis Acquired in Corsica, France

    PubMed Central

    Mockenhaupt, Frank P.; von Sonnenburg, Frank; Rothe, Camilla; Libman, Michael; Van De Winkel, Kristina; Bottieau, Emmanuel; Grobusch, Martin P.; Hamer, Davidson H.; Esposito, Douglas H.; Parola, Philippe; Schlagenhauf, Patricia

    2015-01-01

    We report 11 cases of schistosomiasis in international travelers who had bathed in rivers in Corsica, France, during 2012–2014. The infections were diagnosed in 2014 and reported to the GeoSentinel Surveillance Network and European Travel Medicine Network. Travelers can be sentinels for emerging infections; thus, this situation warrants a concerted human and veterinary epidemiologic response. PMID:26401954

  5. [Schistosomiasis in an ecotourism area in Minas Gerais State, Brazil].

    PubMed

    Massara, Cristiano Lara; Amaral, Graciela Larissa; Caldeira, Roberta Lima; Drummond, Sandra Costa; Enk, Martin Johannes; Carvalho, Omar dos Santos

    2008-07-01

    This paper discusses schistosomiasis transmission in São José da Serra, a village with a population of 500 in the county of Jaboticatubas, Minas Gerais State, Brazil. The area receives thousands of visitors a year for ecotourism. The study was motivated by a case of acute schistosomiasis involving a couple that spent the 2007 Carnival (Mardi Gras) holiday in the area. Stool tests from 268 local residents (53.6% of the population) showed that 35 (13%) were positive for the infection. A comparison with a previous survey (2005) in the same location showed an increase in the schistosomiasis-positive rate from 9.6% to 12.5%, among the 56 individuals who participated in both surveys. A malacological survey of 65 Biomphalaria glabrata snails showed one specimen (1.5%) eliminating cercariae. In a similar survey in 2005, no positive snail specimens were found. The study indicates that active schistosomiasis transmission is occurring in the area, and that integrated educational programs are needed for both the local community and tourists. PMID:18670694

  6. Possible eggshell protein gene from Schistosoma mansoni.

    PubMed

    Johnson, K S; Taylor, D W; Cordingley, J S

    1987-01-01

    We have identified and sequenced a cDNA clone of a mRNA found only in mature female schistosomes. This mRNA is not detectably synthesized by female worms from single sex infections (unisexual females), by males or by the developing miracidia in the eggs. The clone hybridises to a highly abundant polyadenylated mRNA of approximately 1500 nucleotides. The nucleotide sequence of the clone predicts a polypeptide comprising two repetitive regions. A pentapeptide repeat with the consensus sequence Gly-Tyr-Asp-Lys-Tyr, and a region rich in histidine residues. Hybrid selected mRNA translated in vitro with [3H]tyrosine as labelled amino acid yields a polypeptide of 48 kDa (p48) that corresponds to the major [3H]tyrosine labelled translation product of female worm total mRNA. p48 does not label with [35S]methionine and is absent from the translation products of male and unisexual female mRNAs. The amino acid sequence of p48 has significant homologies to silk moth chorion proteins and we suggest that it is one of the major components of the schistosome eggshell probably accounting for the high level of [3H]tyrosine incorporation into the vitellaria of Schistosoma mansoni. The tyrosine content of the polypeptide suggests that it may play a role in phenol oxidase mediated cross-linking of the schistosome eggshell and in support of this we find that mushroom phenol oxidase will cause the specific cross-linking of p48 in in vitro translation products. PMID:3100949

  7. Impact of human schistosomiasis in sub-Saharan Africa.

    PubMed

    Adenowo, Abiola Fatimah; Oyinloye, Babatunji Emmanuel; Ogunyinka, Bolajoko Idiat; Kappo, Abidemi Paul

    2015-01-01

    Schistosomiasis, a neglected tropical disease of poverty ranks second among the most widespread parasitic disease in various nations in sub-Saharan Africa. Neglected tropical diseases are causes of about 534,000 deaths annually in sub-Saharan Africa and an estimated 57 million disability-adjusted life-years are lost annually due to the neglected tropical diseases. The neglected tropical diseases exert great health, social and financial burden on economies of households and governments. Schistosomiasis has profound negative effects on child development, outcome of pregnancy, and agricultural productivity, thus a key reason why the "bottom 500 million" inhabitants of sub-Saharan Africa continue to live in poverty. In 2008, 17.5 million people were treated globally for schistosomiasis, 11.7 million of those treated were from sub-Saharan Africa. This enervating disease has been successfully eradicated in Japan, as well as in Tunisia. Morocco and some Caribbean Island countries have made significant progress on control and management of this disease. Brazil, China and Egypt are taking steps towards elimination of the disease, while most sub-Saharan countries are still groaning under the burden of the disease. Various factors are responsible for the continuous and persistent transmission of schistosomiasis in sub-Saharan Africa. These include climatic changes and global warming, proximity to water bodies, irrigation and dam construction as well as socio-economic factors such as occupational activities and poverty. The morbidity and mortality caused by this disease cannot be overemphasized. This review is an exposition of human schistosomiasis as it affects the inhabitants of various communities in sub-Sahara African countries. It is hoped this will bring a re-awakening towards efforts to combat this impoverishing disease in terms of vaccines development, alternative drug design, as well as new point-of-care diagnostics. PMID:25636189

  8. Access to, and use of, water by populations living in a schistosomiasis and fascioliasis co-endemic area of northern Côte d'Ivoire.

    PubMed

    Krauth, Stefanie J; Musard, Capucine; Traoré, Seïdinan I; Zinsstag, Jakob; Achi, Louise Y; N'Goran, Eliézer K; Utzinger, Jürg

    2015-09-01

    Water is an essential element of life, but it can also be a source of disease. Apart from direct consumption of unsafe water, direct contact and indirect consumption puts people at risk of many different types of pathogens. Employing a mixed methods approach, consisting of questionnaires and direct observations, we assessed access to, and use of, different water sources by the participants of the district des Savanes in northern Côte d'Ivoire. The use of water sources was put in relation to the potential risk of acquiring schistosomiasis and fascioliasis. Overall, 489 people aged 8 to 82 years participated. While all participants had access to safe water, 63% were in direct contact with unimproved water and 31% directly consumed unsafe water. More than a third of the people who otherwise reported using only improved water for all activities came in contact with unimproved water through crossing open water when going to their workplace, school or other destinations. Self-reported blood in urine - a marker for Schistosoma haematobium with reasonable sensitivity and specificity - was reported by 6% (n=30), self-reported blood in stool - an unspecific marker for Schistosoma mansoni - was reported by 7% (n=35), while blood co-occurring in both urine and stool was reported by another 10% (n=48) of participants. Accessing unimproved water for any activity (including crossing) was associated with higher odds of reporting blood in urine and/or blood in stool (odds ratio: 1.90; 95% confidence interval: 1.07-3.36). Our results have important rami-fications for intervention programmes targeting neglected tropical diseases, and emphasize the need for a wider supply of safe water to rural populations, since the water supply at the workplace needs to be considered as well next to the water supply at home. Crossing of open water sources is an important risk factor for sustained transmission of schistosomiasis. PMID:26004285

  9. Whole genome resequencing of the human parasite Schistosoma mansoni reveals population history and effects of selection

    PubMed Central

    Crellen, Thomas; Allan, Fiona; David, Sophia; Durrant, Caroline; Huckvale, Thomas; Holroyd, Nancy; Emery, Aidan M.; Rollinson, David; Aanensen, David M.; Berriman, Matthew; Webster, Joanne P.; Cotton, James A.

    2016-01-01

    Schistosoma mansoni is a parasitic fluke that infects millions of people in the developing world. This study presents the first application of population genomics to S. mansoni based on high-coverage resequencing data from 10 global isolates and an isolate of the closely-related Schistosoma rodhaini, which infects rodents. Using population genetic tests, we document genes under directional and balancing selection in S. mansoni that may facilitate adaptation to the human host. Coalescence modeling reveals the speciation of S. mansoni and S. rodhaini as 107.5–147.6KYA, a period which overlaps with the earliest archaeological evidence for fishing in Africa. Our results indicate that S. mansoni originated in East Africa and experienced a decline in effective population size 20–90KYA, before dispersing across the continent during the Holocene. In addition, we find strong evidence that S. mansoni migrated to the New World with the 16–19th Century Atlantic Slave Trade. PMID:26879532

  10. Whole genome resequencing of the human parasite Schistosoma mansoni reveals population history and effects of selection.

    PubMed

    Crellen, Thomas; Allan, Fiona; David, Sophia; Durrant, Caroline; Huckvale, Thomas; Holroyd, Nancy; Emery, Aidan M; Rollinson, David; Aanensen, David M; Berriman, Matthew; Webster, Joanne P; Cotton, James A

    2016-01-01

    Schistosoma mansoni is a parasitic fluke that infects millions of people in the developing world. This study presents the first application of population genomics to S. mansoni based on high-coverage resequencing data from 10 global isolates and an isolate of the closely-related Schistosoma rodhaini, which infects rodents. Using population genetic tests, we document genes under directional and balancing selection in S. mansoni that may facilitate adaptation to the human host. Coalescence modeling reveals the speciation of S. mansoni and S. rodhaini as 107.5-147.6KYA, a period which overlaps with the earliest archaeological evidence for fishing in Africa. Our results indicate that S. mansoni originated in East Africa and experienced a decline in effective population size 20-90KYA, before dispersing across the continent during the Holocene. In addition, we find strong evidence that S. mansoni migrated to the New World with the 16-19th Century Atlantic Slave Trade. PMID:26879532

  11. Parasitological, Pathological, and Immunological Parameters Associated with Schistosoma mansoni Infection and Reinfection in BALB/c AND C57BL/6 Mice.

    PubMed

    Alves, Clarice Carvalho; Araujo, Neusa; Cassali, Geovanni Dantas; Fonseca, Cristina Toscano

    2016-06-01

    Schistosome-host interaction is influenced by multiple factors, such as the type of immune response developed by the host, host genetic background, intensity, and number of infections. Those factors not only affect the development and elimination of Schistosoma mansoni , but also the pathology triggered by infection with this parasite. In the present study, we assessed the parasitological, pathological, and immunological aspects elicited by infection and reinfection in 2 different mouse strains commonly used as models in studies on schistosomiasis: BALB/c and C57BL/6. No differences in worm burden recovery or in the number of eggs per gram of intestine or feces were observed between the strains or between infected and reinfected mice from the same strain. However, the number of eggs trapped in the liver of the reinfected mice was significantly higher than the number of eggs in the liver of the infected animals. But, the granulomatous area was significantly lower in reinfected animals than in infected ones. Additionally, granuloma in the infected BALB/c mice was greater than in infected C57BL/6 animals. Regarding the cytokine profile, spleen cells from the infected/reinfected C57BL/6 mice produced higher interleukin 10 (IL-10) levels against egg antigens than BALB/c-infected/reinfected mice. BALB/c mice, in contrast, produced significantly higher IL-4 and IL-13 cytokines after infection/reinfection than the C57BL/6 mice, with the highest levels of IL-13 being observed after reinfection. Our results demonstrate that, although different host backgrounds did not impact resistance to S. mansoni , they result in different immunological profiles that suggest different pathological impacts on the liver. PMID:26928866

  12. Schistosoma mansoni venom allergen-like protein 4 (SmVAL4) is a novel lipid-binding SCP/TAPS protein that lacks the prototypical CAP motifs

    SciTech Connect

    Kelleher, Alan; Darwiche, Rabih; Rezende, Wanderson C.; Farias, Leonardo P.; Leite, Luciana C. C.; Schneiter, Roger; Asojo, Oluwatoyin A.

    2014-08-01

    The first structure of an S. mansoni venom allergen-like protein is presented. Schistosomiasis is a parasitic disease that affects over 200 million people. Vaccine candidates have been identified, including Schistosoma mansoni venom allergen-like proteins (SmVALs) from the SCP/TAPS (sperm-coating protein/Tpx/antigen 5/pathogenesis related-1/Sc7) superfamily. The first SmVAL structure, SmVAL4, was refined to a resolution limit of 2.16 Å. SmVAL4 has a unique structure that could not be predicted from homologous structures, with longer loops and an unusual C-terminal extension. SmVAL4 has the characteristic α/β-sandwich and central SCP/TAPS cavity. Furthermore, SmVAL4 has only one of the signature CAP cavity tetrad amino-acid residues and is missing the histidines that coordinate divalent cations such as Zn{sup 2+} in other SCP/TAPS proteins. SmVAL4 has a cavity between α-helices 1 and 4 that was observed to bind lipids in tablysin-15, suggesting the ability to bind lipids. Subsequently, SmVAL4 was shown to bind cholesterol in vitro. Additionally, SmVAL4 was shown to complement the in vivo sterol-export phenotype of yeast mutants lacking their endogenous CAP proteins. Expression of SmVAL4 in yeast cells lacking endogenous CAP function restores the block in sterol export. These studies suggest an evolutionarily conserved lipid-binding function shared by CAP proteins such as SmVAL4 and yeast CAP proteins such as Pry1.

  13. Schistosoma mansoni Soluble Egg Antigens Induce Expression of the Negative Regulators SOCS1 and SHP1 in Human Dendritic Cells via Interaction with the Mannose Receptor

    PubMed Central

    Klaver, Elsenoor J.; Kuijk, Loes M.; Lindhorst, Thisbe K.; Cummings, Richard D.; van Die, Irma

    2015-01-01

    Schistosomiasis is a common debilitating human parasitic disease in (sub)tropical areas, however, schistosome infections can also protect against a variety of inflammatory diseases. This has raised broad interest in the mechanisms by which Schistosoma modulate the immune system into an anti-inflammatory and regulatory state. Human dendritic cells (DCs) show many phenotypic changes upon contact with Schistosoma mansoni soluble egg antigens (SEA). We here show that oxidation of SEA glycans, but not heat-denaturation, abrogates the capacity of SEA to suppress both LPS-induced cytokine secretion and DC proliferation, indicating an important role of SEA glycans in these processes. Remarkably, interaction of SEA glycans with DCs results in a strongly increased expression of Suppressor Of Cytokine Signalling1 (SOCS1) and SH2-containing protein tyrosine Phosphatase-1 (SHP1), important negative regulators of TLR4 signalling. In addition, SEA induces the secretion of transforming growth factor β (TGF-β), and the surface expression of the costimulatory molecules Programmed Death Ligand-1 (PD-L1) and OX40 ligand (OX40L), which are known phenotypic markers for the capacity of DCs to polarize naïve T cells into Th2/Treg cell subsets. Inhibition of mannose receptor (MR)-mediated internalization of SEA into DCs by blocking with allyl α-D-mannoside or anti-MR antibodies, significantly reduced SOCS1 and SHP1 expression. In conclusion, we demonstrate that SEA glycans are essential for induction of enhanced SOCS1 and SHP1 levels in DCs via the MR. Our data provide novel mechanistic evidence for the potential of S. mansoni SEA glycans to modulate human DCs, which may contribute to the capacity of SEA to down-regulate inflammatory responses. PMID:25897665

  14. Telmisartan, an AT1 receptor blocker and a PPAR gamma activator, alleviates liver fibrosis induced experimentally by Schistosoma mansoni infection

    PubMed Central

    2013-01-01

    Background Hepatic schistosomiasis is considered to be one of the most prevalent forms of chronic liver disease in the world due to its complication of liver fibrosis. The demonstration of the pro-fibrogenic role of angiotensin (Ang) II in chronic liver disease brought up the idea that anti-Ang II agents may be effective in improving hepatic fibrosis by either blocking Ang II type 1 (AT1) receptors or inhibiting the angiotensin converting enzyme. Peroxisome proliferator-activated receptors gamma (PPARγ) activation has been also shown to inhibit hepatic stellate cell activation and progression of fibrosis. The present study has aimed at testing the anti-fibrogenic effects of telmisartan; an AT1 receptor blocker and a PPARγ partial agonist, alone or combined with praziquantel (PZQ) on Schistosoma mansoni-induced liver fibrosis in mice. Methods To achieve the aim of the study, two sets of experiments were performed in which telmisartan was initiated at the 5th (set 1) and the 10th (set 2) weeks post infection to assess drug efficacy in both acute and chronic stages of liver fibrosis, respectively. Schistosoma mansoni-infected mice were randomly divided into the following four groups: infected-control (I), telmisartan-treated (II), PZQ-treated (III), and telmisartan+PZQ-treated (IV). In addition, a normal non-infected group was used for comparison. Parasitological (hepatomesenteric worm load and oogram pattern), histopathological, morphometric, immunohistochemical (hepatic expressions of matrix metalloproteinase-2; MMP-2 and tissue inhibitor of metalloproteinase-2; TIMP-2), and biochemical (serum transforming growth factor beta 1; TGF-β1 and liver function tests) studies were performed. Results Telmisartan failed to improve the parasitological parameters, while it significantly (P<0.05) decreased the mean granuloma diameter, area of fibrosis, and serum TGF-β1. Additionally, telmisartan increased MMP-2 and decreased TIMP-2 hepatic expression. Combined treatment

  15. Impact of schistosomiasis on quality of life and productivity of workers.

    PubMed

    Kamel, M I; Moustafa, Y A; Foda, N; Khashab, S; Moemen, M; Abo el-Naga, R M

    2002-01-01

    The effect of schistosomiasis on quality of life (QOL) and productivity of workers was examined. In a textile factory in Alexandria, Egypt, personal, occupational and sociodemographic data were collected from 172 workers with schistosomiasis and 172 workers without schistosomiasis. Several indicators of productivity and the World Health Organization QOL brief were used to determine the impact of schistosomiasis. The disease affected the general, physical and independence, psychological and spiritual, and social domains of QOL. Although the productivity score of workers with schistosomiasis did not differ significantly from the control group, they had significantly lower additional hours of work and lower total incentives/month. A significant relationship was found between severity of schistosomiasis and QOL domains and productivity indicators. PMID:15339125

  16. Spatiotemporal Patterns of Schistosomiasis-Related Deaths, Brazil, 2000–2011

    PubMed Central

    Martins-Melo, Francisco Rogerlândio; Pinheiro, Marta Cristhiany Cunha; Ramos, Alberto Novaes; Alencar, Carlos Henrique; Bezerra, Fernando Schemelzer de Moraes

    2015-01-01

    We analyzed spatiotemporal patterns of 8,756 schistosomiasis-related deaths in Brazil during 2000–2011 and identified high-risk clusters of deaths, mainly in highly schistosomiasis-endemic areas along the coast of Brazil’s Northeast Region. Schistosomiasis remains a neglected public health problem with a high number of deaths in disease-endemic and emerging focal areas. PMID:26401716

  17. Evidence for a permanent presence of schistosomiasis in Corsica, France, 2015.

    PubMed

    Berry, Antoine; Fillaux, Judith; Martin-Blondel, Guillaume; Boissier, Jérôme; Iriart, Xavier; Marchou, Bruno; Magnaval, Jean François; Delobel, Pierre

    2016-01-01

    We present a case of acute schistosomiasis acquired in Corsica after bathing in the Cavu River during the summer of 2015. The diagnosis was made following epidemiological, laboratory and serological assessments. After a previous outbreak of urogenital schistosomiasis during the summer of 2013, when more than 120 infections were diagnosed, this further case indicates transmission was still effective in 2015, thus suggesting a permanent presence of schistosomiasis in Corsica. PMID:26767427

  18. [Epidemic characteristics and security implications of Africa schistosomiasis on people who go to Africa].

    PubMed

    Pan, Xiang; Zhou, Yi-biao; Yang, Ya; Song, Xiu-xia; Jiang, Qing-wu

    2015-08-01

    With the economic globalization, and the economic and trade cooperation and cultural communication between China and African countries, more and more Chinese people go to Africa for work or travel. However, there is a quick increase of imported schistosomiasis patients who return from Africa. This paper analyzes the security implications of epidemic characteristics of Africa schistosomiasis on the people who go to Africa, and put forward several suggestions to help them to prevent from schistosomiasis. PMID:26767275

  19. Additional Evaluation of the Point-of-Contact Circulating Cathodic Antigen Assay for Schistosoma mansoni Infection

    PubMed Central

    Mwinzi, Pauline N. M.; Kittur, Nupur; Ochola, Elizabeth; Cooper, Philip J.; Campbell, Carl H.; King, Charles H.; Colley, Daniel G.

    2015-01-01

    Studies of the urine-based point-of-contact cathodic circulating antigen test (POC-CCA) in Schistosoma mansoni-endemic settings in Africa indicate it has good sensitivity in detecting infections, but in areas of low prevalence, the POC-CCA can be positive for persons who are egg-negative by Kato-Katz stool assays. We examined the POC-CCA assay for: (a) batch-to-batch stability; (b) intra-reader and inter-reader variability; (c) day-to-day variability compared to Kato-Katz stool assays, and (d) to see if praziquantel (PZQ) treatment converted Kato-Katz-negative/POC-CCA positive individuals to POC-CCA negativity. We found essentially no batch-to-batch variation, negligible intra-reader variability (2%), and substantial agreement for inter-reader reliability. Some day-to-day variation was observed over 5 days of urine collection, but less than the variation in Kato-Katz stool assays over 3 days. To evaluate the effect of treatment on Kato-Katz(−)/POC-CCA(+) children, 149 children in an area of 10–15% prevalence who were Kato-Katz(−) based on 3 stool samples but POC-CCA(+) were enrolled. Seven days after treatment (PZQ 40 mg/kg) samples were again collected and tested. Almost half (47%) POC-CCA positive children turned negative. Those still POC-CCA positive received a second treatment, and 34% of them turned POC-CCA negative upon this second treatment. Most who remained POC-CCA positive shifted each time to a “lesser” POC-CCA “level of positivity.” The data suggest that most Kato-Katz-negative/POC-CCA positive individuals harbor low-intensity infections, and each treatment kills all or some of their adult worms. The data also suggest that when evaluated by a more sensitive assay, the effective cure rates for PZQ are significantly less than those inferred from fecal testing. These findings have public health significance for the mapping and monitoring of Schistosoma infections and in planning the transition from schistosomiasis morbidity control to

  20. Population Pharmacokinetics and Pharmacodynamics of Praziquantel in Ugandan Children with Intestinal Schistosomiasis: Higher Dosages Are Required for Maximal Efficacy

    PubMed Central

    Waterhouse, David; de Sousa-Figueiredo, Jose C.; Roberts, Stephen A.; Atuhaire, Aaron; Van Dam, Govert J.; Corstjens, Paul L. A. M.; Scott, Janet T.; Stanton, Michelle C.; Kabatereine, Narcis B.; Ward, Stephen; Hope, William W.; Stothard, J. Russell

    2016-01-01

    ABSTRACT Each year, millions of African children receive praziquantel (PZQ) by mass drug administration (MDA) to treat schistosomiasis at a standard single dose of 40 mg/kg of body weight, a direct extrapolation from studies of adults. A higher dose of 60 mg/kg is also acceptable for refractory cases. We conducted the first PZQ pharmacokinetic (PK) and pharmacodynamic (PD) study in young children comparing dosing. Sixty Ugandan children aged 3 to 8 years old with egg patent Schistosoma mansoni received PZQ at either 40 mg/kg or 60 mg/kg. PK parameters of PZQ racemate and enantiomers (R and S) were quantified. PD outcomes were assessed by standard fecal egg counts and novel schistosome-specific serum (circulating anodic antigen [CAA]) and urine (circulating cathodic antigen [CCA]) antigen assays. Population PK and PD analyses were performed to estimate drug exposure in individual children, and the relationship between drug exposure and parasitological cure was estimated using logistic regression. Monte Carlo simulations were performed to identify better, future dosing regimens. There was marked PK variability between children, but the area under the concentration-time curve (AUC) of PZQ was strongly predictive of the parasitological cure rate (CR). Although no child achieved antigenic cure, which is suggestive of an important residual adult worm burden, higher AUC was associated with greater CAA antigenic decline at 24 days. To optimize the performance of PZQ, analysis of our simulations suggest that higher doses (>60 mg/kg) are needed, particularly in smaller children. PMID:27507822

  1. Spatio-temporal patterns of schistosomiasis japonica in lake and marshland areas in China: the effect of snail habitats.

    PubMed

    Hu, Yi; Gao, Jie; Chi, Meina; Luo, Can; Lynn, Henry; Sun, Liqian; Tao, Bo; Wang, Decheng; Zhang, Zhijie; Jiang, Qingwu

    2014-09-01

    The progress of the integrated control policy for schistosomiasis implemented since 2005 in China, which is aiming at reducing the roles of bovines and humans as infection sources, may be challenged by persistent presence of infected snails in lake and marshland areas. Based on annual parasitologic data for schistosomiasis during 2004-2011 in Xingzi County, a spatio-temporal kriging model was used to investigate the spatio-temporal pattern of schistosomiasis risk. Results showed that environmental factors related to snail habitats can explain the spatio-temporal variation of schistosomiasis. Predictive maps of schistosomiasis risk illustrated that clusters of the disease fluctuated during 2004-2008; there was an extensive outbreak in 2008 and attenuated disease occurrences afterwards. An area with an annually constant cluster of schistosomiasis was identified. Our study suggests that targeting snail habitats located within high-risk areas for schistosomiasis would be an economic and sustainable way of schistosomiasis control in the future. PMID:24980498

  2. Spatio-Temporal Patterns of Schistosomiasis Japonica in Lake and Marshland Areas in China: The Effect of Snail Habitats

    PubMed Central

    Hu, Yi; Gao, Jie; Chi, Meina; Luo, Can; Lynn, Henry; Sun, Liqian; Tao, Bo; Wang, Decheng; Zhang, Zhijie; Jiang, Qingwu

    2014-01-01

    The progress of the integrated control policy for schistosomiasis implemented since 2005 in China, which is aiming at reducing the roles of bovines and humans as infection sources, may be challenged by persistent presence of infected snails in lake and marshland areas. Based on annual parasitologic data for schistosomiasis during 2004–2011 in Xingzi County, a spatio-temporal kriging model was used to investigate the spatio-temporal pattern of schistosomiasis risk. Results showed that environmental factors related to snail habitats can explain the spatio-temporal variation of schistosomiasis. Predictive maps of schistosomiasis risk illustrated that clusters of the disease fluctuated during 2004–2008; there was an extensive outbreak in 2008 and attenuated disease occurrences afterwards. An area with an annually constant cluster of schistosomiasis was identified. Our study suggests that targeting snail habitats located within high-risk areas for schistosomiasis would be an economic and sustainable way of schistosomiasis control in the future. PMID:24980498

  3. Interleukin 5 is required for the blood and tissue eosinophilia but not granuloma formation induced by infection with Schistosoma mansoni.

    PubMed Central

    Sher, A; Coffman, R L; Hieny, S; Scott, P; Cheever, A W

    1990-01-01

    Eosinophils are thought to play a major role in the immunobiology of schistosomiasis. To investigate the immunologic basis of the eosinophil response and directly assess the function of eosinophils in egg-induced pathology, mice infected with Schistosoma mansoni were injected with a monoclonal antibody produced against interleukin 5 (IL-5), a cytokine previously shown to stimulate eosinophil differentiation in vitro. This treatment suppressed the generation of eosinophil myelocyte precursors in the bone marrow and reduced to background levels the numbers of mature eosinophils in the marrow, in circulation, and within acute schistosome egg granulomas. Nevertheless, granulomas in the anti-IL-5-treated/eosinophil-depleted mice at 8 weeks of infection were only marginally smaller than those in animals injected with control monoclonal antibody, and hepatic fibrosis was comparable in the two groups. Additional parameters such as worm burden, egg output, and serum IgE levels were unaltered by the anti-IL-5 treatment. In contrast, infected animals injected with monoclonal antibody against gamma interferon (IFN-gamma) displayed circulating eosinophil levels that were elevated with respect to control mice, possibly because of an enhanced release of mature eosinophils from the marrow, and developed egg granulomas that were indistinguishable in size and cellular composition from those in control animals. Immunologic assays revealed that lymphocytes from acutely infected mice produce large quantities of IL-5 but minimal IFN-gamma when stimulated with either egg antigen or mitogen. Taken together, these results indicate that neither IL-5 nor eosinophils are essential for egg-induced pathology but suggest that lymphocytes that belong to the IL-5-producing TH2 subset predominate during acute infection and may induce granuloma formation by the production of other cytokines. Images PMID:2104985

  4. Effect of Ketoconazole, a Cytochrome P450 Inhibitor, on the Efficacy of Quinine and Halofantrine against Schistosoma mansoni in Mice

    PubMed Central

    Sabra, Abdel-Nasser Abdel-Aal; Hammam, Olfat Ali; El-Lakkany, Naglaa Mohamed

    2013-01-01

    The fear that schistosomes will become resistant to praziquantel (PZQ) motivates the search for alternatives to treat schistosomiasis. The antimalarials quinine (QN) and halofantrine (HF) possess moderate antischistosomal properties. The major metabolic pathway of QN and HF is through cytochrome P450 (CYP) 3A4. Accordingly, this study investigates the effects of CYP3A4 inhibitor, ketoconazole (KTZ), on the antischistosomal potential of these quinolines against Schistosoma mansoni infection by evaluating parasitological, histopathological, and biochemical parameters. Mice were classified into 7 groups: uninfected untreated (I), infected untreated (II), infected treated orally with PZQ (1,000 mg/kg) (III), QN (400 mg/kg) (IV), KTZ (10 mg/kg)+QN as group IV (V), HF (400 mg/kg) (VI), and KTZ (as group V)+HF (as group VI) (VII). KTZ plus QN or HF produced more inhibition (P<0.05) in hepatic CYP450 (85.7% and 83.8%) and CYT b5 (75.5% and 73.5%) activities, respectively, than in groups treated with QN or HF alone. This was accompanied with more reduction in female (89.0% and 79.3%), total worms (81.4% and 70.3%), and eggs burden (hepatic; 83.8%, 66.0% and intestinal; 68%, 64.5%), respectively, and encountering the granulomatous reaction to parasite eggs trapped in the liver. QN and HF significantly (P<0.05) elevated malondialdehyde levels when used alone or with KTZ. Meanwhile, KTZ plus QN or HF restored serum levels of ALT, albumin, and reduced hepatic glutathione (KTZ+HF) to their control values. KTZ enhanced the therapeutic antischistosomal potential of QN and HF over each drug alone. Moreover, the effect of KTZ+QN was more evident than KTZ+HF. PMID:23710083

  5. Murine immunization by cesium-137 irradiation attenuated Schistosoma mansoni cercariae

    SciTech Connect

    Stek, M. Jr.; Minard, P.; Cruess, D.F.

    1984-06-01

    Cesium-137, becoming a more readily available ionizing gamma radiation source for laboratory use, was shown to effectively attenuate Schistosoma mansoni cercariae for vaccine production. In parallel comparison studies with the murine model, cesium-137 attenuated cercariae consistently afforded better protection than did the cobalt-60 prepared vaccine. Dose-response data indicated that the optimal total irradiation with cesium-137 was between 45 and 50 Krad.

  6. Acute schistosomiasis outbreak in the metropolitan area of Belo Horizonte, Minas Gerais: alert about the risk of unnoticed transmission increased by growing rural tourism.

    PubMed

    Enk, Martin J; Amorim, Amanda; Schall, Virginia T

    2003-09-01

    The present article describes the occurrence of 17 cases of acute schistosomiasis in the metropolitan area of Belo Horizonte, state of Minas Gerais, Brazil. All individuals affected took a bath in a swimming pool of a holiday resort that was provided with water from a nearby brook. The apparently clean water and the absence of snails in the pool gave the wrong impression that there was no risk for infection. During a malacological survey at the site snails of the species Biomphalaria glabrata were found and tested positive for Schistosoma mansoni. All the patients live in the middle-class area of Barreiro, metropolitan area of Belo Horizonte and have medium grade school education. The difficulties in establishing the right diagnosis is expressed by the search for medical attention in 17 different medical facilities, the wide range of laboratory test and the inadequate treatment administration. A lack of knowledge about the disease was found in all groups studied. The booming rural tourism in endemic areas is identified as a probable risk factor for infection, especially for individuals of the non-immune middle and upper class parts of the society in urban centers. Special attention is given to a multidisciplinary approach to the complex issue of disease control and prevention. PMID:14595449

  7. Schistosomiasis in Egypt: A never-ending story?

    PubMed

    Othman, Ahmad A; Soliman, Rasha H

    2015-08-01

    Schistosomiasis has plagued the Egyptian population since the antiquity. The disease is still a public health problem in Egypt, despite the tendency of being overlooked. In the first part of this review, the past and current trends of schistosomiasis in Egypt are reviewed, including history, epidemiology, morbidity, therapy, and control of the disease. Most of these aspects are more or less relevant to other schistosome-endemic regions all over the world. As only one drug is currently available for individual treatment and preventive mass chemotherapy, the quest for complementary measures is urgently warranted. Indeed, one promising approach is the discovery of a vaccine. Herein, we point out the efforts of the Egyptian scientists to develop an efficacious and affordable vaccine against schistosomiasis - a step forward in the battle of elimination of Schistosoma infection. Based on the candidate vaccine antigens, four types of vaccine formulations are discussed: purified antigen vaccines, DNA constructs, attenuated cercariae, and excretory-secretory antigen vaccines. Finally, this review provides insights into this ancient seemingly long-lasting parasitic disease. PMID:25959770

  8. New endemic foci of schistosomiasis infections in the Philippines.

    PubMed

    Leonardo, Lydia; Rivera, Pilarita; Saniel, Ofelia; Antonio Solon, Juan; Chigusa, Yuichi; Villacorte, Elena; Christoper Chua, James; Moendeg, Kharleezelle; Manalo, Daria; Crisostomo, Bobby; Sunico, Louie; Boldero, Nicasio; Payne, Lara; Hernandez, Leda; Velayudhan, Raman

    2015-01-01

    Schistosomiasis affects 28 provinces in the Philippines found along the southeastern part where there is continuous rainfall throughout the year. In 2002 and 2005 respectively, two new endemic foci were reported in the northernmost (Gonzaga, Cagayan) and central (Calatrava, Negros Occidental) parts of the country. This study conducted in March 2008-March 2009 confirmed the presence of the disease by determining its prevalence using four diagnostic tests - Kato-Katz, circumoval precipitin test (COPT), ELISA and ultrasonography. Oncomelania hupensis quadrasi was identified through snail surveys conducted in possible snail habitats in the seven new endemic villages. Animal surveys through stool examination confirmed the presence of schistosomiasis infection in animals in Gonzaga but not in Calatrava. Compared to Calatrava, Gonzaga demonstrated markedly higher prevalence of schistosomiasis using all four diagnostic methods. Proximity of snail habitats to human habitation including higher snail density and snail infection rate could be responsible for the high prevalence. Snail sites were more widespread in Gonzaga whereas those in Calatrava were confined only in areas not frequented by the general population except by farmers. GIS maps showing spatial distribution of snails in Gonzaga and Calatrava indicated differences in elevation among the snail sites. It is hypothesized that the snail intermediate host has been in these sites for sometime but discovered only lately. Migration of people from endemic provinces into Gonzaga and Calatrava brought in cases and in the presence of snail intermediate hosts, emergence of disease was just a matter of time. PMID:23583862

  9. Maternal schistosomiasis: a growing concern in sub-Saharan Africa

    PubMed Central

    Salawu, Oyetunde T; Odaibo, Alexander B

    2014-01-01

    Schistosomiasis remains one of the most important tropical parasitic infections threatening millions of lives in endemic areas. Cases of infections due to Schistosoma spp, the diecious digenetic trematodes have been on the increase over the last decades. While considerable efforts have been made to reduce infections and morbidities in most endemic areas, these efforts seem to be tailored only towards a specific group (school-based resources). This bias towards school children in epidemiological studies has also been observed in various research efforts in sub-Saharan Africa, thus making it difficult to produce a reliable estimate of the extent of infection in other strata of the population at risk. In recent times, attention has been drawn to Schistosoma spp infections in infants and preschool children, while studies on epidemiology of maternal schistosomiasis still suffer neglect. Considering the potential morbidity of Schistosoma infections on the mothers, fetuses, and neonates, as evidenced in some animal models and human case studies, more attention is solicited in all areas of observational studies and clinical trials, for maternal schistosomiasis with the aim of providing relevant data and information for effective management of the disease during pregnancy. PMID:25223633

  10. Spatio-temporal Transmission and Environmental Determinants of Schistosomiasis Japonica in Anhui Province, China

    PubMed Central

    Hu, Yi; Li, Rui; Bergquist, Robert; Lynn, Henry; Gao, Fenghua; Wang, Qizhi; Zhang, Shiqing; Sun, Liqian; Zhang, Zhijie; Jiang, Qingwu

    2015-01-01

    Background Schistosomiasis japonica still remains of public health and economic significance in China, especially in the lake and marshland areas along the Yangtze River Basin, where the control of transmission has proven difficult. In the study, we investigated spatio-temporal variations of S. japonicum infection risk in Anhui Province and assessed the associations of the disease with key environmental factors with the aim of understanding the mechanism of the disease and seeking clues to effective and sustainable schistosomiasis control. Methodology/Principal Findings Infection data of schistosomiasis from annual conventional surveys were obtained at the village level in Anhui Province, China, from 2000 to 2010 and used in combination with environmental data. The spatio-temporal kriging model was used to assess how these environmental factors affected the spatio-temporal pattern of schistosomiasis risk. Our results suggested that seasonal variation of the normalized difference vegetation index (NDVI), seasonal variation of land surface temperature at daytime (LSTD), and distance to the Yangtze River were negatively significantly associated with risk of schistosomiasis. Predictive maps showed that schistosomiasis prevalence remained at a low level and schistosomiasis risk mainly evolved along the Yangtze River. Schistosomiasis risk also followed a focal spatial pattern, fluctuating temporally with a peak (the largest spatial extent) in 2005 and then contracting gradually but with a scattered distribution until 2010. Conclusion The fitted spatio-temporal kriging model can capture variations of schistosomiasis risk over space and time. Combined with techniques of geographic information system (GIS) and remote sensing (RS), this approach facilitates and enriches risk modeling of schistosomiasis, which in turn helps to identify prior areas for effective and sustainable control of schistosomiasis in Anhui Province and perhaps elsewhere in China. PMID:25659112

  11. Long-Term Impact of the World Bank Loan Project for Schistosomiasis Control: A Comparison of the Spatial Distribution of Schistosomiasis Risk in China

    PubMed Central

    Zhang, Zhijie; Zhu, Rong; Ward, Michael P.; Xu, Wanghong; Zhang, Lijuan; Guo, Jiagang; Zhao, Fei; Jiang, Qingwu

    2012-01-01

    Background The World Bank Loan Project (WBLP) for controlling schistosomiasis in China was implemented during 1992–2001. Its short-term impact has been assessed from non-spatial perspective, but its long-term impact remains unclear and a spatial evaluation has not previously been conducted. Here we compared the spatial distribution of schistosomiasis risk using national datasets in the lake and marshland regions from 1999–2001 and 2007–2008 to evaluate the long-term impact of WBLP strategy on China's schistosomiasis burden. Methodology/Principal Findings A hierarchical Poisson regression model was developed in a Bayesian framework with spatially correlated and uncorrelated heterogeneities at the county-level, modeled using a conditional autoregressive prior structure and a spatially unstructured Gaussian distribution, respectively. There were two important findings from this study. The WBLP strategy was found to have a good short-term impact on schistosomiasis control, but its long-term impact was not ideal. It has successfully reduced the morbidity of schistosomiasis to a low level, but can not contribute further to China's schistosomiasis control because of the current low endemic level. A second finding is that the WBLP strategy could not effectively compress the spatial distribution of schistosomiasis risk. To achieve further reductions in schistosomiasis-affected areas, and for sustainable control, focusing on the intermediate host snail should become the next step to interrupt schistosomiasis transmission within the two most affected regions surrounding the Dongting and Poyang Lakes. Furthermore, in the lower reaches of the Yangtze River, the WBLP's morbidity control strategy may need to continue for some time until snails in the upriver provinces have been well controlled. Conclusion It is difficult to further reduce morbidity due to schistosomiasis using a chemotherapy-based control strategy in the lake and marshland regions of China because of the

  12. Global assessment of schistosomiasis control over the past century shows targeting the snail intermediate host works best

    USGS Publications Warehouse

    Sokolow, Susanne H.; Wood, Chelsea L.; Jones, Isabel J.; Swartz, Scott J.; Lopez, Melina; Hsieh, Michael H.; Lafferty, Kevin D.; Kuris, Armand M.; Rickards, Chloe; De Leo, Giulio A.

    2016-01-01

    Snail control has been the most effective way to reduce schistosomiasis prevalence. Despite evidence that snail control leads to long-term disease reduction and elimination, most current schistosomiasis control efforts emphasize MDA using praziquantel over snail control. Combining drug-based control programs with affordable snail control seems the best strategy for eliminating schistosomiasis.

  13. Spatial Analysis of Schistosomiasis in Hubei Province, China: A GIS-Based Analysis of Schistosomiasis from 2009 to 2013

    PubMed Central

    Chen, Yan-Yan; Huang, Xi-Bao; Xiao, Ying; Jiang, Yong; Shan, Xiao-wei; Zhang, Juan; Cai, Shun-Xiang; Liu, Jian-Bing

    2015-01-01

    Background Schistosomiasis remains a major public health problem in China. The major endemic areas are located in the lake and marshland regions of southern China, particularly in areas along the middle and low reach of the Yangtze River. Spatial analytical techniques are often used in epidemiology to identify spatial clusters in disease regions. This study assesses the spatial distribution of schistosomiasis and explores high-risk regions in Hubei Province, China to provide guidance on schistosomiasis control in marshland regions. Methods In this study, spatial autocorrelation methodologies, including global Moran’s I and local Getis–Ord statistics, were utilized to describe and map spatial clusters and areas where human Schistosoma japonicum infection is prevalent at the county level in Hubei province. In addition, linear logistic regression model was used to determine the characteristics of spatial autocorrelation with time. Results The infection rates of S. japonicum decreased from 2009 to 2013. The global autocorrelation analysis results on the infection rate of S. japonicum for five years showed statistical significance (Moran’s I > 0, P < 0.01), which suggested that spatial clusters were present in the distribution of S. japonicum infection from 2009 to 2013. Local autocorrelation analysis results showed that the number of highly aggregated areas ranged from eight to eleven within the five-year analysis period. The highly aggregated areas were mainly distributed in eight counties. Conclusions The spatial distribution of human S. japonicum infections did not exhibit a temporal change at the county level in Hubei Province. The risk factors that influence human S. japonicum transmission may not have changed after achieving the national criterion of infection control. The findings indicated that spatial–temporal surveillance of S. japonicum transmission plays a significant role on schistosomiasis control. Timely and integrated prevention should be

  14. The Use of Reverse Vaccinology and Molecular Modeling Associated with Cell Proliferation Stimulation Approach to Select Promiscuous Epitopes from Schistosoma mansoni.

    PubMed

    Oliveira, Flávio M; Coelho, Ivan E V; Lopes, Marcelo D; Taranto, Alex G; Junior, Moacyr C; Santos, Luciana L D; Villar, José A P F; Fonseca, Cristina T; Lopes, Débora D O

    2016-07-01

    Schistosomiasis remains an important parasitic disease that affects millions of individuals worldwide. Despite the availability of chemotherapy, the occurrence of constant reinfection demonstrates the need for additional forms of intervention and the development of a vaccine represents a relevant strategy to control this disease. With the advent of genomics and bioinformatics, new strategies to search for vaccine targets have been proposed, as the reverse vaccinology. In this work, computational analyses of Schistosoma mansoni membrane proteins were performed to predict epitopes with high affinity for different human leukocyte antigen (HLA)-DRB1. Ten epitopes were selected and along with murine major histocompatibility complex (MHC) class II molecule had their three-dimensional structures optimized. Epitope interactions were evaluated against murine MHC class II molecule through molecular docking, electrostatic potential, and molecular volume. The epitope Sm141290 and Sm050890 stood out in most of the molecular modeling analyses. Cellular proliferation assay was performed to evaluate the ability of these epitopes to bind to murine MHC II molecules and stimulate CD4+ T cells showing that the same epitopes were able to significantly stimulate cell proliferation. This work showed an important strategy of peptide selection for epitope-based vaccine design, achieved by in silico analyses that can precede in vivo and in vitro experiments, avoiding excessive experimentation. PMID:26979443

  15. Distribution and Schistosoma mansoni infection of Biomphalaria glabrata in different habitats in a rural area in the Jequitinhonha Valley, Minas Gerais, Brazil: environmental and epidemiological aspects.

    PubMed

    Kloos, Helmut; Passos, Liana Kanovaloff Janotti; Loverde, Philip; Oliveira, Rodrigo Correa; Gazzinelli, Andréa

    2004-11-01

    This paper examines the distribution and infection of Biomphalaria glabrata with Schistosoma mansoni in all aquatic snail habitats in a rural area in the state of Minas Gerais, Brazil, in relation to physico/biotic and behavioral factors. Snail and environmental surveys were carried out semi-annually between July 2001 and November 2002 at 106 sites. Collected snails were examined in the laboratory for infection. B. glabrata densities were highest in overflow ponds, irrigation ponds, springs, canals and wells, and lowest in fishponds and water tanks. Snail densities were higher during the hot, rainy season except for streams and canals and were statistically associated with the presence of fish, pollution, and vegetation density. Tilapia fish and an unidentified Diptera larva were found to be predators of B. glabrata but ducks were not. Twenty-four of the 25 infected snails were collected in 2001(1.4% infection rate) and only one in 2002, after mass chemotherapy. The occurrence of B. glabrata in all 11 snail habitats both at and away from water contact sites studied indicates widespread risk of human infection in the study area. In spite of the strong association between B. glabrata and tilapia in fishponds we do not recommend its use in schistosomiasis control for ecological reasons and its relative inefficiency in streams and dams. PMID:15654420

  16. Avidity of immunoglobulin G antibody response to the different antigenic fractions of soluble Schistosoma mansoni adult worm antigen preparation (SWAP) using avidity immunoblotting assay.

    PubMed

    Tawfeek, Gihan M; Hameed, Dina M Abdel; el-Hoseiny, Laila M

    2004-08-01

    The detection of IgG antibodies against the different SWAP antigenic fractions plus the determination of their avidity in avidity immunoblotting assay using 6 M urea wash, presents a novel alternative for the characterization of optimal antigenic markers for acute and chronic phases of Schistosoma mansoni infection and for vaccine development. Human serum samples from 25 acute schistosomiasis patients, 20 chronic cases and 15 normal healthy controls were analysed by IgG avidity enzyme linked immunosorbent assay (ELISA) and IgG avidity immunoblotting assay. Using avidity ELISA, a pronounced overlap of avidity index values was observed between acute and chronic infections with a range of uncertainty (0.86-1) which was encountered in both groups. Using avidity immunoblotting assay, antigenic bands at >116, 84, 48, 40 & 34 KDa were exclusive for the acute phase. From these bands, 34 KDa was recognized mostly by low-avidity antibodies and showed a high sensitivity (96%) and specificity (100%) making it an optimal marker for the acute phase. 40 KDa band was recognized mostly by high-avidity antibodies even during acute infection. Bands of 80, 70, 42, 36, 30 & 26 KDa were exclusive for the chronic phase. Only 70 KDa band was recognized by high-avidity antibodies yet, with low sensitivity (35%), that limits its use as an optimal marker for the chronic infection. Meanwhile, 70 and 40 KDa bands, recognized by high-avidity antibodies, are considered as potential vaccine antigen candidates. PMID:15287177

  17. [Discussion on water conservancy projects and schistosomiasis control in Poyang Lake area].

    PubMed

    Liu, Dao-Nan

    2013-02-01

    According to the schistosomiasis endemic situation in the Poyang Lake area, this paper analyzes the relationship between the water conservancy projects and schistosomiasis control, and reviews and discusses the effects of the Water Level Control Project of Poyang Lake, the Lake Dike Slope Hardening Project, and the Lifting Delta and Descending Beach Project on Oncomelania snail control. PMID:23687826

  18. Potential immunomodulatory effects of plant lectins in Schistosoma mansoni infection.

    PubMed

    Reis, Eliana A G; Athanazio, Daniel A; Cavada, Benildo Sousa; Teixeira, Edson Holanda; de Paulo Teixeira Pinto, Vicente; Carmo, Theomira M A; Reis, Alice; Trocolli, Graziela; Croda, Julio; Harn, Donald; Barral-Netto, Manoel; Reis, Mitermayer G

    2008-01-01

    Lectins are sugar-binding glycoproteins that can stimulate, in a non-antigen-specific fashion, lymphocytes, leading to proliferation and cytokine production. Some lectins are utilized as in vitro mitogenic lymphocyte stimulators and their use as immunomodulators against infectious diseases has been evaluated experimentally. In the experimental murine model, the immune response to schistosomiasis is Th1-like during the initial stage of infection, with a shift towards a Th2-like response after oviposition. We report the response of schistosomiasis patients' (n=37) peripheral blood mononuclear cells (PBMC) to stimulation by lectins, including newly isolated lectins from Brazilian flora, and by Schistosomamansoni soluble egg antigens (SEA). Cytokine production upon lectin stimulation ex vivo was assessed in PBMC supernatants, collected at 24 and 72 h, by sandwich ELISA to IL-5, IL-10, TNF-alpha and IFN-gamma. In PBMC from infected patients all but one of the lectins induced a Th2-like cytokine response, characterized by elevated IL-5 production that was higher than that induced by SEA stimulation alone. Our results show that the Th2 environment present during schistosomiasis is not affected and that it may be further stimulated by the presence of lectins. PMID:18579103

  19. Persistent Transmission of Schistosomiasis in Southwest Nigeria: Contexts of Culture and Contact with Infected River Water.

    PubMed

    Olorunlana, Adetayo; Jegede, Ayodele Samuel; Morenikeji, Olajumoke; Hassan, Adesola A; Nwuba, Roseangela I; Anumudu, Chiaka I; Salawu, Oyetunde T; Odaibo, Alexander B

    2016-01-01

    Transmission of schistosomiasis is aided by human behaviour. Globally, about 800 million people are at risk of schistosomiasis infection. Data exist on biomedical understanding of the disease transmission; there is a dearth of information from the social science perspective. Hence, this study explored the social and cultural context of schistosomiasis transmission among Yewa People in Nigeria. Qualitative methods were employed with purposive sampling, using the key informant interviews and focus group discussions, among 57 participants aged 17 to 54 years. The data were content-analyzed. River water was the most reported source of water supply among others. Participants drew from the cultural milieu the use of river water for "drinking" and "swimming" as part of the continual transmission of schistosomiasis. Transmission of schistosomiasis may not be abated without behavioural change. PMID:27009769

  20. Papain-Based Vaccination Modulates Schistosoma mansoni Infection-Induced Cytokine Signals.

    PubMed

    Abdel Aziz, N; Tallima, H; Hafez, E A; El Ridi, R

    2016-02-01

    We have previously shown that immunization of outbred rodents with cysteine peptidases-based vaccine elicited type 2-biased immune responses associated with consistent and reproducible protection against challenge Schistosoma mansoni. We herein start to elucidate the molecular basis of C57BL/6 mouse resistance to S. mansoni following treatment with the cysteine peptidase, papain. We evaluated the early cytokine signals delivered by epidermal, dermal, and draining lymph node cells of naïve, and S. mansoni -infected mice treated 1 day earlier with 0 or 50 μg papain, or immunized twice with papain only (10 μg/mouse), papain-free recombinant S. mansoni glyceraldehyde 3-phosphate dehydrogenase and 2-Cys peroxiredoxin peptide (10 and 15 μg/mouse, respectively = antigen Mix), or papain-adjuvanted antigen Mix. Schistosoma mansoni infection induced epidermal and lymph node cells to release type 1, type 2 and type 17 cytokines, known to counteract each other. Expectedly, humoral immune responses were negligible until patency. Papain pretreatment or papain-based vaccination diminished or shut off S. mansoni infection early induction of type 1, type 17 and type 2 cytokines except for thymic stromal lymphopoietin and programmed the immune system towards a polarized type 2 immune milieu, associated with highly significant (P < 0.005 - <0.0001) resistance to S. mansoni infection. PMID:26603950

  1. Prevention and control of schistosomiasis: a current perspective

    PubMed Central

    Inobaya, Marianette T; Olveda, Remigio M; Chau, Thao NP; Olveda, David U; Ross, Allen GP

    2014-01-01

    Schistosomiasis is a neglected tropical disease that ranks second only to malaria in terms of human suffering in the tropics and subtropics. Five species are known to infect man and there are currently over 240 million people infected worldwide. The cornerstone of control to date has been mass drug administration with 40 mg/kg of praziquantel but there are problems with this approach. Human and bovine vaccines are in various stages of development. Integrated control, targeting the life cycle, is the only approach that will lead to sustainability and future elimination. PMID:25400499

  2. Progress in the national schistosomiasis control programme of Iran

    PubMed Central

    Massoud, J.; Arfaa, F.; Farahmandian, I.; Ardalan, A.; Mansoorian, A.

    1982-01-01

    A combination of chemotherapy and mollusciciding has been used in Khuzestan, south-west Iran, since 1966, to try to control urinary schistosomiasis. The total amount of molluscicide used each year varied between 702 and 3505 kg and between 287 and 1320 infected persons were detected and treated annually. The prevalence of infection has gradually declined from 8.3% in 1970 to 0.7% in 1979. Similarly, the incidence of infection among schoolchildren decreased from 3.5% in 1970 to 0.7% in 1979. The proportion of Bulinus-infested habitats also decreased from 10% in 1971 to 2.4% in 1979. PMID:6982780

  3. Identification of new markers for the Schistosoma mansoni vitelline lineage.

    PubMed

    Wang, Jipeng; Collins, James J

    2016-06-01

    Schistosomes cause significant morbidity and mortality in millions of the world's poorest people. While parasite egg-induced inflammation is the primary driver of host pathology, relatively little is known at the molecular level about the organ systems that participate in schistosome egg production (i.e., testes, ovaries and vitellaria). Here we use transcriptional profiling and in situ hybridization to characterise the vitellarium of Schistosoma mansoni. We uncovered several previously uncharacterised vitellaria-specific factors and defined molecular markers for various stages in the vitellocyte differentiation process. These data provide the framework for future in-depth molecular studies exploring the biology of this important parasite organ. PMID:27056273

  4. Shifts in the Spatiotemporal Dynamics of Schistosomiasis: A Case Study in Anhui Province, China

    PubMed Central

    Chen, Yue; Gao, Fenghua; Wang, Qizhi; Zhang, Shiqing; Zhang, Zhijie; Jiang, Qingwu

    2015-01-01

    Background The Chinese national surveillance system showed that the risk of Schistosoma japonicum infection fluctuated temporally. This dynamical change might indicate periodicity of the disease, and its understanding could significantly improve targeted interventions to reduce the burden of schistosomiasis. The goal of this study was to investigate how the schistosomiasis risk varied temporally and spatially in recent years. Methodology/Principal Findings Parasitological data were obtained through repeated cross-sectional surveys that were carried out during 1997-2010 in Anhui Province, East China. A multivariate autoregressive model, combined with principal oscillation pattern (POP) analysis, was used to evaluate the spatio-temporal variation of schistosomiasis risk. Results showed that the temporal changes of schistosomiasis risk in the study area could be decomposed into two sustained damped oscillatory modes with estimated period of approximately 2.5 years. The POPs associated with these oscillatory components showed that the pattern near the Yangtze River varied markedly and that the disease risk appeared to evolve in a Southwest/Northeast orientation. The POP coefficients showed decreasing tendency until 2001, then increasing during 2002-2005 and decaying afterwards. Conclusion The POP analysis characterized the variations of schistosomiasis risk over space and time and demonstrated that the disease mainly varied temporally along the Yangtze River. The schistosomiasis risk declined periodically with a temporal fluctuation. Whether it resulted from previous national control strategies on schistosomiasis needs further investigations. PMID:25881189

  5. Have You Heard of Schistosomiasis? Knowledge, Attitudes and Practices in Nampula Province, Mozambique

    PubMed Central

    Rassi, Christian; Kajungu, Dan; Martin, Sandrine; Arroz, Jorge; Tallant, Jamie; Zegers de Beyl, Celine; Counihan, Helen; Newell, James N.; Phillips, Anna; Whitton, Jane; Muloliwa, Artur Manuel; Graham, Kirstie

    2016-01-01

    Background Schistosomiasis is a parasitic disease which affects almost 300 million people worldwide each year. It is highly endemic in Mozambique. Prevention and control of schistosomiasis relies mainly on mass drug administration (MDA), as well as adoption of basic sanitation practices. Individual and community perceptions of schistosomiasis are likely to have a significant effect on prevention and control efforts. In order to establish a baseline to evaluate a community engagement intervention with a focus on schistosomiasis, a survey to determine knowledge, attitudes and practices relating to the disease was conducted. Methodology/Principal Findings A representative cross-sectional household survey was carried out in four districts of Nampula province, Mozambique. Interviews were conducted in a total of 791 households, using a structured questionnaire. While awareness of schistosomiasis was high (91%), correct knowledge of how it is acquired (18%), transmitted (26%) and prevented (13%) was low among those who had heard of the disease. Misconceptions, such as the belief that schistosomiasis is transmitted through sexual contact (27%), were common. Only about a third of those who were aware of the disease stated that they practiced a protective behaviour and only a minority of those (39%) reported an effective behaviour. Despite several rounds of MDA for schistosomiasis in the recent past, only a small minority of households with children reported that at least one of them had received a drug to treat the disease (9%). Conclusion/Significance Poor knowledge of the causes of schistosomiasis and how to prevent it, coupled with persisting misconceptions, continue to pose barriers to effective disease prevention and control. To achieve high levels of uptake of MDA and adoption of protective behaviours, it will be essential to engage individuals and communities, improving their understanding of the causes and symptoms of schistosomiasis, recommended prevention

  6. [Observation on negative changes of indirect hemagglutination assay in chronic schistosomiasis patients].

    PubMed

    Gao, Hong

    2012-04-01

    A total of 135 chronic schistosomiasis patients were investigated with indirect hemagglutination assay (IHA) kit for schistosomiasis issued by the national authority, and the titer > or = 1 : 10 was deemed as positive. The IHA positive patients were investigated with Kato-Katz technique and the hatching method, and the water contact survey was performed every year and the re-infection patients were excluded. In the fourth year, 93.65 per thousand of the patients became IHA negative. In conclusion, the schistosome antibody levels of the population by IHA test can be one of important indexes to judge whether the epidemic situation relapses in the process of continuous schistosomiasis surveillance. PMID:22799183

  7. Specific humoral response of hosts with variable schistosomiasis susceptibility.

    PubMed

    Driguez, Patrick; McWilliam, Hamish E G; Gaze, Soraya; Piedrafita, David; Pearson, Mark S; Nakajima, Rie; Duke, Mary; Trieu, Angela; Doolan, Denise L; Cardoso, Fernanda C; Jasinskas, Algis; Gobert, Geoffrey N; Felgner, Philip L; Loukas, Alex; Meeusen, Els; McManus, Donald P

    2016-01-01

    The schistosome blood flukes are some of the largest global causes of parasitic morbidity. Further study of the specific antibody response during schistosomiasis may yield the vaccines and diagnostics needed to combat this disease. Therefore, for the purposes of antigen discovery, sera and antibody-secreting cell (ASC) probes from semi-permissive rats and sera from susceptible mice were used to screen a schistosome protein microarray. Following Schistosoma japonicum infection, rats had reduced pathology, increased antibody responses and broader antigen recognition profiles compared with mice. With successive infections, rat global serological reactivity and the number of recognized antigens increased. The local antibody response in rat skin and lung, measured with ASC probes, increased after parasite migration and contributed antigen-specific antibodies to the multivalent serological response. In addition, the temporal variation of anti-parasite serum antibodies after infection and reinfection followed patterns that appear related to the antigen driving the response. Among the 29 antigens differentially recognized by the infected hosts were numerous known vaccine candidates, drug targets and several S. japonicum homologs of human schistosomiasis resistance markers-the tegument allergen-like proteins. From this set, we prioritized eight proteins that may prove to be novel schistosome vaccine and diagnostic antigens. PMID:26044065

  8. Sandwich mapping of schistosomiasis risk in Anhui Province, China.

    PubMed

    Hu, Yi; Bergquist, Robert; Lynn, Henry; Gao, Fenghua; Wang, Qizhi; Zhang, Shiqing; Li, Rui; Sun, Liqian; Xia, Congcong; Xiong, Chenglong; Zhang, Zhijie; Jiang, Qingwu

    2015-01-01

    Schistosomiasis mapping using data obtained from parasitological surveys is frequently used in planning and evaluation of disease control strategies. The available geostatistical approaches are, however, subject to the assumption of stationarity, a stochastic process whose joint probability distribution does not change when shifted in time. As this is impractical for large areas, we introduce here the sandwich method, the basic idea of which is to divide the study area (with its attributes) into homogeneous subareas and estimate the values for the reporting units using spatial stratified sampling. The sandwich method was applied to map the county-level prevalence of schistosomiasis japonica in Anhui Province, China based on parasitological data collected from sample villages and land use data. We first mapped the county-level prevalence using the sandwich method, then compared our findings with block Kriging. The sandwich estimates ranged from 0.17 to 0.21% with a lower level of uncertainty, while the Kriging estimates varied from 0 to 0.97% with a higher level of uncertainty, indicating that the former is more smoothed and stable compared to latter. Aside from various forms of reporting units, the sandwich method has the particular merit of simple model assumption coupled with full utilization of sample data. It performs well when a disease presents stratified heterogeneity over space. PMID:26054518

  9. Leucocyte migration inhibitory factor assay in Nigerians with urinary schistosomiasis.

    PubMed

    Arinola, O G; Salimonu, L S

    1999-01-01

    Schistosome antigens (soluble egg antigen and adult worm antigen) and non-schistosome antigens (Bacille Calmette Guerin vaccine antigen and measles virus vaccine antigen) were used to assay for leucocyte migration inhibitory factors (LMIF) in Nigerian children with and without Schistosoma haematobium infection. The severity of S. haematobium infection was graded into light infection (1-49 eggs/ 10 ml urine) or heavy infection (more than or equal to 50 eggs/10 ml urine). The mean percentage migration indices were significantly reduced in heavily infected urinary schistosomiasis (USS) subjects compared with the controls or lightly infected subjects when non-antigens were used to stimulate LMIF production. When Schistosome antigens were used to stimulate LMIF production, there were no significant decreases in the % migration indices in heavily infected USS subjects compared with the light USS subjects. The mean percentage migration index was significantly increased when schistosome antigen was used to stimulate LMIF production in treated USS subjects compared with untreated USS subjects but the increase was not significant when non-schistosome antigen was used. The conclusion that could be drawn from this study is that LMIF assay using schistosome antigen(s) has epidemiological value in schistosomiasis. PMID:10504865

  10. [Endemic status of schistosomiasis in People's Republic of China in 2014].

    PubMed

    Lei, Zheng-long; Zhang, Li-juan; Xu, Zhi-min; Dang, Hui; Xu, Jing; Lv, Shan; Cao, Chun-li; Li, Shi-zhu; Zhou, Xiao-nong

    2015-12-01

    This report presented the endemic status of schistosomiasis in the People's Republic of China at national level in 2014, and analyzed the data captured from the national schistosomiasis prevention and control system and 81 national schistosomiasis surveillance sites. Among the 12 provinces (municipality and autonomous region) endemic for schistosomiasis japonica in China, 5 provinces (municipality and autonomous region) of Shanghai, Zhejiang, Fujian, Guangdong and Guangxi had achieved transmission interruption, 4 provinces of Sichuan, Yunnan, Jiangsu and Hubei had achieved transmission control, and Anhui, Jiangxi and Hunan provinces were still at infection control until 2014. There were 453 counties (city, district) endemic for schistosomiasis, with 251 million residents, and 30,048 villages endemic for schistosomiasis, with 68 million 507 thousand and 3 hundred residents. Among the 453 endemic counties (city, district), 69.09% (313/453) and 29.80% (135/ 453) endemic counties (city, district) reached the transmission interruption and transmission control respectively while the number of counties (city, district) at the stage of infection control reduced from 34 in 2013 to 5 in 2014 (accounted for 1.10% of the total number of endemic counties, 5/53). Till 2014, 115,614 people were estimated to have schistosomiasis and only 2 acute schistosomiasis cases were reported. In addition, there were 30,880 advanced schistosomiasis cases documented in 2014. In 2014, a total of 9,461,348 individuals received schistosomiasis examinations and 8,270 persons were found stool positives with the reduction rate of 50.96% as compared to that (16,865 cases) in 2013. The Oncomelania hupensis snail survey was performed in 20 123 endemic villages in 2014, and the snails were detected in 5,653 villages, which accounted for 28.09% of total villages, with 13 newly detected villages with snails. The snail survey covered an area of 576,506.37 hm² and snails were found in an area of 364 324

  11. Global Assessment of Schistosomiasis Control Over the Past Century Shows Targeting the Snail Intermediate Host Works Best

    PubMed Central

    Sokolow, Susanne H.; Wood, Chelsea L.; Jones, Isabel J.; Lopez, Melina; Lafferty, Kevin D.; Kuris, Armand M.; Rickards, Chloe; De Leo, Giulio A.

    2016-01-01

    Background Despite control efforts, human schistosomiasis remains prevalent throughout Africa, Asia, and South America. The global schistosomiasis burden has changed little since the new anthelmintic drug, praziquantel, promised widespread control. Methodology We evaluated large-scale schistosomiasis control attempts over the past century and across the globe by identifying factors that predict control program success: snail control (e.g., molluscicides or biological control), mass drug administrations (MDA) with praziquantel, or a combined strategy using both. For data, we compiled historical information on control tactics and their quantitative outcomes for all 83 countries and territories in which: (i) schistosomiasis was allegedly endemic during the 20th century, and (ii) schistosomiasis remains endemic, or (iii) schistosomiasis has been "eliminated," or is "no longer endemic," or transmission has been interrupted. Principal Findings Widespread snail control reduced prevalence by 92 ± 5% (N = 19) vs. 37 ± 7% (N = 29) for programs using little or no snail control. In addition, ecological, economic, and political factors contributed to schistosomiasis elimination. For instance, snail control was most common and widespread in wealthier countries and when control began earlier in the 20th century. Conclusions/Significance Snail control has been the most effective way to reduce schistosomiasis prevalence. Despite evidence that snail control leads to long-term disease reduction and elimination, most current schistosomiasis control efforts emphasize MDA using praziquantel over snail control. Combining drug-based control programs with affordable snail control seems the best strategy for eliminating schistosomiasis. PMID:27441556

  12. Thoracoscopic examination of empyema in a patient with sparganosis mansoni.

    PubMed

    Takeda, Keita; Suzuki, Junko; Nagai, Hideaki; Watanabe, Kaoru; Yokoyama, Akira; Ando, Takahiro; Suzuki, Jun; Ohshima, Nobuharu; Masuda, Kimihiko; Tamura, Atsuhisa; Akagawa, Shinobu; Kitani, Masashi; Hebisawa, Akira; Matsui, Hirotoshi; Kobayashi, Nobuyuki; Maruyama, Haruhiko; Ohta, Ken

    2016-02-01

    A 27-year-old man was admitted to our hospital with right pleural effusion. He had suffered from right chest and back pain and a high fever for one week prior to the admission. He had been treated with clarithromycin without improvement. Since thoracoscopy under local anesthesia revealed purulent effusion, synechiae and fibrous septa in the thoracic cavity, synechiotomy was performed and we started antibiotic treatment with the diagnosis of acute bacterial empyema. At the same time, we also suspected parasitic infection because of massive eosinophilic infiltration in pleural effusion and his dietary history of eating raw frogs. During the course of the disease, he had an infiltration in the right lower lobe and pneumothorax. Finally, we diagnosed him with sparganosis mansoni because his serum as well as pleural effusion was positive for the binding to sparganosis mansoni plerocercoid antigen, without any positive findings in bacteriology. His pleural effusion and lung infiltration were resolved after the administration of a high-dose praziquantel. We report this rare parasitic empyema with findings by thoracoscopic examination. PMID:26603428

  13. IL-4Rα Responsiveness of Non-CD4 T Cells Contributes to Resistance in Schistosoma mansoni Infection in Pan-T Cell-Specific IL-4Rα-Deficient Mice

    PubMed Central

    Dewals, Benjamin; Hoving, Jennifer C.; Leeto, Mosiuoa; Marillier, Reece G.; Govender, Umeshree; Cutler, Antony J.; Horsnell, William G.C.; Brombacher, Frank

    2009-01-01

    Interleukin (IL)-4 and IL-13 are T helper 2 cytokines whose biological functions are induced through a common IL-4 receptor α chain (IL-4Rα). CD4+ T cell-specific IL-4Rα-mediated signaling drives susceptibility to Leishmania major infection, but is not essential to host survival following Schistosoma mansoni infection. Here we generated a novel mouse model lacking IL-4Rα expression specifically on all T cells (iLckcreIl4ra−/lox), which was compared with CD4+ T cell-specific IL-4Rα-deficient mice (LckcreIl4ra−/lox), to investigate the possible roles of IL-4Rα responsive non-CD4+ T cells during either L. major or S. mansoni infection. Our results demonstrate a successful generation of transgene-bearing hemizygous iLckcreIl4ra−/lox BALB/c mice that have effective deletion of IL-4Rα on all T-cell populations. We show that iLckcreIl4ra−/lox mice infected with L. major developed a healing disease phenotype as previously observed in LckcreIl4ra−/lox mice, demonstrating that absence of IL-4Rα-responsive non-CD4+ in addition to CD4+ T cells does not further affect transformation of BALB/c to a healer phenotype. In acute schistosomiasis, however, iLckcreIl4ra−/lox mice showed enhanced mortality compared with Il4ra−/lox and LckcreIl4ra−/lox mice. iLckcreIl4ra−/lox mice died with similar kinetics to highly susceptible Il4ra−/− mice, despite controlling gut inflammation. In addition, iLckcreIl4ra−/lox mice presented increased liver granuloma sizes, as compared with LckcreIl4ra−/lox mice, with similar eosinophils, fibrosis, and liver damage. In conclusion, IL-4Rα-responsive non-CD4+ T cells prolong survival to acute schistosomiasis and contribute to the better control of hepatic granulomatous inflammation. PMID:19628763

  14. Combined immunization using DNA-Sm14 and DNA-Hsp65 increases CD8+ memory T cells, reduces chronic pathology and decreases egg viability during Schistosoma mansoni infection

    PubMed Central

    2014-01-01

    Background Schistosomiasis is one of the most important neglected diseases found in developing countries and affects 249 million people worldwide. The development of an efficient vaccination strategy is essential for the control of this disease. Previous work showed partial protection induced by DNA-Sm14 against Schistosoma mansoni infection, whereas DNA-Hsp65 showed immunostimulatory properties against infectious diseases, autoimmune diseases, cancer and antifibrotic properties in an egg-induced granuloma model. Methods C57BL/6 mice received 4 doses of DNA-Sm14 (100 μg/dose) and DNA-Hsp65 (100 μg/dose), simultaneously administrated, or DNA-Sm14 alone, once a week, during four weeks. Three groups were included: 1- Control (no immunization); 2- DNA-Sm14; 3- DNA-Sm14/DNA-Hsp65. Two weeks following last immunization, animals were challenged subcutaneously with 30 cercariae. Fifteen, 48 and 69 days after infection splenocytes were collected to evaluate the number of CD8+ memory T cells (CD44highCD62low) using flow cytometry. Forty-eight days after challenge adult worms were collected by portal veins perfusion and intestines were collected to analyze the intestinal egg viability. Histological, immunohistochemical and soluble quantification of collagen and α-SMA accumulation were performed on the liver. Results In the current work, we tested a new vaccination strategy using DNA-Sm14 with DNA-Hsp65 to potentiate the protection against schistosomiasis. Combined vaccination increased the number of CD8+ memory T cells and decreased egg viability on the intestinal wall of infected mice. In addition, simultaneous vaccination with DNA-Sm14/DNA-Hsp65 reduced collagen and α-SMA accumulation during the chronic phase of granuloma formation. Conclusion Simultaneous vaccination with DNA-Sm14/DNA-Hsp65 showed an immunostimulatory potential and antifibrotic property that is associated with the reduction of tissue damage on Schistosoma mansoni experimental infection. PMID

  15. Schistosoma mansoni infection in mice augments the capacity for interleukin 3 (IL-3) and IL-9 production and concurrently enlarges progenitor pools for mast cells and granulocytes-macrophages.

    PubMed Central

    Khalil, R M; Luz, A; Mailhammer, R; Moeller, J; Mohamed, A A; Omran, S; Dörmer, P; Hültner, L

    1996-01-01

    Mast cells and granulocytes-macrophages (GM) are components of the host defense system against worm infections, including schistosomiasis. Here we report the kinetics of changes in the number of colony-forming cells (CFC) for mast cells and GM during the course of a primary experimental infection of mice with Schistosoma mansoni cercariae over a period of 24 weeks postinfection (p.i.). Concurrently, we measured known myelopoietic and/or mast cell-stimulating cytokines (i.e., interleukin 3 [IL-3] and IL-9) in pokeweed mitogen-activated spleen cell-conditioned medium. Our results show that during the acute phase of the hepatic granulomatous reaction, the numbers of both mast-CFC and GM-CFC were significantly elevated in bone marrow. However, while femoral GM-CFC numbers had returned to normal control values at week 16 p.i., femoral and splenic mast-CFC numbers remained significantly elevated until week 20 p.i., which corresponds to the chronic fibrotic phase of hepatic granulomatous inflammation. Increased GM-CFC numbers correlated with elevated IL-3 levels, while increased mast-CFC numbers paralleled the increased IL-9 concentrations in spleen cell-conditioned medium. By the reverse transcription-PCR method, enhanced expression of IL-3 and IL-9 transcripts was found in RNA samples obtained from livers and spleens of infected mice. Our data demonstrate that during the course of infection of mice with S. mansoni, the coordinate need for mast cells and GM is at least partly regulated at the stage of progenitor cell commitment in the bone marrow and spleen. It appears that IL-3 and IL-9 help to promote at this stage the ultimate generation of mature effector cells. PMID:8945533

  16. Immunization of mice with ultraviolet-irradiated Schistosoma mansoni cercariae: a re-evaluation

    SciTech Connect

    Dean, D.A.; Murrell, K.D.; Xu, S.; Mangold, B.L.

    1983-07-01

    Mice immunized by percutaneous exposure to ultraviolet-irradiated Schistosoma mansoni cercariae developed levels of resistance to subsequent S. mansoni infection comparable to those induced by gamma-irradiated cercariae (50-70% reduction in adult worm burden). Cercariae treated with ultraviolet doses ranging from one to three times the minimum dose required to prevent long-term survival induced the highest levels of resistance.

  17. Immunization of mice with ultraviolet-irradiated Schistosoma mansoni cercariae: a re-evaluation.

    PubMed

    Dean, D A; Murrell, K D; Xu, S T; Mangold, B L

    1983-07-01

    Mice immunized by percutaneous exposure to ultraviolet-irradiated Schistosoma mansoni cercariae developed levels of resistance to subsequent S. mansoni infection comparable to those induced by gamma-irradiated cercariae (50-70% reduction in adult worm burden). Cercariae treated with ultraviolet doses ranging from one to three times the minimum dose required to prevent long-term survival induced the highest levels of resistance. PMID:6881427

  18. Effect of Schistosomiasis and Soil-Transmitted Helminth Infections on Physical Fitness of School Children in Côte d'Ivoire

    PubMed Central

    Müller, Ivan; Coulibaly, Jean T.; Fürst, Thomas; Knopp, Stefanie; Hattendorf, Jan; Krauth, Stefanie J.; Stete, Katarina; Righetti, Aurélie A.; Glinz, Dominik; Yao, Adrien K.; Pühse, Uwe; N'Goran, Eliézer K.; Utzinger, Jürg

    2011-01-01

    Background Schistosomiasis and soil-transmitted helminthiasis are important public health problems in sub-Saharan Africa causing malnutrition, anemia, and retardation of physical and cognitive development. However, the effect of these diseases on physical fitness remains to be determined. Methodology We investigated the relationship between schistosomiasis, soil-transmitted helminthiasis and physical performance of children, controlling for potential confounding of Plasmodium spp. infections and environmental parameters (i.e., ambient air temperature and humidity). A cross-sectional survey was carried out among 156 school children aged 7–15 years from Côte d'Ivoire. Each child had two stool and two urine samples examined for helminth eggs by microscopy. Additionally, children underwent a clinical examination, were tested for Plasmodium spp. infection with a rapid diagnostic test, and performed a maximal multistage 20 m shuttle run test to assess their maximal oxygen uptake (VO2 max) as a proxy for physical fitness. Principal Findings The prevalence of Schistosoma haematobium, Plasmodium spp., Schistosoma mansoni, hookworm and Ascaris lumbricoides infections was 85.3%, 71.2%, 53.8%, 13.5% and 1.3%, respectively. Children with single, dual, triple, quadruple and quintuple species infections showed VO2 max of 52.7, 53.1, 52.2, 52.6 and 55.6 ml kg−1 min−1, respectively. The VO2 max of children with no parasite infections was 53.5 ml kg−1 min−1. No statistically significant difference was detected between any groups. Multivariable analysis revealed that VO2 max was influenced by sex (reference: female, coef. = 4.02, p<0.001) and age (years, coef. = −1.23, p<0.001), but not by helminth infection and intensity, Plasmodium spp. infection, and environmental parameters. Conclusion/Significance School-aged children in Côte d'Ivoire showed good physical fitness, irrespective of their helminth infection status. Future studies on children's physical fitness

  19. Repurposing pharma assets: an accelerated mechanism for strengthening the schistosomiasis drug development pipeline.

    PubMed

    Ramamoorthi, Roopa; Graef, Katy M; Dent, Jennifer

    2015-01-01

    Schistosomiasis, one of 17 diseases deemed to be neglected by the World Health Organization, has received little attention from the biopharmaceutical industry. Due to this, only a handful of drugs have been developed to treat schistosomiasis, with only one, praziquantel, used in most endemic regions. Growing concern over resistance coupled with praziquantel's incomplete efficacy across all stages of the Schistosoma platyhelminth life cycle highlights the urgent need for new drugs. The WIPO Re:Search consortium is a platform whereupon biopharmaceutical company compounds are being repurposed to efficiently and cost-effectively develop new drugs for neglected diseases such as schistosomiasis. This article summarizes recent clinical-stage efforts to identify new antischistosomals and highlights biopharmaceutical company compounds with potential for repurposing to treat schistosomiasis. PMID:25996066

  20. [Epidemic situation of schistosomiasis in a provincial surveillance site of Shengzhou City, 2008-2011].

    PubMed

    Wang, Yong; Wang, Yao-Rong; Ying, Xi-Jun; Zhu, Xiao-Chun

    2013-02-01

    According to "The Scheme of Schistosomiasis Surveillance in Zhejiang Province", the status of Oncomelania snails, and the schistosome infection of permanent residents, floating population, and livestock were surveyed in a provincial surveillance site of Shengzhou City, from 2008 to 2011. In 4 years, the area with residual snails was 3,060 m2, and no infected snails were found among 595 living snails. The positive rate of sero-tests for schistosomiasis of the permanent residents was 0.77%, and that of the floating population was 1.09%. No schistosomiasis cases were found. In conclusion, the area with residual snails is small and its distribution is scattered, and we still should strengthen the surveillance of snail status and imported schistosomiasis cases. PMID:23687831

  1. China-Africa and China-Asia Collaboration on Schistosomiasis Control: A SWOT Analysis.

    PubMed

    Xu, J; Bergquist, R; Qian, Y-J; Wang, Q; Yu, Q; Peeling, R; Croft, S; Guo, J-G; Zhou, X-N

    2016-01-01

    Schistosomiasis, a disease caused by a trematode, parasitic worm, is a worldwide public health problem. In spite of great progress with regard to morbidity control, even elimination of this infection in recent decades, there are still challenges to overcome in sub-Saharan Africa and endemic areas in Southeast Asia. Regarded as one of the most successful countries with respect to schistosomiasis control, The People's Republic of China has accumulated considerable experience and learnt important lessons in various local settings that could benefit schistosomiasis control in other endemic countries. Based on an analysis of conceived strengths, weaknesses, opportunities and threats (SWOT) of potential collaborative activities with regard to schistosomiasis in Africa and Asia, this article addresses the importance of collaborative efforts and explores the priorities that would be expected to facilitate the transfer of Chinese experience to low- and middle-income countries in Africa and Asia. PMID:27137455

  2. Applications of Spatial Technology in Schistosomiasis Control Programme in The People's Republic of China.

    PubMed

    Wang, X-Y; He, J; Yang, K; Liang, S

    2016-01-01

    Schistosomiasis, as the important parasitic disease, has caused serious threats to human health globally. The People's Republic of China has acquired significant achievements based on large-scale interventions and innovational technology. The spatial technology was introduced in 1980s and widely used in the study and control of schistosomiasis in The People's Republic of China. This chapter reviews the progress and application of spatial technology in schistosomiasis control by analysing the spatiotemporal pattern of and the impact of ecological changes on schistosomiasis transmission, which have provided the information to design and select the control strategy, and assisted the establishment of the monitoring and early warning system in The People's Republic of China, especially in the marshland and mountainous regions. PMID:27137446

  3. The Effect of Increasing Water Temperatures on Schistosoma mansoni Transmission and Biomphalaria pfeifferi Population Dynamics: An Agent-Based Modelling Study

    PubMed Central

    McCreesh, Nicky; Booth, Mark

    2014-01-01

    Introduction There is increasing interest in the control and elimination of schistosomiasis. Little is known, however, about the likely effects of increasing water-body temperatures on transmission. Methods We have developed an agent-based model of the temperature-sensitive stages of the Schistosoma and intermediate host snail life-cycles, parameterised using data from S. mansoni and Biomphalaria pfeifferi laboratory and field-based observations. Infection risk is calculated as the number of cercariae in the model, adjusted for their probability of causing infection. Results The number of snails in the model is approximately constant between 15–31°C. Outside this range, snail numbers drop sharply, and the snail population cannot survive outside the range 14–32°C. Mean snail generation time decreases with increasing temperature from 176 days at 14°C to 46 days at 26°C. Human infection risk is highest between 16–18°C and 1 pm and 6–10 pm in calm water, and 20–25°C and 12–4 pm in flowing water. Infection risk increases sharply when temperatures increase above the minimum necessary for sustained transmission. Conclusions The model suggests that, in areas where S. mansoni is already endemic, warming of the water at transmission sites will have differential effects on both snails and parasites depending on abiotic properties of the water-body. Snail generation times will decrease in most areas, meaning that snail populations will recover faster from natural population reductions and from snail-control efforts. We suggest a link between the ecological properties of transmission sites and infection risk which could significantly affect the outcomes of interventions designed to alter water contact behaviour – proposing that such interventions are more likely to reduce infection levels at river locations than lakes, where infection risk remains high for longer. In cooler areas where snails are currently found, increasing temperatures may significantly

  4. Safety and efficacy of praziquantel syrup (Epiquantel®) against Schistosoma haematobium and Schistosoma mansoni in preschool-aged children in Niger.

    PubMed

    Garba, Amadou; Lamine, Mariama S; Djibo, Ali; Tahirou, Almoustapha; Aouami, Mahamadou Aboubacar; Alfari, Aichatou; Phillips, Anna E; Fenwick, Alan; Utzinger, Jürg

    2013-11-01

    Given the characteristic age-prevalence curve of Schistosoma infection, preventive chemotherapy with praziquantel is primarily targeted at school-aged children, whilst, in highly endemic areas, other high-risk groups might be included for regular treatment. Nevertheless, schistosomiasis can affect children well before they reach school-age, but this population group is usually excluded from preventive chemotherapy. We assessed the safety and efficacy of praziquantel syrup (Epiquantel®) in preschool-aged children in three villages of Niger. Children aged ≤72 months provided multiple urine and stool samples that were microscopically examined using standard protocols. Schistosoma-positive children were treated with praziquantel syrup at a dose of 40 mg/kg after a meal of millet porridge. Children remained under medical supervision for 4h and adverse events were recorded. Additionally, a questionnaire was administrated to the mothers/guardians 24h post-treatment for further probing of adverse events. Treatment efficacy was evaluated 3 and 6 weeks post-treatment using multiple stool and urine samples. A third of the 243 treated children reported adverse events within 4h, whilst a further 6.2% reported adverse events upon probing 24h post-treatment. Abdominal pain, bloody diarrhoea and sleepiness were the most common adverse events, but these were transient and self-limiting. Praziquantel syrup showed moderate-to-high efficacy against Schistosoma haematobium with egg reduction rates of 69.4% and 71.2% 3 and 6 weeks post-treatment and cure rates of 85.7% (95% confidence interval (CI) 79.7-90.5%) and 94.9% (95% CI 90.5-97.6%), respectively. Considerably lower cure and egg reduction rates were observed against Schistosoma mansoni (e.g. cure rate at 6-week post-treatment follow-up was only 50.6% (95% CI 39.9-61.2%). Concluding, praziquantel syrup is well tolerated in preschool-aged children with moderate-to-high efficacy against S. haematobium, but considerably lower

  5. Structure-Bioactivity Relationship for Benzimidazole Thiophene Inhibitors of Polo-Like Kinase 1 (PLK1), a Potential Drug Target in Schistosoma mansoni

    PubMed Central

    Long, Thavy; Neitz, R. Jeffrey; Beasley, Rachel; Kalyanaraman, Chakrapani; Suzuki, Brian M.; Jacobson, Matthew P.; Dissous, Colette; McKerrow, James H.; Drewry, David H.; Zuercher, William J.; Singh, Rahul; Caffrey, Conor R.

    2016-01-01

    Background Schistosoma flatworm parasites cause schistosomiasis, a chronic and debilitating disease of poverty in developing countries. Praziquantel is employed for treatment and disease control. However, its efficacy spectrum is incomplete (less active or inactive against immature stages of the parasite) and there is a concern of drug resistance. Thus, there is a need to identify new drugs and drug targets. Methodology/Principal Findings We show that RNA interference (RNAi) of the Schistosoma mansoni ortholog of human polo-like kinase (huPLK)1 elicits a deleterious phenotypic alteration in post-infective larvae (schistosomula or somules). Phenotypic screening and analysis of schistosomula and adult S. mansoni with small molecule inhibitors of huPLK1 identified a number of potent anti-schistosomals. Among these was a GlaxoSmithKline (GSK) benzimidazole thiophene inhibitor that has completed Phase I clinical trials for treatment of solid tumor malignancies. We then obtained GSKs Published Kinase Inhibitor Sets (PKIS) 1 and 2, and phenotypically screened an expanded series of 38 benzimidazole thiophene PLK1 inhibitors. Computational analysis of controls and PLK1 inhibitor-treated populations of somules demonstrated a distinctive phenotype distribution. Using principal component analysis (PCA), the phenotypes exhibited by these populations were mapped, visualized and analyzed through projection to a low-dimensional space. The phenotype distribution was found to have a distinct shape and topology, which could be elicited using cluster analysis. A structure-activity relationship (SAR) was identified for the benzimidazole thiophenes that held for both somules and adult parasites. The most potent inhibitors produced marked phenotypic alterations at 1–2 μM within 1 h. Among these were compounds previously characterized as potent inhibitors of huPLK1 in cell assays. Conclusions/Significance The reverse genetic and chemical SAR data support a continued investigation of Sm

  6. Epidemiological Features and Control Progress of Schistosomiasis in Waterway-Network Region in The People's Republic of China.

    PubMed

    Shi, L; Li, W; Wu, F; Zhang, J-F; Yang, K; Zhou, X-N

    2016-01-01

    Schistosomiasis was one of the most serious parasitic diseases in The People's Republic of China, and the endemic region was classified into three types according to the epidemiological characteristics and living conditions of the intermediate host. After more than 60years of efforts, schistosomiasis control programme has made great strides in waterway-network regions. We analyse the epidemic changes of schistosomiasis and its control progress through the schistosomiasis regions' documents and investigation data to evaluate the efficacy of the schistosomiasis control strategies in the waterway-network-type endemic region, which provides the basis for refinement of efforts, as well as summary of the Chinese schistosomiasis control experience in the waterway-network areas. PMID:27137444

  7. [Epidemiological survey of suspected natural foci of schistosomiasis in Luxi City].

    PubMed

    Gong, Su-Ming; Liang, Wei; Luo, Qi-Song; Han, Ji-Zhou; Duan, Pei-Zhi; Li, Jia-Cai; Liu, Zhi-Yuan; Zhang, Bao-Sen; Li, Fa-You; Du, Xiao-Hong; Jiang, Qing-Wu

    2011-02-01

    Three schistosomiasis patients pathologically diagnosed were detected in Luxi City, Yunnan Province, a non-endemic area of schistosomiasis. All the cases were hospitalized for serious intestinal diseases, and Schistosoma japonicum eggs were detected under their colonic mucosa. The 3 patients all denied they had contacted with infested water outside their resident place, and it was suggested that they might be infected in the local area. PMID:22164393

  8. [Recent evolution of schistosomiasis in the water project of Sourou in Burkina Faso].

    PubMed

    Poda, J N; Wango, S P; Sorgho, H; Dianou, D

    2004-02-01

    In order to help the hydro-agricultural projects in the management of water resources together with a schistosomiasis control programme, it is important to evaluate the extent of the problem. This is the reason why parasitological and clinical surveys were conducted in schools associated with malacological surveys in transmission sites of several water projects including the one from Sourou. The data-collecting for the research on molluscs was carried out in surface water and as for parasitologic investigations on school-aged children, urine filtration and Kato-Katz were used to evaluate the parasitic load. The levels of prevalence were respectively in Guiédougou, Niassan, Di and Toma-île, in 2000, 60.5%, 40%, 48.8% and 51.9% for the urinary schistosomiasis, 5.3%, 0%, 6.9% and 50.6% for the intestinal schistosomiasis and in 2002, 56%, 51.9%, 51.6% and 43.4% for the urinary schistosomiasis, 10.1%, 8.2%, 22.7% and 90.8% for the intestinal schistosomiasis. The molluscs species collected and identified were: Biomphalaria pfeifferi for the intestinal schistosomiasis and Bulinus truncatus rohlfsi and B. senegalensis for the urinary schistosomiasis. B. senegalensis and B. truncatus were found naturally infested by S. haematobium. Water projects constitute amplifying factors of the proliferation of the species and parasitic exchange. All the actors (developers, populations, scientists) are questioning the means at their disposal to reduce the development of schistosomiasis which decrease the expected benefit of hydro-agricultural installations. PMID:15104151

  9. A Hybrid Model for Predicting the Prevalence of Schistosomiasis in Humans of Qianjiang City, China

    PubMed Central

    Wang, Ying; Lu, Zhouqin; Tian, Lihong; Tan, Li; Shi, Yun; Nie, Shaofa; Liu, Li

    2014-01-01

    Backgrounds/Objective Schistosomiasis is still a major public health problem in China, despite the fact that the government has implemented a series of strategies to prevent and control the spread of the parasitic disease. Advanced warning and reliable forecasting can help policymakers to adjust and implement strategies more effectively, which will lead to the control and elimination of schistosomiasis. Our aim is to explore the application of a hybrid forecasting model to track the trends of the prevalence of schistosomiasis in humans, which provides a methodological basis for predicting and detecting schistosomiasis infection in endemic areas. Methods A hybrid approach combining the autoregressive integrated moving average (ARIMA) model and the nonlinear autoregressive neural network (NARNN) model to forecast the prevalence of schistosomiasis in the future four years. Forecasting performance was compared between the hybrid ARIMA-NARNN model, and the single ARIMA or the single NARNN model. Results The modelling mean square error (MSE), mean absolute error (MAE) and mean absolute percentage error (MAPE) of the ARIMA-NARNN model was 0.1869×10−4, 0.0029, 0.0419 with a corresponding testing error of 0.9375×10−4, 0.0081, 0.9064, respectively. These error values generated with the hybrid model were all lower than those obtained from the single ARIMA or NARNN model. The forecasting values were 0.75%, 0.80%, 0.76% and 0.77% in the future four years, which demonstrated a no-downward trend. Conclusion The hybrid model has high quality prediction accuracy in the prevalence of schistosomiasis, which provides a methodological basis for future schistosomiasis monitoring and control strategies in the study area. It is worth attempting to utilize the hybrid detection scheme in other schistosomiasis-endemic areas including other infectious diseases. PMID:25119882

  10. Induction of Protective Immune Responses Against Schistosomiasis haematobium in Hamsters and Mice Using Cysteine Peptidase-Based Vaccine

    PubMed Central

    Tallima, Hatem; Dalton, John P.; El Ridi, Rashika

    2015-01-01

    One of the major lessons we learned from the radiation-attenuated cercariae vaccine studies is that protective immunity against schistosomiasis is dependent on the induction of T helper (Th)1-/Th2-related immune responses. Since most schistosome larval and adult-worm-derived molecules used for vaccination uniformly induce a polarized Th1 response, it was essential to include a type 2 immune response-inducing molecule, such as cysteine peptidases, in the vaccine formula. Here, we demonstrate that a single subcutaneous injection of Syrian hamsters with 200 μg active papain, 1 h before percutaneous exposure to 150 cercariae of Schistosoma haematobium, led to highly significant (P < 0.005) reduction of >50% in worm burden and worm egg counts in intestine. Immunization of hamsters with 20 μg recombinant glyceraldehyde 3-phosphate dehydrogenase (rSG3PDH) and 20 μg 2-cys peroxiredoxin-derived peptide in a multiple antigen peptide construct (PRX MAP) together with papain (20 μg/hamster), as adjuvant led to considerable (64%) protection against challenge S. haematobium infection, similar to the levels reported with irradiated cercariae. Cysteine peptidases-based vaccination was also effective in protecting outbred mice against a percutaneous challenge infection with S. haematobium cercariae. In two experiments, a mixture of Schistosoma mansoni cathepsin B1 (SmCB1) and Fasciola hepatica cathepsin L1 (FhCL1) led to highly significant (P < 0.005) reduction of 70% in challenge S. haematobium worm burden and 60% reduction in liver egg counts. Mice vaccinated with SmCB1/FhCL1/rSG3PDH mixture and challenged with S. haematobium cercariae 3 weeks after the second immunization displayed highly significant (P < 0.005) reduction of 72% in challenge worm burden and no eggs in liver of 8–10 mice/group, as compared to unimmunized mice, associated with production of a mixture of type 1- and type 2-related cytokines and antibody responses. PMID:25852696

  11. Monitoring schistosomiasis risk in East China over space and time using a Bayesian hierarchical modeling approach.

    PubMed

    Hu, Yi; Ward, Michael P; Xia, Congcong; Li, Rui; Sun, Liqian; Lynn, Henry; Gao, Fenghua; Wang, Qizhi; Zhang, Shiqing; Xiong, Chenglong; Zhang, Zhijie; Jiang, Qingwu

    2016-01-01

    Schistosomiasis remains a major public health problem and causes substantial economic impact in east China, particularly along the Yangtze River Basin. Disease forecasting and surveillance can assist in the development and implementation of more effective intervention measures to control disease. In this study, we applied a Bayesian hierarchical spatio-temporal model to describe trends in schistosomiasis risk in Anhui Province, China, using annual parasitological and environmental data for the period 1997-2010. A computationally efficient approach-Integrated Nested Laplace Approximation-was used for model inference. A zero-inflated, negative binomial model best described the spatio-temporal dynamics of schistosomiasis risk. It predicted that the disease risk would generally be low and stable except for some specific, local areas during the period 2011-2014. High-risk counties were identified in the forecasting maps: three in which the risk remained high, and two in which risk would become high. The results indicated that schistosomiasis risk has been reduced to consistently low levels throughout much of this region of China; however, some counties were identified in which progress in schistosomiasis control was less than satisfactory. Whilst maintaining overall control, specific interventions in the future should focus on these refractive counties as part of a strategy to eliminate schistosomiasis from this region. PMID:27053447

  12. Distribution of Peripheral Memory T Follicular Helper Cells in Patients with Schistosomiasis Japonica

    PubMed Central

    Chen, Xiaojun; Li, Wei; Zhang, Yang; Song, Xian; Xu, Lei; Xu, Zhipeng; Zhou, Sha; Zhu, Jifeng; Jin, Xin; Liu, Feng; Chen, Gengxin; Su, Chuan

    2015-01-01

    Background Schistosomiasis is a helminthic disease that affects more than 200 million people. An effective vaccine would be a major step towards eliminating the disease. Studies suggest that T follicular helper (Tfh) cells provide help to B cells to generate the long-term humoral immunity, which would be a crucial component of successful vaccines. Thus, understanding the biological characteristics of Tfh cells in patients with schistosomiasis, which has never been explored, is essential for vaccine design. Methodology/Principal Findings In this study, we investigated the biological characteristics of peripheral memory Tfh cells in schistosomiasis patients by flow cytometry. Our data showed that the frequencies of total and activated peripheral memory Tfh cells in patients were significantly increased during Schistosoma japonicum infection. Moreover, Tfh2 cells, which were reported to be a specific subpopulation to facilitate the generation of protective antibodies, were increased more greatly than other subpopulations of total peripheral memory Tfh cells in patients with schistosomiasis japonica. More importantly, our result showed significant correlations of the percentage of Tfh2 cells with both the frequency of plasma cells and the level of IgG antibody. In addition, our results showed that the percentage of T follicular regulatory (Tfr) cells was also increased in patients with schistosomiasis. Conclusions/Significance Our report is the first characterization of peripheral memory Tfh cells in schistosomasis patients, which not only provides potential targets to improve immune response to vaccination, but also is important for the development of vaccination strategies to control schistosomiasis. PMID:26284362

  13. Monitoring schistosomiasis risk in East China over space and time using a Bayesian hierarchical modeling approach

    PubMed Central

    Hu, Yi; Ward, Michael P.; Xia, Congcong; Li, Rui; Sun, Liqian; Lynn, Henry; Gao, Fenghua; Wang, Qizhi; Zhang, Shiqing; Xiong, Chenglong; Zhang, Zhijie; Jiang, Qingwu

    2016-01-01

    Schistosomiasis remains a major public health problem and causes substantial economic impact in east China, particularly along the Yangtze River Basin. Disease forecasting and surveillance can assist in the development and implementation of more effective intervention measures to control disease. In this study, we applied a Bayesian hierarchical spatio-temporal model to describe trends in schistosomiasis risk in Anhui Province, China, using annual parasitological and environmental data for the period 1997–2010. A computationally efficient approach–Integrated Nested Laplace Approximation–was used for model inference. A zero-inflated, negative binomial model best described the spatio-temporal dynamics of schistosomiasis risk. It predicted that the disease risk would generally be low and stable except for s