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Sample records for schistosomiasis mansoni magnetic

  1. Schistosoma Mansoni Infection: Intestinal Schistosomiasis

    DTIC Science & Technology

    1992-01-01

    patients should be :reated. The two mnain Diagnosis oral drugs available for the treatment of all stages of S. mansoni infection are praziquantel and...rep~eatedlly for laterally spilled eggs. Eosino- * praziquantel is administered either as a single dose, philia is usual in acute, but not chronic...with praziquantel , 75 mg/kg in three divided doses 4-hourly. Cortico- steroidls (prednisone, 5 mig t.d.s.) are used for 2-3 days to control the fever and

  2. Osteopontin Is Upregulated in Human and Murine Acute Schistosomiasis Mansoni

    PubMed Central

    Pereira, Thiago Almeida; Syn, Wing-Kin; Amâncio, Frederico Figueiredo; Cunha, Pedro Henrique Diniz; Caporali, Julia Fonseca Morais; Trindade, Guilherme Vaz de Melo; Santos, Elisângela Trindade; Souza, Márcia Maria; Andrade, Zilton Araújo; Witek, Rafal P; Secor, William Evan; Pereira, Fausto Edmundo Lima; Lambertucci, José Roberto; Diehl, Anna Mae

    2016-01-01

    Background Symptomatic acute schistosomiasis mansoni is a systemic hypersensitivity reaction against the migrating schistosomula and mature eggs after a primary infection. The mechanisms involved in the pathogenesis of acute schistosomiasis are not fully elucidated. Osteopontin has been implicated in granulomatous reactions and in acute hepatic injury. Our aims were to evaluate if osteopontin plays a role in acute Schistosoma mansoni infection in both human and experimentally infected mice and if circulating OPN levels could be a novel biomarker of this infection. Methodology/Principal Findings Serum/plasma osteopontin levels were measured by ELISA in patients with acute (n = 28), hepatointestinal (n = 26), hepatosplenic (n = 39) schistosomiasis and in uninfected controls (n = 21). Liver osteopontin was assessed by immunohistochemistry in needle biopsies of 5 patients. Sera and hepatic osteopontin were quantified in the murine model of schistosomiasis mansoni during acute (7 and 8 weeks post infection, n = 10) and chronic (30 weeks post infection, n = 8) phase. Circulating osteopontin levels are increased in patients with acute schistosomiasis (p = 0.0001). The highest levels of OPN were observed during the peak of clinical symptoms (7–11 weeks post infection), returning to baseline level once the granulomas were modulated (>12 weeks post infection). The plasma levels in acute schistosomiasis were even higher than in hepatosplenic patients. The murine model mirrored the human disease. Macrophages were the major source of OPN in human and murine acute schistosomiasis, while the ductular reaction maintains OPN production in hepatosplenic disease. Soluble egg antigens from S. mansoni induced OPN expression in primary human kupffer cells. Conclusions/Significance S. mansoni egg antigens induce the production of OPN by macrophages in the necrotic-exudative granulomas characteristic of acute schistosomiasis mansoni. Circulating OPN levels are upregulated in human and

  3. Pseudotumoral form of cerebral Schistosomiasis Mansoni

    PubMed Central

    Romero, FR; Zanini, MA; Ducati, LG; Gabarra, RC; Haddad, GR; de Souza, V

    2012-01-01

    The authors report a case of 36-year-old woman presented with epileptic seizures and headaches. Magnetic resonance imaging (MRI) revealed an enhancing lesion with surrounding edema and mild mass effect in the left frontal lobe. Stereotactic brain biopsy demonstrated intraparenchymal granulomas surrounding S. mansoni eggs. Praziquantel was started (60mg/kg of body weight, in a single dose), followed by Prednisone (80mg/day) for seven days to treat the cerebral edema. The patient’s symptoms resolved following medical treatment and the follow-up MRI yielded normal findings. PMID:24960795

  4. Immunomodulatory effects of curcumin treatment on murine schistosomiasis mansoni.

    PubMed

    Allam, Gamal

    2009-01-01

    Curcumin is a polyphenol derived from the dietary spice turmeric. It has been shown to regulate numerous transcription factors, cytokines, adhesion molecules, and enzymes that have been linked to inflammation. In addition to inhibiting the growth of a variety of pathogens, curcumin has been shown to have nematocidal activity. The present study was designed to evaluate the schistosomicidal activity of curcumin in vivo as well as immunomodulation of granulomatous inflammation and liver pathology in acute schistosomiasis mansoni. Mice were infected each with 80 Schistosoma (S.) mansoni cercariae and injected intraperitoneally with curcumin at a total dose of 400mg/kg body weight. Curcumin was effective in reducing worm and tissue-egg burdens, hepatic granuloma volume and liver collagen content by 44.4%, 30.9%, 79%, and 38.6%, respectively. Curcumin treatment restored hepatic enzymes activities to the normal levels and enhanced catalase activity in the liver tissue of infected mice. Moreover, hepato-spleenomegaly and eosinophilia induced by S. mansoni infection were largely improved with curcumin treatment. Infected mice treated with curcumin showed low serum level of both interleukin (IL)-12 and tumor necrosis factor alpha (TNF-alpha), but IL-10 level was not significantly altered. Specific IgG and IgG1 responses against both soluble worm antigen (SWAP) and soluble egg antigen (SEA) were augmented with curcumin treatment, but IgM and IgG2a responses were not significantly changed. In conclusion, curcumin treatment modulates cellular and humoral immune responses of infected mice and lead to a significant reduction of parasite burden and liver pathology in acute murine schistosomiasis mansoni.

  5. 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

  6. Environmental inducers of schistosomiasis mansoni in Campinas, Brazil.

    PubMed

    Anaruma Filho, Francisco; Sant'Ana, João Moreno; dos Santos, Rozely Ferreira; Castagna, Cláudio Luiz

    2010-11-01

    Human occupation/activity in the suburbs of the large cities in Brazil, together with high social vulnerability associated with poor living conditions, influence the dynamics of schistosomiasis mansoni as well as several other emerging and re-emerging diseases. Previous notification data surveys for Campinas, São Paulo state, Brazil, carried out by the Information System for Notification Disease, show that there are distinct prevalence differences across healthcare districts of the city. This paper supports the hypothesis that the distribution of schistosomiasis is not random and that the centralized location of cases are linked to human behaviour, in particular to human activities that interfere with basic landscape structure. This paper analyzes the spatial patterns of the parasitic worm Schistosoma mansoni and its intermediate host Biomphalaria comparing disease prevalence with natural conditions and the current pattern of territory occupation by the population. The spatial and hierarchical distribution of factors related to the environmental conditions and land use that indicate the risk for schistosomiasis has been surveyed. It was found that landscape characteristics define the areas at risk for this endemic disease and, as a result, a risk map comprising different risk classes was established. This risk map highlights the regions prone to become new foci for infection or that serves to maintain an existing focus. The research approach used attempts to introduce "geotechnology", i.e. a social application in which better knowledge about these foci, designated endemic "hot spots" can assist preventive public intervention measures in a way that is inexpensive and easy to handle.

  7. Intestinal schistosomiasis caused by both Schistosoma intercalatum and Schistosoma mansoni.

    PubMed

    Tzanetou, Konstantina; Astriti, Myrto; Delis, Vassilios; Moustakas, George; Choreftaki, Theodosia; Papaliodi, Eugenia; Sarri, Katerina; Adamis, George

    2010-05-01

    A case is presented of intestinal schistosomiasis due to both Schistosoma intercalatum and Schistosoma mansoni in a 30-year-old man from Senegal with discussion of diagnostic approach, species identification and determination of the effect of treatment. The patient was admitted to hospital for investigation of renal failure, arterial hypertension and hypereosinophilia. Repeated stool examinations for ova and parasites were negative. Ultrasonography (US) and computed tomography (CT) of the abdomen showed no abnormalities. US of the urinary tract showed kidneys of borderline size with increased echogenicity. Cystoscopy and histopathological examination of bladder biopsy specimens were normal. Flexible colonoscopy revealed numerous nodular lesions in the rectosigmoid region and a few similar lesions in the transverse colon, the histopathological examination of which showed deposition of Schistosoma ova with granuloma formation. Examination of multiple crush biopsy specimens from the rectosigmoid region revealed numerous granulomas formed around Schistosoma eggs which had a terminal spine and were identified as S. intercalatum (longer than Schistosoma haematobium and with a slightly curved terminal spine) and a very few S. mansoni eggs. Crush biopsies from the lesions in the transverse colon showed only S. mansoni eggs. In conclusion, the examination of multiple crush biopsy specimens is a very sensitive and specific technique for species identification of Schistosoma, especially in mixed infections, and for defining the location and extent of the granulomas evoked by each species.

  8. 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

  9. Immunoprotection of Mice against Schistosomiasis Mansoni Using Solubilized Membrane Antigens

    PubMed Central

    Sulbarán, Guidenn; Noya, Oscar; Brito, Beatríz; Ballén, Diana E.; Cesari, Italo M.

    2013-01-01

    Background Schistosomiasis continues to be one of the most prevalent parasitic diseases in the world. Despite the existence of a highly effective antischistosome drug, the disease is spreading into new areas, and national control programs do not arrive to complete their tasks particularly in low endemic areas. The availability of a vaccine could represent an additional component to chemotherapy. Experimental vaccination studies are however necessary to identify parasite molecules that would serve as vaccine candidates. In the present work, C57BL/6 female mice were subcutaneously immunized with an n-butanol extract of the adult worm particulate membranous fraction (AWBE) and its protective effect against a S. mansoni challenge infection was evaluated. Methodology and Findings Water-saturated n-butanol release into the aqueous phase a set of membrane-associated (glyco)proteins that are variably recognized by antibodies in schistosome-infected patients; among the previously identified AWBE antigens there is Alkaline Phosphatase (SmAP) which has been associated with resistance to the infection in mice. As compared to control, a significantly lower number of perfuse parasites was obtained in the immunized/challenged mouse group (P<0.05, t test); and consequently, a lower number of eggs and granulomas (with reduced sizes), overall decreasing pathology. Immunized mice produced high levels of sera anti-AWBE IgG recognizing antigens of ∼190-, 130-, 98-, 47-, 28-23, 14-, and 9-kDa. The ∼130-kDa band (the AP dimer) exhibited in situ SmAP activity after addition of AP substrate and the activity was not apparently inhibited by host antibodies. A preliminary proteomic analysis of the 25-, 27-, and 28-kDa bands in the immunodominant 28–23 kDa region suggested that they are composed of actin. Conclusions Immunization with AWBE induced the production of specific antibodies to various adult worm membrane molecules (including AP) and a partial (43%) protection against a

  10. A review of schistosomiasis in immigrants in Western Australia, demonstrating the unusual longevity of Schistosoma mansoni.

    PubMed

    Harris, A R; Russell, R J; Charters, A D

    1984-01-01

    Sixteen patients with imported schistosomiasis in Western Australia, a non-endemic area, are recorded. Ten with Schistosoma mansoni had lived there for over 20 years, three for over 31 years and two for more than 32 years. No record of a life span of 31 years for S. mansoni can be found in the literature. The principal symptomatology in three patients with S. mansoni was hypersplenism. Four patients with S. mansoni were asymptomatic. Ten had eosinophil counts greater than 0.3 X 10(9)/1 and one who showed no peripheral eosinophilia had numerous eosinophil myelocytes in his bone marrow. A diagnosis of schistosomiasis was initially suspected in five cases by respective discovery of eosinophil myelocytes in the bone marrow, radiological evidence of calcification of the bladder wall and beading of both ureters, cytoscopic findings of sandy patches in the bladder, discovery of ova in the wall of a fallopian tube at ectopic gestation and the presence of ova and an adult worm in a uterine leiomyoma. The risk of infection of the Ord River Dam is greater for S. japonicum than for the African species. An epidemiological feature of this series is that refugees from Poland contracted schistosomiasis (S. mansoni) in refugee camps in East Africa and then migrated to Western Australia between 1950 and 1953.

  11. Schistosoma mansoni: a diagnostic approach to detect acute schistosomiasis infection in a murine model by PCR.

    PubMed

    Sandoval, Nidia; Siles-Lucas, Mar; Lopez Aban, Julio; Pérez-Arellano, José Luis; Gárate, Teresa; Muro, Antonio

    2006-10-01

    Schistosomiasis represents an increasing problem in non-endemic areas, due to the growing number of immigrants and to tourists contracting this disease in "off-the-beaten-track" tourism. Acute schistosomiasis is not diagnosed early due to the lack of diagnostic tools that are sufficiently sensitive enough to detect the parasite during the first weeks of infection. We have developed a diagnostic approach based on the detection of parasite DNA by polymerase chain reaction (PCR) in urine, comparing the performance of this new approach with the two currently used schistosomiasis diagnostic tools (Kato-Katz and ELISA) and the PCR in stool samples. This comparison was done in a Schistosoma mansoni murine experimental model, which permits follow up of the parasite from the acute to the chronic stage of infection. Our results suggest that this new PCR-based approach could be useful for the detection of acute schistosomiasis in easy-to-handle clinical samples such the urine.

  12. 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

  13. [Critical analysis of the estimated number of Schistosomiasis mansoni carriers in Brazil].

    PubMed

    Katz, N; Peixoto, S V

    2000-01-01

    The number of carriers of Schistosoma mansoni infection in Brazil was estimated based on the results of parasitological examinations of feces carried out by the Fundação Nacional de Saúde (FNS - National Health Foundation) in 1996 and 1997, as well as population data from 18 states collected by the Instituto Brasileiro de Geografia e Estatística (IBGE - Brazilian Institute of Geography and Statistics). This information allowed the number of carriers of schistosomiasis mansoni to be estimated at 7.1 million in 1996 and 6. 3 million in 1997. These figures may not reflect the true situation since the population sample used was not originally selected for this purpose. The absence of precise data indicates the need for an adequate national survey of the prevalence of schistosomiasis, which continues to be an important endemic parasitic disease, justifying greater efforts for its control in Brazil.

  14. Genital Schistosomiasis: A Report on Two Cases of Ovarian Carcinomas Containing Viable Eggs of Schistosoma mansoni

    PubMed Central

    Gonçalves Amorim, Andressa; Alves Barbosa Pagio, Fernanda; Neves Ferreira, Rodrigo; Chambô Filho, Antônio

    2014-01-01

    Schistosomiasis is a parasitic infection that is highly prevalent worldwide, with a variety of species being responsible for causing the disease. In Brazil, however, the only identified species is Schistosoma mansoni. The adult parasites inhabit the blood vessels of the hepatic portal system of the main host. The disease may range from being asymptomatic to provoking liver damage or portal hypertension. Furthermore, ectopic schistosomiasis may develop, and several hypotheses have been raised to explain the occurrence of the disease. This paper describes two cases, one in a 39-year-old woman and the other in a 47-year-old woman. Both had similar symptoms of pain and abdominal distension caused by a large abdominal/pelvic mass. Histopathology of the ovary showed a mucinous cystadenocarcinoma of the intestinal type in the first patient and a papillary serous carcinoma in the second, with both tumors containing viable eggs of Schistosoma mansoni. The neoplasms probably serve as a migratory route for the adult parasites and the embolization of eggs. Nevertheless, there is insufficient evidence to confirm the malignization of a benign lesion due to the presence of Schistosoma mansoni. Few cases have been reported in the international literature on the association between ovarian schistosomiasis and neoplasms. PMID:25587473

  15. Phytol, a Diterpene Alcohol from Chlorophyll, as a Drug against Neglected Tropical Disease Schistosomiasis Mansoni

    PubMed Central

    de Moraes, Josué; de Oliveira, Rosimeire N.; Costa, Jéssica P.; Junior, Antonio L. G.; de Sousa, Damião P.; Freitas, Rivelilson M.; Allegretti, Silmara M.; Pinto, Pedro L. S.

    2014-01-01

    Background Schistosomiasis is a major endemic disease that affects hundreds of millions worldwide. Since the treatment and control of this parasitic disease rely on a single drug, praziquantel, it is imperative that new effective drugs are developed. Here, we report that phytol, a diterpene alcohol from chlorophyll widely used as a food additive and in medicinal fields, possesses promising antischistosomal properties in vitro and in a mouse model of schistosomiasis mansoni. Methods and findings In vitro, phytol reduced the motor activity of worms, caused their death and confocal laser scanning microscopy analysis showed extensive tegumental alterations in a concentration-dependent manner (50 to 100 µg/mL). Additionally, phytol at sublethal doses (25 µg/mL) reduced the number of Schistosoma mansoni eggs. In vivo, a single dose of phytol (40 mg/kg) administered orally to mice infected with adult S. mansoni resulted in total and female worm burden reductions of 51.2% and 70.3%, respectively. Moreover, phytol reduced the number of eggs in faeces (76.6%) and the frequency of immature eggs (oogram pattern) was significantly reduced. The oogram also showed increases in the proportion of dead eggs. Confocal microcopy studies revealed tegumental damage in adult S. mansoni recovered from mice, especially in female worms. Conclusions The significant reduction in parasite burden by this chlorophyll molecule validates phytol as a promising drug and offers the potential of a new direction for chemotherapy of human schistosomiasis. Phytol is a common food additive and nonmutagenic, with satisfactory safety. Thus, phytol has potential as a safe and cost-effective addition to antischistosomal therapy. PMID:24392173

  16. 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

  17. [Chemoprophylactic activity of soaps containing essential oil from the fruit of Pterodon pubescens in schistosomiasis mansoni].

    PubMed

    Santos Filho, D; Sarti, S J; Katz, N; Araújo, N; Rocha Filho, P A; Abreu, J E; Bortolin, M E

    1987-01-01

    It has been studied the chemoprophylactic action on experimental schistosomiasis of the essential oil from Pterodon pubescens "sucupira branca" as an additive through different formulations, in toilet soap. Immediately or 24 hours later, groups of mice were exposed by tail method to Schistosoma mansoni cercariae. After 45 days of the exposition, the protective action of these soaps were evaluated. The results showed different levels of protection, ranging from 29.0 to 100.0%. Further studies are on going with the most promising formulations.

  18. Schistosomiasis mansoni in Burundi: progress in its control since 1985.

    PubMed Central

    Engels, D.; Ndoricimpa, J.; Gryseels, B.

    1993-01-01

    Described is the evolution of the schistosomiasis control programme in Burundi since 1985. A single round of selective population chemotherapy was carried out in the Rusizi Plain and the Bugesera focus from 1985 to 1990. The prevalences and intensities of infection as well as the number of symptomatic cases detected in general health services decreased considerably. Annual sample surveys in the treated areas showed, however, that these improvements were rapidly reversed by reinfection of the demographically changing population. Since repeated selective population chemotherapy was not sustainable in the long term, a primary health care approach was adopted. In areas with good access to basic health services, approximately 10% of all schistosomiasis cases now receive treatment annually through this approach. Yearly selective chemotherapy in primary schools in suburban Bujumbura reduced the prevalence of schistosomal infection among pupils from 23% to 9% over the period 1984-90, and this programme has now been extended to highly endemic areas in Imbo-Sud. Focal snail control produced disappointing results, and emphasis has therefore shifted towards health education and environmental control of transmission. PMID:8490984

  19. Macrophage-derived Hedgehog Ligands Promotes Fibrogenic and Angiogenic Responses in Human Schistosomiasis mansoni

    PubMed Central

    Pereira, Thiago A.; Xie, Guanhua; Choi, Steve S.; Syn, Wing-Kin; Voieta, Izabela; Lu, Jiuyi; Chan, Isaac S.; Swiderska, Marzena; Amaral, Kirsten B.; Antunes, Carlos Maurício; Secor, William E.; Witek, Rafal P.; Lambertucci, José Roberto; Pereira, Fausto L.; Diehl, Anna Mae

    2012-01-01

    Background Schistosomiasis mansoni is a major cause of portal fibrosis and portal hypertension. The Hedgehog pathway regulates fibrogenic repair in some types of liver injury. Aims Determine if Hedgehog-pathway activation occurs during fibrosis progression in schistosomiasis and to determine if macrophage-related mechanisms are involved. Methods Immunohistochemistry was used to characterize the cells that generate and respond to Hedgehog ligands in 28 liver biopsies from patients with different grades of schistosomiasis fibrosis staged by ultrasound. Cultured macrophages (RAW264.7 and primary rat Kupffer cells) and primary rat liver sinusoidal endothelial cells (LSEC) were treated with schistosome egg antigen (SEA) and evaluated by qRT-PCR. Inhibition of the Hedgehog-pathway was used to investigate its role in alternative activation of macrophages (M2) and vascular tube formation. Results Patients with schistosomiasis expressed more ligands (Shh and Ihh) and target genes (Patched and Gli2) than healthy individuals. Activated LSEC and myofibroblasts were Hedgehog-responsive (Gli2(+)) and accumulated in parallel with fibrosis stage (p<0.05). Double IHC for Ihh/CD68 showed that Ihh(+) cells were macrophages. In vitro studies demonstrated that SEA stimulated macrophages to express Ihh and Shh mRNA (p<0.05). Conditioned media from such macrophages induced luciferase production by Shh-LightII cells (p<0.001) and Hedgehog inhibitors blocked this effect (p<0.001). SEA-treated macrophages also up-regulated their own expression of M2 markers, and Hh-pathway inhibitors abrogated this response (p<0.01). Inhibition of the Hedgehog pathway in LSEC blocked SEA-induced migration and tube formation. Conclusion SEA stimulates liver macrophages to produce Hh-ligands, which promote alternative activation of macrophages, fibrogenesis, and vascular remodeling in schistosomiasis. PMID:23121638

  20. [Hypocomplementary membrano-proliferative glomerulonephritis in a Malagasy patient with schistosomiasis mansoni (detection of bilharzial antigen on glomerular basement membrane using monoclonal antibodies)].

    PubMed

    Rajaonarivelo, P; Rajaona, H R; Alix, J L; Couderc, P; Daveau, C; Santoro, F; Nogueira-Quetroz, J A; Lovens, M; Capron, A; Cordonnier, D

    1986-01-01

    Schistosomiasis due to Schistosoma mansoni affects more than 40 millions people all over the world. Renal involvement is observed mainly in endemic areas. We report a case of hypocomplementemic membrano-proliferative glomerulonephritis in a malagasy man who suffered also from hepatosplenic bilharziosis. The relation between Schistosoma mansoni and the nephropathy was proved by indirect immunofluorescence test using a monoclonal antibody directed against the caecum of adult Schistosoma mansoni.

  1. 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.

  2. 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.

  3. [Evaluation of 10 years of research on S. mansoni schistosomiasis A in the French West Indies].

    PubMed

    Combes, C; Golvan, Y; Salvat, B

    1982-03-01

    From 1971 until 1982, we studied the ecological factors which stead fast a perennial schistosomiasis in Guadeloupe on an exhaustive mode. More recently, we start a similar investigation in Martinique. In Guadeloupe the single vector of Schistosoma mansoni is the snail Biomphalaria glabrata which is an ubiquist species. But the transmission to man is restricted to the "canal-sewers" where faeces are dropped and not in the rivers of Basse-Terre or the ponds of Grande-Terre. Moreover, the infection is possible only during the hottest hours of the day, when the cercariae get out of the snail. We built a "cercariometer" with which we are able to know the number of cercariae per litre in a given place at every hour of day and night. The black rat (and not the grey rat!) seems, alone, able to maintain the life-cycle of the parasite, at least in the mangrove forests. It is now possible to "clone" S. mansoni by sporocysts transplantation in non-infected snails. The biological control of B. glabrata populations is possible by sterilizating Trematodes such as Ribeiroia guadeloupensis. A new built irrigation reservoir in Grande-Terre give a chance of spread for the endemy in an area which was, till now, unharmed.

  4. [Chemoprophylactic activity on Schistosomiasis mansoni of soaps containing essential oil from the fruits of Pterodon pubescens].

    PubMed

    Katz, N; dos Santos Filho, D; Sarti, S J; Mendes, N M; Rocha Filho, P A; Araujo, N

    1993-01-01

    The chemoprophylactic action of the essential oil of the fruit of Pterodon pubescens Benth (Leguminosae), incorporated in different soap formulations, was studied in experimental schistosomiasis. The formulations were used locally on the tails of mice which were exposed to Schistosoma mansoni cercariae immediately, 24, 72 or 168 hours later by the method of tail immersion. Protection was evaluated 45 days after exposure when the mice were sacrificed and the worms collected by perfusion. The results showed levels of protection varying from 0.0 to 100% depending on the formulation used. A methodology that allowed the evaluation of soap protection of mice exposed to natural infection in snail infested streams on the outskirts of Belo Horizonte, MG, was also developed. Promising results were obtained in that protection of between 57.5 and 31.1% was observed in field trials when soap was applied to the animals 24 and 48 hours earlier. Preliminary studies evaluating irritation and toxicity were favorable and showed that this new prophylactic weapon could contribute to the control of schistosomiasis.

  5. Spatial modeling of the schistosomiasis mansoni in Minas Gerais State, Brazil using spatial regression.

    PubMed

    Fonseca, F; Freitas, C; Dutra, L; Guimarães, R; Carvalho, O

    2014-05-01

    Schistosomiasis is a transmissible parasitic disease caused by the etiologic agent Schistosoma mansoni, whose intermediate hosts are snails of the genus Biomphalaria. The main goal of this paper is to estimate the prevalence of schistosomiasis in Minas Gerais State in Brazil using spatial disease information derived from the state transportation network of roads and rivers. The spatial information was incorporated in two ways: by introducing new variables that carry spatial neighborhood information and by using spatial regression models. Climate, socioeconomic and environmental variables were also used as co-variables to build models and use them to estimate a risk map for the whole state of Minas Gerais. The results show that the models constructed from the spatial regression produced a better fit, providing smaller root mean square error (RMSE) values. When no spatial information was used, the RMSE for the whole state of Minas Gerais reached 9.5%; with spatial regression, the RMSE reaches 8.8% (when the new variables are added to the model) and 8.5% (with the use of spatial regression). Variables representing vegetation, temperature, precipitation, topography, sanitation and human development indexes were important in explaining the spread of disease and identified certain conditions that are favorable for disease development. The use of spatial regression for the network of roads and rivers produced meaningful results for health management procedures and directing activities, enabling better detection of disease risk areas.

  6. 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.

  7. 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.

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

    PubMed

    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; Diehl, Anna Mae

    2015-11-01

    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.

  9. Serological Differentiation of Acute and Chronic Schistosomiasis mansoni by Antibody Responses to Keyhole Limpet Hemocyanin

    DTIC Science & Technology

    1989-01-01

    89020297 miast& mansoni 11 Identification of resistant 2 hfottRS._Dixoril. 1982 Collaborative study on indisiduals. and analysis of their immune re...AP, Strand M, 1985 Identification of 1S MctLaren DJ, Smruthees SR. 1987 The immune anrigenic Schistosoma mansoni glycoprotins, response to schistotomes...evem if F eetey and identify by blots, OUbe,) PELD GROU SUBG P SChisttstass mansoni . Serological differentiationl; XLII; Patienrts; Egypt. 19 ABUTRACT

  10. Chemotherapy Studies on Schistosomiasis.

    DTIC Science & Technology

    Schistosoma mansoni, *Chemotherapy, *Prophylaxis, Preventive medicine, Mice, Drugs, Brazil , Laboratory tests, Snails, Cercariae, Tropical medicine, Selection, Parasitology, Schistosomiasis, Chemotherapeutic agents, Medical research

  11. The epidemiology of schistosomiasis mansoni and soil-transmitted helminths in elementary school children from the South Gondar Zone of the Amhara National Regional State, Ethiopia.

    PubMed

    Jemaneh, L

    2000-04-01

    In a cross-sectional survey undertaken in 22 communities of 6 districts in the South Gondar Zone of the Amhara National Regional State, 2279 school children had their stools examined for schistosomiasis mansoni and soil-transmitted helminths using the Kato-Katz technique. Overall the prevalence rates were 16.4%, 28.9%, 9.5% and 12.9% for S. mansoni, A. lumbricoides, T. trichiura and the hookworms, respectively. S. mansoni infection was registered from 14 of the 22 communities, in more than 60% of which the prevalence was over 20%. Infection with A. lumbricoides was noted in 20 schools and except in three schools the prevalence was above 20%. T. trichiura infection was found in 19 of the 22 schools with prevalence rates from 1.7% to 20.0%. Infection due to the hookworms was recorded in 17 schools, in 40% of which the prevalence was 20% or more. Generally communities of the western districts of the zone had higher infection rates of schistosomiasis mansoni and soil-transmitted helminthiasis as compared to those in the eastern districts. The presence of S. mansoni foci in 9 communities is reported for the first time. In general neither sex nor age were related to prevalence or intensity of infection. Forty nine percent of the examined children had one or more types of helminths, of which 32.5%, 13.3% and 2.4% were single, double and triple infections, respectively. A. lumbricoides commonly occurred with the other helminths. Multiplicity of infection was not sex related. 14.6%, 28.4%, 8.3% and 12.1% of the children had moderate or heavy infections of schistosomiasis mansoni, ascariasis, trichuriasis and hookworms, respectively.

  12. 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.

  13. Schistosomiasis

    MedlinePlus

    ... the United States. It is common in many tropical and subtropical areas worldwide. Symptoms Symptoms vary with ... schistosomiasis, especially if you have: Traveled to a tropical or subtropical area where the disease is known ...

  14. 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

  15. [Serodiagnosis of schistosomiasis mansoni using an egg extract semi-purified by precipitation with ammonium sulfate].

    PubMed

    Ouattara, S A; Sauneron, M F; Tribouley-Duret, J; Tribouley, J

    1986-01-01

    Fifty one sera from bilharziosis patients and thirty control sera were examined with a Schistosoma mansoni egg antigen purified by precipitation with ammonium sulphate at 50% saturation. Sensitivity and specificity were good and showed a good correlation with results obtained by MSA1 antigen, but antigen tested is far more easier to prepare than MSA1.

  16. 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

  17. Vasoactive intestinal peptide inhibits liver pathology in acute murine schistosomiasis mansoni and modulates IL-10, IL-12 and TNF-alpha production.

    PubMed

    Allam, Gamal

    2007-01-01

    Vasoactive intestinal peptide (VIP) exerts a broad range of biologic actions that may include modulation of hepatic granuloma formation. This study aimed to investigate the effect of VIP administration on the course of acute murine schistosomiasis mansoni. Mice were infected each with 40 Schistosoma (S.) mansoni cercariae and injected intraperitoneally with VIP at a total dose of 1mug/kg body weight. VIP treatment was very effective in diminishing worm fecundity, hepatic granuloma size and number by about 54%, 75% and 51%, respectively, and reducing liver collagen content. Serum level of interleukin (IL)-10 was increased, while level of IL-12 and tumor necrosis factor (TNF)-alpha were decreased as a result of VIP administration. Carbohydrate antigen 19.9 (CA 19.9) induced by S. mansoni infection was decreased with VIP treatment. Activities of hepatic gamma-glutamyl transferase (gamma-GT), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) in liver tissue homogenate of infected treated mice were increased. These results indicate that suitable administration of exogenous VIP can be effective in ameliorating immunopathologic damage associated with schistosomiasis.

  18. Rapid competitive enzyme-linked immunosorbent assay using a monoclonal antibody reacting with a 15-kilodalton tegumental antigen of Schistosoma mansoni for serodiagnosis of schistosomiasis.

    PubMed Central

    Da Silva, A J; Piuvezam, M R; de Moura, H; Maddison, S; Peralta, J M

    1993-01-01

    A competitive enzyme-linked immunosorbent assay (CELISA) for antibody detection was developed by using a monoclonal antibody which reacts with a 15-kDa tegumental antigen of the adult worm of Schistosoma mansoni. This monoclonal antibody was not able to react with antigens of Schistosoma japonicum or Schistosoma haematobium in enzyme-linked immunoelectrotransfer blot (EITB) and indirect immunofluorescence tests. The assay was performed in a period of 1 h using an adult worm crude extract antigen. To evaluate the CELISA, a total of 73 serum samples was analyzed: 35 were from S. mansoni-infected patients, 23 were from individuals with parasitic infections other than schistosomiasis, and 14 were from healthy individuals. All serum samples from healthy individuals and from patients infected with other parasites were negative, as were two (6%) samples from patients infected with S. mansoni. EITB analysis showed that 32 of 33 CELISA-positive samples were positive in the EITB but with different patterns of reactivity. A 15-kDa protein reacted with 60% of serum samples, and a 60-kDa protein showed the highest level of reactivity (85%). The two samples from patients infected with S. mansoni that were negative in the CELISA reacted with 70-, 60-, 50-, 47-, and 38-kDa proteins. One sample, positive in CELISA, did not react with proteins of the antigenic extract. Images PMID:8408548

  19. Crystal structure of Schistosoma mansoni arginase, a potential drug target for the treatment of schistosomiasis.

    PubMed

    Hai, Yang; Edwards, Jennifer E; Van Zandt, Michael C; Hoffmann, Karl F; Christianson, David W

    2014-07-22

    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.

  20. 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.

  1. In vitro evaluation of permeation, toxicity and effect of praziquantel-loaded solid lipid nanoparticles against Schistosoma mansoni as a strategy to improve efficacy of the schistosomiasis treatment.

    PubMed

    de Souza, Ana Luiza Ribeiro; Andreani, Tatiana; de Oliveira, Rosimeire Nunes; Kiill, Charlene Priscila; dos Santos, Fernanda Kolenyak; Allegretti, Silmara Marques; Chaud, Marco Vinícius; Souto, Eliana B; Silva, Amélia M; Gremião, Maria Palmira Daflon

    2014-03-10

    Solid lipid nanoparticles (SLN) are a promising drug delivery system for oral administration of poorly-water soluble drugs because of their capacity to increase the solubility of drug molecules when loaded in their lipid matrices, with the resulting improvement of the drug bioavailability. In the present work, we have developed praziquantel (PZQ)-loaded SLN and explored the biological applications of this system for intestinal permeation of PZQ. The effect in vitro on Schistosoma mansoni culture and the cytotoxicity in HepG2 line cell were also evaluated. The results showed a significant decrease in the intestinal absorption of PZQ loaded in SLN compared to free PZQ, suggesting that the SLN matrix could act as reservoir system. In culture of S. mansoni, we observed that PZQ-loaded SLN were more effective than free PZQ, leading the death of the parasites in less time. The result was proportional to doses of PZQ (25 and 50 μg mL⁻¹) and lipid concentration. Regarding cytotoxicity, the encapsulation of PZQ into SLN decreased the toxicity in HepG2 cells in comparison to the free PZQ. From the obtained results, PZQ-loaded SLN could be a new drug delivery system for the schistosomiasis treatment especially in marginalized communities, improving the therapeutic efficacy and reducing the toxic effects of PZQ.

  2. Detection of Schistosoma mansoni Eggs in Feces through their Interaction with Paramagnetic Beads in a Magnetic Field

    PubMed Central

    Fagundes Teixeira, Candida; Neuhauss, Erli; Ben, Renata; Romanzini, Juliano; Graeff-Teixeira, Carlos

    2007-01-01

    Background Diagnosis of intestinal schistosomiasis in low endemic areas is a problem because often control measures have reduced egg burdens in feces to below the detection limits of classical coproparasitological methods. Evaluation of molecular methods is hindered by the absence of an established standard with maximum sensitivity and specificity. One strategy to optimize method performance, where eggs are rare events, is to examine large amounts of feces. A novel diagnostic method for isolation of Schistosoma mansoni eggs in feces, and an initial evaluation of its performance is reported here. Methodology/Principal Findings Known amounts of S. mansoni eggs were seeded into 30 g of normal human feces and subjected to a sequence of spontaneous sedimentation, sieving, Ritchie method, incubation and isolation through interaction with paramagnetic beads. Preliminary tests demonstrated the efficacy of lectins as ligands, but they also indicated that the paramagnetic beads alone were sufficient to isolate the eggs under a magnetic field through an unknown mechanism. Eggs were identified by microscopic inspection, with a sensitivity of 100% at 1.3 eggs per gram of feces (epg). Sensitivity gradually decreased to 25% at a concentration of 0.1 epg. In a preliminary application of the new method to the investigation of a recently established focus in southern Brazil, approximately 3 times more eggs were detected than with the thick-smear Kato-Katz method. Conclusions/Significance The novel S. mansoni detection method may significantly improve diagnosis of infections with low burdens in areas of recent introduction of the parasite, areas under successful control of transmission, or in infected travelers. It may also improve the evaluation of new treatments and vaccines. PMID:18060086

  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. [Endocervical schistosomiasis: case report].

    PubMed

    Delmondes, Leda Maria; Cruz, Mário Augusto Ferreira; Guimarães, Matheus Kummer Hora; Santana, Luan Garcez; Gonçalves, Valma Passos Chagas; Brito, Hugo Leite de Farias

    2014-06-01

    Schistosomiasis mansoni is found in different endemic areas of Brazil. It is a serious public health problem in Brazil and worldwide. Ectopic forms of the disease may affect the female reproductive system, representing a rare type of Schistosoma mansoni infection. A 26-year-old patient complained of vaginal discharge, dyspareunia and pain on palpation of the hypogastrium. Gynecological examination revealed an endocervical polyp. A biopsy was performed. Under microscopy, several granulomas surrounding degenerate and viable eggs of Schistosoma mansoni were seen. Treated with praziquantel, she was asymptomatic after four weeks of treatment. Vaginal discharge and dyspareunia may be secondary causes of cervicitis caused by Schistosoma mansoni. The search for eggs in routine vaginal smear or histological examination should be part of the gynecologic evaluation of patients from endemic areas, with the purpose of tracking ectopic schistosomiasis of the female genital tract.

  5. Endogenous IL-10 regulates IFN-gamma and IL-5 cytokine production and the granulomatous response in Schistosomiasis mansoni-infected mice.

    PubMed Central

    Boros, D L; Whitfield, J R

    1998-01-01

    In murine Schistosomiasis mansoni circumovum, granuloma formation is regulated by pro- and anti-inflammatory cytokines. Among the latter, interleukin-10 (IL-10) has been shown to regulate the inflammatory response. In this study we examined the role of endogenously produced IL-10 in T-helper 1 (Th1)- and Th2-type cytokine production and granuloma formation. The dynamics of IL-10 production through the course of the infection were different in granuloma versus splenic cells. In the former, production peaked during the early developmental stage (6 weeks of infection) of the granuloma and then declined. In splenocytes production peaked at 12 weeks, before down-modulation of the granuloma response. In the developing granuloma both macrophages and T cells secreted IL-10. In anti-IL-10 monoclonal antibody (mAb)-supplemented granuloma cell cultures endogenous IL-10-mediated regulation of interferon-gamma (IFN-gamma) was manifest only at 6 weeks; that of IL-2 continued throughout the infection (6-20 weeks). IL-4 production was unaffected, but IL-5 production was regulated at the 6 and 8 weeks time point. Splenocytes showed regulation of IFN-gamma and IL-2 production at the peak of the granulomatous response (8 weeks). IL-4 production was not regulated, whereas IL-5 production was regulated only at 6 weeks. Repeated injections of anti-IL-10 mAb given to mice at 6, 12 or 20 weeks of the infection significantly enhanced liver and lung granuloma growth, tissue eosinophilia, and IFN-gamma, IL-5 production at the early developmental phase (6 weeks) of the lesions. Thus, in schistosome-infected mice endogenous IL-10 is shown to regulate Th1- and Th2-type cytokine production and granuloma formation during the early Th0/Th1 phase of the immune response. PMID:9767435

  6. [Schistosomiasis and acute appendicitis].

    PubMed

    Figueiredo, Jacinta; Santos, Ângela; Clemente, Horácio; Lourenço, Augusto; Costa, Sandra; Grácio, Maria Amélia; Belo, Silvana

    2014-01-01

    Acute appendicitis associated to Schistosoma haematobium and S. mansoni infection has been found in patients submitted to urgent appendectomy at the Hospital Américo Boavida in Luanda. Due to the high prevalence and morbidity caused by schistosomiasis (or bilharziasis) in the country, we suspect that the involvement of Schistosoma infection on appendicular pathology could be very frequent, in particular for those individuals more exposed to the parasite transmission. We report two clinical cases of acute appendicitis whose surgical specimens of the appendix revealed S. haematobium and S. mansoni eggs in histological samples. The reported patients live in endemic areas and have been exposed to schistosome during childhood, which may explain the infection's chronicity. Information of these clinical cases could be relevant, particularly for surgery specialists and clinical pathologists, due to the possibility of finding more patients with concurrent appendicitis and schistosomiasis.

  7. Cutaneous ectopic schistosomiasis: diagnostic challenge*

    PubMed Central

    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

  8. 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.

  9. 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.

  10. 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.

  11. Metabonomic investigation of human Schistosoma mansoni infection.

    PubMed

    Balog, Crina I A; Meissner, Axel; Göraler, Sibel; Bladergroen, Marco R; Vennervald, Birgitte J; Mayboroda, Oleg A; Deelder, André M

    2011-05-01

    Schistosomiasis is a parasitic infection that is endemic in many developing countries in the tropics and subtropics afflicting more than 207 million people primarily in rural areas. After malaria, it is the second most important parasitic infection in terms of socio-economic and public health. Investigation of the host-parasite interaction at the molecular level and identification of biomarkers of infection and infection-related morbidity would be of value for improved strategies for treatment and morbidity control. To this end, we conducted a nuclear magnetic resonance (NMR) based metabonomics study involving a well-characterized cohort of 447 individuals from a rural area in Uganda near Lake Victoria with a high prevalence of Schistosoma mansoni, a species predominantly occurring in Africa including Madagascar and parts of South America. Cohort samples were collected from individuals at five time-points, before and after (one or two times) chemotherapy with praziquantel (PZQ). Using supervised multivariate statistical analysis of the recorded one-dimensional (1D) NMR spectra, we were able to discriminate infected from uninfected individuals in two age groups (children and adults) based on differences in their urinary profiles. The potential molecular markers of S. mansoni infection were found to be primarily linked to changes in gut microflora, energy metabolism and liver function. These findings are in agreement with data from earlier studies on S. mansoni infection in experimental animals and thus provide corroborating evidence for the existence of metabolic response specific for this infection.

  12. Magnetic Resonance Spectroscopy for Evaluating Portal-Systemic Encephalopathy in Patients with Chronic Hepatic Schistosomiasis Japonicum

    PubMed Central

    Li, Ying; Mei, Lihong; Qiang, Jinwei; Ju, Shuai; Zhao, Shuhui

    2016-01-01

    Portal-systemic encephalopathy (PSE) is classified as type B hepatic encephalopathy. Portal-systemic shunting rather than liver dysfunction is the main cause of PSE in chronic hepatic schistosomiasis japonicum (HSJ) patients. Owing to lack of detectable evidence of intrinsic liver disease, chronic HSJ patients with PSE are frequently clinically undetected or misdiagnosed, especially chronic HSJ patients with covert PSE (subclinical encephalopathy). In this study, we investigated whether magnetic resonance spectroscopy (MRS) could be a useful tool for diagnosing PSE in chronic HSJ patients. Magnetic resonance (MR) T1-weighted imaging, diffusion-weighted imaging, and MRS were performed in 41 chronic HSJ patients with suspected PSE and in 21 age-matched controls. The T1 signal intensity index (T1SI) and apparent diffusion coefficient (ADC) value were obtained in the Globus pallidus. Liver function was also investigated via serum ammonia and liver function tests. Higher T1SI and ADC values, increased lactate and glutamine levels, and decreased myo-inositol were found in the bilateral Globus pallidus in chronic HSJ patients with PSE. No significantly abnormal serum ammonia or liver function tests were observed in chronic HSJ patients with PSE. On the basis of these findings, we propose a diagnostic procedure for PSE in chronic HSJ patients. This study reveals that MRS can be useful for diagnosing PSE in chronic HSJ patients. PMID:27977668

  13. Magnetic Resonance Spectroscopy for Evaluating Portal-Systemic Encephalopathy in Patients with Chronic Hepatic Schistosomiasis Japonicum.

    PubMed

    Li, Ying; Mei, Lihong; Qiang, Jinwei; Ju, Shuai; Zhao, Shuhui

    2016-12-01

    Portal-systemic encephalopathy (PSE) is classified as type B hepatic encephalopathy. Portal-systemic shunting rather than liver dysfunction is the main cause of PSE in chronic hepatic schistosomiasis japonicum (HSJ) patients. Owing to lack of detectable evidence of intrinsic liver disease, chronic HSJ patients with PSE are frequently clinically undetected or misdiagnosed, especially chronic HSJ patients with covert PSE (subclinical encephalopathy). In this study, we investigated whether magnetic resonance spectroscopy (MRS) could be a useful tool for diagnosing PSE in chronic HSJ patients. Magnetic resonance (MR) T1-weighted imaging, diffusion-weighted imaging, and MRS were performed in 41 chronic HSJ patients with suspected PSE and in 21 age-matched controls. The T1 signal intensity index (T1SI) and apparent diffusion coefficient (ADC) value were obtained in the Globus pallidus. Liver function was also investigated via serum ammonia and liver function tests. Higher T1SI and ADC values, increased lactate and glutamine levels, and decreased myo-inositol were found in the bilateral Globus pallidus in chronic HSJ patients with PSE. No significantly abnormal serum ammonia or liver function tests were observed in chronic HSJ patients with PSE. On the basis of these findings, we propose a diagnostic procedure for PSE in chronic HSJ patients. This study reveals that MRS can be useful for diagnosing PSE in chronic HSJ patients.

  14. Manipulation of the immune evasive properties of circulating cathodic antigen induces protective immunity against Schistosomiasis mansoni in C57BL/6 mice.

    PubMed

    Abdeen, Sherif H

    2010-01-01

    Schistosome circulating cathodic antigen (CCA) has been hypothesized to take part in immune evasion mechanisms that protect against host's immunity. To dissect its immunogenicity, lymphoproliferative responses of splenocytes were assessed in C57BL/6 mice immunized with recombinant plasmid constructs expressing full-length and truncated fragments of CCA cDNA, before and after challenge infection with S. mansoni cercariae. Prior to challenge, splenocytes of immunized mice showed low responses to phytohaemagglutinin (PHA) and high responses to native CCA, compared to controls. After challenge, PHA-responses increased on day 3 through day 7 and subsequently declined. On the other hand, CCA-induced responses increased on day 3 post-challenge then declined in mice immunized with CCA fragments lacking the N-terminus (-N CCA). Whereas, mice immunized with full-length or CCA fragment lacking the C-terminus (-C CCA) showed a delayed increase of CCA-induced responses that maximize on day 25. Interestingly, animals immunized with -N CCA showed a significant reduction in worm burden between 42-51%, while, mice immunized with full-length or -C CCA showed lower protection levels of about 15 and 37%, respectively. These findings suggest that CCA may contain immunosuppressive epitopes on the N-terminus. Abrogation of these epitopes could disrupt the immune evasion mechanism orchestrated by CCA, which could aid the development of an alternative vaccination approach.

  15. 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.

  16. Hepatobiliary Schistosomiasis

    PubMed Central

    Shaker, Yehia; Samy, Nervana; Ashour, Esmat

    2014-01-01

    Schistosomiasis is an ancient parasitic disease that has afflicted Egyptians since the time of the pharaohs. The disease is caused by lodged schistosome eggs in the host liver, evoking an immune response and leading in some patients to the development of hepatic granuloma and fibrosis. Here, we review the epidemiology, immunopathogenesis, and clinical profile of schistosomiasis. This information may aid in the development of more efficacious treatments and improved disease prognosis. PMID:26357627

  17. Mitochondrial dynamics in the mouse liver infected by Schistosoma mansoni.

    PubMed

    Chen, Tina Tu-Wen; Wu, Lawrence Shih Hsin; Hsu, Paul Wei-Che; Pang, Cheng-Yoong; Lee, Kin-Mu; Cheng, Po-Ching; Peng, Shih-Yi

    2015-08-01

    Mitochondrial dynamics is crucial for regulation of cell homeostasis. Schistosoma mansoni is one of the most common parasites known to cause liver disease. Mice infected by S. mansoni show acute symptoms of schistosomiasis after 8 weeks. Hence, in this study, we attempted to assess the direct effects of S. mansoni infection on mice liver, and to explore the expression of mitochondrial morphology, dynamics, and function. Our recent findings show that S. mansoni infection changes mitochondrial morphology and affects mitochondrial functions, which attenuates mitochondrial membrane potential and ATP generation. S. mansoni-infected mice increases mitochondrial numbers by upregulating of genes involved in mitochondrial biogenesis, including peroxisome proliferator-activated receptor c co-activator 1α (PGC1α) and mitochondrial transcription factor A (Tfam). This may promote mitochondria generation for accelerating the recovery of mitochondrial functions. Moreover, S. mansoni would disrupt mitochondrial dynamics including induced mitochondrial fission and promoted mitochondrial fragmentation in mice liver. More importantly, S. mansoni further stimulated upregulation both extrinsic and intrinsic apoptosis pathway in infected mice liver. The intrinsic pathway was triggered by cytochrome c release. Additionally, NFκB (nuclear factor-kappa B, p65) could play a protective role to inhibit apoptosis through reducing active caspase-3 expression. Therefore, our results confirmed the liver damage mechanism of experimental schistosomiasis in mice model.

  18. 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.

  19. Barbatic Acid Offers a New Possibility for Control of Biomphalaria Glabrata and Schistosomiasis.

    PubMed

    Martins, Mônica Cristina Barroso; Silva, Monique Costa; Silva, Hianna Arely Milca Fagundes; Silva, Luanna Ribeiro Santos; Albuquerque, Mônica Camelo Pessoa de Azevedo; Aires, André Lima; Falcão, Emerson Peter da Silva; Pereira, Eugênia C; de Melo, Ana Maria Mendonça Albuquerque; da Silva, Nicácio Henrique

    2017-03-31

    This study evaluated the biological activity of an ether extract and barbatic acid (BAR) from Cladia aggregata on embryos and adult mollusks of Biomphalaria glabrata, cercariae of Schistosoma mansoni and the microcrustacean Artemia salina. The ether extract and BAR were obtained by successive extractions with diethyl ether. The obtained extracts were analyzed using thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), proton nuclear magnetic resonance (¹H-NMR) and infrared (IR) spectroscopy. The results demonstrated that the ether extract exerted embryotoxic effects at 50 and 100 µg/mL and molluscicidal effects at 20 and 25 µg/mL. BAR exhibited no embryotoxicity, and its molluscicidal concentration was equal to that of the ether extract. However, after 60 min of exposure, 1 µg/mL BAR presented cercaricidal activity against the parasite S. mansoni at the second larval stage. Neither substance induced toxicity against A. salina. These results indicate the potential molluscicidal activities of the ether extract and BAR against B. glabrata and S. mansoni cercariae. In addition to these effects, there was a lack of toxicity against the aquatic environment and no damage to the biota, indicating the potential of these products for large-scale control and/or eradication of schistosomiasis.

  20. 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

  1. 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

  2. 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

  3. 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.

  4. 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

  5. Genitourinary schistosomiasis.

    PubMed

    Al-Ghorab, M M; Smith, D R

    1979-01-01

    Schistosomiasis is a chronic granulomatous disease endemic in the Middle East and Africa, which undermines the function of the genitourinary tract to a serious degree. It is amenable to medical treatment in the early stages but therapy usually is negated by frequent reinfestations. Patients who have complications in the chronic stage of the disease require the level of judicious handling that always taxes the ingenuity and skill of the urologic surgeon.

  6. Evaluation of a linear spectral mixture model and vegetation indices (NDVI and EVI) in a study of schistosomiasis mansoni and Biomphalaria glabrata distribution in the state of Minas Gerais, Brazil.

    PubMed

    Guimarães, Ricardo J P S; Freitas, Corina C; Dutra, Luciano V; Scholte, Ronaldo G C; Amaral, Ronaldo S; Drummond, Sandra C; Shimabukuro, Yosio E; Oliveira, Guilherme C; Carvalho, Omar S

    2010-07-01

    This paper analyses the associations between Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) on the prevalence of schistosomiasis and the presence of Biomphalaria glabrata in the state of Minas Gerais (MG), Brazil. Additionally, vegetation, soil and shade fraction images were created using a Linear Spectral Mixture Model (LSMM) from the blue, red and infrared channels of the Moderate Resolution Imaging Spectroradiometer spaceborne sensor and the relationship between these images and the prevalence of schistosomiasis and the presence of B. glabrata was analysed. First, we found a high correlation between the vegetation fraction image and EVI and second, a high correlation between soil fraction image and NDVI. The results also indicate that there was a positive correlation between prevalence and the vegetation fraction image (July 2002), a negative correlation between prevalence and the soil fraction image (July 2002) and a positive correlation between B. glabrata and the shade fraction image (July 2002). This paper demonstrates that the LSMM variables can be used as a substitute for the standard vegetation indices (EVI and NDVI) to determine and delimit risk areas for B. glabrata and schistosomiasis in MG, which can be used to improve the allocation of resources for disease control.

  7. Discovery of Potent Inhibitors of Schistosoma mansoni NAD⁺ Catabolizing Enzyme.

    PubMed

    Jacques, Sylvain A; Kuhn, Isabelle; Koniev, Oleksandr; Schuber, Francis; Lund, Frances E; Wagner, Alain; Muller-Steffner, Hélène; Kellenberger, Esther

    2015-04-23

    The blood fluke Schistosoma mansoni is the causative agent of the intestinal form of schistosomiasis (or bilharzia). Emergence of Schistosoma mansoni with reduced sensitivity to praziquantel, the drug currently used to treat this neglected disease, has underlined the need for development of new strategies to control schistosomiasis. Our ability to screen drug libraries for antischistosomal compounds has been hampered by the lack of validated S. mansoni targets. In the present work, we describe a virtual screening approach to identify inhibitors of S. mansoni NAD(+) catabolizing enzyme (SmNACE), a receptor enzyme suspected to be involved in immune evasion by the parasite at the adult stage. Docking of commercial libraries into a homology model of the enzyme has led to the discovery of two in vitro micromolar inhibitors. Further structure-activity relationship studies have allowed a 3-log gain in potency, accompanied by a largely enhanced selectivity for the parasitic enzyme over the human homologue CD38.

  8. Prolonged latent schistosomiasis diagnosed 38 years after infestation in a HIV patient.

    PubMed

    Payet, Barry; Chaumentin, Gilles; Boyer, Michelle; Amaranto, Paula; Lemonon-Meric, Claire; Lucht, Frederic

    2006-01-01

    We report a case of Schistosoma mansoni bilharziasis in a HIV patient 38 y after leaving an endemic region. A viable S. mansoni egg on a liver biopsy sample was diagnostic. Despite severe concomitant immunodeficiency the effective treatment was a single dose of praziquantel. Worms' intravascular longevity and the role of immunodeficiency as a possible factor in eggs retention after such prolonged latent schistosomiasis are discussed.

  9. Schistosomiasis in Omo National Park of southwest Ethiopia.

    PubMed

    Fuller, G K; Lemma, A; Haile, T

    1979-05-01

    Schistosomiasis mansoni infection was found in more than 50 tourists who had visited Omo National Park, Ethiopia, and bathed and swum in the Mui River. A survey revealed Schistosoma mansoni infection in 41% of Park residents and in 33% of the neighboring Suri people. Eggs were found in stools and adult worms at autopsy of wild Papio anubis and Cercopithecus aethiops. Trematode larvae were found in 27% of Biomphalaria pfeifferi snails found in the Mui River. The source of the disease and the implications of its spread with the future development of the Omo Valley are discussed.

  10. 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.

  11. Enhancing Schistosomiasis Control Strategy for Zimbabwe: Building on Past Experiences

    PubMed Central

    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

  12. Collaborative study on antigens for immunodiagnosis of schistosomiasis*

    PubMed Central

    Mott, K. E.; Dixon, H.

    1982-01-01

    Eight research laboratories in Europe and the United States of America were selected on the basis of having published data on Schistosoma mansoni and S. japonicum antigens to participate in a study of various antigen/test combinations for immunodiagnosis of schistosomiasis. The serum bank consisted of 395 well documented sera from four endemic areas in Brazil (2 areas), Kenya, and the Philippines. Altogether, 21 S. mansoni and four S. japonicum antigen and immunoassay combinations were evaluated. S. mansoni egg antigens yielded a higher combined sensitivity than adult worm antigens, irrespective of their purity, in active S. mansoni infections before and after specific treatment. Quantitative seroreactivity of characterized S. mansoni egg antigens showed good correlation with faecal egg counts in the 5-14 year age group. No correlation between morbidity related to S. mansoni and seroreactivity was observed in any test system. Three S. japonicum egg antigens showed high sensitivity and specificity in relation to the presence or absence of eggs in the stool. The quantitative seroreactivity of the characterized S. japonicum egg antigens correlated directly with the intensity of S. japonicum infection in all age groups. The enzyme-linked immunosorbent assay (ELISA), using several different procedures, performed well with the antigens used in the study. The indium slide immunoassay (ISI), a simple qualitative visual test system using an S. mansoni egg antigen, demonstrated a high degree of sensitivity and specificity. The results did not indicate the superiority of any particular immunodiagnostic method for detecting antischistosome antibodies. This collaborative study is considered a first step towards developing and standardizing antigens for immunodiagnosis of schistosomiasis. PMID:6983926

  13. 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.

  14. 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

  15. [On the reversal of schistosomiasis hepatic fibrosis after specific therapy. Histopathologic study].

    PubMed

    Chapadeiro, E; Pitanga, L C

    1997-01-01

    Surgical liver biopsies of patients of both sexes, between 18 and 72 years old, with the compensated hepatoesplenic form of schistosomiasis mansoni, previously treated with oxaminique (Mansil) were studied by histological and immunohistochemical methods. Although the search for parasites and/or granulomas was negative in all specimen studied, the portal fibrosis remained.

  16. 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

    2015-11-19

    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

  17. Spatial distribution of Biomphalaria spp., the intermediate host snails of Schistosoma mansoni, in Brazil.

    PubMed

    Scholte, Ronaldo G C; Carvalho, Omar S; Malone, John B; Utzinger, Jürg; Vounatsou, Penelope

    2012-09-01

    Schistosomiasis mansoni remains an important parasitic disease of man, endemic in large parts of sub-Saharan Africa, the Middle East, South America and the Caribbean. The aetiological agent is the trematode Schistosoma mansoni, whereas aquatic snails of the genus Biomphalaria act as intermediate hosts in the parasite life cycle. In Brazil, the distribution of Biomphalaria spp. is closely associated with the occurrence of schistosomiasis. The purpose of this study was to map and predict the spatial distribution of the intermediate host snails of S. mansoni across Brazil. We assembled snail "presenceonly" data and used a maximum entropy approach, along with climatic and environmental variables to produce predictive risk maps. We identified a series of risk factors that govern the distribution of Biomphalaria snails. We find that high-risk areas for B. glabrata are concentrated in the regions of Northeast and Southeast and the northern part of the South region. B. straminea are found in the Northeast and Southeast regions, and B. tenagophila are concentrated in the Southeast and South regions. Our findings confirm that the presence of the intermediate host snails is correlated with the occurrence of schistosomiasis mansoni. The generated risk maps of intermediate host snails might assist the national control programme for spatial targeting of control interventions and to ultimately move towards schistosomiasis elimination in Brazil.

  18. Acute schistosomiasis among Americans rafting the Omo River, Ethiopia.

    PubMed

    Istre, G R; Fontaine, R E; Tarr, J; Hopkins, R S

    1984-01-27

    An outbreak of acute schistosomiasis occurred among a group of adventurers who took part in a rafting expedition on the Omo River in Ethiopia in November 1981. Six (55%) of the 11 members of the expedition experienced Schistosoma mansoni infection confirmed by stool examination. Five of these six had symptoms compatible with acute schistosomiasis. Eosinophilia was the most frequent sign of infection (five of six), and fever, the most common symptom (four of six). Despite medical evaluations, illnesses had remained undiagnosed until January 1982. This outbreak should alert physicians to the risk of schistosomiasis among travelers to this part of Africa and the difficulty of correct diagnosis early in the course of the disease.

  19. Ocular pathological changes in hamsters experimentally infected with Schistosoma mansoni.

    PubMed

    Ismail, H I H; Ashour, D S; Abou Rayia, D M; Ali, A L

    2016-11-01

    Ocular lesions have been reported in patients with schistosomiasis; however, the problem with studying schistosomal infection of the human eye is that biopsies are almost impossible to take, and histopathological examination of suspicious lesions can only be undertaken post-mortem or after enucleation. This work aimed to study the possible effects and pathogenesis of schistosomiasis on the eye. This study involved 55 hamsters; five hamsters remained non-infected and the remaining 50 hamsters were infected with Schistosoma mansoni cercariae. Infected hamsters were sacrificed on weeks 8, 12, 16 and 20 post-infection (pi). Eye sections were prepared and stained for histopathological and immunohistochemical studies. Histopathological changes detected in hamsters infected after 16 and 20 weeks included looseness and oedema of the innermost retinal layers together with hyperplastic polypoid growth. Neither eggs nor granulomata were detected in eye sections throughout the experimental period. Deposition of S. mansoni antigen was revealed in 35% of infected hamsters. Later, on weeks 16 and 20 pi, moderate subepithelial conjuctival deposits and marked subchoroidal and scleral deposition were detected. In conclusion, the deposition of schistosomal antigen and immune complexes may play a pivotal role in the ocular changes that occur in schistosomiasis, even in the absence of detectable Schistosoma eggs. Schistosomiasis should be suspected in cases with unexplained ophthalmological findings, especially in endemic areas.

  20. Human schistosomiasis.

    PubMed

    Colley, Daniel G; Bustinduy, Amaya L; Secor, W Evan; King, Charles H

    2014-06-28

    Human schistosomiasis--or bilharzia--is a parasitic disease caused by trematode flukes of the genus Schistosoma. By conservative estimates, at least 230 million people worldwide are infected with Schistosoma spp. Adult schistosome worms colonise human blood vessels for years, successfully evading the immune system while excreting hundreds to thousands of eggs daily, which must either leave the body in excreta or become trapped in nearby tissues. Trapped eggs induce a distinct immune-mediated granulomatous response that causes local and systemic pathological effects ranging from anaemia, growth stunting, impaired cognition, and decreased physical fitness, to organ-specific effects such as severe hepatosplenism, periportal fibrosis with portal hypertension, and urogenital inflammation and scarring. At present, preventive public health measures in endemic regions consist of treatment once every 1 or 2 years with the isoquinolinone drug, praziquantel, to suppress morbidity. In some locations, elimination of transmission is now the goal; however, more sensitive diagnostics are needed in both the field and clinics, and integrated environmental and health-care management will be needed to ensure elimination.

  1. Current Status of Vaccines for Schistosomiasis

    PubMed Central

    McManus, Donald P.; Loukas, Alex

    2008-01-01

    Schistosomiasis, caused by trematode blood flukes of the genus Schistosoma, is recognized as the most important human helminth infection in terms of morbidity and mortality. Infection follows direct contact with freshwater harboring free-swimming larval (cercaria) forms of the parasite. Despite the existence of the highly effective antischistosome drug praziquantel (PZQ), schistosomiasis is spreading into new areas, and although it is the cornerstone of current control programs, PZQ chemotherapy does have limitations. In particular, mass treatment does not prevent reinfection. Furthermore, there is increasing concern about the development of parasite resistance to PZQ. Consequently, vaccine strategies represent an essential component for the future control of schistosomiasis as an adjunct to chemotherapy. An improved understanding of the immune response to schistosome infection, both in animal models and in humans, suggests that development of a vaccine may be possible. This review considers aspects of antischistosome protective immunity that are important in the context of vaccine development. The current status in the development of vaccines against the African (Schistosoma mansoni and S. haematobium) and Asian (S. japonicum) schistosomes is then discussed, as are new approaches that may improve the efficacy of available vaccines and aid in the identification of new targets for immune attack. PMID:18202444

  2. T-lymphocyte responsiveness in murine schistosomiasis mansoni is dependent upon the adhesion molecules intercellular adhesion molecule-1, lymphocyte function-associated antigen-1, and very late antigen-4.

    PubMed Central

    Langley, J G; Boros, D L

    1995-01-01

    Granuloma formation in murine schistosomiasis is dependent on CD4+ Th lymphocytes and requires recruitment and accumulation of inflammatory cells at the site of egg deposition. The present study examined the role of three adhesion molecules, intercellular adhesion molecule-1 (ICAM-1), lymphocyte function-associated antigen-1 (LFA-1), and very late antigen-4 (VLA-4), that participate in cellular recruitment, interaction, and lymphocyte activation during in vitro activation of acutely and chronically infected spleen and liver granuloma lymphocytes. Blockade of ICAM-1, LFA-1, or VLA-4 by rat monoclonal antibody inhibited spleen and granuloma lymphocyte interleukin-2 (IL-2) and IL-4 production as well as lymphoproliferative responses at similar levels (66 to 87%). The down-modulated cytokine and proliferative responses of chronically infected lymphocytes were inhibited to the same extent as their acutely infected counterparts. Cell sorting analysis demonstrated that acutely and chronically infected splenic and granuloma lymphocytes expressed similar levels of LFA-1, ICAM-1, and VLA-4 and that more ICAM-1 was expressed on infected than on uninfected mouse lymphocytes. By exposure of cells to paired monoclonal antibodies at suboptimal doses, it was determined that whereas all three adhesion molecules may participate, only ICAM-1 and LFA-1 showed synergistic interactions in determining lymphocyte responsiveness. These data suggest that spleen and liver granuloma lymphocytes are equally well armed with functional adhesion receptors. Thus, ICAM-1, LFA-1, and VLA-4 play an important accessory role in inflammatory cytokine production and lymphocyte proliferation, and therefore these adhesion molecules may participate in the initiation and maintenance of the granulomatous inflammation. PMID:7558308

  3. Evaluation of Eight Serological Tests for Diagnosis of Imported Schistosomiasis

    PubMed Central

    Dittrich, Sabine; Bäumer, Britta

    2012-01-01

    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

  4. Use of Indicator Kriging to Investigate Schistosomiasis in Minas Gerais State, Brazil

    PubMed Central

    Guimarães, Ricardo J. P. S.; Freitas, Corina C.; Dutra, Luciano V.; Felgueiras, Carlos A.; Drummond, Sandra C.; Tibiriçá, Sandra H. C.; Oliveira, Guilherme; Carvalho, Omar S.

    2012-01-01

    Geographic Information Systems (GISs) are composed of useful tools to map and to model the spatial distribution of events that have geographic importance as schistosomiasis. This paper is a review of the use the indicator kriging, implemented on the Georeferenced Information Processing System (SPRING) to make inferences about the prevalence of schistosomiasis and the presence of the species of Biomphalaria, intermediate hosts of Schistosoma mansoni, in areas without this information, in the Minas Gerais State, Brazil. The results were two maps. The first one was a map of Biomphalaria species, and the second was a new map of estimated prevalence of schistosomiasis. The obtained results showed that the indicator kriging can be used to better allocate resources for study and control of schistosomiasis in areas with transmission or the possibility of disease transmission. PMID:22291716

  5. Use of indicator kriging to investigate schistosomiasis in minas gerais state, Brazil.

    PubMed

    Guimarães, Ricardo J P S; Freitas, Corina C; Dutra, Luciano V; Felgueiras, Carlos A; Drummond, Sandra C; Tibiriçá, Sandra H C; Oliveira, Guilherme; Carvalho, Omar S

    2012-01-01

    Geographic Information Systems (GISs) are composed of useful tools to map and to model the spatial distribution of events that have geographic importance as schistosomiasis. This paper is a review of the use the indicator kriging, implemented on the Georeferenced Information Processing System (SPRING) to make inferences about the prevalence of schistosomiasis and the presence of the species of Biomphalaria, intermediate hosts of Schistosoma mansoni, in areas without this information, in the Minas Gerais State, Brazil. The results were two maps. The first one was a map of Biomphalaria species, and the second was a new map of estimated prevalence of schistosomiasis. The obtained results showed that the indicator kriging can be used to better allocate resources for study and control of schistosomiasis in areas with transmission or the possibility of disease transmission.

  6. Schistosoma mansoni: Antiparasitic effects of orally administered Nigella sativa oil and/or Chroococcus turgidus extract.

    PubMed

    Ali, Medhat; Eldahab, Marwa Abou; Mansour, Hoda Anwer; Nigm, Ahmed

    2016-09-01

    Schistosoma mansoni is one of the parasites causing schistosomiasis, a disease which threatens millions of people all over the world. Traditional chemical drugs are not fully effective against schistosomaisis due to the evolving drug resistant worm strains, so exploring new remedies derived from natural products is a good way to fight schistosomiasis. In the present investigation two natural products, Nigella sativa oil and Chroococcus turgidus extract were used separately or in a combination to explore their effect on S. mansoni. The infected mice treated with Chroococcus turgidus extract or/and sativa seed oil showed a significant decrease in the total worm burden. The total number of deposited eggs by females of S. mansoni was significantly decreased in the liver of mice treated with Chroococcus turgidus extract or/and sativa seed oil. However, in the intestine, the number of eggs was significantly reduced in mice treated with algal extract and those treated with both algal extract and oil. Fecundity of female S. mansoni showed a significant decrease from mice treated with algal extract or/and sativa seed oil. According to SEM investigations the tegmental surface, oral and ventral suckers of worms also showed considerable changes; as the tubercles lost their spines, some are swollen and torn out. The suckers become edematous and enlarged while the tegmental surface is damaged due to the treatment with Chroococcus turgidus extract or/and sativa seed oil. In conclusion, the Nigella sativa oil and Chroococcus turgidus extract are promising natural compounds that can be used in fighting schistosomiasis.

  7. 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.

  8. 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

  9. Urban schistosomiasis: morbidity, sociodemographic characteristics and water contact patterns predictive of infection.

    PubMed

    Firmo, J O; Lima Costa, M F; Guerra, H L; Rocha, R S

    1996-12-01

    During 1991-1992 in the Gorduras district of Belo Horizonte, the capital of Minas Gerais State in Brazil, data on 451 persons over 2 years old who carried Schistosoma mansoni eggs, as detected on at least 1 of 4 slides, were compared with data on 465 same-age persons who were free of such eggs to describe the epidemiology of schistosomiasis in this urban area. The schistosome host, Biomphalaria glabrata, was present at all 11 monitored points along streams. Snails infected with S. mansoni were found at 6 points. Sewerage was entering the streams at 2 points. 92.7% of households had a piped water supply. 89.4% had a sewerage system. 20% of the 3049 sampled peoples had schistosomiasis. The geometric mean of S. mansoni eggs stood at 70.8 eggs/gram. Only 4.7% of persons infected with S. mansoni eggs had bloody stools. Less than 3% had a hardened enlarged liver. No one had splenomegaly or splenectomy. Signs and symptoms independently associated with S. mansoni infection included bloody stools (odds ratio [OR] = 8), palpable hardened liver at the middle clavicular line (OR = 5.5), and palpable hardened liver at the middle sternal line (OR = 8). Sociodemographic variables and reasons for water contact independently associated with S. mansoni infection were age (OR = 7.1 for 10-19 years; OR = 3.3 for =or + 20 years), being male (OR = 3.1), swimming and/or playing in water (OR = 2.2 for =or- 2 times/month; OR = 3 for 2 times/month), and living in Belo Horizonte (OR = 2.5). There was no association between infection and water supply. These findings suggest a need for schistosomiasis control measures centering on water contacts for leisure in this area.

  10. [Laboratory animal infection in modeling intestinal schistosomiasis].

    PubMed

    Zelia, O P

    1984-01-01

    A comparative efficiency of different regimes for infecting laboratory animals has been determined in order to find out optimal conditions under which an experimental model of intestinal schistosomiasis (infection with Schistosoma mansoni) can be maintained. When evaluating the results of laboratory definitive hosts infection we took into account the character of Schistosoma distribution in animals, which with high probability rate was modelled by means of negative binomial distribution. The main parameters of this distribution were used for determination of effective doses and methods of animals infection alongside with generally accepted indices of infection rate and intensiveness. Analysis of the data obtained has shown that the infection of 150 cercarians per mouse and 200 cercarians per golden and striped hairy-footed hamster by their subcutaneous administration creates optimal density of parasites in the host. Results of investigations have shown that striped hairy-footed hamsters can be used as definitive hosts of Schistosoma.

  11. African schistosomiasis in mainland China: risk of transmission and countermeasures to tackle the risk.

    PubMed

    Wang, Wei; Liang, You-Sheng; Hong, Qing-Biao; Dai, Jian-Rong

    2013-08-28

    Schistosomiasis is a major disease of public health importance in humans occurring in 76 countries of the tropics and sub-tropics. In China, schistosomiasis japonica is one of the highest priorities in communicable disease control defined by the central government. Since 1970s, the habitats of Biomphalaria straminea, an intermediate host of Schistosoma mansoni in South America, have been identified in Hong Kong Special Administrative Region and Shenzhen city, Guangdong province of China. With the sharp growth in the China-aided projects in Africa and labor services export to Africa, a gradual rise in the cases infected with S. haematobium or S. mansoni is reported in those returning from Africa to China. The existence of intermediate snail hosts and import of infectious source of schistosomiasis results in concern about the transmission of African schistosomiasis in mainland China in the context of global climate change. This paper evaluates the risk of transmission of African schistosomiasis in China, and proposes countermeasures and research priorities to tackle the risk.

  12. African schistosomiasis in mainland China: risk of transmission and countermeasures to tackle the risk

    PubMed Central

    2013-01-01

    Schistosomiasis is a major disease of public health importance in humans occurring in 76 countries of the tropics and sub-tropics. In China, schistosomiasis japonica is one of the highest priorities in communicable disease control defined by the central government. Since 1970s, the habitats of Biomphalaria straminea, an intermediate host of Schistosoma mansoni in South America, have been identified in Hong Kong Special Administrative Region and Shenzhen city, Guangdong province of China. With the sharp growth in the China-aided projects in Africa and labor services export to Africa, a gradual rise in the cases infected with S. haematobium or S. mansoni is reported in those returning from Africa to China. The existence of intermediate snail hosts and import of infectious source of schistosomiasis results in concern about the transmission of African schistosomiasis in mainland China in the context of global climate change. This paper evaluates the risk of transmission of African schistosomiasis in China, and proposes countermeasures and research priorities to tackle the risk. PMID:23985040

  13. 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

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

    PubMed

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

    2015-12-01

    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.

  15. 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

  16. Immunopathogenesis of human schistosomiasis.

    PubMed

    Burke, M L; Jones, M K; Gobert, G N; Li, Y S; Ellis, M K; McManus, D P

    2009-04-01

    Schistosomiasis continues to be a significant cause of parasitic morbidity and mortality worldwide. This review considers the basic features of the pathology and clinical outcomes of hepatointestinal and genitourinary schistosomiasis, presents an overview of the numerous studies on animal models that have clarified many of the immunopathological features, and provides insight into our current understanding of the immunopathogenesis and genetic control of human schistosomiasis. In murine schistosomiasis, pathology is induced by a CD4(+) Th2 driven granulomatous response directed against schistosome eggs lodged in the host liver. The Th2 cytokines IL-4 and IL-13 drive this response, whereas IL-10, IL13Ralpha2, IFN-gamma and a subset of regulatory T-cells act to limit schistosome induced pathology. A variety of cell types including hepatic stellate cells, alternatively activated macrophages and regulatory T-cells have also been implicated in the pathogenesis of schistosomiasis. Current knowledge suggests the immunopathogenic mechanisms underlying human schistosomiasis are likely to be similar. The review also considers the future development of anti-pathology schistosome vaccines. As fibrosis is an important feature of many other diseases such as Crohn's disease and sarcoidosis, a comprehensive understanding of the cellular and molecular mechanisms involved in schistosomiasis may also ultimately contribute to the development an effective disease intervention strategy for other granulofibrotic diseases.

  17. The spatial distribution of Schistosoma mansoni infection in four regions of western Côte d'Ivoire.

    PubMed

    Assaré, Rufin K; Lai, Ying-Si; Yapi, Ahoua; Tian-Bi, Yves-Nathan T; Ouattara, Mamadou; Yao, Patrick K; Knopp, Stefanie; Vounatsou, Penelope; Utzinger, Jürg; N'Goran, Eliézer K

    2015-06-03

    Schistosomiasis poses a considerable public health burden in sub- Saharan Africa and a sound understanding of the spatial distribution facilitates to better target control interventions. The objectives of this study were i) to assess the prevalence of Schistosoma mansoni among school-aged children in four regions of western Côte d'Ivoire; ii) to determine demographic, climatic and environmental factors that influence the distribution of S. mansoni; and iii) to map and predict the distribution of S. mansoni in non-sampled locations. Parasitological surveys were carried out in 264 schools from June to December 2011. In each school, we aimed to examine 50 children for S. mansoni infection using duplicate Kato-Katz thick smears. Schools were georeferenced using a hand-held global positioning system receiver. Demographic data were obtained from readily available school lists, while climatic and environmental data were extracted from open-access remote sensing databases. Multivariable, binary non-spatial models and a Bayesian geostatistical logistic regression model were used to identify demographic, climatic and environmental risk factors for S. mansoni infection. Risk maps were developed based on observed S. mansoni prevalences and using Bayesian geostatistical models to predict prevalences at non-sampled locations. Overall, 12,462 children provided a sufficiently large stool sample to perform at least one Kato-Katz thick smear. The observed overall prevalence of S. mansoni infection was 39.9%, ranging from 0 to 100% at the unit of the school. Bayesian geostatistical analysis revealed that age, sex, altitude and difference between land surface temperature at day and night were significantly associated with S. mansoni infection. The S. mansoni risk map presented here is being been used by the national schistosomiasis control programme for spatial targeting of praziquantel and other interventions.

  18. Transmission of Schistosoma mansoni in Rhino Camp, Uganda.

    PubMed

    Loroni-Lakwo, T; Odongo-Aginya, E I; Schweigmann, U; Schickerling, S; Lindner, D; Doehring-Schwerdtfeger, E

    1994-03-01

    Non-participant observations totalling 204 hours relevant to the transmission of Schistosoma mansoni infection were carried out in Rhino Camp at the shores of Albert Nile in North Uganda. A cross-sectional study of 636 individuals from Rhino Camp revealed a prevalence of S. mansoni infection of 77.8%. Occupational and domestic purposes were the most important reasons for water contact, whereas recreational purposes ranked lower and mainly concerned children. Both sexes were equally active in water contacts. A distinct preference of Nile water was noted despite availability of borehole water in the area. It is concluded that control measures against schistosomiasis have to take into consideration that water contact for recreational purposes might be minimized, whereas it is expected to be extremely difficult to reduce occupational and domestic water contacts.

  19. 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

  20. Assessment of schistosomiasis in the Dominican Republic.

    PubMed Central

    Schneider, C R; Hiatt, R A; Malek, E A; Ruiz-Tiben, E

    1985-01-01

    Active transmission of intestinal schistosomiasis is currently limited to the southeastern part of the Dominican Republic. A population-based stool survey in 1980 detected 4 asymptomatic individuals among 114 selected at random in 2 towns and a rural community in El Seibo Province. The distribution of the transmitting snail, Biomphalaria glabrata, considerably exceeds that of Schistosoma mansoni, extending to the National District and capital city of Santo Domingo and well into certain central valley provinces. There is evidence that transmission sites have shifted during the past three decades because of urban development, molluscicidal activities and, perhaps, introduction of competing mollusks. In spite of intermittent control activities, the combination of domestic and recreational use of streams with consequent fecal contamination, and the extended distribution of B. glabrata indicates that the potential for new transmission foci is as great today as it was 10 years ago. This potential transmission of S. mansoni is a continuing threat to public health in the Dominican Republic. PMID:3931167

  1. 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

  2. [Risk assessment and control measures for import of African schistosomiasis into China].

    PubMed

    Liang, You-Sheng; Wang, Wei; Hong, Qing-Biao; Dai, Jian-Rong

    2013-06-01

    The habitats of Biomphalaria straminea, the intermediate host of Schistosoma mansoni, have been found in Hong Kong Special Administrative Region and Shenzhen City of People's Republic of China. Currently, there is a sharp increase in the number of Africa-aid projects and workers moving to Africa, and more and more cases infected with S. mansoni or S. haematobium returning from African countries have been detected in China. The possibility of transmission of African schistosomiasis in Chinese mainland, in the context of global climate warming, has received much attention. This paper illustrates the risk of transmission of African schistosomiasis in China based on biological and epidemiological features, and proposes interventions to tackle the risk.

  3. Application in Europe of a urine-based rapid diagnostic test for confirmation of Schistosoma mansoni infection in migrants from endemic areas.

    PubMed

    Becker, S L; Marti, H; Zimmermann, S; Vidacek, D; Herrmann, M; Utzinger, J; Schnabel, P A; Bohle, R M

    2015-06-11

    In February 2015, a male patient from Eritrea with persistent abdominal pain and rectal bleeding was diagnosed with Schistosoma mansoni infection upon examination of a rectal biopsy. In May 2015, repeated stool microscopy identified S. mansoni infection in another Eritrean patient with abdominal pain and considerable eosinophilia (34%). Use of point-of-care circulating cathodic antigen (POC-CCA) tests on urine confirmed S. mansoni infection in both patients. Wider application of non-invasive POC-CCA urine tests will improve schistosomiasis diagnosis and clinical management in migrants.

  4. 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

  5. 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

  6. Genetic variation between Biomphalaria alexandrina snails susceptible and resistant to Schistosoma mansoni infection.

    PubMed

    El-Nassery, Suzanne M F; Abou-El-Naga, Iman F; Allam, Sonia R; Shaat, Eman A; Mady, Rasha F M

    2013-01-01

    Much effort has been made to control schistosomiasis infection in Egypt. However, enduring effects from such strategies have not yet been achieved. In this study, we sought to determine the genetic variability related to the interaction between Biomphalaria alexandrina snails and Schistosoma mansoni. Using RAPD-PCR with eight (10 mers) random primers, we were able to determine the polymorphic markers that differed between snails susceptible and resistant to Schistosoma mansoni infection using five primers out of the eight. Our results suggest that the RAPD-PCR technique is an efficient means by which to compare genomes and to detect genetic variations between schistosomiasis intermediate hosts. The RAPD technique with the above-noted primers can identify genomic markers that are specifically related to the Biomphalaria alexandrina/Schistosoma mansoni relationship in the absence of specific nucleotide sequence information. This approach could be used in epidemiologic surveys to investigate genetic diversity among Biomphalaria alexandrina snails. The ability to determine resistant markers in Biomphalaria alexandrina snails could potentially lead to further studies that use refractory snails as agents to control the spread of schistosomiasis.

  7. 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.

  8. Combination of the two schistosomal antigens Sm14 and Sm29 elicits significant protection against experimental Schistosoma mansoni infection.

    PubMed

    Ewaisha, Radwa E; Bahey-El-Din, Mohammed; Mossallam, Shereen F; Amer, Eglal I; Aboushleib, Hamida M; Khalil, Amal M

    2014-10-01

    Schistosomiasis continues to be a serious helminthic disease that is widespread in many regions in the world. Disease management relies mainly on early treatment with praziquantel, nevertheless, re-infection rates can still be high. An effective vaccine against Schistosoma mansoni is still lacking; a situation which hinders the efforts to eradicate the disease worldwide. Most investigators test S. mansoni antigens individually, rather than in combination, in their vaccine trials. A single-antigen vaccine is likely to elicit less protection against schistosomiasis than a multi-antigen vaccine. In the current study, we have selected two promising S. mansoni antigens, Sm14 and Sm29, and investigated their combination as a potential vaccine. Recombinant Sm14 and a truncated form of Sm29, designated TrSm29, were successfully expressed in Escherichiacoli. The two antigens were purified using affinity chromatography and administered to Swiss albino mice individually and in combination. Significant protection against S. mansoni infection was observed in mice immunized with the Sm14/TrSm29 combination in the presence/absence of the immunoadjuvant poly (I:C). The poly (I:C)-adjuvanted combination resulted in 40.3%, 68.2%, and 57.9% reduction in adult worm burden, liver egg burden and intestinal eggs, respectively. Granuloma size and count were also reduced besides improvement of the histopathological picture of livers of immunized mice. This study demonstrates the importance of using multi-antigen vaccines as an effective and simple approach to fulfill enhanced protection against schistosomiasis.

  9. Immunity in Schistosoma mansoni using antigens of Fasciola hepatica isolated by concanavalin A affinity chromatography.

    PubMed Central

    Hillyer, G V; Sagramoso de Ateca, L

    1979-01-01

    Antigens of Fasciola hepatica adult worms were chromatographed using concanavalin A-Sepharose 4B. Two unbound peaks appeared in the inclusion volume (DT-1 and DT-2), and one peak was eluted with alpha-methylglucoside (E1-1). At least seven peaks were obtained by isoelectric focusing of E1-1. The largest of these peaks, with an average pI of 4.0, contained the antigens reactive with antibodies to Schistosoma mansoni. Mice immunized with DT-2 or E1-1 and challenged with S. mansoni cercariae developed 39 to 82% fewer worms than controls. DT-1 had no protective effect. Combining DT-1 and DT-2 abolished this protection. These experiments demonstrate that F. hepatica glycoprotein antigens induce in mice significant protection to infection with S. mansoni and offer an interesting approach to the study of vaccines in experimental schistosomiasis. PMID:118932

  10. 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.

  11. Arginase activity in peripheral blood of patients with intestinal schistosomiasis, Wonji, Central Ethiopia.

    PubMed

    Getaneh, A; Tamrat, A; Tadesse, K

    2015-07-01

    Morbidity and mortality caused by schistosomiasis usually results from immunopathology. But the underlying mechanisms are not yet clearly understood. Th2-type immune response is thought to be dominant during chronic schistosomiasis, and upregulation of arginase-I is one component of this milieu. A cohort study was conducted to assess arginase activity in peripheral blood of humans with intestinal schistosomiasis in Wonji-Shoa Sugar Estate, Central Ethiopia. Laboratory-confirmed 30 Schistosoma mansoni-infected patients and 18 apparently healthy controls were recruited. Faecal egg count was carried out by Kato-Katz technique. Plasma and peripheral blood mononuclear cells (PBMCs) were isolated from whole blood. Activity of arginase in plasma and PBMC lysates was measured, and results were compared with that of controls. Twenty-one of 30 patients had light infection, whereas moderate and heavy intensity infections were observed in eight and only one patient(s), respectively. A significant increase in both PBMC (patients: 59.96 + 82.99, controls: 25.44 + 24.6 mU/mg protein, P < 0.0001) and plasma (patients: 1.61 + 2.19, controls: 0.31 + 0.73 mU/mL plasma, P < 0.0001) arginase activity was observed during human S. mansoni infection. Arginase activity increases in peripheral blood of patients with intestinal schistosomiasis.

  12. Schistosomiasis in Lake Malawi.

    PubMed

    Cetron, M S; Chitsulo, L; Sullivan, J J; Pilcher, J; Wilson, M; Noh, J; Tsang, V C; Hightower, A W; Addiss, D G

    1996-11-09

    Schistosomiasis is a parasitic infection caused by trematodes. Humans are infected through skin contact with free-swimming cercariae which develop in freshwater snails. Schistosomiasis has been endemic to Malawi for several decades, but the open waters and shores of Lake Malawi have long been thought to be risk-free with regard to schistosomiasis transmission. However, in 1992, two US Peace Corps volunteers developed central nervous system schistosomiasis due to infection with Schistosoma haematobium following recreational water exposure at Cape Maclear on Lake Malawi. In light of these infections, a cross-sectional survey of resident expatriates and visitors to Malawi was subsequently conducted during March-April 1993 to determine the transmission potential and risk for acquiring schistosomiasis in the lake. 305 US citizens and 650 non-US foreign nationals participated in the study. Serological evidence of current or past schistosome infection was identified in 303 subjects. Indeed, seroprevalence was 32% among expatriates whose freshwater exposure was limited to Lake Malawi; S. haematobium antibodies were found in 135 of 141 seropositive specimens. The risk of seropositivity increased with the number of freshwater exposures at Lake Malawi resorts. While many resort areas in the southwestern lake region posed a significant risk, Cape Maclear was the location most strongly associated with seropositivity. Schistosome-infected Bulinus globosus, the snail vector of S. haematobium in Malawi, were found at Cape Maclear and other locations along the lakeshore.

  13. 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

  14. Control of schistosomiasis in Brazil: perspectives and proposals.

    PubMed

    Coura, J R

    1995-01-01

    Attempts to control schistosomiasis have hitherto involved the use of one or more of the following methods, either in isolation or in combination: (1) control of the intermediate host using molluscicides or biological methods; (2) basic sanitation and clean water supply; (3) health education; (4) individual or mass treatment; (5) protection of individuals in such a way as to prevent cercariae from penetrating the skin; (6) vaccine-based strategies against schistosomiasis. None of these methods is capable, on its own, of bringing about effective control of schistosomiasis, except in populations of a very limited size or under very special conditions. Molluscicides, besides expensive and toxic, have only a temporary effect. As for biological control, there is no effective method yet. Basic sanitation and clean water supply combined with health education potentially constitute the most effective approach, but only in the mid-to-long term. Mass treatment reduces morbidity, but does not control transmission. Protection of individuals has proved to be impracticable on a large scale. Vaccine-based strategies against schistosomiasis are still in the experimental stage. Experiments carried out in Brazil in the last 20 years have shown that mass treatment with single doses of oxamniquine or praziquantel can rapidly reduce levels of Shistosoma mansoni infection and morbidity in endemic areas. They have also shown that subsequent transmission and reinfection frequently occur in defined foci or "clusters", due to human contact with water, and in inverse proportion to the number and frequency of treatments carried out. On the basis of these experiments, the author suggests a multidisciplinary strategy for schistosomiasis control.

  15. Use of Molecular Methods for the Rapid Mass Detection of Schistosoma mansoni (Platyhelminthes: Trematoda) in Biomphalaria spp. (Gastropoda: Planorbidae)

    PubMed Central

    Jannotti-Passos, Liana Konovaloffi; Dos Santos Carvalho, Omar

    2017-01-01

    The low stringency-polymerase chain reaction (LS-PCR) and loop-mediated isothermal amplification (LAMP) assays were used to detect the presence of S. mansoni DNA in (1) Brazilian intermediate hosts (Biomphalaria glabrata, B. straminea, and B. tenagophila) with patent S. mansoni infections, (2) B. glabrata snails with prepatent S. mansoni infections, (3) various mixtures of infected and noninfected snails; and (4) snails infected with other trematode species. The assays showed high sensitivity and specificity and could detect S. mansoni DNA when one positive snail was included in a pool of 1,000 negative specimens of Biomphalaria. These molecular approaches can provide a low-cost, effective, and rapid method for detecting the presence of S. mansoni in pooled samples of field-collected Biomphalaria. These assays should aid mapping of transmission sites in endemic areas, especially in low prevalence regions and improve schistosomiasis surveillance. It will be a useful tool to monitor low infection rates of snails in areas where control interventions are leading towards the elimination of schistosomiasis. PMID:28246533

  16. Surgical pathology of schistosomiasis.

    PubMed Central

    Mohammed, Aminu Z.; Edino, Steven T.; Samaila, Adamu A.

    2007-01-01

    Schistosomiasis remains an important health problem in many tropical countries and is being seen with increasing frequency in immigrant populations and tourists in developed countries. The pattern of organ involvement and clinical presentation of schistosomiasis in 80 patients (male: female, 9:1) during a five-year period (2001-2005) was examined from archival histopathology records. The urinary bladder was the most common organ affected [50 (62.5%)]. Gastrointestinal, male and female genital schistosomiasis were detected in 12 (15%), eight (10%) and five (6.1%) cases, respectively. Hematuria was the most common presenting symptom [34 (42.5%)], and bladder cancer was the only malignancy found to be associated with the infection. A high clinical index of suspicion usually allows for a preoperative diagnosis where indicated and avoidance of radical surgery. While research for the development of an effective vaccine continues, a plea is made for the expansion of multinational control programs in sub-Saharan Africa. PMID:17534016

  17. Schistosomiasis: Traverers in Africa.

    PubMed

    Strohmayer, Jeremy; Matthews, Ian; Locke, Robert

    2016-01-01

    Schistosomiasis is a parasitic infection acquired through freshwater exposure in the tropics. It is an infection that can have devastating implications to military personnel if it is not recognized and treated, especially later in life. While there is an abundance of information available about schistosomiasis in endemic populations, the information on nonendemic populations, such as deployers, is insufficient. Definitive studies for this population are lacking, but there are actions that can and should be taken to prevent infection and to treat patients. This literary review presents a case study, reviews basic science, and explores the information available about schistosomiasis in nonendemic populations. Specifically, the authors provide recommendations for the prevention, diagnosis, and postexposure management in military personnel.

  18. Questionnaires in the screening for Schistosoma mansoni infection: a study of socio demographic and water contact variables in four communities in Brazil.

    PubMed

    Lima e Costa, M F; Rocha, R S; Firmo, J O; Guerra, H L; Passos, V A; Katz, N

    1998-01-01

    The use of questionnaires has been recommended for identifying, at a lower cost, individuals at risk for schistosomiasis. In this study, validity of information obtained by questionnaire in the screening for Schistosoma mansoni infection was assessed in four communities in the State of Minas Gerais, Brazil. Explanatory variables were water contact activities, sociodemographic characteristics and previous treatment for schistosomiasis. From 677, 1474, 766 and 3290 individuals eligible for stool examination in the communities, 89 to 97% participated in the study. The estimated probability of individuals to be infected, if they have all characteristics identified as independently associated with S.mansoni infection, varied from 15% in Canabrava, to 42% in Belo Horizonte, 48% in Comercinho and 80% in São José do Acácio. Our results do not support the hypothesis that a same questionnaire on risk factors could be used in screening for S.mansoni infection in different communities.

  19. Accessibility to and utilisation of schistosomiasis-related health services in a rural area of state of Minas Gerais, Brazil.

    PubMed

    Reis, Dener Carlos dos; Kloos, Helmut; King, Charles; Quites, Humberto Ferreira Oliveira; Matoso, Leonardo Ferreira; Coelho, Kellen Rosa; Gazzinelli, Andrea

    2010-07-01

    The objective of the present paper was to compare accessibility and utilisation of schistosomiasis diagnostic and treatment services in a small village and the surrounding rural area in northern part of the state of Minas Gerais Brazil. The study included 1,228 individuals: 935 central village residents and 293 rural residents of São Pedro do Jequitinhonha. Schistosoma mansoni infection rates were significantly higher in the central village than in the rural area during a survey in 2007 (44.3% and 23.5%, respectively) and during the 2002 schistosomiasis case-finding campaign (33.1% and 26.5%, respectively) (p < 0.001). However, during the 2002-2006 period, only 23.7% of the villagers and 27% of the rural residents obtained tests on their own from health centres, hospitals and private clinics in various nearby towns. In 2007, 63% of the villagers and 70.5% of the rural residents reported never having received treatment for schistosomiasis. This paper reveals considerable variation in the accessibility and utilisation of schistosomiasis-related health services between the central village and the rural area. A combination of low utilisation rates between 2002-2006 and persistently high S. mansoni infection rates suggest that the schistosomiasis control program must be more rapidly incorporated into the primary health services.

  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. Impact of schistosomiasis on increase incidence of occult hepatitis B in chronic hepatitis C patients in Egypt.

    PubMed

    Omar, Hanan H; Taha, Samaa A; Hassan, Wafaa H; Omar, Hamdy H

    2017-02-09

    Co-infection of schistosomiasis, HBV and HCV is common in countries where schistosomiasis is endemic. Occult hepatitis B occurs in patients at high risk for HBV infection (e.g., patients on hemodialysis, patients receiving blood transfusions). Schistosomal infection is a risk factor of HBV infection that can increase the incidence of occult hepatitis B. We aimed to determine the prevalence of occult hepatitis B in chronic hepatitis C patients with and without schistosomiasis and to assess the effect of schistosomal infection on the increased risk of exposure to HBV infection and to occult hepatitis B. Two hundred chronic hepatitis C patients who were negative for HBsAg participated. All patients were tested for the following: Anti-schistosome antibodies, Anti-HBc, serum HBV DNA, CBC and liver function. The prevalence of occult hepatitis B in CHC patients with/without schistosomiasis were 12.8% and 8.5% (P=0.042), respectively. Next, 63.8% of CHC patients with schistosomiasis were exposed to HBV infection (Anti-HBc +ve) during their lifetime. In conclusion, the prevalence of occult hepatitis B is higher in CHC patients with schistosomiasis compared to those without schistosomiasis. Periodic laboratory investigations of Schistosoma mansoni, HBV and HCV are recommended for the early detection of the infection and, especially in endemic areas, to avoid infection complications.

  2. CHARACTERIZATION OF THE METHIONINE SULFOXIDE REDUCTASES OF SCHISTOSOMA MANSONI

    PubMed Central

    Oke, Tolulope T.; Moskovitz, Jackob; Williams, David L.

    2013-01-01

    Schistosomiasis, also known as Bilharzia, is an infectious disease caused by several species of Schistosoma. Twenty million individuals suffer severe symptoms and 200,000 people die annually from the disease. The host responds to the presence of S. mansoni by producing reactive oxygen species that cause oxidative stress. We hypothesized that schistosomes produce antioxidants in response to oxidative stress. A known antioxidant protein is methionine sulfoxide reductase (Msr). Methionine residues can be oxidized to methionine sulfoxide in the presence of oxidizing agents, which is readily reversed by the action of the Msr system. Two S. mansoni MsrB genes (MsrB1 and MsrB2) were cloned and the recombinant proteins expressed in bacteria and purified. The S. mansoni MsrB proteins contained the common conserved catalytic and zinc coordinating cysteines. Analysis of the proteins showed that both proteins promote the reduction of both free methionine sulfoxide (Met[O]) and dabsyl-Met(O) to free methionine (Met) and dabsyl-Met, respectively, while exhibiting differences in their specific activities towards these substrates. Using real-time PCR, both proteins were found to be expressed in all stages of the parasite’s life cycle with the highest level of expression of both proteins in the egg stage. This is the first description of MsrB proteins from a parasite. PMID:19604033

  3. A Schistosomiasis Research Agenda

    PubMed Central

    Colley, Daniel G.; Secor, W. Evan

    2007-01-01

    There is a long and rich history of research and control in the field of schistosomiasis that has resulted in major scientific and public health accomplishments. Examples of such findings and accomplishments include immunologic regulation in chronic infections [1], the association of helminth infections with Th1-regulating Th2-type immune responses [2], the critical role of interleukin-13 in fibrogenesis [3], and the development and validation of the “dose pole” for determining praziquantel dosages in the field [4],[5]. Perhaps in part because of this broad and successful history, those who work on schistosomiasis come from a wide variety of backgrounds and interests. While such variety is enriching to the field, it sometimes results in diverse opinions about which of the many research opportunities should be pursued. Such diversity, we believe, has at times led to a divisiveness that has harmed overall progress in the field. Partly in response to such events, we have worked with as many of those interested in schistosomiasis as we could identify to develop what we feel is a comprehensive and cohesive agenda for schistosomiasis research (Image 1). PMID:18060081

  4. Schistosoma mansoni cercariae swim efficiently by exploiting an elastohydrodynamic coupling

    NASA Astrophysics Data System (ADS)

    Krishnamurthy, Deepak; Katsikis, Georgios; Bhargava, Arjun; Prakash, Manu

    2016-10-01

    The motility of many parasites is critical for infecting their host, as exemplified in the transmission cycle of the parasite Schistosoma mansoni. In its human infectious stage, submillimetre-scale forms of the parasite known as cercariae swim in freshwater and infect humans by penetrating the skin. This infection causes schistosomiasis, a disease comparable to malaria in global socio-economic impact. Given that cercariae do not feed and hence have a lifetime of around 12 hours, efficient motility is crucial for schistosomiasis transmission. Despite this, a first-principles understanding of how cercariae swim is lacking. Combining biological experiments, a novel theoretical model and its robotic realization, we show that cercariae use their forked tail to swim against gravity using a novel swimming gait, described here as a `T-swimmer gait'. During this gait, cercariae beat their tail periodically while maintaining an increased flexibility near their posterior and anterior ends. This flexibility allows an interaction between fluid drag and bending resistance--an elastohydrodynamic coupling, to naturally break time-reversal symmetry and enable locomotion at small length scales. Finally, we find that cercariae maintain this flexibility at an optimal regime for efficient swimming. We anticipate that our work sets the ground for linking the swimming of cercariae to disease transmission, and could potentially enable explorations of novel strategies for schistosomiasis control and prevention.

  5. Schistosomiasis and soil-transmitted helminthiasis in Rwanda: an update on their epidemiology and control.

    PubMed

    Rujeni, Nadine; Morona, Domenica; Ruberanziza, Eugene; Mazigo, Humphrey D

    2017-03-01

    Even though Rwanda lies within a region that has a high prevalence of schistosomiasis and soil-transmitted helminth (STH) infections, epidemiological information regarding these infections in the country remains scarce. The present review attempts to compile the available data on schistosomiasis and STHs, from 1940 to 2014, to provide an insight on the epidemiological profile of these infections. This information will, in turn, support the design and implementation of sustainable control measures. The available records indicate that only Schistosoma mansoni and all the major species of STHs are endemic in Rwanda. In 2008, the national prevalence of S. mansoni was reported to be 2.7%, ranging from 0 to 69.5%, and that of STH infections was 65.8% (diagnosed using the Kato-Katz technique). The prevalence of these infections varies from one district to another, with schoolchildren remaining a highly affected group. The main control approach is mass drug administration using albendazole and praziquantel, mostly targeting school-aged children in school environments. In 2008, adult individuals living in areas with a prevalence of S. mansoni ≥30% were also included in the mass drug administration programme. However, despite Rwanda achieving an almost 100% coverage of this programme in 2008-2010, the transmission of S. mansoni and STHs continues to take place, as illustrated by the most recent surveys. If Rwanda is to achieve sustainable control and elimination of schistosomiasis and STHs, there is a need to revise the country's control strategy and adopt an integrated control approach that involves a combination of measures.

  6. Galectin-3, histone deacetylases, and Hedgehog signaling: Possible convergent targets in schistosomiasis-induced liver fibrosis.

    PubMed

    de Oliveira, Felipe Leite; Carneiro, Katia; Brito, José Marques; Cabanel, Mariana; Pereira, Jonathas Xavier; Paiva, Ligia de Almeida; Syn, Wingkin; Henderson, Neil C; El-Cheikh, Marcia Cury

    2017-02-01

    Schistosomiasis affects approximately 240 million people in the world. Schistosoma mansoni eggs in the liver induce periportal fibrosis and hepatic failure driven by monocyte recruitment and macrophage activation, resulting in robust Th2 response. Here, we suggested a possible involvement of Galectin-3 (Gal-3), histone deacetylases (HDACs), and Hedgehog (Hh) signaling with macrophage activation during Th1/Th2 immune responses, fibrogranuloma reaction, and tissue repair during schistosomiasis. Gal-3 is highly expressed by liver macrophages (Kupffer cells) around Schistosoma eggs. HDACs and Hh regulate macrophage polarization and hepatic stellate cell activation during schistosomiasis-associated fibrogenesis. Previously, we demonstrated an abnormal extracellular matrix distribution in the liver that correlated with atypical monocyte-macrophage differentiation in S. mansoni-infected, Gal-3-deficient (Lgals3-/-) mice. New findings explored in this review focus on the chronic phase, when wild-type (Lgals3+/+) and Lgals3-/- mice were analyzed 90 days after cercariae infection. In Lgals3-/- infected mice, there was significant inflammatory infiltration with myeloid cells associated with egg destruction (hematoxylin and eosin staining), phagocytes (specifically Kupffer cells), numerically reduced and diffuse matrix extracellular deposition in fibrotic areas (Gomori trichrome staining), and severe disorganization of collagen fibers surrounding the S. mansoni eggs (reticulin staining). Granuloma-derived stromal cells (GR cells) of Lgals3-/- infected mice expressed lower levels of alpha smooth muscle actin (α-SMA) and eotaxin and higher levels of IL-4 than Lgals3+/+ mice (real-time PCR). The relevant participation of macrophages in these events led us to suggest distinct mechanisms of activation that culminate in defective fibrosis in the liver of Lgals3-/- infected mice. These aspects were discussed in this review, as well as the possible interference between Gal-3, HDACs

  7. Galectin-3, histone deacetylases, and Hedgehog signaling: Possible convergent targets in schistosomiasis-induced liver fibrosis

    PubMed Central

    de Oliveira, Felipe Leite; Carneiro, Katia; Brito, José Marques; Cabanel, Mariana; Pereira, Jonathas Xavier; Paiva, Ligia de Almeida; Syn, Wingkin; Henderson, Neil C.; El-Cheikh, Marcia Cury

    2017-01-01

    Schistosomiasis affects approximately 240 million people in the world. Schistosoma mansoni eggs in the liver induce periportal fibrosis and hepatic failure driven by monocyte recruitment and macrophage activation, resulting in robust Th2 response. Here, we suggested a possible involvement of Galectin-3 (Gal-3), histone deacetylases (HDACs), and Hedgehog (Hh) signaling with macrophage activation during Th1/Th2 immune responses, fibrogranuloma reaction, and tissue repair during schistosomiasis. Gal-3 is highly expressed by liver macrophages (Kupffer cells) around Schistosoma eggs. HDACs and Hh regulate macrophage polarization and hepatic stellate cell activation during schistosomiasis-associated fibrogenesis. Previously, we demonstrated an abnormal extracellular matrix distribution in the liver that correlated with atypical monocyte–macrophage differentiation in S. mansoni-infected, Gal-3-deficient (Lgals3-/-) mice. New findings explored in this review focus on the chronic phase, when wild-type (Lgals3+/+) and Lgals3-/- mice were analyzed 90 days after cercariae infection. In Lgals3-/- infected mice, there was significant inflammatory infiltration with myeloid cells associated with egg destruction (hematoxylin and eosin staining), phagocytes (specifically Kupffer cells), numerically reduced and diffuse matrix extracellular deposition in fibrotic areas (Gomori trichrome staining), and severe disorganization of collagen fibers surrounding the S. mansoni eggs (reticulin staining). Granuloma-derived stromal cells (GR cells) of Lgals3-/- infected mice expressed lower levels of alpha smooth muscle actin (α-SMA) and eotaxin and higher levels of IL-4 than Lgals3+/+ mice (real-time PCR). The relevant participation of macrophages in these events led us to suggest distinct mechanisms of activation that culminate in defective fibrosis in the liver of Lgals3-/- infected mice. These aspects were discussed in this review, as well as the possible interference between Gal-3, HDACs

  8. Biompha-LAMP: A New Rapid Loop-Mediated Isothermal Amplification Assay for Detecting Schistosoma mansoni in Biomphalaria glabrata Snail Host

    PubMed Central

    Hernández-Goenaga, Juan; López-Abán, Julio; Vicente, Belén; Muro, Antonio

    2016-01-01

    Background Schistosomiasis remains one of the most common endemic parasitic diseases affecting over 230 million people worlwide. Schistosoma mansoni is the main species causing intestinal and hepatic schistosomiasis and the fresh water pulmonate snails of the genus Biomphalaria are best known for their role as intermediate hosts of the parasite. The development of new molecular monitoring assays for large-scale screening of snails from transmission sites to detect the presence of schistosomes is an important point to consider for snail control interventions related to schistosomiasis elimination. Our work was focussed on developing and evaluating a new LAMP assay combined with a simple DNA extraction method to detect S. mansoni in experimentally infected snails as a diagnostic tool for field conditions. Methodology/Principal findings A LAMP assay using a set of six primers targeting a sequence of S. mansoni ribosomal intergenic spacer 28S-18S rRNA was designed. The detection limit of the LAMP assay was 0.1 fg of S. mansoni DNA at 63°C for 50 minutes. LAMP was evaluated by examining S. mansoni DNA in B. glabrata snails experimentally exposed to miracidia at different times post-exposure: early prepatent period (before cercarial shedding), light infections (snails exposed to a low number of miracidia) and detection of infected snails in pooled samples (within a group of uninfected snails). DNA for LAMP assays was obtained by using a commercial DNA extraction kit or a simple heat NaOH extraction method. We detected S. mansoni DNA in all groups of snails by using no complicated requirement procedure for DNA obtaining. Conclusions/Significance Our LAMP assay, named Biompha-LAMP, is specific, sensitive, rapid and potentially adaptable as a cost-effective method for screening of intermediate hosts infected with S. mansoni in both individual snails and pooled samples. The assay could be suitable for large-scale field surveys for schistosomes control campaigns in endemic

  9. Schistosomiasis in Lake Malaŵi villages.

    PubMed

    Madsen, Henry; Bloch, Paul; Makaula, Peter; Phiri, Happy; Furu, Peter; Stauffer, Jay R

    2011-06-01

    Historically, open shorelines of Lake Malaŵi were free from schistosome, Schistosoma haematobium, transmission, but this changed in the mid-1980s, possibly as a result of over-fishing reducing density of molluscivore fishes. Very little information is available on schistosome infections among people in lake-shore communities and therefore we decided to summarise data collected from 1998 to 2007. Detailed knowledge of the transmission patterns is essential to design a holistic approach to schistosomiasis control involving the public health, fisheries and tourism sectors. On Nankumba Peninsula, in the southern part of the lake, inhabitants of villages located along the shores of Lake Malaŵi have higher prevalence of S. haematobium infection than those living in inland villages. Overall prevalence (all age classes combined) of urinary schistosomiasis in 1998/1999 ranged from 10.2% to 26.4% in inland villages and from 21.0% to 72.7% in lakeshore villages; for school children prevalence of infection ranged from 15.3% to 57.1% in inland schools and from 56.2% to 94.0% in lakeshore schools. Inhabitants on the islands, Chizumulu and Likoma, also have lower prevalence of infection than those living in lakeshore villages on Nankumba Peninsula. This increased prevalence in lakeshore villages is not necessarily linked to transmission taking place in the lake itself, but could also be due to the presence of more numerous typical inland transmission sites (e.g., streams, ponds) being close to the lake. Temporal data witness of intense transmission in some lakeshore villages with 30-40% of children cleared from infection becoming reinfected 12 months later (also lakeshore village). The level of S. mansoni infection is low in the lakeshore communities. Findings are discussed in relation to fishing in the lake.

  10. Amelioration of Murine Schistosoma mansoni Induced Liver Fibrosis by Mesenchymal Stem Cells.

    PubMed

    Abdel Aziz, Mt; Atta, Hm; Roshdy, Nk; Rashed, LA; Sabry, D; Hassouna, Aa; Aboul Fotouh, Gi; Hasan, Nm; Younis, Rh; Chowdhury, Jr

    2012-01-01

    Schistosomiasis is a common chronic helminthic infection of the liver that causes hepatic fibrosis and portal hypertension,contributing to the death of over half a million people a year. Infusion of autologous bone marrow cells into patients with hepatic cirrhosis has been reported to ameliorate symptoms of portal hypertension and improve liver function, either by conversion of the infused mesenchymal stem cells (MSCs) to hepatocytes or by modulating of the hepatic fibrosis. Here,we have investigated the antifibrotic effect of mesenchymal stem cells (MSCs) using S. mansoni-induced liver fibrosis in mice, which causes an intense, stable fibrosis. MSCs derived from bone marrow of male mice were then infused intravenously into female mice that had received intraperitoneal injection of S.mansoni cercariae. Mice were divided into 4 groups: Untreated control; MSCs infusion only; Schistosomiasis only; and Schistosomiasis plus MSCs infusion. Serum alanine aminotransferase (ALT) and liver histopathology were evaluated. Expression of the collagen gene (type I),transforming growth factor (TGF-β), matrix metalloproteinase (MMP2), tissue inhibitor of metalloproteinase (TIMP-1),stromal cell-derived factor-1(SDF-1) and its receptor (CXCR4) were analyzed. MSC infusion resulted in significant decrease in liver collagen and TGF-β gene expression in the Schistosomiasis mice. The ratio of MMP-2 to TIMP-1 expression increased. SDF-1 and CXCR4 mRNA expression also increased. There was overall improvement of liver histology and a statistically significant reduction of serum ALT level. MSCs infusion ameliorated S. mansoni-induced liver fibrosis, probably by modulating the relative expression of MMP and TIMP. The findings support the hypothesis that MSCs participate in liver regeneration and functional improvement by reducing liver fibrosis.

  11. Efficacy of praziquantel and reinfection patterns in single and mixed infection foci for intestinal and urogenital schistosomiasis in Cameroon.

    PubMed

    Tchuem Tchuenté, Louis-Albert; Momo, Sabine C; Stothard, J Russell; Rollinson, David

    2013-11-01

    The regular administration of the anthelminthic drug praziquantel (PZQ) to school-aged children (and other high-risk groups) is the cornerstone of schistosomiasis control. Whilst the performance of PZQ against single schistosome species infections is well-known, performance against mixed species infections is less so, as are patterns of re-infection following treatment. To address this, a study using a double treatment with PZQ, administered at 40 mg/kg spaced by 3 weeks, took place in two mixed intestinal-urogenital schistosomiasis foci in northern Cameroon (Bessoum and Ouro-Doukoudje) and in one single intestinal schistosomiasis infection focus (Makenene). A total of just under 1000 children were examined and the Schistosoma-infected children were re-examined at several parasitological follow-ups over a 1-year period posttreatment. Overall cure rates against Schistosoma spp. in the three settings were good, 83.3% (95% confidence interval (CI)=77.9-87.7%) in Bessoum, 89.0% (95% CI=79.1-94.6%) in Ouro Doukoudje, and 95.3% (95% CI=89.5-98.0%) in Makenene. Interestingly, no case of mixed schistosome infection was found after treatment. Cure rates for S. mansoni varied from 99.5% to 100%, while that for S. haematobium were considerably lower, varying from 82.7% to 88.0%. Across transmission settings, patterns of re-infection for each schistosome species were different such that generalizations across foci were difficult. For example, at the 6-month follow-up, re-infection rates were higher for S. haematobium than for S. mansoni with re-infection rates for S. haematobium varying from 9.5% to 66.7%, while for S. mansoni, lower rates were observed, ranging between nil and 24.5%. At the 12-month follow-up, re-infection rates varied from 9.1% to 66.7% for S. haematobium and from nil to 27.6% for S. mansoni. Alongside these parasitological studies, concurrent malacological surveys took place to monitor the presence of intermediate host snails of schistosomiasis. In the two

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

    PubMed

    Coelho, Pmz; Caldeira, R L

    2016-07-04

    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.

  13. Use of circulating cathodic antigen (CCA) dipsticks for detection of intestinal and urinary schistosomiasis.

    PubMed

    Stothard, J Russell; Kabatereine, Narcis B; Tukahebwa, Edridah M; Kazibwe, Francis; Rollinson, David; Mathieson, William; Webster, Joanne P; Fenwick, Alan

    2006-02-01

    An evaluation of a commercially available antigen capture dipstick that detects schistosome circulating cathodic antigen (CCA) in urine was conducted in representative endemic areas for intestinal and urinary schistosomiasis in Uganda and Zanzibar, respectively. Under field-based conditions, the sensitivity (SS) and specificity (SP) of the dipstick was 83 and 81% for detection of Schistosoma mansoni infections while positive predictive (PPV) and negative predictive values (NPV) were 84%. Light egg-positive infections were sometimes CCA-negative while CCA-positives included egg-negative children. A positive association between faecal egg output and intensity of CCA test band was observed. Estimating prevalence of intestinal schistosomiasis by school with dipsticks was highly correlated (r=0.95) with Kato-Katz stool examinations, typically within +/-8.5%. In Zanzibar, however, dipsticks totally failed to detect S. haematobium despite examining children with egg-patent schistosomiasis. This was also later corroborated by further surveys in Niger and Burkina Faso. Laboratory testing of dipsticks with aqueous adult worm lysates from several reference species showed correct functioning, however, dipsticks failed to detect CCA in urine from S. haematobium-infected hamsters. While CCA dipsticks are a good alternative, or complement, to stool microscopy for field diagnosis of intestinal schistosomiasis, they have no proven value for field diagnosis of urinary schistosomiasis. At approximately 2.6 US dollars per dipstick, they are presently too expensive to be cost-effective for wide scale use in disease mapping surveys unless Lot Quality Assurance Sampling (LQAS) strategies are developed.

  14. 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.

  15. Immunological Approach in Schistosomiasis.

    DTIC Science & Technology

    1979-06-01

    study during the last year ,Study No. 1 with reference to our last report of 1978 immunization experiments with high doses of irrad- iation with Cobalt ...doses of cobalt . 60 irradiated cercariae was carried out The results were rather encouraging yet follow up of immunized animals failed to give...strain Cercariae : - Pooled cercariae from large numbers of Planorbis boissyi snails infected with an Egyptian strain of S.mansoni . Cobalt 60

  16. 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.

  17. 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

  18. Successful detection, expression and purification of the alternatively spliced truncated Sm14 antigen of an Egyptian strain of Schistosoma mansoni.

    PubMed

    Ewaisha, R E; Bahey-El-Din, M; Mossallam, S F; Khalil, A M; Aboushleib, H M

    2015-11-01

    Schistosoma mansoni causes intestinal schistosomiasis, a disease that is prevalent in several regions worldwide. To date, a protective vaccine against S. mansoni is still lacking. Several promising antigens have been discovered and evaluated for vaccine protection, such as Sm14 and Sm28GST. In this short communication, we report the successful detection of an alternatively spliced truncated form of Sm14 which was highly expressed in an Egyptian strain of S. mansoni. This truncated Sm14 (TrSm14) protein was formerly reported to be practically non-existent and its complementary DNA (cDNA) was thought to be 'a rare misprocessing of mRNA precursor'. Our finding demonstrates that there is inter-strain variation in the S. mansoni transcriptome and subsequently in the role/function of the expressed proteins. We expressed TrSm14 successfully in Escherichia coli as a fusion protein with the schistosomal antigen Sm28GST. The fusion protein was purified using metal affinity chromatography and was found to be reactive with serum from S. mansoni-infected patients. This suggests a possible diagnostic value for this protein in detection of anti-schistosomal antibodies. In addition, this fusion protein could offer a potential bivalent vaccine candidate against S. mansoni that is worthy of further investigation.

  19. 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

  20. Immunological and parasitological parameters in Schistosoma mansoni-infected mice treated with crude extract from the leaves of Mentha x piperita L.

    PubMed

    Dejani, Naiara N; Souza, Laís C; Oliveira, Sandra R P; Neris, Débora M; Rodolpho, Joice M A; Correia, Ricardo O; Rodrigues, Vanderlei; Sacramento, Luis V S; Faccioli, Lúcia H; Afonso, Ana; Anibal, Fernanda F

    2014-08-01

    Schistosomiasis is a chronic disease caused by an intravascular trematode of the genus Schistosoma. Praziquantel is the drug used for treatment of schistosomiasis; nevertheless failure of treatment has been reported. Consequently, the identification of new effective schistosomicidal compounds is essential to ensure the effective control of schistosomiasis in the future. In this work we investigated the immunomodulatory and antiparasitic effects of the crude leaves extract of Mentha x piperita L. (peppermint) on murine Schistosomiasis mansoni. Female Balb/c mice were infected each with 50 S. mansoni cercariae and divided into three experimental groups: (I) untreated; (II) treated daily with M. x piperita L. (100mg/kg) and III) treated on 1/42/43 days post-infection with Praziquantel (500mg/kg). Another group with uninfected and untreated mice was used as a control. Subsequently, seven weeks post-infection, S. mansoni eggs were counted in the feces, liver and intestine. Worms were recovered by perfusion of the hepatic portal system and counted. Sera levels of IL-10, IL-5, IL-13, IFN-γ, IgG1, IgE and IgG2a were assayed by ELISA. Animals treated with a daily dose of M. x piperita L. showed increased sera levels of IL-10, IFN-γ, IgG2a and IgE. Besides, M. x piperita L. treatment promoted reduction in parasite burden by 35.2% and significant decrease in egg counts in the feces and intestine.

  1. 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.

  2. Immunoaffinity fractionation of Schistosoma mansoni worm antigens using human antibodies and its application for serodiagnosis.

    PubMed Central

    Boctor, F N; Shaheen, H I

    1986-01-01

    A crude Schistosoma mansoni soluble worm antigen preparation (SWAP) was fractionated using an immunoaffinity column consisting of specific human anti-SWAP antibodies obtained from chronic S. mansoni-infected human sera and bound to CNBr-activated Sepharose 4B. The chromatographic separation resulted in three fractions: the unbound material (FW), and the eluted antigens with glycine-HCl (F1) and glycine-HCl-NaCl (F2). Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) showed that the purified antigens F1 and F2 consisted of several bands when stained with Coomassie blue and silver stain, with molecular weights between 20 X 10(3) and 200 X 10(3). The F1 and F2 fractions in addition to FW and SWAP were used in an enzyme-linked immunosorbent assay (ELISA) to measure antibody levels in sera from schistosomiasis patients. Each individual serum assessed with the purified F2 antigen gave 100% positivity and three to four times higher optical density in comparison to SWAP with only 88% positivity. No detectable cross-reactive antibodies against F2 were found when a limited number of sera from filariasis, fascioliasis and trichinellosis patients were screened. Furthermore, F2 was also used and found to be more sensitive generally in detecting anti-adult worm antibodies than SWAP in recently schistosomiasis-infected persons. Thus, F2 appears to be a highly sensitive and specific reagent for the serodiagnosis of schistosomiasis infection. Images Figure 3 Figure 7 PMID:3082749

  3. Spotlight on the in vitro effect of artemisinin-naphthoquine phosphate on Schistosoma mansoni and its snail host Biomphalaria alexandrina.

    PubMed

    El-Beshbishi, Samar N; El Bardicy, Samia; Tadros, Menerva; Ayoub, Magda; Taman, Amira

    2015-01-01

    Malaria and schistosomiasis are the two most important parasitic diseases in the tropics and sub-tropics with geographic overlap. Efforts have been made for developing new schistosomicidal drugs, or testing existing drugs originally used for non-related diseases. The antimalarial artemisinin-naphthoquine phosphate combination (CO-ArNp) was recently reported to be a promising novel antischistosomal therapy with potent in vivo activity against Schistosoma mansoni. In this work, we report the in vitro dose- and time-response effect of CO-ArNp against the Egyptian strain of S. mansoni, and its snail host, Biomphalaria alexandrina. Incubation of adult S. mansoni with CO-ArNp at 40 or 20 μg/ml for 48 or 72 h killed all worms. Exposure of S. mansoni miracidia and cercariae to the molluscicidal LC50 of CO-ArNp (16.8 μg/ml) resulted in 100% mortality of the free larval stages within 90 and 15 min, respectively. Moreover, incubation of adult B. alexandrina snails with this drug combination killed all snails at 40 μg/ml within 24h. Scanning electron microscope revealed marked morphological and tegumental alterations on the different stages of the parasite and its snail soft tissue. Our study highlights the schistosomicidal and molluscicidal effects of artemisinin-naphthoquine phosphate. No doubt more studies are needed to clarify its potential value to control schistosomiasis.

  4. 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

  5. Portal vein thrombosis associated with protein C deficiency and elevated Factor VIII in hepatosplenic schistosomiasis.

    PubMed

    Leite, Luiz Arthur Calheiros; Ferreira, Rita de Cássia dos Santos; Hatzlhofer, Betânia Lucena Domingues; Correia, Maria Conceição Barros; Bandeira, Ângela Pontes; Owen, James Stuart; Lima, Vera Lúcia de Menezes; Domingues, Ana Lúcia Coutinho; Lopes, Edmundo Pessoa

    2016-03-01

    Portal vein thrombosis is considered a vaso-occlusive process that can appear during the course of hepatosplenic Schistosoma mansoni, but may result from impaired portal blood flow or be associated with acquired or inherited thrombophilic factors. Here, we report the case of a 67-year-old woman who developed thrombocytopenia as a result of hypersplenism. Following the diagnosis of hepatosplenic schistosomiasis, portal vein thrombosis was detected by ultrasound examination, while haematological tests revealed low levels of protein C (43.3%) and high levels of factor VIII (183.1%). The pathogenesis of portal vein thrombosis remains unclear in some patients with S. mansoni. We recommend, therefore, that early clinical and haemostatic investigations are done to evaluate risk of portal vein thrombosis and hence avoid further complications.

  6. Ineffectiveness of myrrh-derivative Mirazid against schistosomiasis and fascioliasis in humans.

    PubMed

    Osman, M M; El-Taweel, H A; Shehab, A Y; Farag, H F

    2010-09-01

    The present study assessed the schistosomicidal and fasciolicidal actions of the myrrh-derivative Mirazid in an area of low schistosomiasis transmission. A total of 27 patients infected with Schistosoma mansoni and 16 with Fasciola spp. received the maximum recommended dose of Mirazid. Pretreatment egg counts in 4 Kato-Katz slides were compared with similar counts in stool samples collected 1 and 2 months after treatment. Standard procedures and quality control measures were followed. The results revealed that Mirazid used as schistosomicidal or fasciolicidal agent in the maximum recommended dose has a low cure rate and produced a negligible reduction in egg counts. Prescribing such an ineffective drug in Egypt might endanger the achievements of the schistosomiasis control strategy.

  7. Cutaneous immediate and late phase reactions to schistosomin in schistosomiasis patients.

    PubMed

    Marotto, P C; Michalany, N S; Vilela, M P; Mendes, N F; Mendes, E

    1995-01-01

    Cutaneous immediate and late phase reactions (LPR) to schistosomin were studied in 29 patients with schistosomiasis mansoni. In 12 of these patients, the determination of total and specific serum IgE by immunoenzymatic method against schistosome antigen was carried out using serum samples obtained on the same day as the cutaneous tests. Skin biopsies were taken from 4 typical LPRs. Immediate reactions occurred in all except one and LPRs in 12 (41.3%). Patients with positive cutaneous reactions had highe levels of specific serum IgE against schistosome antigen. Histopathological studies showed a moderate exudate consisting mainly of neutrophils (60%) and eosinophils (40%). LPRs in schistosomiasis have the same characteristics reported in the medical literature in relation to time of appearance, morphology and histopathology. The immunopathogenic role played by LPRs in the patients remains to be clarified.

  8. The genomic proliferation of transposable elements in colonizing populations: Schistosoma mansoni in the new world.

    PubMed

    Wijayawardena, Bhagya K; DeWoody, J Andrew; Minchella, Dennis J

    2015-06-01

    Transposable elements (TEs) are mobile genes with an inherent ability to move within and among genomes. Theory predicts that TEs proliferate extensively during physiological stress due to the breakdown of TE repression systems. We tested this hypothesis in Schistosoma mansoni, a widespread trematode parasite that causes the human disease schistosomiasis. According to phylogenetic analysis, S. mansoni invaded the new world during the last 500 years. We hypothesized that new world strains of S. mansoni would have more copies of TEs than old world strains due to the physiological stress associated with invasion of the new world. We quantified the copy number of six TEs (Saci-1, Saci-2 and Saci-3, Perere-1, Merlin-sm1, and SmTRC1) in the genome and the transcriptome of old world and new world strains of S. mansoni, using qPCR relative quantification. As predicted, the genomes of new world parasites contain significantly more copies of class I and class II TEs in both laboratory and field strains. However, such differences are not observed in the transcriptome suggesting that either TE silencing mechanisms have reactivated to control the expression of these elements or the presence of inactive truncated copies of TEs.

  9. Drug Target Exploitable Structural Features of Adenylyl Cyclase Activity in Schistosoma mansoni

    PubMed Central

    Mbah, Andreas N.; Kamga, Henri L.; Awofolu, Omotayo R.; Isokpehi, Raphael D.

    2012-01-01

    The draft genome sequence of the parasitic flatworm Schistosoma mansoni (S. mansoni), a cause of schistosomiasis, encodes a predicted guanosine triphosphate (GTP) binding protein tagged Smp_059340.1. Smp_059340.1 is predicted to be a member of the G protein alpha-s subunit responsible for regulating adenylyl cyclase activity in S. mansoni and a possible drug target against the parasite. Our structural bioinformatics analyses identified key amino acid residues (Ser53, Thr188, Asp207 and Gly210) in the two molecular switches responsible for cycling the protein between active (GTP bound) and inactive (GDP bound) states. Residue Thr188 is located on Switch I region while Gly210 is located on Switch II region with Switch II longer than Switch I. The Asp207 is located on the G3 box motif and Ser53 is the binding residue for magnesium ion. These findings offer new insights into the dynamic and functional determinants of the Smp_059340.1 protein in regulating the S. mansoni life cycle. The binding interfaces and their residues could be used as starting points for selective modulations of interactions within the pathway using small molecules, peptides or mutagenesis. PMID:23133313

  10. Neonatal Idiotypic Exposure Alters Subsequent Cytokine, Pathology, and Survival Patterns in Experimental Schistosoma mansoni Infections

    PubMed Central

    Angela Montesano, M.; Colley, Daniel G.; Eloi-Santos, Silvana; Freeman, George L.; Secor, W. Evan

    1999-01-01

    Exposure to maternal idiotypes (Ids) or antigens might predispose a child to develop an immunoregulated, asymptomatic clinical presentation of schistosomiasis. We have used an experimental murine system to address the role of Ids in this immunoregulation. Sera from mice with 8-wk Schistosoma mansoni infection, chronic (20-wk infection) moderate splenomegaly syndrome (MSS), or chronic hypersplenomegaly syndrome (HSS) were passed over an S. mansoni soluble egg antigen (SEA) immunoaffinity column to prepare Ids (8WkId, MSS Id, HSS Id). Newborn mice were injected with 8WkId, MSS Id, HSS Id, or normal mouse immunoglobulin (NoMoIgG) and infected with S. mansoni 8 wk later. Mice exposed to 8WkId or MSS Id as newborns had prolonged survival and decreased morbidity compared with mice that received HSS Id or NoMoIgG. When stimulated with SEA, 8WkId, or MSS Id, spleen cells from mice neonatally injected with 8WkId or MSS Id produced more interferon γ than spleen cells from mice neonatally injected with HSS Id or NoMoIgG. Furthermore, neonatal exposure to 8WkId or MSS Id, but not NoMoIgG or HSS Id, led to significantly smaller granuloma size and lower hepatic fibrosis levels in infected mice. Together, these results indicate that perinatal exposure to appropriate anti-SEA Ids induces long-term effects on survival, pathology, and immune response patterns in mice subsequently infected with S. mansoni. PMID:9989978

  11. Susceptibility or resistance of praziquantel in human schistosomiasis: a review.

    PubMed

    Wang, Wei; Wang, Li; Liang, You-Sheng

    2012-11-01

    Since praziquantel was developed in 1970s, it has replaced other antischistosomal drugs to become the only drug of choice for treatment of human schistosomiases, due to high efficacy, excellent tolerability, few and transient side effects, simple administration, and competitive cost. Praziquantel-based chemotherapy has been involved in the global control strategy of the disease and led to the control strategy shifting from disease control to morbidity control, which has greatly reduced the prevalence and intensity of infections. Given that the drug has been widely used for morbidity control in endemic areas for more than three decades, the emergence of resistance of Schistosoma to praziquantel under drug selection pressure has been paid much attention. It is possible to induce resistance of Schistosoma mansoni and Schistosoma japonicum to praziquantel in mice under laboratorial conditions, and a reduced susceptibility to praziquantel in the field isolates of S. mansoni has been found in many foci. In addition, there are several schistosomiasis cases caused by Schistosoma haematobium infections in which repeated standard treatment fails to clear the infection. However, in the absence of exact mechanisms of action of praziquantel, the mechanisms of drug resistance in schistosomes remain unclear. The present review mainly demonstrates the evidence of drug resistance in the laboratory and field and the mechanism of praziquantel resistance and proposes some strategies for control of praziquantel resistance in schistosomes.

  12. 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

  13. Glomerular lesions in experimental infections of Schistosoma mansoni in Cebus apella monkeys.

    PubMed

    De Brito, T; Gunji, J; Camargo, M E; Ceravolo, A; Da Silva, L C

    1971-01-01

    Three monkeys (Cebus apella) experimentally infected with Schistosoma mansoni studied for periods of 19, 14, and 11 months showed deposits containing gamma-globulin in subendothelial and subepithelial basal membranes and in basement membranes proper. The glomeruli showed mild reactivity characterized by local hypertrophy and hyperplasia of mesangial cells. Such findings were close to those observed by us in the kidney of hepatosplenic schistosomiasis patients without evidence of renal disease. The distribution of the deposits, both in human and experimental disease, are suggestive of preformed, non-glomerular antigen-antibody complexes that form in a zone of excess antigen and become trapped in the glomerular capillaries.The possibility exists, but has not yet been proved beyond doubt, that renal disease in schistosomiasis patients could be the end result of this pathogenetic mechanism.

  14. Immunology of human schistosomiasis

    PubMed Central

    Colley, D G; Secor, W E

    2014-01-01

    There is a wealth of immunologic studies that have been carried out in experimental and human schistosomiasis that can be classified into three main areas: immunopathogenesis, resistance to reinfection and diagnostics. It is clear that the bulk of, if not all, morbidity due to human schistosomiasis results from immune-response-based inflammation against eggs lodged in the body, either as regulated chronic inflammation or resulting in fibrotic lesions. However, the exact nature of these responses, the antigens to which they are mounted and the mechanisms of the critical regulatory responses are still being sorted out. It is also becoming apparent that protective immunity against schistosomula as they develop into adult worms develops slowly and is hastened by the dying of adult worms, either naturally or when they are killed by praziquantel. However, as with anti-egg responses, the responsible immune mechanisms and inducing antigens are not clearly established, nor are any potential regulatory responses known. Finally, a wide variety of immune markers, both cellular and humoral, can be used to demonstrate exposure to schistosomes, and immunologic measurement of schistosome antigens can be used to detect, and thus diagnose, active infections. All three areas contribute to the public health response to human schistosome infections. PMID:25142505

  15. 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

  16. Schistosomiasis control: praziquantel forever?

    PubMed

    Cioli, Donato; Pica-Mattoccia, Livia; Basso, Annalisa; Guidi, Alessandra

    2014-06-01

    Since no vaccine exists against schistosomiasis and the molluscs acting as intermediate hosts are not easy to attack, chemotherapy is the main approach for schistosomiasis control. Praziquantel is currently the only available antischistosomal drug and it is distributed mainly through mass administration programs to millions of people every year. A number of positive features make praziquantel an excellent drug, especially with regard to safety, efficacy, cost and ease of distribution. A major flaw is its lack of efficacy against the immature stages of the parasite. In view of its massive and repeated use on large numbers of individuals, the development of drug resistance is a much feared possibility. The mechanism of action of praziquantel is still unclear, a fact that does not favor the development of derivatives or alternatives. A large number of compounds have been tested as potential antischistosomal agents. Some of them are promising, but none so far represents a suitable substitute or adjunct to praziquantel. The research of new antischistosomal compounds is an imperative and urgent matter.

  17. [Schistosomiasis epidemiology (author's transl)].

    PubMed

    Picq, J J; Roux, J

    1980-01-01

    Schistosomiasis are, with three hundred million of infested people, the second world endemy, after malaria. For each of the four species, the distribution areas, the life cycle and the main epidemiological features are recalled in the first chapter. In the five following chapters, the authors consider the human or animal reservoirs of virus, the importance of these diseases towards public health, the gasteropod molluscs acting as intermediate hosts, and the problems of immunity in man. The concepts of "schistosomian infection" and "schistosomian disease" are exposed as well as the differences affecting the various strains of schistosomes and snails intermediate hosts. The authors emphasize the value of quantitative parasitological techniques and sero-immunological methods for epidemiological surveys. They underline the difficulties met in the evaluation of the effect of these diseases upon public health. The main causes inducing the duration of the endemy and those responsible for its extension are studied. The value of mathematic patterns is briefly discussed. Quantitative data compiled through epidemiological surveys should improve the use of the various means presently available for controling schistosomiasis.

  18. Developmental Regulation of Genes Encoding Universal Stress Proteins in Schistosoma mansoni

    PubMed Central

    Isokpehi, Raphael D.; Mahmud, Ousman; Mbah, Andreas N.; Simmons, Shaneka S.; Avelar, Lívia; Rajnarayanan, Rajendram V.; Udensi, Udensi K.; Ayensu, Wellington K.; Cohly, Hari H.; Brown, Shyretha D.; Dates, Centdrika R.; Hentz, Sonya D.; Hughes, Shawntae J.; Smith-McInnis, Dominique R.; Patterson, Carvey O.; Sims, Jennifer N.; Turner, Kelisha T.; Williams, Baraka S.; Johnson, Matilda O.; Adubi, Taiwo; Mbuh, Judith V.; Anumudu, Chiaka I.; Adeoye, Grace O.; Thomas, Bolaji N.; Nashiru, Oyekanmi; Oliveira, Guilherme

    2011-01-01

    The draft nuclear genome sequence of the snail-transmitted, dimorphic, parasitic, platyhelminth Schistosoma mansoni revealed eight genes encoding proteins that contain the Universal Stress Protein (USP) domain. Schistosoma mansoni is a causative agent of human schistosomiasis, a severe and debilitating Neglected Tropical Disease (NTD) of poverty, which is endemic in at least 76 countries. The availability of the genome sequences of Schistosoma species presents opportunities for bioinformatics and genomics analyses of associated gene families that could be targets for understanding schistosomiasis ecology, intervention, prevention and control. Proteins with the USP domain are known to provide bacteria, archaea, fungi, protists and plants with the ability to respond to diverse environmental stresses. In this research investigation, the functional annotations of the USP genes and predicted nucleotide and protein sequences were initially verified. Subsequently, sequence clusters and distinctive features of the sequences were determined. A total of twelve ligand binding sites were predicted based on alignment to the ATP-binding universal stress protein from Methanocaldococcus jannaschii. In addition, six USP sequences showed the presence of ATP-binding motif residues indicating that they may be regulated by ATP. Public domain gene expression data and RT-PCR assays confirmed that all the S. mansoni USP genes were transcribed in at least one of the developmental life cycle stages of the helminth. Six of these genes were up-regulated in the miracidium, a free-swimming stage that is critical for transmission to the snail intermediate host. It is possible that during the intra-snail stages, S. mansoni gene transcripts for universal stress proteins are low abundant and are induced to perform specialized functions triggered by environmental stressors such as oxidative stress due to hydrogen peroxide that is present in the snail hemocytes. This report serves to catalyze the

  19. Intestinal schistosomiasis and soil-transmitted helminthiasis in Ugandan schoolchildren: a rapid mapping assessment.

    PubMed

    Standley, Claire J; Adriko, Moses; Alinaitwe, Moses; Kazibwe, Francis; Kabatereine, Narcis B; Stothard, J Russell

    2009-11-01

    Even with a national control programme in place, intestinal schistosomiasis continues to be a major public health problem in school-aged children and other community members in Uganda. This is especially the case in the environments around the Great Lakes, where disease transmission is high, such as Lake Victoria. Moreover, in the most remote areas, some schools might periodically miss large-scale drug administrations owing to inaccessibility. To provide contemporary monitoring and surveillance data, 27 schools along the lakeshore were surveyed with a rapid assessment protocol to determine both prevalence and intensity of Schistosoma mansoni and soil-transmitted helminth infections. In total, 25 (92.6%) of schools were positive for S. mansoni, with an average prevalence across the surveyed children of 42% and average infection intensity of 634 eggs per gram of faeces. Mean prevalence of Trichuris trichiura, Ascaris lumbricoides and hookworm was 12.9%, 9.3% and 2.4%, respectively. Results from questionnaire data revealed a high level of itinerancy among the children, and a total of 38.2% reported to have never received treatment for schistosomiasis, despite 96% living in districts targeted by the national control programme. A birthplace outside of Uganda was a significant predictor for increased risk of schistosomiasis infection (odds ratio (OR) = 9.6), and being resident at a school for less than a year was significantly associated with absence of praziquantel treatment (OR = 0.3). Univariate regression analysis showed a trend of increasing schistosomiasis towards the eastern region of Uganda, while semivariograms of infection prevalence demonstrated a range of spatial autocorrelation of ~78 km. Soil-transmitted helminth infections were more common in the Western region. Our results emphasise how social and demographic variables such as migration may affect epidemiological trends and confound the impact of existing treatment regimes.

  20. Basophil depletion downregulates Schistosoma mansoni egg-induced granuloma formation.

    PubMed

    Anyan, William K; Seki, Takenori; Kumagai, Takashi; Obata-Ninomiya, Kazushige; Furushima-Shimogawara, Rieko; Kwansa-Bentum, Bethel; Akao, Nobuaki; Bosompem, Kwabena M; Boakye, Daniel A; Wilson, Michael D; Karasuyama, Hajime; Ohta, Nobuo

    2013-12-01

    Granuloma formation around parasite eggs during schistosomal infection is considered to be controlled by Th2 cytokines. However, it is still controversial which cell populations are responsible for the host Th2 cytokine-dependent granuloma formation. Basophils have recently attracted attention because of their ability to produce large amounts of IL-4. Therefore, we investigated whether basophils play an essential role in the induction of granuloma formation induced by Schistosoma mansoni eggs. Together with our previous observation that basophil numbers increased markedly in the spleen at 7 weeks postinfection, immunohistochemical staining using anti-mMCP8 monoclonal antibody (mAb) showed basophil infiltration in the granulomatous lesions formed around parasite eggs. To examine the roles of basophils more directly, we treated mice with anti-CD200R3 mAb to deplete basophils. Depletion of basophils resulted in a reduction of basophil number with concomitant downregulation of egg granuloma formation at 7 weeks postinfection. Moreover, we observed a significant reduction in the size of egg granulomas formed in basophil-depleted mice in the pulmonary granuloma model. Taken together, these findings indicated that basophils are essential for S. mansoni egg-induced granuloma formation, and this may serve as a novel therapeutic target in ameliorating the pathology of schistosomiasis.

  1. Molecular epidemiology and phylogeography of Schistosoma mansoni around Lake Victoria.

    PubMed

    Standley, C J; Kabatereine, N B; Lange, C N; Lwambo, N J S; Stothard, J R

    2010-11-01

    Intestinal schistosomiasis continues to be a major public health problem in sub-Saharan Africa, and is endemic in communities around Lake Victoria. Interest is growing in the molecular evolution and population genetic structure of Schistosoma mansoni and we describe a detailed analysis of the molecular epidemiology and phylogeography of S. mansoni from Lake Victoria. In total, 388 cytochrome oxidase 1 (COI) sequences were obtained from 25 sites along the Ugandan, Tanzanian and Kenyan shorelines of Lake Victoria, and 122 unique barcodes were identified; 9 corresponded to previously discovered barcodes from Lakes Victoria and Albert. A subset of the data, composed of COI sequences from miracidia from 10 individual children, was used for population genetics analyses; these results were corroborated by microsatellite analysis of 4 isolates of lab-passaged adult worms. Overall, 12 barcodes were found to be shared across all 3 countries, whereas the majority occurred singly and were locally restricted. The population genetics analyses were in agreement in revealing high diversity at the level of the human host and negligible population structuring by location. The lack of correlation between genetic distance and geographical distance in these data may be attributed to the confounding influence of high intra-individual diversity as well as human migration between communities.

  2. Structural and kinetic analysis of Schistosoma mansoni Adenylosuccinate Lyase (SmADSL).

    PubMed

    Romanello, Larissa; Serrão, Vitor Hugo Balasco; de Souza, Juliana Roberta Torini; Bird, Louise E; Nettleship, Joanne E; Rada, Heather; Reddivari, Yamini; Owens, Ray J; de Marco, Ricardo; Brandão-Neto, José; Pereira, Humberto D'Muniz

    2017-03-24

    Schistosoma mansoni is the parasite responsible for schistosomiasis, a disease that affects about 218 million people worldwide. Currently, both direct treatment and disease control initiatives rely on chemotherapy using a single drug, praziquantel. Concerns over the possibility of resistance developing to praziquantel, have stimulated efforts to develop new drugs for the treatment of schistosomiasis. Schistosomes do not have the de novo purine biosynthetic pathway, and instead depend entirely on the purine salvage pathway to supply its need for purines. The purine salvage pathway has been reported as a potential target for developing new drugs against schistosomiasis. Adenylosuccinate lyase (SmADSL) is an enzyme in this pathway, which cleaves adenylosuccinate (ADS) into adenosine 5'-monophosphate (AMP) and fumarate. SmADSL kinetic characterization was performed by isothermal titration calorimetry (ITC) using both ADS and SAICAR as substrates. Structures of SmADSL in Apo form and in complex with AMP were elucidated by x-ray crystallography revealing a highly conserved tetrameric structure required for their function since the active sites is formed from residues of three different subunits. The active sites are also highly conserved between species and it is difficult to identify a potent species-specific inhibitor for the development of new therapeutic agents. In contrast, several mutagenesis studies have demonstrated the importance of dimeric interface residues in the stability of the quaternary structure of the enzyme. The lower conservation of these residues between SmADSL and human ADSL could be used to lead the development of anti-schistosomiasis drugs based on disruption of subunit interfaces. These structures and kinetics data add another layer of information to Schistosoma mansoni purine salvage pathway.

  3. 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.

  4. New diagnostic tools in schistosomiasis.

    PubMed

    Utzinger, J; Becker, S L; van Lieshout, L; van Dam, G J; Knopp, S

    2015-06-01

    Schistosomiasis is a water-based parasitic disease that affects over 250 million people. Control efforts have long been in vain, which is one reason why schistosomiasis is considered a neglected tropical disease. However, since the new millennium, interventions against schistosomiasis are escalating. The initial impetus stems from a 2001 World Health Assembly resolution, urging member states to scale-up deworming of school-aged children with the anthelminthic drug praziquantel. Because praziquantel is safe, efficacious and inexpensive when delivered through the school platform, diagnosis before drug intervention was deemed unnecessary and not cost-effective. Hence, there was little interest in research and development of novel diagnostic tools. With the recent publication of the World Health Organization (WHO) Roadmap to overcome the impact of neglected tropical diseases in 2020, we have entered a new era. Elimination of schistosomiasis has become the buzzword and this has important ramifications for diagnostic tools. Indeed, measuring progress towards the WHO Roadmap and whether local elimination has been achieved requires highly accurate diagnostic assays. Here, we introduce target product profiles for diagnostic tools that are required for different stages of a schistosomiasis control programme. We provide an update of the latest developments in schistosomiasis diagnosis, including microscopic techniques, rapid diagnostic tests for antigen detection, polymerase chain reaction (PCR) assays and proxy markers for morbidity assessments. Particular emphasis is placed on challenges and solutions for new technologies to enter clinical practice.

  5. SCHISTOSOMIASIS IN NAG HAMMADY CITY, RELATIONSHIP BETWEEN INFECTION AND ANEMIA AMONG CHILDREN AND YOUTH, QENA GOVERNORATE, EGYPT.

    PubMed

    Abd Ellah, Osama H; Zaytoun, Sameh Sh; Ahmed, Ahmed E; Hussein, Abdel-Nasser A; Ahmed, Amal M

    2015-08-01

    The highest prevalence of schistosomiasis is usually found in school-age children and youth, where it represents the main cause of iron deficiency anemia. Study was done on 859 patients; their age from 5-18 years old at Nag Hammady at the period from July 2013 to July 2014 all of them had subjective history of contact or swimming in water canals. Urine was examined for urinary schistosomiasis by concentration and positive cases were subjected to urine analysis by Nucleopore filtration technique, S. haematobium was 30.96%, while stool samples were macroscopically examined mainly for enterobiasis and gravid segments and then were microscopically examined as stained direct smear and by sedimentation and Kato-Katz techniques. The intestinal parasites other than intestinal schistosomiasis were not encountered and the pure S. mansoni was 0.69% of examined patients. The overall pure schistosomiasis was 31.66%. Iron deficiency anemia was 27.7% in non-infected cases and in schistosomiasis patients iron deficiency anemia were found in 43.38% with statistically significant (P value=0.001).

  6. Clinical Report: Schistosomiasis Exposure in U.S. Service Personnel During Whitewater Rafting on the Nile River in Jinja, Uganda.

    PubMed

    Maluil, Samuel; Stevens, Rom A

    2016-11-01

    Schistosomiasis is a known risk after exposure to freshwater in tropical parts of the world. In March 2014, 28 off-duty U.S. service members went on a water adventure in the Nile River in Jinja, Uganda. In April 2014, 10 of the 28 service members returned for a second water adventure. Twelve weeks after freshwater exposure, schistosomiasis enzyme-linked immunosorbent assay testing was performed. Twenty-five percent had elevated Schistosomiasis mansoni immunoglobulin G (7 positive of 28 exposed); all had negative pre-exposure serology. The serology-positive service members were treated with oral praziquantel 60 mg/kg in divided doses. Our report is the first schistosomiasis report among U.S. service members deployed to Africa since World War II. The absence of reports among U.S. service members and several reports among deployed foreign military units and tourists in sub-Saharan Africa suggest a lack of postexposure testing. We recommend schistosomiasis testing of prior and future U.S. military units deployed to sub-Saharan Africa with fresh water exposure. Unit commanders and medical personnel should discourage unnecessary fresh water contact in sub-Saharan Africa.

  7. 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

    2015-07-16

    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.

  8. 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.

  9. Liver collagen synthesis in murine schistosomiasis.

    PubMed Central

    Dunn, M A; Rojkind, M; Warren, K S; Hait, P K; Rifas, L; Seifter, S

    1977-01-01

    Collagen synthesis was measured in liver slices obtained from mice with hepatosplenic schistosomiasis. Enlarged fibrotic livers from these mice contained 20 times more collagen than normal. This model of hepatic fibrosis results from an inflammatory granulomatous host response to Schistosoma mansoni ova in portal tracts, rather than from direct lover cell injury as with carbon tetrachloride-induced liver fibrosis. Collagen synthesis, as measured by the formation of labeled protein-bound hydroxyproline, occurred in granulomas isolated from fibrotic livers. Labeled collagen that cochromatographed with type I collagen was extracted with neutral salt solution from liver slices incubated with labeled proline. The free proline pool of the liver was doubled in infected mice; coordinately, liver slices from these animals showed maximal collagen production when the concentration of free proline in the medium was raised to 0.4 mM, the same level measured in the fibrotic livers. Under such conditions, collagen synthesis was at a rate equivalent to the formation of 5.4 nmol of protein-bound hydroxyproline per g liver in 6 h. In comparative incubations in medium containing 0.2 mM proline, fibrotic liver slices produced 16-fold more collagen than normal slices. The proline analogue, L-azetidine 2-carboxylic acid, effectively inhibited synthesis of labeled collagen by fibrotic liver slices. These studies show the synthesis of collagen in a reproducible animal model of the most prevalent form of human liver fibrosis. Difinitition of the controlling factors in this system is of interest for the general problem of fibrosis produced by immunological responses. Images PMID:845255

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

    PubMed Central

    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

  11. Epitopes rationally selected through computational analyses induce T-cell proliferation in mice and are recognized by serum from individuals infected with Schistosoma mansoni.

    PubMed

    Lopes, Marcelo D; Oliveira, Flávio M; Coelho, Ivan E V; Passos, Maria J F; Alves, Clarice C; Taranto, Alex G; Júnior, Moacyr C; Santos, Luciana L; Fonseca, Cristina T; Villar, José A F P; Lopes, Débora O

    2017-04-03

    Schistosomiasis is the second leading cause of death due to parasitic diseases in the world. Seeking an alternative for the control of disease, the World Health Organization funded the genome sequencing of the major species related to schistosomiasis to identify potential vaccines and therapeutic targets. Therefore, the aim of this work was to select T and B-cell epitopes from Schistosoma mansoni through computational analyses and evaluate the immunological potential of epitopes in vitro. Extracellular regions of membrane proteins from the Schistosoma mansoni were used to predict promiscuous epitopes with affinity to different human Major Histocompatibility Class II (MHCII) molecules by bioinformatics analysis. The three-dimensional structure of selected epitopes was constructed and used in molecular docking to verify the interaction with murine MHCII H2-IA(b) . In this process, four epitopes were selected and synthesized to assess their ability to stimulate proliferation of CD4(+) T lymphocytes in mice splenocyte cultures. The results showed that Sm041370 and Sm168240 epitopes induced significant cell proliferation. Additionally, the four epitopes were used as antigens in the Indirect Enzyme-Linked Immunosorbent Assay (ELISA) to assess the recognition by serum from individuals infected with Schistosoma mansoni. Sm140560, Sm168240 and Sm041370 epitopes were recognized by infected individuals IgG antibodies. Therefore, Sm041370 and Sm168240 epitopes that stood out in in silico and in vitro analyses could be promising antigens in schistosomiasis vaccine development or diagnostic kits. This article is protected by copyright. All rights reserved.

  12. 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

  13. [An outbreak of acute schistosomiasis at Porto de Galinhas beach, Pernambuco, Brazil].

    PubMed

    Barbosa, C S; Domingues, A L; Abath, F; Montenegro, S M; Guida, U; Carneiro, J; Tabosa, B; Moraes, C N; Spinelli, V

    2001-01-01

    We recently confirmed several cases of acute schistosomiasis in Porto de Galinhas beach, Northeast Brazil. A total of 662 patients were diagnosed by parasitological and clinical examinations. The infection likely occurred during the September 7 national holiday, when heavy rainfall flooded the Ipojuca River and people were infected when the water covered their yards. Families were continuously exposed to infection for a period of three weeks until the water had completely dried up. Previous investigation suggests that snail vectors were introduced as a result of landfill in marshy areas. The swamp-flooding of such areas facilitated the emergence of slums surrounded by snail breeding sites. Heavy rainfall caused open-air sewage ditches to overflow, allowing for infection of snails by Schistosoma mansoni. Thus, continuous floods were responsible for the spread of human infection. Clinical and laboratory results identified 62% of acute cases of S. mansoni. Complementary studies are being conducted to define the impact and epidemiological meaning of the acute schistosomiasis outbreak.

  14. Noradrenaline-induced contraction of mice aorta is enhanced in schistosomiasis.

    PubMed

    Silva, C L M; Gontijo, L S; Noël, F

    2007-02-01

    Schistosomiasis, an intravascular parasitic disease caused by Schistosoma mansoni, is related to alterations of murine vascular reactivity in the mesenteric bed, characterized by an impairment of the l-arginine/NO pathway and an increased potency of 5-hydroxytryptamine. The current study was performed to test the hypothesis that a similar alteration of reactivity also occurs in the aorta and to identify the mechanism behind such an increase. We found that aorta from mice infected with male S. mansoni exhibited an enhanced contraction in response to noradrenaline and 100 mM KCl. The inhibition of nitric oxide synthase increased aortic maximal contraction in response to noradrenaline in both groups, but the effect was less pronounced in infected mice than in control mice. Endothelium-dependent relaxation induced by acetylcholine was also smaller in infected mice compared to control mice, while endothelial-independent relaxation induced by sodium nitroprusside and forskolin was similar in both groups. The inhibition of voltage-dependent L-type Ca(2+) channels reduced the maximal contraction in response to noradrenaline more effectively in infected than in control mice. Conversely the inhibition of K(ATP) channels had a smaller effect in the infected group. As a conclusion, our data indicate that schistosomiasis also alters murine vascular reactivity outside the mesenteric bed, due to a partial impairment of NO signaling, a reduced contribution of K(ATP) channels and an increased Ca(2+) influx through L-type Ca(2+) channels.

  15. 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.

  16. 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

  17. Hepatic and Intestinal Schistosomiasis: Review

    PubMed Central

    Elbaz, Tamer; Esmat, Gamal

    2013-01-01

    Schistosomiasis is an endemic disease in Egypt caused by the trematode Schistosoma which has different species. Hepatic schistosomiasis represents the best known form of chronic disease with a wide range of clinical manifestations. The pathogenesis of schistosomiasis is related to the host cellular immune response. This leads to granuloma formation and neo angiogenesis with subsequent periportal fibrosis manifested as portal hypertension, splenomegaly and esophageal varices. Intestinal schistosomiasis is another well identified form of chronic schistosomal affection. Egg deposition and granuloma formation eventually leads to acute then chronic schistosomal colitis and is commonly associated with polyp formation. It frequently presents as abdominal pain, diarrhea, tenesmus and anal pain. Definite diagnosis of schistosomiasis disease depends on microscopy and egg identification. Marked progress regarding serologic diagnosis occurred with development of recent PCR techniques that can confirm schistosomal affection at any stage. Many antischistosomal drugs have been described for treatment, praziquantel being the most safe and efficient drug. Still ongoing studies try to develop effective vaccines with identification of many target antigens. Preventive programs are highly needed to control the disease morbidity and to break the cycle of transmission. PMID:25685451

  18. Still hope for schistosomiasis vaccine.

    PubMed

    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.

  19. Microarray based analysis of temperature and oxidative stress induced messenger RNA in Schistosoma mansoni

    PubMed Central

    Aragon, Anthony D.; Imani, Reza A.; Blackburn, Vint R.; Cunningham, Charles

    2008-01-01

    The body’s defense against schistosome infection can take many forms. For example, upon developing acute schistosomiasis, patients often have fever coinciding with larval maturation, migration and early oviposition. As the infection becomes established, the parasite comes under oxidative stress generated by the host immune system. The most common treatment for schistosomiasis is the anti-helminthic drug praziquantel. Its effectiveness, however, is limited due to its inability to kill schistosomes 2 – 4 weeks post-infection. Clearly there is a need for new antischistosomal drugs. We hypothesize that gene products expressed as part of a protective response against heat and/or oxidative stress are potential therapeutic targets for future drug development. Using a 12,166 element oligonucleotide microarray to characterize Schistosoma mansoni genes induced by heat and oxidative stress we found that 1,878 S. mansoni elements were significantly induced by heat stress. These included previously reported heat-shock genes expressing homologs of HSP40, HSP70 and HSP86. One thousand and one elements were induced by oxidative stress including those expressing homologs of superoxide dismutase, glutathione peroxidase and aldehyde dehydrogenase. Seventy-two elements were common to both stressors and could potentially be exploited in the development of novel anti-schistosomal therapeutics. PMID:18775750

  20. The chronic enteropathogenic disease schistosomiasis.

    PubMed

    Olveda, David U; Olveda, Remigio M; McManus, Donald P; Cai, Pengfei; Chau, Thao N P; Lam, Alfred K; Li, Yuesheng; Harn, Donald A; Vinluan, Marilyn L; Ross, Allen G P

    2014-11-01

    Schistosomiasis is a chronic enteropathogenic disease caused by blood flukes of the genus Schistosoma. The disease afflicts approximately 240 million individuals globally, causing approximately 70 million disability-adjusted life years lost. Chronic infections with morbidity and mortality occur as a result of granuloma formation in the intestine, liver, or in the case of Schistosoma haematobium, the bladder. Various methods are utilized to diagnose and evaluate liver fibrosis due to schistosomiasis. Liver biopsy is still considered the gold standard, but it is invasive. Diagnostic imaging has proven to be an invaluable method in assessing hepatic morbidity in the hospital setting, but has practical limitations in the field. The potential of non-invasive biological markers, serum antibodies, cytokines, and circulating host microRNAs to diagnose hepatic fibrosis is presently undergoing evaluation. This review provides an update on the recent advances made with respect to gastrointestinal disease associated with chronic schistosomiasis.

  1. The schistosomiasis problem in Egypt.

    PubMed

    Mobarak, A B

    1982-01-01

    This report provides an overview of past and current efforts to control schistosomiasis in Egypt, describes recent trends, and analyzes factors responsible for changes in transmission. For the purpose of long-term planning and developing control strategies, the country has been divided into eight geographic zones: Suez Canal Zone, Sainai, Nile Delta, Guiza, Fayoum, Middle Egypt, Upper Egypt, and the High Dam Lake Zone. Overall control priorities are examined and the strategy for each zone is described. The most recent information on changes in epidemiologic patterns of schistosomiasis in Egypt is mentioned, as well as the introduction of newer therapeutic agents. Lastly, the role of outside funding agencies in supporting schistosomiasis control is examined.

  2. 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.

  3. Schistosoma mansoni in infants (aged < 3 years) along the Ugandan shoreline of Lake Victoria.

    PubMed

    Odogwu, S E; Ramamurthy, N K; Kabatereine, N B; Kazibwe, F; Tukahebwa, E; Webster, J P; Fenwick, A; Stothard, J R

    2006-06-01

    In two complementary epidemiological surveys of villages on the Ugandan shoreline of Lake Victoria, the putative occurrence of intestinal schistosomiasis in the local infants (children aged < 3 years) was investigated. When, during the first survey, 136 mother-and-infant pairs from a total of 12 villages were studied, only 7% of the infants but 45% of the mothers were found to be egg-patent for Schistosoma mansoni infection. The use of dipstick tests for urine-circulating cathodic antigen indicated, however, a much higher prevalence, of approximately 40%, among the infants. In the second survey, urine samples and multiple, not single, stool samples were collected from another 19 mother-and-infant pairs in two of the 12 study villages (Bugoto and Bwondha), and a standardized questionnaire was implemented. The prevalence of egg-patent infection was then found to be markedly higher in the study infants from Bugoto (86%) than in those from Bwondha (25%). A greater level of mother-and-infant water contact, a higher abundance of (infected) Biomphalaria choanomphala, and an unusual lakeshore topology may explain why S. mansoni infection was so much more common in the Bugoto subjects than in the Bwondha. All but one of the infants studied in the second survey were found to be anaemic (with <110 g haemoglobin/litre). Taken together, these children were less likely to be found infected with hookworm (16%), Hymenolepis nana (11%) or Trichuris trichiura (5%) than with S. mansoni (47%). Infection with the parasites causing intestinal schistosomiasis can be common among the infants living in these lakeshore villages. Although the immediate and later-life clinical impacts of such infection have yet to be elucidated, such infants would probably benefit from regular de-worming. Mothers should be strongly encouraged to visit the nearest health-services clinic, with their infants, for any necessary anthelmintic treatment.

  4. 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

  5. Schistosoma mansoni Infections, Undernutrition and Anaemia among Primary Schoolchildren in Two Onshore Villages in Rorya District, North-Western Tanzania

    PubMed Central

    2016-01-01

    Background Undernutrition and anaemia remains to be a major public health problem in many developing countries, where they mostly affect children. Intestinal parasitic infections are known to affect both growth and haemoglobin levels. Much has been reported on the impact of geohelminths on anaemia and undernutrition, leaving that of Schistosoma mansoni not well studied. Therefore this study intended to determine the association between S.mansoni infections, anaemia and undernutrition among schoolchildren in Rorya district, Northwestern Tanzania. Methodology A cross-sectional study was carried among schoolchildren in two onshore villages namely Busanga and Kibuyi in Rorya district. Single stool specimens were collected from 513 randomly selected schoolchildren and processed for microscopic examination using the Kato-Katz method. Nutritional status was determined by anthropometry. Blood samples were also collected and examined for malaria parasites and haemoglobin levels using the Giemsa stain and HaemoCue methods, respectively. A pretested questionnaire was used to collect socio-demographic data and associated factors. Results The prevalence of S. mansoni infection and malaria was 84.02% and 9.16%, respectively. Other parasites found were Ascaris lumbricoides (1.36%) and Hookworm (1.36%). The prevalence of stunting and wasting was 38.21% and 14.42%, respectively. The prevalence of anaemia was 29.43%, whereby 0.58% had severe anaemia. S. mansoni infection was not found to be associated with undernutrition or anaemia (p>0.05). The risk of stunting and wasting increased with increasing age (p<0.001). Anaemia was associated with age, sex and village of residence (p<0.05). Conclusions S.mansoni, undernutrition and anaemia are highly prevalent in the study area. The observed rates of undernutrition and anaemia were seen not to be associated with S.mansoni infection suggesting possibly being a result of poor dietary nutrients. This study suggests that policy makers should

  6. Notes on the use of urine-CCA dipsticks for detection of intestinal schistosomiasis in preschool children.

    PubMed

    Navaratnam, A M D; Mutumba-Nakalembe, M J; Stothard, J R; Kabatereine, N B; Fenwick, A; Sousa-Figueiredo, J C

    2012-10-01

    Urine-dipstick diagnostic tests that detect schistosome circulating cathodic antigen (CCA) have the potential to provide more sensitive and rapid testing for intestinal schistosomiasis in field-based surveys; this is especially so when examining preschool children, from whom it may be difficult to obtain consecutive stool samples. To assess the performance of urine dipsticks, 569 preschool children from four villages along the shore of Lake Albert, Uganda, were screened for Schistosoma mansoni by Kato-Katz (K-K) examination of a single stool sample and CCA urine dipsticks. The prevalence of infection was 32.2% by K-K and 40.0% by CCA tests. Sensitivity and specificity were influenced by whether 'trace' results from the CCA test were characterised as positive or negative for infection with S. mansoni; ambiguities around this issue need to be resolved. Nevertheless, the CCA test showed particular promise for routine epidemiological screening in this setting.

  7. Schistosomes of small mammals from the Lake Victoria Basin, Kenya: new species, familiar species, and implications for schistosomiasis control.

    PubMed

    Hanelt, B; Mwangi, I N; Kinuthia, J M; Maina, G M; Agola, L E; Mutuku, M W; Steinauer, M L; Agwanda, B R; Kigo, L; Mungai, B N; Loker, E S; Mkoji, G M

    2010-06-01

    Recent schistosomiasis control efforts in sub-Saharan Africa have focused nearly exclusively on treatment of humans with praziquantel. However, the extent to which wild mammals act as reservoirs for Schistosoma mansoni and therefore as sources of renewed transmission following control efforts is poorly understood. With the objective to study the role of small mammals as reservoir hosts, 480 animals belonging to 9 rodent and 1 insectivore species were examined for infection with schistosomes in Kisumu, in the Lake Victoria Basin, Kenya. Animals were collected from 2 sites: near the lakeshore and from Nyabera Marsh draining into the lake. A total of 6.0% of the animals captured, including 5 murid rodent species and 1 species of shrew (Crocidura olivieri) were infected with schistosomes. Four schistosome species were recovered and identified using cox1 DNA barcoding: S. mansoni, S. bovis, S. rodhaini and S. kisumuensis, the latter of which was recently described from Nyabera Marsh. Schistosoma mansoni and S. rodhaini were found infecting the same host individual (Lophuromys flavopunctatus), suggesting that this host species could be responsible for the production of hybrid schistosomes found in the area. Although the prevalence of S. mansoni infection in these reservoir populations was low (1.5%), given their potentially vast population size, their impact on transmission needs further study. Reservoir hosts could perpetuate snail infections and favour renewed transmission to humans once control programmes have ceased.

  8. Flavonoids and Sesquiterpene Lactones from Artemisia absinthium and Tanacetum parthenium against Schistosoma mansoni Worms

    PubMed Central

    de Almeida, Luísa Maria Silveira; Gazolla, Matheus Coutinho; Silva Pinto, Pedro Luiz; da Silva, Marcos Paulo Nascimento; de Moraes, Josué

    2016-01-01

    Human schistosomiasis, caused by trematode worms of the genus Schistosoma, is one of the most significant neglected tropical diseases, affecting more than 200 million individuals worldwide and praziquantel is the only available drug to treat this disease. Artemisia absinthium L. and Tanacetum parthenium L. are species popularly used as anthelmintics. We investigated the in vitro schistosomicidal activity of crude extracts of A. absinthium (AA) and T. parthenium (TP) and their isolated compounds. AA and TP, at 200 μg/mL, were active, causing 100% mortality of all adult worms. Chromatographic fractionation of AA leads to isolation of artemetin and hydroxypelenolide, while santin, apigenin, and parthenolide were isolated from TP. Artemetin, hydroxypelenolide, santin, and apigenin, at 100 μM, were inactive against adult worms. Parthenolide (12.5 to 100 μM) caused 100% mortality, tegumental alterations, and reduction of motor activity of all adult worms of S. mansoni, without affecting mammalian cells. Confocal laser scanning microscopy showed tegumental morphological alterations and changes on the numbers of tubercles of S. mansoni worms. This report provides the first evidence for the in vitro activity of parthenolide against adult worms of S. mansoni, opening the route to further schistosomicidal studies with this compound. PMID:27980595

  9. 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

  10. 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

  11. Analysis of cDNA encoding the hypoxanthine-guanine phosphoribosyltransferase (HGPRTase) of Schistosoma mansoni; a putative target for chemotherapy.

    PubMed Central

    Craig, S P; McKerrow, J H; Newport, G R; Wang, C C

    1988-01-01

    Because of the lack of de novo purine biosynthesis, hypoxanthine-guanine phosphoribosyltransferase (HGPRTase) is a critical enzyme in the purine metabolic pathway of the human parasite, Schistosoma mansoni. Using a cDNA clone encoding mouse HGPRTase and subsequently a synthetic oligonucleotide derived from sequencing a clone of genomic DNA, two clones were isolated from an adult schistosome cDNA library. One clone is 1.374 Kilobases (Kb) long and has an open reading frame of 693 bases. The deduced 231 amino acid sequence has 47.9% identity in a 217 amino acid overlap with human HGPRTase. Northern blot analysis indicates that the full length of mRNA for the S. mansoni HGPRTase is 1.45-1.6 Kb. Analysis of the primary structures of the putative active site for human and parasite enzymes reveal specific differences which may eventually be exploitable in the design of drugs for the treatment of schistosomiasis. Images PMID:3136439

  12. Spatial risk prediction and mapping of Schistosoma mansoni infections among schoolchildren living in western Côte d'Ivoire.

    PubMed

    Raso, G; Matthys, B; N'Goran, E K; Tanner, M; Vounatsou, P; Utzinger, J

    2005-07-01

    The objectives of this study were (1) to examine risk factors for Schistosoma mansoni infection among schoolchildren living in western Côte d'Ivoire, and (2) to carry forward spatial risk prediction and mapping at non-sampled locations. First, demographic and socio-economic data were obtained from 3818 children, aged 6-16 years, from 55 schools. Second, a single stool sample was examined from each child by the Kato-Katz technique to assess infection status of S. mansoni and its intensity. Third, remotely sensed environmental data were derived from satellite imagery and digitized ground maps. With these databases a comprehensive geographical information system was established. Bayesian variogram models were applied for spatial risk modelling and prediction. The infection prevalence of S. mansoni was 38.9%, ranging from 0% to 89.3% among schools. Results showed that age, sex, the richest wealth quintile, elevation and rainfall explained the geographical variation of the school prevalences of S. mansoni infection. The goodness of fit of different spatial models revealed that age, sex and socio-economic status had a stronger influence on infection prevalence than environmental covariates. The generated risk map can be used by decision-makers for the design and implementation of schistosomiasis control in this setting. If successfully validated elsewhere, this approach can guide control programmes quite generally.

  13. DNA 'barcoding' of Schistosoma mansoni across sub-Saharan Africa supports substantial within locality diversity and geographical separation of genotypes.

    PubMed

    Webster, Bonnie L; Webster, Joanne P; Gouvras, Anouk N; Garba, Amadou; Lamine, Mariama S; Diaw, Oumar T; Seye, Mohmoudane M; Tchuem Tchuenté, Louis-Albert; Simoonga, Christopher; Mubila, Likezo; Mwanga, Joseph R; Lwambo, Nicholas J S; Kabatereine, Narcis B; Lange, Charles N; Kariuki, Curtis; Mkoji, Gerald M; Rollinson, David; Stothard, J Russell

    2013-11-01

    Schistosoma mansoni is a widespread human helminth and causes intestinal schistosomiasis in 54 countries, mainly across Africa but also in Madagascar, the Arabian Peninsula and the neotropics. The geographical range of this parasite relies on the distribution of certain species of freshwater pulmonate snails of the genus Biomphalaria. Whilst S. mansoni is known to exhibit high population diversity the true extent of this diversity is still to be fully elucidated as sampling of this taxon progressively accrues. Here a DNA 'barcoding' approach is taken using sequence analysis of a 450bp region within the mitochondrial cox1 gene to assess the genetic diversity within a large number of S. mansoni larval stages collected from their natural human hosts across sub-Saharan Africa. Five hundred and sixty one individual parasite samples were examined from 22 localities and 14 countries. Considerable within-species diversity was found with 120 unique haplotypes splitting geographically into five discrete lineages. The highest diversity was found in East Africa with samples forming three of the five lineages. Less diversity was found in the Far and Central Western regions of Africa with haplotypes from the New World showing a close affinity to the Far Western African S. mansoni populations supporting the hypothesis of a colonisation of South America via the West African slave trade. The data are discussed in relation to parasite diversity and disease epidemiology.

  14. [Sociodemographic and behavioral factors related to schistosomiasis in a rural village of the sugar cane belt in Pernambuco State, Brazil

    PubMed

    Moza; Pieri; Barbosa; Rey

    1998-04-30

    Failure of intensive chemotherapy to control schistosomiasis in a highly endemic area of Northeast Brazil led to the hypothesis that sociodemographic and/or behavioral variables could be involved in the persistent transmission. A univariate analysis of such variables in relation to infection by Schistosoma mansoni showed that water contact patterns for recreation and personal hygiene are important risk factors in the area. However, sociodemographic variables were not related to infection, probably because the local population lives under evenly precarious socioeconomic and sanitary conditions. We thus recommend that chemotherapy be combined with other measures like snail control, health education, and improved sanitation and water supply.

  15. Alternative approaches in schistosomiasis control.

    PubMed

    Barbosa, F S; Coimbra Júnior, C E

    1992-01-01

    Measures for the control of schistosomiasis were implemented in Egypt beginning 1922. This shows that developing endemic countries are facing this problem for near 70 years. However, results in the control of this infection have not been satisfactorily obtained in spite of the technologies and strategies recently developed. The idea that social and economic components are relevant in the control of schistosomiasis is not new although its extension and profundity have not usually been well understood. More recently, most of the workers have recognized that the focal distribution of the prevalence rates of schistosomiasis should not be neglected in the control of the infection. At present, field work projects on the control of schistosomiasis are being developed in rural areas of two Brazilian studies (Espírito Santo and Pernambuco). The adopted strategy aims to interfere in the complex relationships between man and his bio-social-cultural environment, without forgetting that the unequal distribution of the space is a consequence of the political and economic organization of the Society.

  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. Schistosoma mansoni egg glycoproteins and C-type lectins of host immune cells: molecular partners that shape immune responses.

    PubMed

    Meevissen, Moniek H J; Yazdanbakhsh, Maria; Hokke, Cornelis H

    2012-09-01

    Schistosome eggs and egg-derived molecules are potent immunomodulatory agents. There is increasing evidence that the interplay between egg glycoproteins and host C-type lectins plays an important role in shaping immune responses during schistosomiasis. As most experiments in this field so far have been performed using complex protein/glycoprotein mixtures or synthetic model glycoconjugates, it is still largely unclear which individual moieties of schistosome eggs are immunologically active. In this review we will discuss molecular aspects of Schistosoma mansoni egg glycoproteins, their interactions with C-type lectins, and the relevance to schistosome egg immunobiology.

  18. 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

  19. Mapping of Schistosoma mansoni in the Nile Delta, Egypt: Assessment of the prevalence by the circulating cathodic antigen urine assay.

    PubMed

    Haggag, Ayat A; Rabiee, Amal; Abd Elaziz, Khaled M; Gabrielli, Albis F; Abdel Hay, Rehab; Ramzy, Reda M R

    2017-03-01

    In line with WHO recommendations on elimination of schistosomiasis, accurate identification of all areas of residual transmission is a key step to design and implement measures aimed at interrupting transmission in low-endemic settings. To this purpose, we assessed the prevalence of active S. mansoni infection in five pilot governorates in the Nile Delta of Egypt by examining schoolchildren (6-15 years) using the Urine-Circulating Cathodic Antigen (Urine-CCA) cassette test; we also carried out the standard Kato-Katz (KK) thick smear, the monitoring and evaluation tool employed by Egypt's national schistosomiasis control programme. Prevalence rates determined by the Urine-CCA test for all governorates were higher than those determined by KK (p<0.01). Of 35 districts surveyed in the five governorates, S. mansoni infection was detected in 19 districts (54.3%) using KK, and in 31 districts (88.6%) by Urine-CCA (χ2=9.94; P=0.0016). S. mansoni infections were detected by Urine-CCA, but not by KK in 12 districts (34.3%), and infection was not detected by either of the two diagnostic methods in four districts in Qalyubia governorate. Males and higher age-groups have significantly higher Urine-CCA prevalence rates. Based on the findings of the current S. mansoni mapping exercise, authorities of the Ministry of Health and Population (MoHP) adopted a new elimination strategy by readjusting thresholds for mass treatment with praziquantel and targeting all transmission areas. MoHP is now planning to remap in all other endemic governorates using Urine-CCA with the aim of identifying all areas of transmission where the elimination strategy should be applied.

  20. The prevalence of schistosomiasis in school-aged children as an appropriate indicator of its prevalence in the community.

    PubMed

    Pereira, Ana Paula Braz; Favre, Tereza Cristina; Galvão, Aline Favre; Beck, Lilian; Barbosa, Constança Simões; Pieri, Otávio Sarmento

    2010-07-01

    School-aged children (6-15 years) from the endemic area of Pernambuco were evaluated both as a target group for and an indicator of schistosomiasis control in the community. Parasitological data were drawn from baseline stool surveys of whole populations that were obtained to diagnose Schistosoma mansoni infection. Nineteen representative localities were selected for assessing the prevalence of schistosomiasis among individuals in the following age groups: 0-5, 6-15, 16-25, 26-40 and 41-80 years. For each locality, the prevalence in each age group was compared to that of the overall population using contingency table analysis. To select a reference group, the operational difficulties of conducting residential surveys were considered. School-aged children may be considered to be the group of choice as the reference group for the overall population for the following reasons: (i) the prevalence of schistosomiasis in this age group had the highest correlation with the prevalence in the overall population (r = 0.967), (ii) this age group is particularly vulnerable to infection and plays an important role in parasite transmission and (iii) school-aged children are the main target of the World Health Organization in terms of helminth control. The Schistosomiasis Control Program should consider school-aged children both as a reference group for assessing the need for intervention at the community level and as a target group for integrated health care actions of the Unified Health System that are focused on high-risk groups.

  1. Macrophage P2X7 Receptor Function Is Reduced during Schistosomiasis: Putative Role of TGF-β1

    PubMed Central

    Oliveira, Suellen D'arc Santos; Nanini, Hayandra Ferreira; Savio, Luiz Eduardo Baggio; Waghabi, Mariana Caldas; Silva, Claudia Lucia Martins

    2014-01-01

    Schistosomiasis is a chronic inflammatory disease whose macrophages are involved in immunopathology modulation. Although P2X7 receptor signaling plays an important role in inflammatory responses mediated by macrophages, no reports have examined the role of P2X7 receptors in macrophage function during schistosomiasis. Thus, we evaluated P2X7 receptor function in peritoneal macrophages during schistosomiasis using an ATP-induced permeabilization assay and measurements of the intracellular Ca2+ concentration. ATP treatment induced significantly less permeabilization in macrophages from S. mansoni-infected mice than in control cells from uninfected animals. Furthermore, P2X7-mediated increases in intracellular Ca2+ levels were also reduced in macrophages from infected mice. TGF-β1 levels were increased in the peritoneal cavity of infected animals, and pretreatment of control macrophages with TGF-β1 reduced ATP-induced permeabilization, mimicking the effect of S. mansoni infection. Western blot and qRT-PCR data showed no difference in P2X7 protein and mRNA between uninfected, infected, and TGF-β1-treated groups. However, immunofluorescence analysis revealed reduced cell surface localization of P2X7 receptors in macrophages from infected and TGF-β1-treated mice compared to controls. Therefore, our data suggest that schistosomiasis reduces peritoneal macrophage P2X7 receptor signaling. This effect is likely due to the fact that infected mice have increased levels of TGF-β1, which reduces P2X7 receptor cell surface expression. PMID:25276050

  2. 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.

  3. [Travel related urinary schistosomiasis: case report].

    PubMed

    Özvatan, Tülay Şener; Koçak, Cengiz; Alver, Oktay; Mıstık, Reşit; Aslan, Emel

    2011-01-01

    Schistosomiasis is the second most frequent parasitic infection worldwide after malaria and is a major public health problem in various countries of the world. In our country due to the increasingf travel to endemic regions, the number of cases is also rising. We report herein a case of schistosomiasis who resided in Africa five years earlier and was referred to hospital with hematuria. Direct microscopic examination of the urine specimen revealed Schistosoma haematobium eggs. Epidemiology and clinical significance of schistosomiasis are also discussed.

  4. Ivermectin efficacy against Biomphalaria, intermediate host snail vectors of Schistosomiasis.

    PubMed

    Katz, Naftale; Araújo, Neusa; Coelho, Paulo Marcos Zech; Morel, Carlos Medicis; Linde-Arias, Ana Rosa; Yamada, Takeshi; Horimatsu, Yuki; Suzuki, Koh; Sunazuka, Toshiaki; Ōmura, Satoshi

    2017-03-15

    The impact of ivermectin on adult snails of the genus Biomphalaria (B. glabrata, B. tenagophila and B. straminea), B. glabrata infected with Schistosoma mansoni, snail egg-masses cercariae and miracidia, as well as on guppy fish (Poecilia reticulata) was examined and evaluated. Biomphalaria snails, egg-masses, parasite stages and guppies were all exposed to different concentrations of ivermectin for 24 h, followed by regular observations of mortality. The calculated lethal doses of ivermectin were around an LD50 of 0.03 μg ml(-1), and an LD90 of 0.3 μg ml(-1) for the three species of snails. Specimens of B. glabrata actually shedding parasite cercariae all died when exposed to ivermectin at a concentration of a mere 0.01 μg ml(-1). Ivermectin B1a, the major (80%) component of commercially available ivermectin, proved to be inactive, and it was the minor (20%) component, ivermectin B1b, which caused snail death. Snail egg-masses were not affected, even at the highest concentration of 100 μg ml(-1). With respect to S. mansoni parasite stages, 0.2 μg ml(-1) ivermectin killed 50% of cercariae and miracidia within five minutes, rising to 90% after 30 min. Mortality of guppy fish within 24 h of exposure to ivermectin at concentrations of 0.5 μg ml(-1) and 0.01 μg ml(-1), were 100% and 30%, respectively. The concentration of 0.01 μg ml(-1) that killed Schistosoma mansoni-infected snails only caused 30% mortality in guppy fish. Ivermectin can be considered a promising molluscicide, especially as it is more potent against infected snails than uninfected ones, although it has no impact on egg-masses. Ivermectin and its derivatives could be explored in the search for a new agent to help control schistosomiasis transmission.The Journal of Antibiotics advance online publication, 15 March 2017; doi:10.1038/ja.2017.31.

  5. Day-to-day fluctuation of point-of-care circulating cathodic antigen test scores and faecal egg counts in children infected with Schistosoma mansoni in Ethiopia

    PubMed Central

    2014-01-01

    Background Determining the variation of circulating cathodic antigen (CCA) in urine and egg counts variation in stool between days in Schistosoma mansoni (S. mansoni) infected individuals is vital to decide whether or not to rely on a single-sample test for diagnosis of Schistosomiasis. In this study, the magnitude of day-to-day variation in urine-CCA test scores and in faecal egg counts was evaluated in school children in Ethiopia. Methods A total of 620 school children (age 8 to 12 years) were examined for S. mansoni infection using double Kato-Katz and single urine-CCA cassette methods (batch 32727) on three consecutive days. Results The prevalence of S. mansoni infection was 81.1% based on triple urine-CCA-cassette test and 53.1% based on six Kato-Katz thick smears. Among the study participants, 26.3% showed fluctuation in urine CCA and 32.4% showed fluctuation in egg output. Mean egg count as well as number of cases in each class of intensity and intensity of cassette band color varied over the three days of examination. Over 85% of the children that showed day-to-day variations in status of S. mansoni infection from negative to positive or vice versa by the Kato-Katz and the CCA methods had light intensity of infection. The fluctuation in both the CCA test scores and faecal egg count was not associated with age and sex. Conclusions The current study showed day-to-day variation in CCA and Kato-Katz test results of children infected with S. mansoni. This indicates the necessity of more than one urine or stool samples to be collected on different days for more reliable diagnosis of S. mansoni infection in low endemic areas. PMID:24742192

  6. Disposition of Mefloquine and Enpiroline Is Highly Influenced by a Chronic Schistosoma mansoni Infection

    PubMed Central

    Ingram, Katrin; Duthaler, Urs; Vargas, Mireille; Ellis, William

    2013-01-01

    Chronic Schistosoma mansoni infections lead to severe tissue destruction of the gut wall and liver and can influence drug disposition. This study aimed to investigate the impact of a chronic S. mansoni infection on the pharmacokinetic (PK) parameters of two promising antischistosomal lead candidates (mefloquine and enpiroline) in mice. Studies were conducted in two different mouse cohorts (S. mansoni-infected and uninfected mice) for both drugs. Plasma samples were collected at various time points after oral treatment (200 mg/kg of body weight) with study drugs. A high-performance liquid chromatography (HPLC) method was validated to analyze enpiroline and mefloquine in plasma. Livers and intestines were collected from infected animals to determine the onset of action, hepatic shift, and worm burden reduction. Following mefloquine administration, hepatic shifting and significant worm burden reductions (79.2%) were observed after 72 h. At 1 week posttreatment with enpiroline, the majority of worms had migrated to the liver and significant worm burden reductions were observed (93.1%). The HPLC method was selective, accurate (87.8 to 111.4%), and precise (<10%) for the analysis of both drugs in plasma samples. The PK profiles revealed increased values for half-life (t1/2) and area under the concentration-time curve (AUC) for both drugs in infected animals compared to the t1/2 and AUC values in uninfected animals. Considerable changes were observed for mefloquine, with a 5-fold increase of t1/2 (182.7 h versus 33.6 h) and 2-fold increase of AUC (1,116,517.8 ng · h/ml versus 522,409.1 ng · h/ml). S. mansoni infections in mice influence the PK profiles of enpiroline and mefloquine, leading to delayed clearance. Our data confirm that drug disposition should be carefully studied in schistosomiasis patients. PMID:23836173

  7. 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

  8. Disposition of mefloquine and enpiroline is highly influenced by a chronic Schistosoma mansoni infection.

    PubMed

    Ingram, Katrin; Duthaler, Urs; Vargas, Mireille; Ellis, William; Keiser, Jennifer

    2013-09-01

    Chronic Schistosoma mansoni infections lead to severe tissue destruction of the gut wall and liver and can influence drug disposition. This study aimed to investigate the impact of a chronic S. mansoni infection on the pharmacokinetic (PK) parameters of two promising antischistosomal lead candidates (mefloquine and enpiroline) in mice. Studies were conducted in two different mouse cohorts (S. mansoni-infected and uninfected mice) for both drugs. Plasma samples were collected at various time points after oral treatment (200 mg/kg of body weight) with study drugs. A high-performance liquid chromatography (HPLC) method was validated to analyze enpiroline and mefloquine in plasma. Livers and intestines were collected from infected animals to determine the onset of action, hepatic shift, and worm burden reduction. Following mefloquine administration, hepatic shifting and significant worm burden reductions (79.2%) were observed after 72 h. At 1 week posttreatment with enpiroline, the majority of worms had migrated to the liver and significant worm burden reductions were observed (93.1%). The HPLC method was selective, accurate (87.8 to 111.4%), and precise (<10%) for the analysis of both drugs in plasma samples. The PK profiles revealed increased values for half-life (t1/2) and area under the concentration-time curve (AUC) for both drugs in infected animals compared to the t1/2 and AUC values in uninfected animals. Considerable changes were observed for mefloquine, with a 5-fold increase of t1/2 (182.7 h versus 33.6 h) and 2-fold increase of AUC (1,116,517.8 ng · h/ml versus 522,409.1 ng · h/ml). S. mansoni infections in mice influence the PK profiles of enpiroline and mefloquine, leading to delayed clearance. Our data confirm that drug disposition should be carefully studied in schistosomiasis patients.

  9. 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

  10. 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

  11. 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

  12. 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.

  13. Molluscicide for the control of schistosomiasis in irrigation schemes

    PubMed Central

    Shiff, C. J.; Clarke, V. de V.; Evans, A. C.; Barnish, G.

    1973-01-01

    The development of large areas of irrigation farming in the south-eastern lowveld of Southern Rhodesia has produced the risk of severe transmission of schistosomiasis over an extent of some 30 000 ha. Control measures instituted by the Ministry of Health were primarily directed against the large and widely distributed snail populations by using molluscicides. The chemical was applied to the irrigation water by drip-feed methods once every 6-8 months. The drains, however, were treated routinely by pairs of rangers searching for snails and applying chemical where they were found. The efficacy of control operations has been assessed by longitudinal studies in children free from infection to determine the incidence of infection. The results indicate that transmission of both Schistosoma haematobium and S. mansoni has been reduced to a level below that measured in areas of the country where irrigation is not practised. The total annual cost for this work was US$ 54 800-55 500. PMID:4542798

  14. Schistosomiasis and Human Immunodeficiency Virus in Men in Tanzania.

    PubMed

    Downs, Jennifer A; de Dood, Claudia J; Dee, Hannah E; McGeehan, Megan; Khan, Hijab; Marenga, Abena; Adel, Patrick E; Faustine, Edward; Issarow, Benson; Kisanga, Emmanuel F; Kisigo, Godfrey Alfred; Ngahyolerwa, Salvius; Zahoro, Frank; Miyaye, Donald; Magawa, Ruth Gideon; Mngara, Julius; Lee, Myung Hee; Corstjens, Paul L A M; van Dam, Govert J; Fitzgerald, Daniel W

    2017-02-06

    Schistosomiasis is a parasitic worm infection that affects over 260 million individuals worldwide. Women with schistosome infections have been demonstrated to have a 4-fold increase in the odds of human immunodeficiency virus (HIV) infection compared with women without schistosome infections. A relationship between schistosome and HIV infections has not been clearly defined in men. Among 674 men aged 18-50 years living in rural Tanzania, we identified 429 (63.6%) who had a schistosome infection as defined by serum positivity for schistosome circulating anodic antigen, visualization of parasite eggs in urine or stool, or both. HIV infection was identified in 38 (5.6%). The odds of HIV infection was 1.3 [95% confidence interval = 0.6-2.5] (P = 0.53) among men with any schistosome infection (Schistosoma haematobium or Schistosoma mansoni), and it was 1.4 [0.6-3.3] (P = 0.43) among men with S. haematobium infection. Men with S. haematobium infection were significantly more likely to report the symptom of hemospermia than men without S. haematobium infection. We conclude that schistosome infections appear to have little to no association with HIV infection in men.

  15. 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

  16. 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.

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

    PubMed Central

    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

    2016-01-01

    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. The genome of the blood fluke Schistosoma mansoni.

    PubMed

    Berriman, Matthew; Haas, Brian J; LoVerde, Philip T; Wilson, R Alan; Dillon, Gary P; Cerqueira, Gustavo C; Mashiyama, Susan T; Al-Lazikani, Bissan; Andrade, Luiza F; Ashton, Peter D; Aslett, Martin A; Bartholomeu, Daniella C; Blandin, Gaelle; Caffrey, Conor R; Coghlan, Avril; Coulson, Richard; Day, Tim A; Delcher, Art; DeMarco, Ricardo; Djikeng, Appolinaire; Eyre, Tina; Gamble, John A; Ghedin, Elodie; Gu, Yong; Hertz-Fowler, Christiane; Hirai, Hirohisha; Hirai, Yuriko; Houston, Robin; Ivens, Alasdair; Johnston, David A; Lacerda, Daniela; Macedo, Camila D; McVeigh, Paul; Ning, Zemin; Oliveira, Guilherme; Overington, John P; Parkhill, Julian; Pertea, Mihaela; Pierce, Raymond J; Protasio, Anna V; Quail, Michael A; Rajandream, Marie-Adèle; Rogers, Jane; Sajid, Mohammed; Salzberg, Steven L; Stanke, Mario; Tivey, Adrian R; White, Owen; Williams, David L; Wortman, Jennifer; Wu, Wenjie; Zamanian, Mostafa; Zerlotini, Adhemar; Fraser-Liggett, Claire M; Barrell, Barclay G; El-Sayed, Najib M

    2009-07-16

    Schistosoma mansoni is responsible for the neglected tropical disease schistosomiasis that affects 210 million people in 76 countries. Here we present analysis of the 363 megabase nuclear genome of the blood fluke. It encodes at least 11,809 genes, with an unusual intron size distribution, and new families of micro-exon genes that undergo frequent alternative splicing. As the first sequenced flatworm, and a representative of the Lophotrochozoa, it offers insights into early events in the evolution of the animals, including the development of a body pattern with bilateral symmetry, and the development of tissues into organs. Our analysis has been informed by the need to find new drug targets. The deficits in lipid metabolism that make schistosomes dependent on the host are revealed, and the identification of membrane receptors, ion channels and more than 300 proteases provide new insights into the biology of the life cycle and new targets. Bioinformatics approaches have identified metabolic chokepoints, and a chemogenomic screen has pinpointed schistosome proteins for which existing drugs may be active. The information generated provides an invaluable resource for the research community to develop much needed new control tools for the treatment and eradication of this important and neglected disease.

  19. Refolding of the recombinant protein Sm29, a step toward the production of the vaccine candidate against schistosomiasis.

    PubMed

    Chura-Chambi, Rosa M; Nakajima, Erika; de Carvalho, Roberta R; Miyasato, Patricia A; Oliveira, Sergio C; Morganti, Ligia; Martins, Elizabeth A L

    2013-12-01

    Schistosomiasis is an important parasitic disease, with about 240 million people infected worldwide. Humans and animals can be infected, imposing an enormous social and economic burden. The only drug available for chemotherapy, praziquantel, does not control reinfections, and an efficient vaccine for prophylaxis is still missing. However, the tegumental protein Sm29 of Schistosoma mansoni was shown to be a promising antigen to compose an anti-schistosomiasis vaccine. Though, recombinant Sm29 is expressed in Escherichia coli as insoluble inclusion bodies requiring an efficient process of refolding, thus, hampering its production in large scale. We present in this work studies to refold the recombinant Sm29 using high hydrostatic pressure, a mild condition to dissociate aggregated proteins, leading to refolding on a soluble conformation. Our studies resulted in high yield of rSm29 (73%) as a stably soluble and structured protein. The refolded antigen presented protective effect against S. mansoni development in immunized mice. We concluded that the refolding process by application of high hydrostatic pressure succeeded, and the procedure can be scaled-up, allowing industrial production of Sm29.

  20. Schistosomiasis in non-endemic countries.

    PubMed

    Coltart, Cordelia; Whitty, Christopher J M

    2015-02-01

    Schistosomiasis is one of the major parasitic diseases of the tropics, causing acute and long-term clinical syndromes. Almost all schistosomiasis is now imported from sub-Saharan Africa. This article summarises the aetiology, clinical presentation, diagnosis and management of schistosomiaisis for clinicians in non-endemic countries.

  1. Schistosomiasis Japonicum Involving the Liver and Colon

    DTIC Science & Technology

    2007-02-01

    presentation, typical imaging findings, and treatment of Schistosomiasis. Schistosomiasis is a chronic infection caused by parasitic trematode worms that...ova are subsequently deposited within the liver, gastrointestinal tract, and genitourinary tract and a granulomatous and fibrotic reaction ensues...potentially result in permanent gastrointestinal and urinary system damage if not appropriately treated. History A 51-year-old female

  2. 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

  3. A quantitative proteomic analysis of the tegumental proteins from Schistosoma mansoni schistosomula reveals novel potential therapeutic targets.

    PubMed

    Sotillo, Javier; Pearson, Mark; Becker, Luke; Mulvenna, Jason; Loukas, Alex

    2015-07-01

    The tegument of Schistosoma mansoni plays an integral role in host-parasite interactions, particularly during the transition from the free-living cercariae to the intra-mammalian schistosomula stages. This developmental period is characterised by the transition from a trilaminate surface to a heptalaminate tegument that plays key roles in immune evasion, nutrition and excretion. Proteins exposed at the surface membranes of newly transformed schistosomula are therefore thought to be prime targets for the development of new vaccines and drugs for schistosomiasis. Using a combination of tegumental labelling and high-throughput quantitative proteomics, more than 450 proteins were identified on the apical membrane of S. mansoni schistosomula, of which 200 had significantly regulated expression profiles at different stages of schistosomula development in vitro, including glucose transporters, sterols, heat shock proteins, antioxidant enzymes and peptidases. Current vaccine antigens were identified on the apical membrane (Sm-TSP-1, calpain) or sub-tegumental (Sm-TSP-2, Sm29) fractions of the schistosomula, displaying localisation patterns that, in some cases, differ from that in the adult stage fluke. This work provides the first known in-depth proteomic analysis of the surface-exposed proteins in the schistosomula tegument, and some of the proteins identified are clear targets for the generation of new vaccines and drugs against schistosomiasis.

  4. Changes in the small intestine of Schistosoma mansoni-infected mice fed a high-fat diet.

    PubMed

    Alencar, Alba Cristina Miranda de Barros; Neves, Renata Heisler; de Oliveira, Albanita Viana; Machado-Silva, José Roberto

    2012-05-01

    The consumption of a high-fat diet modifies both the morphology of the small intestine and experimentally tested effects of schistosomiasis mansoni. However, whether a schistosomiasis infection associated with a high-fat diet causes injury to the small intestine has never been investigated. Mice were fed either a high-fat or a standard-fat diet for 6 months and were then infected with Schistosoma mansoni cercariae. Physical characteristics of the intestinal tissue (mucosal thickness, small intestinal villi length and height, and abundance of goblet cells and enterocytes on the villous surface) and the distribution of granulomas along the intestinal segments and their developmental stage were measured at the time of sacrifice (9 or 17 weeks post-infection). The group fed a high-fat diet exhibited different granuloma stages, whereas the control group possessed only exudative granulomas. The chronically infected mice fed a high-fat diet exhibited higher granuloma and egg numbers than the acutely infected group. Exudative, exudative/exudative-productive and exudative-productive granulomas were present irrespective of diet. Computer-aided morphometric analysis confirmed that villus length, villus width, muscular height and submucosal height of the duodenal and jejunal segments were affected by diet and infection. In conclusion, a high-fat diet and infection had a significant impact on the small intestine morphology and morphometry among the animals tested.

  5. Geostatistical Model-Based Estimates of Schistosomiasis Prevalence among Individuals Aged ≤20 Years in West Africa

    PubMed Central

    Schur, Nadine; Hürlimann, Eveline; Garba, Amadou; Traoré, Mamadou S.; Ndir, Omar; Ratard, Raoult C.; Tchuem Tchuenté, Louis-Albert; Kristensen, Thomas K.; Utzinger, Jürg; Vounatsou, Penelope

    2011-01-01

    Background Schistosomiasis is a water-based disease that is believed to affect over 200 million people with an estimated 97% of the infections concentrated in Africa. However, these statistics are largely based on population re-adjusted data originally published by Utroska and colleagues more than 20 years ago. Hence, these estimates are outdated due to large-scale preventive chemotherapy programs, improved sanitation, water resources development and management, among other reasons. For planning, coordination, and evaluation of control activities, it is essential to possess reliable schistosomiasis prevalence maps. Methodology We analyzed survey data compiled on a newly established open-access global neglected tropical diseases database (i) to create smooth empirical prevalence maps for Schistosoma mansoni and S. haematobium for individuals aged ≤20 years in West Africa, including Cameroon, and (ii) to derive country-specific prevalence estimates. We used Bayesian geostatistical models based on environmental predictors to take into account potential clustering due to common spatially structured exposures. Prediction at unobserved locations was facilitated by joint kriging. Principal Findings Our models revealed that 50.8 million individuals aged ≤20 years in West Africa are infected with either S. mansoni, or S. haematobium, or both species concurrently. The country prevalence estimates ranged between 0.5% (The Gambia) and 37.1% (Liberia) for S. mansoni, and between 17.6% (The Gambia) and 51.6% (Sierra Leone) for S. haematobium. We observed that the combined prevalence for both schistosome species is two-fold lower in Gambia than previously reported, while we found an almost two-fold higher estimate for Liberia (58.3%) than reported before (30.0%). Our predictions are likely to overestimate overall country prevalence, since modeling was based on children and adolescents up to the age of 20 years who are at highest risk of infection. Conclusion/Significance We

  6. 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.

  7. 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

  8. Significantly Reduced Intensity of Infection but Persistent Prevalence of Schistosomiasis in a Highly Endemic Region in Mali after Repeated Treatment

    PubMed Central

    Landouré, Aly; Dembélé, Robert; Goita, Seydou; Kané, Mamadou; Tuinsma, Marjon; Sacko, Moussa; Toubali, Emily; French, Michael D.; Keita, Adama D.; Fenwick, Alan; Traoré, Mamadou S.; Zhang, Yaobi

    2012-01-01

    Background Preventive chemotherapy against schistosomiasis has been implemented since 2005 in Mali, targeting school-age children and adults at high risk. A cross-sectional survey was conducted in 2010 to evaluate the impact of repeated treatment among school-age children in the highly-endemic region of Segou. Methodology/Principal Findings The survey was conducted in six sentinel schools in three highly-endemic districts, and 640 school children aged 7–14 years were examined. Infections with Schistosoma haematobium and S. mansoni were diagnosed with the urine filtration and the Kato-Katz method respectively. Overall prevalence of S. haematobium infection was 61.7%, a significant reduction of 30% from the baseline in 2004 (p<0.01), while overall prevalence of S. mansoni infection was 12.7% which was not significantly different from the baseline. Overall mean intensity of S. haematobium and S. mansoni infection was 180.4 eggs/10 ml of urine and 88.2 epg in 2004 respectively. These were reduced to 33.2 eggs/10 ml of urine and 43.2 epg in 2010 respectively, a significant reduction of 81.6% and 51% (p<0.001). The proportion of heavy S. haematobium infections was reduced from 48.8% in 2004 to 13.8% in 2010, and the proportion of moderate and heavy S. mansoni infection was reduced from 15.6% in 2004 to 9.4% in 2010, both significantly (p<0.01). Mathematical modelling suggests that the observed results were in line with the expected changes. Conclusions/Significance Significant reduction in intensity of infection on both infections and modest but significant reduction in S. haematobium prevalence were achieved in highly-endemic Segou region after repeated chemotherapy. However, persistent prevalence of both infections and relatively high level of intensity of S. mansoni infection suggest that more intensified control measures be implemented in order to achieve the goal of schistosomiasis elimination. In addition, closer monitoring and evaluation activities are needed in

  9. [Urinary schistosomiasis in ancient Egypt].

    PubMed

    Ziskind, Bernard

    2009-12-01

    First described by Theodor Bilharz in 1851, Schistosoma haematobium, the worm responsible for urinary schistosomiasis, was a major health problem along the Nile Valley until the present days. Haematuria, the main symptom of this parasitic disease, was known and treated in Egyptian medical papyri since 1550 B.C. A relationship between haematuria and the god Seth was envisaged. Sir Marc Armand Ruffer, pioneer of paleopathology, found (1910) calcified Schistosoma eggs in Egyptian mummies of the xxth dynasty, establishing that bilharzia plagued ancient Egypt people. The ELISA method demonstrated the Schistosoma circulating anodic antigen in 45% of mummies studied.

  10. Reduced Efficacy of Praziquantel Against Schistosoma mansoni Is Associated With Multiple Rounds of Mass Drug Administration

    PubMed Central

    Crellen, Thomas; Walker, Martin; Lamberton, Poppy H. L.; Kabatereine, Narcis B.; Tukahebwa, Edridah M.; Cotton, James A.; Webster, Joanne P.

    2016-01-01

    Background. Mass drug administration (MDA) with praziquantel is the cornerstone of schistosomiasis control in sub-Saharan Africa. The effectiveness of this strategy is dependent on the continued high efficacy of praziquantel; however, drug efficacy is rarely monitored using appropriate statistical approaches that can detect early signs of wane. Methods. We conducted a repeated cross-sectional study, examining children infected with Schistosoma mansoni from 6 schools in Uganda that had previously received between 1 and 9 rounds of MDA with praziquantel. We collected up to 12 S. mansoni egg counts from 414 children aged 6–12 years before and 25–27 days after treatment with praziquantel. We estimated individual patient egg reduction rates (ERRs) using a statistical model to explore the influence of covariates, including the number of prior MDA rounds. Results. The average ERR among children within schools that had received 8 or 9 previous rounds of MDA (95% Bayesian credible interval [BCI], 88.23%–93.64%) was statistically significantly lower than the average in schools that had received 5 rounds (95% BCI, 96.13%–99.08%) or 1 round (95% BCI, 95.51%–98.96%) of MDA. We estimate that 5.11%, 4.55%, and 16.42% of children from schools that had received 1, 5, and 8–9 rounds of MDA, respectively, had ERRs below the 90% threshold of optimal praziquantel efficacy set by the World Health Organization. Conclusions. The reduced efficacy of praziquantel in schools with a higher exposure to MDA may pose a threat to the effectiveness of schistosomiasis control programs. We call for the efficacy of anthelmintic drugs used in MDA to be closely monitored. PMID:27470241

  11. Evaluation of Urine CCA Assays for Detection of Schistosoma mansoni Infection in Western Kenya

    PubMed Central

    Shane, Hillary L.; Verani, Jennifer R.; Abudho, Bernard; Montgomery, Susan P.; Blackstock, Anna J.; Mwinzi, Pauline N. M.; Butler, Sara E.; Karanja, Diana M. S.; Secor, W. Evan

    2011-01-01

    Although accurate assessment of the prevalence of Schistosoma mansoni is important for the design and evaluation of control programs, the most widely used tools for diagnosis are limited by suboptimal sensitivity, slow turn-around-time, or inability to distinguish current from former infections. Recently, two tests that detect circulating cathodic antigen (CCA) in urine of patients with schistosomiasis became commercially available. As part of a larger study on schistosomiasis prevalence in young children, we evaluated the performance and diagnostic accuracy of these tests—the carbon test strip designed for use in the laboratory and the cassette format test intended for field use. In comparison to 6 Kato-Katz exams, the carbon and cassette CCA tests had sensitivities of 88.4% and 94.2% and specificities of 70.9% and 59.4%, respectively. However, because of the known limitations of the Kato-Katz assay, we also utilized latent class analysis (LCA) incorporating the CCA, Kato-Katz, and schistosome-specific antibody results to determine their sensitivities and specificities. The laboratory-based CCA test had a sensitivity of 91.7% and a specificity of 89.4% by LCA while the cassette test had a sensitivity of 96.3% and a specificity of 74.7%. The intensity of the reaction in both urine CCA tests reflected stool egg burden and their performance was not affected by the presence of soil transmitted helminth infections. Our results suggest that urine-based assays for CCA may be valuable in screening for S. mansoni infections. PMID:21283613

  12. HIV-1 Integrates Widely throughout the Genome of the Human Blood Fluke Schistosoma mansoni

    PubMed Central

    Mann, Victoria H.; Dubrovsky, Larisa; Yan, Hong-bin; Huckvale, Thomas; Protasio, Anna V.; Pushkarsky, Tatiana; Iordanskiy, Sergey; Bukrinsky, Michael I.

    2016-01-01

    Schistosomiasis is the most important helminthic disease of humanity in terms of morbidity and mortality. Facile manipulation of schistosomes using lentiviruses would enable advances in functional genomics in these and related neglected tropical diseases pathogens including tapeworms, and including their non-dividing cells. Such approaches have hitherto been unavailable. Blood stream forms of the human blood fluke, Schistosoma mansoni, the causative agent of the hepatointestinal schistosomiasis, were infected with the human HIV-1 isolate NL4-3 pseudotyped with vesicular stomatitis virus glycoprotein. The appearance of strong stop and positive strand cDNAs indicated that virions fused to schistosome cells, the nucleocapsid internalized and the RNA genome reverse transcribed. Anchored PCR analysis, sequencing HIV-1-specific anchored Illumina libraries and Whole Genome Sequencing (WGS) of schistosomes confirmed chromosomal integration; >8,000 integrations were mapped, distributed throughout the eight pairs of chromosomes including the sex chromosomes. The rate of integrations in the genome exceeded five per 1,000 kb and HIV-1 integrated into protein-encoding loci and elsewhere with integration bias dissimilar to that of human T cells. We estimated ~ 2,100 integrations per schistosomulum based on WGS, i.e. about two or three events per cell, comparable to integration rates in human cells. Accomplishment in schistosomes of post-entry processes essential for HIV-1replication, including integrase-catalyzed integration, was remarkable given the phylogenetic distance between schistosomes and primates, the natural hosts of the genus Lentivirus. These enigmatic findings revealed that HIV-1 was active within cells of S. mansoni, and provided the first demonstration that HIV-1 can integrate into the genome of an invertebrate. PMID:27764257

  13. A Meta-Analysis of Experimental Studies of Attenuated Schistosoma mansoni Vaccines in the Mouse Model

    PubMed Central

    Fukushige, Mizuho; Mitchell, Kate M.; Bourke, Claire D.; Woolhouse, Mark E. J.; Mutapi, Francisca

    2015-01-01

    Schistosomiasis is a water-borne, parasitic disease of major public health importance. There has been considerable effort for several decades toward the development of a vaccine against the disease. Numerous mouse experimental studies using attenuated Schistosoma mansoni parasites for vaccination have been published since 1960s. However, to date, there has been no systematic review or meta-analysis of these data. The aim of this study is to identify measurable experimental conditions that affect the level of protection against re-infection with S. mansoni in mice vaccinated with radiation attenuated cercariae. Following a systematic review, a total of 755 observations were extracted from 105 articles (published 1963–2007) meeting the searching criteria. Random effects meta-regression models were used to identify the influential predictors. Three predictors were found to have statistically significant effects on the level of protection from vaccination: increasing numbers of immunizing parasites had a positive effect on fraction of protection whereas increasing radiation dose and time to challenge infection had negative effects. Models showed that the irradiated cercariae vaccine has the potential to achieve protection as high as 78% with a single dose vaccination. This declines slowly over time but remains high for at least 8 months after the last immunization. These findings provide insights into the optimal delivery of attenuated parasite vaccination and into the nature and development of protective vaccine induced immunity against schistosomiasis, which may inform the formulation of human vaccines and the predicted duration of protection and thus frequency of booster vaccines. PMID:25774157

  14. Evaluation of urine CCA assays for detection of Schistosoma mansoni infection in Western Kenya.

    PubMed

    Shane, Hillary L; Verani, Jennifer R; Abudho, Bernard; Montgomery, Susan P; Blackstock, Anna J; Mwinzi, Pauline N M; Butler, Sara E; Karanja, Diana M S; Secor, W Evan

    2011-01-25

    Although accurate assessment of the prevalence of Schistosoma mansoni is important for the design and evaluation of control programs, the most widely used tools for diagnosis are limited by suboptimal sensitivity, slow turn-around-time, or inability to distinguish current from former infections. Recently, two tests that detect circulating cathodic antigen (CCA) in urine of patients with schistosomiasis became commercially available. As part of a larger study on schistosomiasis prevalence in young children, we evaluated the performance and diagnostic accuracy of these tests--the carbon test strip designed for use in the laboratory and the cassette format test intended for field use. In comparison to 6 Kato-Katz exams, the carbon and cassette CCA tests had sensitivities of 88.4% and 94.2% and specificities of 70.9% and 59.4%, respectively. However, because of the known limitations of the Kato-Katz assay, we also utilized latent class analysis (LCA) incorporating the CCA, Kato-Katz, and schistosome-specific antibody results to determine their sensitivities and specificities. The laboratory-based CCA test had a sensitivity of 91.7% and a specificity of 89.4% by LCA while the cassette test had a sensitivity of 96.3% and a specificity of 74.7%. The intensity of the reaction in both urine CCA tests reflected stool egg burden and their performance was not affected by the presence of soil transmitted helminth infections. Our results suggest that urine-based assays for CCA may be valuable in screening for S. mansoni infections.

  15. HIV-1 Integrates Widely throughout the Genome of the Human Blood Fluke Schistosoma mansoni.

    PubMed

    Suttiprapa, Sutas; Rinaldi, Gabriel; Tsai, Isheng J; Mann, Victoria H; Dubrovsky, Larisa; Yan, Hong-Bin; Holroyd, Nancy; Huckvale, Thomas; Durrant, Caroline; Protasio, Anna V; Pushkarsky, Tatiana; Iordanskiy, Sergey; Berriman, Matthew; Bukrinsky, Michael I; Brindley, Paul J

    2016-10-01

    Schistosomiasis is the most important helminthic disease of humanity in terms of morbidity and mortality. Facile manipulation of schistosomes using lentiviruses would enable advances in functional genomics in these and related neglected tropical diseases pathogens including tapeworms, and including their non-dividing cells. Such approaches have hitherto been unavailable. Blood stream forms of the human blood fluke, Schistosoma mansoni, the causative agent of the hepatointestinal schistosomiasis, were infected with the human HIV-1 isolate NL4-3 pseudotyped with vesicular stomatitis virus glycoprotein. The appearance of strong stop and positive strand cDNAs indicated that virions fused to schistosome cells, the nucleocapsid internalized and the RNA genome reverse transcribed. Anchored PCR analysis, sequencing HIV-1-specific anchored Illumina libraries and Whole Genome Sequencing (WGS) of schistosomes confirmed chromosomal integration; >8,000 integrations were mapped, distributed throughout the eight pairs of chromosomes including the sex chromosomes. The rate of integrations in the genome exceeded five per 1,000 kb and HIV-1 integrated into protein-encoding loci and elsewhere with integration bias dissimilar to that of human T cells. We estimated ~ 2,100 integrations per schistosomulum based on WGS, i.e. about two or three events per cell, comparable to integration rates in human cells. Accomplishment in schistosomes of post-entry processes essential for HIV-1replication, including integrase-catalyzed integration, was remarkable given the phylogenetic distance between schistosomes and primates, the natural hosts of the genus Lentivirus. These enigmatic findings revealed that HIV-1 was active within cells of S. mansoni, and provided the first demonstration that HIV-1 can integrate into the genome of an invertebrate.

  16. Artemether shows promising female schistosomicidal and ovicidal effects on the Egyptian strain of Schistosoma mansoni after maturity of infection.

    PubMed

    Abdul-Ghani, Rashad; Loutfy, Naguiba; Sheta, Manal; Hassan, Azza

    2011-05-01

    Artemether is an artemisinin derivative that is used as an antimalarial drug, especially in situations where chloroquine resistance is suspected. This compound has proved to be a good prophylactic agent against schistosomiasis japonica in China. In the present study, the therapeutic efficacies of different artemether-dosing protocols were evaluated in experimentally infected mice harbouring adult Schistosoma mansoni (Egyptian strain). Mice were treated on day 46 onwards with three dosing protocols (400 mg/kg/day for 2 days; 200 mg/kg/day for 4 days; 100 mg/kg/day for 6 days) after being infected. A number of parasitological and histopathological criteria were employed in the assessment of drug efficacies compared to infected untreated control 2 weeks post-treatment. The results of the present study suggest that artemether is efficacious against the Egyptian strain of S. mansoni with total worm reductions ranging from 40.7% to 59.7% and female worm reductions ranging from 69.3% to >90%. In addition, artemether induced significant reductions, ranging from 75.2% to 82.6%, in the liver tissue egg loads as well as significant reductions, ranging from 68.8% to 78.9% in the intestinal wall egg loads. It also induced significant alterations in the oogram pattern in the intestinal mucosa of infected mice with cessation of oviposition and increased rates of dead eggs. Antipathologic activities were also evident in the amelioration of granulomas in the liver with increased ratios of healed to active ones. In conclusion, artemether could be a promising agent in the control of schistosomiasis mansoni due to its schistosomicidal effects on female worms and to its ovicidal power as well as its potentiality in the improvement of hepatic lesions.

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

    PubMed

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

    2015-12-01

    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.

  18. 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

  19. 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

  20. 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.

  1. 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

  2. Analysis of Schistosoma mansoni genes shared with Deuterostomia and with possible roles in host interactions

    PubMed Central

    Venancio, Thiago M; DeMarco, Ricardo; Almeida, Giulliana T; Oliveira, Katia C; Setubal, João C; Verjovski-Almeida, Sergio

    2007-01-01

    Background: Schistosoma mansoni is a blood helminth parasite that causes schistosomiasis, a disease that affects 200 million people in the world. Many orthologs of known mammalian genes have been discovered in this parasite and evidence is accumulating that some of these genes encode proteins linked to signaling pathways in the parasite that appear to be involved with growth or development, suggesting a complex co-evolutionary process. Results: In this work we found 427 genes conserved in the Deuterostomia group that have orthologs in S. mansoni and no members in any nematodes and insects so far sequenced. Among these genes we have identified Insulin Induced Gene (INSIG), Interferon Regulatory Factor (IRF) and vasohibin orthologs, known to be involved in mammals in mevalonate metabolism, immune response and angiogenesis control, respectively. We have chosen these three genes for a more detailed characterization, which included extension of their cloned messages to obtain full-length sequences. Interestingly, SmINSIG showed a 10-fold higher expression in adult females as opposed to males, in accordance with its possible role in regulating egg production. SmIRF has a DNA binding domain, a tryptophan-rich N-terminal region and several predicted phosphorylation sites, usually important for IRF activity. Fourteen different alternatively spliced forms of the S. mansoni vasohibin (SmVASL) gene were detected that encode seven different protein isoforms including one with a complete C-terminal end, and other isoforms with shorter C-terminal portions. Using S. mansoni homologs, we have employed a parsimonious rationale to compute the total gene losses/gains in nematodes, arthropods and deuterostomes under either the Coelomata or the Ecdysozoa evolutionary hypotheses; our results show a lower losses/gains number under the latter hypothesis. Conclusion: The genes discussed which are conserved between S. mansoni and deuterostomes, probably have an ancient origin and were lost

  3. 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.

  4. 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.

  5. Dracunculiasis, onchocerciasis, schistosomiasis, and trachoma.

    PubMed

    Hopkins, Donald R; Richards, Frank O; Ruiz-Tiben, Ernesto; Emerson, Paul; Withers, P Craig

    2008-01-01

    The four diseases discussed in this chapter (dracunculiasis, onchocerciasis, schistosomiasis, and trachoma) are among the officially designated "Neglected Tropical Diseases," and each is also both the result of and a contributor to the poverty of many rural populations. To various degrees, they all have adverse effects on health, agricultural productivity, and education. The Carter Center decided to work on these health problems because of their adverse effect on the lives of poor people and the opportunity to help implement effective interventions. As a result of the global campaign spearheaded by the Carter Center since 1986, the extent of dracunculiasis has been reduced from 20 to five endemic countries and the number of cases reduced by more than 99%. We have helped administer nearly 20% of the 530 million Mectizan (ivermectin) doses for onchocerciasis, which is now being controlled throughout most of Africa, and is progressing toward elimination in the Americas. Since 1999, two Nigerian states have been using village-based health workers originally recruited to work on onchocerciasis to also deliver mass treatment and health education for schistosomiasis and lymphatic filariasis. They now also distribute vitamin A supplements and bed nets to prevent malaria and lymphatic filariasis. Ethiopia aims to eliminate blinding trachoma in the Amhara Region of that highest-endemicity country by 2012, already constructing more than 300,000 latrines and other complementary interventions. Because of the synergy between these diseases and poverty, controlling or eliminating the disease also reduces poverty and increases self-reliance.

  6. Development and Validation of a Luminescence-based, Medium-Throughput Assay for Drug Screening in Schistosoma mansoni

    PubMed Central

    Lalli, Cristiana; Guidi, Alessandra; Gennari, Nadia; Altamura, Sergio; Bresciani, Alberto; Ruberti, Giovina

    2015-01-01

    Background Schistosomiasis, one of the world’s greatest neglected tropical diseases, is responsible for over 280,000 human deaths per annum. Praziquantel, developed in the 1970s, has high efficacy, excellent tolerability, few and transient side effects, simple administration procedures and competitive cost and it is currently the only recommended drug for treatment of human schistosomiasis. The use of a single drug to treat a population of over 200 million infected people appears particularly alarming when considering the threat of drug resistance. Quantitative, objective and validated methods for the screening of compound collections are needed for the discovery of novel anti-schistosomal drugs. Methodology/Principal Findings The present work describes the development and validation of a luminescence-based, medium-throughput assay for the detection of schistosomula viability through quantitation of ATP, a good indicator of metabolically active cells in culture. This validated method is demonstrated to be fast, highly reliable, sensitive and automation-friendly. The optimized assay was used for the screening of a small compound library on S. mansoni schistosomula, showing that the proposed method is suitable for a medium-throughput semi-automated screening. Interestingly, the pilot screening identified hits previously reported to have some anti-parasitic activity, further supporting the validity of this assay for anthelminthic drug discovery. Conclusions The developed and validated schistosomula viability luminescence-based assay was shown to be successful and suitable for the identification of novel compounds potentially exploitable in future schistosomiasis therapies. PMID:25635836

  7. Natural Schistosoma mansoni Infection in the Wild Reservoir Nectomys squamipes Leads to Excessive Lipid Droplet Accumulation in Hepatocytes in the Absence of Liver Functional Impairment

    PubMed Central

    Amaral, Kátia B.; Silva, Thiago P.; Malta, Kássia K.; Carmo, Lívia A. S.; Dias, Felipe F.; Almeida, Mariana R.; Andrade, Gustavo F. S.; Martins, Jefferson S.; Pinho, Roberto R.; Costa-Neto, Sócrates F.; Gentile, Rosana

    2016-01-01

    Schistosomiasis is a neglected tropical disease of a significant public health impact. The water rat Nectomys squamipes is one of the most important non-human hosts in the schistosomiasis mansoni transmission in Brazil, being considered a wild reservoir. Cellular mechanisms that contribute to the physiological adaptation of this rodent to the Schistosoma mansoni parasite are poorly understood. Here we identified, for the first time, that a hepatic steatosis, a condition characterized by excessive lipid accumulation with formation of lipid droplets (LDs) within hepatocytes, occurs in response to the natural S. mansoni infection of N. squamipes, captured in an endemic region. Significant increases of LD area in the hepatic tissue and LD numbers/hepatocyte, detected by quantitative histopathological and ultrastructural analyses, were paralleled by increased serum profile (total cholesterol and triglycerides) in infected compared to uninfected animals. Raman spectroscopy showed high content of polyunsaturated fatty acids (PUFAs) in the liver of both groups. MALDI-TOFF mass spectroscopy revealed an amplified pool of omega-6 PUFA arachidonic acid in the liver of infected animals. Assessment of liver functional activity by the levels of hepatic transaminases (ALT and AST) did not detect any alteration during the natural infection. In summary, this work demonstrates that the natural infection of the wild reservoir N. squamipes with S. mansoni elicits hepatic steatosis in the absence of liver functional harm and that accumulation of lipids, markedly PUFAs, coexists with low occurrence of inflammatory granulomatous processes, suggesting that lipid stores may be acting as a protective mechanism for dealing with the infection. PMID:27880808

  8. Schistosoma mansoni Infection of Mice, Rats and Humans Elicits a Strong Antibody Response to a Limited Number of Reduction-Sensitive Epitopes on Five Major Tegumental Membrane Proteins

    PubMed Central

    Tremblay, Jacqueline M.; Oliveira, Sergio C.; Da’dara, Akram A.; Skelly, Patrick J.

    2017-01-01

    Schistosomiasis is a major disease of the developing world for which no vaccine has been successfully commercialized. While numerous Schistosoma mansoni worm antigens have been identified that elicit antibody responses during natural infections, little is known as to the identities of the schistosome antigens that are most prominently recognized by antibodies generated through natural infection. Non-reducing western blots probed with serum from schistosome-infected mice, rats and humans on total extracts of larval or adult schistosomes revealed that a small number of antigen bands predominate in all cases. Recognition of each of these major bands was lost when the blots were run under reducing condition. We expressed a rationally selected group of schistosome tegumental membrane antigens in insect host cells, and used the membrane extracts of these cells to unambiguously identify the major antigens recognized by S. mansoni infected mouse, rat and human serum. These results revealed that a limited number of dominant, reduction-sensitive conformational epitopes on five major tegumental surface membrane proteins: SmTsp2, Sm23, Sm29, SmLy6B and SmLy6F, are primary targets of mouse, rat and human S. mansoni infection sera antibodies. We conclude that, Schistosoma mansoni infection of both permissive (mouse) and non-permissive (rat) rodent models, as well as humans, elicit a dominant antibody response recognizing a limited number of conformational epitopes on the same five tegumental membrane proteins. Thus it appears that neither infecting schistosomula nor mature adult schistosomes are substantively impacted by the robust circulating anti-tegumental antibody response they elicit to these antigens. Importantly, our data suggest a need to re-evaluate host immune responses to many schistosome antigens and has important implications regarding schistosome immune evasion mechanisms and schistosomiasis vaccine development. PMID:28095417

  9. A tale of two neglected tropical infections: using GIS to assess the spatial and temporal overlap of schistosomiasis and leprosy in a region of Minas Gerais, Brazil

    PubMed Central

    Phillips, David Alexander; Ferreira, José Antonio; Ansah, Deidra; Teixeira, Herica SA; Kitron, Uriel; de Filippis, Thelma; de Alcântara, Marcelo H; Fairley, Jessica K

    2017-01-01

    BACKGROUND Despite public health efforts to reduce the global burden of leprosy, gaps remain in the knowledge surrounding transmission of infection. Helminth co-infections have been associated with a shift towards the lepromatous end of the disease spectrum, potentially increasing transmission in co-endemic areas. OBJECTIVES Using this biologically plausible association, we conducted a geographic information systems (GIS) study to investigate the spatial associations of schistosomiasis and leprosy in an endemic area of Minas Gerais (MG), Brazil. METHODS Data on new cases of Mycobacterium leprae and Schistosoma mansoni infections from 2007-2014 were retrieved from the Brazilian national notifiable diseases information system for seven municipalities in and surrounding Vespasiano, MG. A total of 139 cases of leprosy and 200 cases of schistosomiasis were mapped to a municipality level. For one municipality, cases were mapped to a neighborhood level and a stratified analysis was conducted to identify spatial associations. FINDINGS A relative risk of 6.80 [95% confidence interval (CI) 1.46 - 31.64] of leprosy was found in neighborhoods with schistosomiasis. Incidence rates of leprosy increased with corresponding incidence rates of schistosomiasis, and the temporal trends of both infections were similar. CONCLUSIONS The associations found in this project support the hypothesis that helminth infections may influence the transmission of leprosy in co-endemic areas. PMID:28327791

  10. 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.

  11. Synergistic effects of in vitro combinations of piplartine, epiisopiloturine and praziquantel against Schistosoma mansoni.

    PubMed

    Campelo, Yuri Dias Macedo; Mafud, Ana Carolina; Véras, Leiz Maria Costa; Guimarães, Maria Adelaide; Yamaguchi, Lydia F; Lima, David Fernandes; Arcanjo, Daniel Dias Rufino; Kato, Massuo J; Mendonça, Ronaldo Z; Pinto, Pedro Luiz Silva; Mascarenhas, Yvonne Primerano; Silva, Marcos P N; de Moraes, Josué; Eaton, Peter; de Souza de Almeida Leite, José Roberto

    2017-04-01

    Schistosomiasis is a world health problem, and praziquantel is the only drug currently used for the treatment. There is some evidence that extensive monotherapy of praziquantel may be leading to drug resistance in the parasite. In order to find alternative treatments, the effects of the combination of epiisopiloturine (EPI), piplartine (PPT) and praziquantel (PZQ) were evaluated. Similarity analysis of these compounds was performed using optimized molecular structures to compare the shape and the charge modeling of combinations between PZQ and EPI or PPT. Supported by this data, in vitro association of PZQ-PPT, PZQ-EPI, and EPI-PPT was carried out, and the activity of these combinations against Schistosoma mansoni was assessed. The results showed synergistic activity with a combination index (CI) of 0.42 for the treatment with PZQ-PPT. Both PZQ-EPI and EPI-PPT combinations also showed synergistic effects, with CI values of 0.86 and 0.61, respectively. Surface alterations in the tegument of adult schistosomes after the treatments were observed using laser confocal microscopy and scanning electron microscopy. Additionally, the association of EPI-PPT decreased the cytotoxicity when compared with both isolated compounds in three different lines of mammalian cells. Thus, synergistic combinations of PZQ-PPT, PZQ-EPI, and EPI-PPT create the possibility of reduced doses to be used against Schistosoma mansoni.

  12. Chemical and Genetic Validation of the Statin Drug Target to Treat the Helminth Disease, Schistosomiasis

    PubMed Central

    Rojo-Arreola, Liliana; Long, Thavy; Asarnow, Dan; Suzuki, Brian M.; Singh, Rahul; Caffrey, Conor R.

    2014-01-01

    The mevalonate pathway is essential in eukaryotes and responsible for a diversity of fundamental synthetic activities. 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) is the rate-limiting enzyme in the pathway and is targeted by the ubiquitous statin drugs to treat hypercholesterolemia. Independent reports have indicated the cidal effects of statins against the flatworm parasite, S. mansoni, and the possibility that SmHMGR is a useful drug target to develop new statin-based anti-schistosome therapies. For six commercially available statins, we demonstrate concentration- and time-dependent killing of immature (somule) and adult S. mansoni in vitro at sub-micromolar and micromolar concentrations, respectively. Cidal activity trends with statin lipophilicity whereby simvastatin and pravastatin are the most and least active, respectively. Worm death is preventable by excess mevalonate, the product of HMGR. Statin activity against somules was quantified both manually and automatically using a new, machine learning-based automated algorithm with congruent results. In addition, to chemical targeting, RNA interference (RNAi) of HMGR also kills somules in vitro and, again, lethality is blocked by excess mevalonate. Further, RNAi of HMGR of somules in vitro subsequently limits parasite survival in a mouse model of infection by up to 80%. Parasite death, either via statins or specific RNAi of HMGR, is associated with activation of apoptotic caspase activity. Together, our genetic and chemical data confirm that S. mansoni HMGR is an essential gene and the relevant target of statin drugs. We discuss our findings in context of a potential drug development program and the desired product profile for a new schistosomiasis drug. PMID:24489942

  13. Localization of serotonin in the nervous system of Biomphalaria glabrata, an intermediate host for schistosomiasis.

    PubMed

    Delgado, Nadia; Vallejo, Deborah; Miller, Mark W

    2012-10-01

    The digenetic trematode Schistosoma mansoni that causes the form of schistosomiasis found in the Western Hemisphere requires the freshwater snail Biomphalaria glabrata as its primary intermediate host. It has been proposed that the transition from the free-living S. mansoni miracidium to parasitic mother sporocyst depends on uptake of biogenic amines, e.g. serotonin, from the snail host. However, little is known about potential sources of serotonin in B. glabrata tissues. This investigation examined the localization of serotonin-like immunoreactivity (5HTli) in the central nervous system (CNS) and peripheral tissues of B. glabrata. Emphasis was placed on the cephalic and anterior pedal regions that are commonly the sites of S. mansoni miracidium penetration. The anterior foot and body wall were densely innervated by 5HTli fibers but no peripheral immunoreactive neuronal somata were detected. Within the CNS, clusters of 5HTli neurons were observed in the cerebral, pedal, left parietal, and visceral ganglia, suggesting that the peripheral serotonergic fibers originate from the CNS. Double-labeling experiments (biocytin backfill × serotonin immunoreactivity) of the tentacular nerve and the three major pedal nerves (Pd n. 10, Pd n. 11, and Pd n. 12) disclosed central neurons that project to the cephalopedal periphery. Overall, the central distribution of 5HTli neurons suggests that, as in other gastropods, serotonin regulates the locomotion, reproductive, and feeding systems of Biomphalaria. The projections to the foot and body wall indicate that serotonin may also participate in defensive, nociceptive, or inflammation responses. These observations identify potential sources of host-derived serotonin in this parasite-host system. Inc.

  14. Revealing praziquantel molecular targets using mass spectrometry imaging: an expeditious approach applied to Schistosoma mansoni.

    PubMed

    Ferreira, Mônica Siqueira; de Oliveira, Rosimeire Nunes; de Oliveira, Diogo Noin; Esteves, Cibele Zanardi; Allegretti, Silmara Marques; Catharino, Rodrigo Ramos

    2015-05-01

    Finding specific molecular targets and the mechanism of action of praziquantel in the treatment of schistosomiasis remains a challenging task. Our efforts were focused on obtaining further information on worm composition before and after exposure to praziquantel in the treatment of schistosomiasis to elucidate the potential sites of action of this drug. Evidence indicates that the lipid bilayer is changed by treatment with praziquantel. Following this rationale, we employed a mass spectrometry imaging-based approach that helped to characterise lipids in specific locations, which are directly involved in the biochemical pathways of the BH strain of Schistosoma mansoni, as well as differentiating the molecular response that each worm sex presents in vivo. Our findings demonstrated significant differences between the chemical markers found in adult worms before and after praziquantel exposure, especially in phospholipids, which were predominantly identified as chemical markers in all samples. Results also indicate that distinct molecular pathways in both male and female worms could be differentially affected by praziquantel treatment. These data shine new light on the mechanism of action of praziquantel, taking a further step towards its full understanding.

  15. Cost Analysis of Tests for the Detection of Schistosoma mansoni Infection in Children in Western Kenya

    PubMed Central

    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

    2015-01-01

    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

  16. Antiparasitic activity of menadione (vitamin K3) against Schistosoma mansoni in BABL/c mice.

    PubMed

    Kapadia, Govind J; Soares, Ingrid A O; Rao, G Subba; Badoco, Fernanda R; Furtado, Ricardo A; Correa, Mariana B; Tavares, Denise C; Cunha, Wilson R; Magalhães, Lizandra G

    2017-03-01

    Schistosomiasis is one of the neglected tropical diseases affecting nearly quarter of a billion people in economically challenged tropical and subtropical countries of the world. Praziquantel (PZQ) is the only drug currently available to treat this parasitic disease in spite being ineffective against juvenile worms and concerns about developing resistance to treat reinfections. Our earlier in vitro viability studies demonstrated significant antiparasitic activity of menadione (MEN) (vitamin K3) against Schistosoma mansoni adult worms. To gain insight into plausible mechanism of antischistosomal activity of MEN, its effect on superoxide anion levels in adult worms were studied in vitro which showed significant increases in both female and male worms. Further confirmation of the deleterious morphological changes in their teguments and organelles were obtained by ultrastructural analysis. Genotoxic and cytotoxic studies in male Swiss mice indicated that MEN was well tolerated at the oral dose of 500mg/kg using the criteria of MNPCE frequency and PCE/RBC ratio in the bone marrow of infected animals. The in vivo antiparasitic activity of MEN was conducted in female BALB/c mice infected with S. mansoni and significant reductions (P<0.001) in total worm burden were observed at single oral doses of 40 and 400mg/kg (48.57 and 61.90%, respectively). Additionally, MEN significantly reduced (P<0.001) the number of eggs in the liver of infected mice by 53.57 and 58.76%, respectively. Similarly, histological analysis of the livers showed a significant reduction (P<0.001) in the diameter of the granulomas. Since MEN is already in use globally as an over-the-counter drug for a variety of common ailments and a dietary supplement with a safety record in par with similar products when used in recommended doses, the above antiparasitic results which compare reasonably well with PZQ, make a compelling case for considering MEN to treat S. mansoni infection in humans.

  17. Functional mapping of protein kinase A reveals its importance in adult Schistosoma mansoni motor activity.

    PubMed

    de Saram, Paulu S R; Ressurreição, Margarida; Davies, Angela J; Rollinson, David; Emery, Aidan M; Walker, Anthony J

    2013-01-01

    Cyclic AMP (cAMP)-dependent protein kinase/protein kinase A (PKA) is the major transducer of cAMP signalling in eukaryotic cells. Here, using laser scanning confocal microscopy and 'smart' anti-phospho PKA antibodies that exclusively detect activated PKA, we provide a detailed in situ analysis of PKA signalling in intact adult Schistosoma mansoni, a causative agent of debilitating human intestinal schistosomiasis. In both adult male and female worms, activated PKA was consistently found associated with the tegument, oral and ventral suckers, oesophagus and somatic musculature. In addition, the seminal vesicle and gynaecophoric canal muscles of the male displayed activated PKA whereas in female worms activated PKA localized to the ootype wall, the ovary, and the uterus particularly around eggs during expulsion. Exposure of live worms to the PKA activator forskolin (50 µM) resulted in striking PKA activation in the central and peripheral nervous system including at nerve endings at/near the tegument surface. Such neuronal PKA activation was also observed without forskolin treatment, but only in a single batch of worms. In addition, PKA activation within the central and peripheral nervous systems visibly increased within 15 min of worm-pair separation when compared to that observed in closely coupled worm pairs. Finally, exposure of adult worms to forskolin induced hyperkinesias in a time and dose dependent manner with 100 µM forskolin significantly increasing the frequency of gross worm movements to 5.3 times that of control worms (P≤0.001). Collectively these data are consistent with PKA playing a central part in motor activity and neuronal communication, and possibly interplay between these two systems in S. mansoni. This study, the first to localize a protein kinase when exclusively in an activated state in adult S. mansoni, provides valuable insight into the intricacies of functional protein kinase signalling in the context of whole schistosome physiology.

  18. 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

  19. Schistosomiasis therapeutics: whats in the pipeline?

    PubMed

    Trainor-Moss, Santiago; Mutapi, Francisca

    2016-01-01

    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.

  20. Interaction between Salmonella and Schistosomiasis: A Review

    PubMed Central

    Hsiao, Amber; Toy, Trevor; Marks, Florian

    2016-01-01

    The interaction between schistosomiasis and Salmonella is a particularly important issue in Africa, where dual infection by the parasite and the bacterium are likely common. In this review, the ways in which schistosomiasis affects human biology as it relates to Salmonella are described. Those who are infected by both organisms experience reduced immunological functioning, exhibit irreversible organ damage due to prolonged schistosomiasis infection, and become latent carriers of Salmonella enterica serotypes Typhi and Paratyphi and S. Typhimurium. The sequestration of the bacteria in the parasite leads to ineffective antibiotic treatment because the bacteria cannot be completely killed, and lingering infection may then lead to antimicrobial resistance. These manifestations are likely not just for those dually infected but also for those first infected with schistosomes and, later, Salmonella. More data are needed to better understand dual infection, particularly as it may impact treatment and prevention of schistosomiasis and Salmonella in sub-Saharan Africa. PMID:27907208

  1. 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

  2. Schistosomiasis and Soil Transmitted Helminths Distribution in Benin: A Baseline Prevalence Survey in 30 Districts

    PubMed Central

    Boko, Pelagie M.; Ibikounle, Moudachirou; Onzo-Aboki, Ablawa; Tougoue, Jean-Jacques; Sissinto, Yollande; Batcho, Wilfrid; Kinde-Gazard, Dorothe; Kabore, Achille

    2016-01-01

    In 2013, Benin developed strategies to control neglected tropical diseases and one of the first step was the disease mapping of the entire country in order to identify endemic districts of schistosomiasis and soil transmitted helminths (STH). This study was carried out in 30 of the 77 districts of Benin. Of these 30 districts 22 were previously treated for Lymphatic Filariasis (LF) using the Ivermectin and Albendazole combination. In each district, five schools were selected and 50 children aged 8 to 14 years were sampled in each school, making a total of 250 children sampled in the district. The schools were selected mainly according to their proximity to lakes or any bodies of water that were likely to have been used by the children. Samples of faeces and urine were collected from each pupil. Urinary schistosomiasis was identified using the urine filtration technique while STH and intestinal schistosomiasis were identified through the Kato Katz method. Overall a total of 7500 pupils were surveyed across 150 schools with a gender ratio of 1:1. Hookworm was identified in all 30 districts with a prevalence ranging from 1.2% (95%CI: 0.0–2.5) to 60% (95%CI: 53.9–66.1). Ascaris lumbricoides was detected in 19 districts with a prevalence rate between 1% (95%CI: 0.0–2.2) and 39% (95%CI: 32.9–45.0). In addition to these common STH, Trichuris trichiura, Enterobius vermicularis and Strongyloides stercoralis were found at low prevalence. Only 16 districts were endemic to Schistosoma mansoni, while 29 districts were endemic to S. haematobium. The S. haematobium prevalence ranged from 0.8% (95% CI: 0.0–1.9) to 56% (95% CI: 50.2–62.5) while the prevalence of S. mansoni varied from 0.4% (95%CI: 0.0–1.2) to 46% (95% CI: 39.8–52.2). The 22 districts, where LF was successfully eliminated, still require mass drug administration (MDA) of albendazole indicating that school-based MDA would be needed even after LF elimination in districts co-endemic to LF and STH in

  3. 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

  4. Low frequency of positive skin tests in asthmatic patients infected with Schistosoma mansoni exposed to high levels of mite allergens.

    PubMed

    Medeiros, Manoel; Almeida, Maria C; Figueiredo, Joanemile P; Atta, Ajax M; Mendes, Carlos M C; Araújo, Maria I; Taketomi, Ernesto A; Terra, Silvia A; Silva, Deise A O; Carvalho, Edgar M

    2004-04-01

    Helminthic infections and allergic diseases are highly prevalent in many parts of the world. Although skin reactivity to indoor allergens is decreased in subjects from helminthic endemic areas, the degree of exposure to mite allergens has not yet been investigated in these areas. This study evaluated the association between exposure to dust mites and skin reactivity to mite allergens in subjects with a history of wheezing in the last 12 months selected from a rural endemic area for schistosomiasis (group I, n = 21), and two non-Schistosoma mansoni endemic locale, a rural area (group II, n = 21) and a urban slum area (group III, n = 21). All subjects were evaluated by skin prick tests with mite allergens, and for total and specific immunoglobulin E (IgE) against dust mites, antibodies for S. mansoni, and for intestinal parasites. Dust samples from each subjects' home were quantified for mite allergen and species of the mite identification. Except for S. mansoni infection which was more prevalent in group I than in groups II and III (p < 0.0001), the prevalence of intestinal parasites, and total and specific IgE levels were similar for all groups. Despite the levels of mite allergens and specifically to Der p 1 detected in dust samples of subjects home from all three areas, the frequency of positive skin reactivity to mite antigens was significantly lower (19.0%) in subjects from group I relative to group II (76.2%) and group III (57.1%; p < 0.001). This result suggests that S. mansoni infection could modulate the immediate hypersensitivity skin response to mite allergens in highly exposed subjects.

  5. 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

  6. SmTRC1, a novel Schistosoma mansoni DNA transposon, discloses new families of animal and fungi transposons belonging to the CACTA superfamily

    PubMed Central

    DeMarco, Ricardo; Venancio, Thiago M; Verjovski-Almeida, Sergio

    2006-01-01

    Background The CACTA (also called En/Spm) superfamily of DNA-only transposons contain the core sequence CACTA in their Terminal Inverted Repeats (TIRs) and so far have only been described in plants. Large transcriptome and genome sequence data have recently become publicly available for Schistosoma mansoni, a digenetic blood fluke that is a major causative agent of schistosomiasis in humans, and have provided a comprehensive repository for the discovery of novel genes and repetitive elements. Despite the extensive description of retroelements in S. mansoni, just a single DNA-only transposon belonging to the Merlin family has so far been reported in this organism. Results We describe a novel S. mansoni transposon named SmTRC1, for S. mansoni Transposon Related to CACTA 1, an element that shares several characteristics with plant CACTA transposons. Southern blotting indicates approximately 30–300 copies of SmTRC1 in the S. mansoni genome. Using genomic PCR followed by cloning and sequencing, we amplified and characterized a full-length and a truncated copy of this element. RT-PCR using S. mansoni mRNA followed by cloning and sequencing revealed several alternatively spliced transcripts of this transposon, resulting in distinct ORFs coding for different proteins. Interestingly, a survey of complete genomes from animals and fungi revealed several other novel TRC elements, indicating new families of DNA transposons belonging to the CACTA superfamily that have not previously been reported in these kingdoms. The first three bases in the S. mansoni TIR are CCC and they are identical to those in the TIRs of the insects Aedes aegypti and Tribolium castaneum, suggesting that animal TRCs may display a CCC core sequence. Conclusion The DNA-only transposable element SmTRC1 from S. mansoni exhibits various characteristics, such as generation of multiple alternatively-spliced transcripts, the presence of terminal inverted repeats at the extremities of the elements flanked by

  7. 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

  8. 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

  9. Testicular Schistosomiasis Mimicking Malignancy in a Child: A Case Report.

    PubMed

    Ekenze, Sebastian O; Modekwe, Victor O; Nzegwu, Martin A; Ekpemo, Samuel C; Ezomike, Uchechukwu O

    2015-08-01

    Schistosomiasis is an important communicable disease in the developing world. However, testicular schistosomiasis is an extremely rare condition. We report a case of testicular schistosomiasis mimicking testicular tumour in a 13 year old who presented with huge unilateral testicular mass. The dilemma encountered in the diagnosis and treatment of this child is presented to highlight the need for high index of suspicion of this pathology in children with testicular mass presenting from schistosomiasis-endemic areas.

  10. 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.

  11. Relationship between Schistosomiasis and Bladder Cancer

    PubMed Central

    Mostafa, M. H.; Sheweita, S. A.; O’Connor, P. J.

    1999-01-01

    Carcinoma of the urinary bladder is the most common malignancy in the Middle East and parts of Africa where schistosomiasis is a widespread problem. Much evidence supports the association between schistosomiasis and bladder cancer: this includes the geographical correlation between the two conditions, the distinctive patterns of gender and age at diagnosis, the clinicopathological identity of schistosome-associated bladder cancer, and extensive evidence in experimentally infected animals. Multiple factors have been suggested as causative agents in schistosome-associated bladder carcinogenesis. Of these, N-nitroso compounds appear to be of particular importance since they were found at high levels in the urine of patients with schistosomiasis-associated bladder cancer. Various strains of bacteria that can mediate nitrosation reactions leading to the formation of N-nitrosamines have been identified in the urine of subjects with schistosomiasis at higher intensities of infection than in normal subjects. In experimental schistosomiasis, the activities of carcinogen-metabolizing enzymes are increased soon after infection but are reduced again during the later chronic stages of the disease. Not only could this prolong the period of exposure to activated N-nitrosamines, but also inflammatory cells, sitmulated as a result of the infection, may induce the endogenous synthesis of N-nitrosamines as well as generating oxygen radicals. Higher than normal levels of host cell DNA damage are therefore anticipated, and they have indeed been observed in the case of alkylation damage, together with an inefficiency in the capacity of relevant enzymes to repair this damaged DNA. In experimental schistosomiasis, it was also found that endogenous levels of host cell DNA damage were related to the intensity of infection. All of these factors could contribute to an increased risk of bladder cancer in patients with schistosomiasis, and in particular, the gene changes observed may have

  12. 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.

  13. Praziquantel treatment of school children from single and mixed infection foci of intestinal and urogenital schistosomiasis along the Senegal River Basin: monitoring treatment success and re-infection patterns.

    PubMed

    Webster, Bonnie L; Diaw, Oumar T; Seye, Mohmoudane M; Faye, Djibril S; Stothard, J Russell; Sousa-Figueiredo, Jose C; Rollinson, David

    2013-11-01

    Following major water development schemes in the 1980s, schistosomiasis has become a serious parasitic disease of children living in the Senegal River Basin. Both urogenital (Schistosoma haematobium) and intestinal (Schistosoma mansoni) schistosomiasis can be highly prevalent in school-aged children, with many individuals infected with both parasites. In order to investigate the transmission and re-infection dynamics of both parasite species, single and mixed infection foci at three villages (Nder and Temeye; S. mansoni and S. haematobium foci and Guia; S. haematobium focus) were studied. In each focus infected children were identified and selected for a 12-month study involving two treatments with praziquantel (40mg/kg) three weeks apart at the beginning of the study and again 6 months into the study. Urine and stool samples were examined for schistosome eggs before and at 6 weeks and 6 months after chemotherapy. Prevalence and intensity of infection were recorded for each child at each time point. Before treatment, in all three villages, the prevalence and intensity of infection was extremely high for both S. mansoni (79-100%) and S. haematobium (81-97%). With the first round of chemotherapy sufficient cure rates (CRs) of both species were achieved in all villages (38-96%) with high egg reduction rates (ERRs) (97-99%). The data show that high and rapid re-infection rates occur, especially for S. mansoni, within a six-month period following treatment. Re-infection must be highly linked to ecological and seasonal factors. The persistence of S. mansoni in Nder could raise concern as levels of infection intensity remain high (geometric mean intensity at baseline 653epg changed to 705epg at 12 months) after four rounds of chemotherapy. This phenomenon could be explained by extremely rapid re-infection dynamics or a sub-optimal efficacy of praziquantel against S. mansoni in this village. High intensities in mixed infections may influence disease epidemiology and

  14. Simplification and Standardization of Dot-ELISA for Human Schistosomiasis Mansoni

    DTIC Science & Technology

    1987-01-01

    for diagnosis is expected to re- to which Leishmania antigen was fixed, has been place the more cumbersome microscopic ex- described (Pappas et al...enzyme linked immunosorbent assay ELISA; this might represent either a false posi- (dot-ELISA): A microtechnique for the rapid di- agnosis of visceral ... leishmaniasis . Journal of Im-tive in the 2 techniques or this person may have munological Methods 64: 205-214. antibody to Schistosoma due to antigen

  15. [Analysis of blood glucose levels in 746 cases of schistosomiasis].

    PubMed

    Hou, An-Ming; Wu, Guo-Hua; Zhang, Gui-Lin

    2011-04-01

    The levels of blood glucose of 746 inpatients with chronic or advanced schistosomiasis were assayed last 3 years and the results were analyzed. There was no significant difference between the pure chronic or advanced schistosomiasis patients and normal population. However, there was a significant difference between the chronic or advanced schistosomiasis patients with viral hepatitis and normal population.

  16. 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.

  17. 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

  18. 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

  19. Closing the praziquantel treatment gap: new steps in epidemiological monitoring and control of schistosomiasis in African infants and preschool-aged children

    PubMed Central

    STOTHARD, J. RUSSELL; SOUSA-FIGUEIREDO, JOSÉ C.; BETSON, MARTHA; GREEN, HELEN K.; SETO, EDMUND Y. W.; GARBA, AMADOU; SACKO, MOUSSA; MUTAPI, FRANCISCA; VAZ NERY, SUSANA; AMIN, MUTAMAD A.; MUTUMBA-NAKALEMBE, MARGARET; NAVARATNAM, ANNALAN; FENWICK, ALAN; KABATEREINE, NARCIS B.; GABRIELLI, ALBIS F.; MONTRESOR, ANTONIO

    2011-01-01

    SUMMARY Where very young children come into contact with water containing schistosome cercariae, infections occur and schistosomiasis can be found. In high transmission environments, where mothers daily bathe their children with environmentally drawn water, many infants and preschool-aged children have schistosomiasis. This ‘new’ burden, inclusive of co-infections with Schistosoma haematobium and Schistosoma mansoni, is being formally explored as infected children are not presently targeted to receive praziquantel (PZQ) within current preventive chemotherapy campaigns. Thus an important PZQ treatment gap exists whereby infected children might wait up to 4–5 years before receiving first treatment in school. International treatment guidelines, set within national treatment platforms, are presently being modified to provide earlier access to medication(s). Although detailed pharmacokinetic studies are needed, to facilitate pragmatic dosing in the field, an extended ‘dose pole’ has been devised and epidemiological monitoring has shown that administration of PZQ (40 mg/kg), in either crushed tablet or liquid suspension, is both safe and effective in this younger age-class; drug efficacy, however, against S. mansoni appears to diminish after repeated rounds of treatment. Thus use of PZQ should be combined with appropriate health education/water hygiene improvements for both child and mother to bring forth a more enduring solution. PMID:21861945

  20. 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.

  1. Advances in the Diagnosis of Human Schistosomiasis

    PubMed Central

    Weerakoon, Kosala G. A. D.; Gobert, Geoffrey N.; Cai, Pengfei

    2015-01-01

    SUMMARY Schistosomiasis is a major neglected tropical disease that afflicts more than 240 million people, including many children and young adults, in the tropics and subtropics. The disease is characterized by chronic infections with significant residual morbidity and is of considerable public health importance, with substantial socioeconomic impacts on impoverished communities. Morbidity reduction and eventual elimination through integrated intervention measures are the focuses of current schistosomiasis control programs. Precise diagnosis of schistosome infections, in both mammalian and snail intermediate hosts, will play a pivotal role in achieving these goals. Nevertheless, despite extensive efforts over several decades, the search for sensitive and specific diagnostics for schistosomiasis is ongoing. Here we review the area, paying attention to earlier approaches but emphasizing recent developments in the search for new diagnostics for schistosomiasis with practical applications in the research laboratory, the clinic, and the field. Careful and rigorous validation of these assays and their cost-effectiveness will be needed, however, prior to their adoption in support of policy decisions for national public health programs aimed at the control and elimination of schistosomiasis. PMID:26224883

  2. Protective capacity of cercarial transformation fluid alone or in combination with crude cercarial antigen against challenge infections of Schistosoma mansoni in mice.

    PubMed

    El Azzouni, M Z; Mady, R F; Gaafar, M R; Arafa, F M; Elhadidi, A

    2017-01-01

    Schistosomiasis is the second major parasitic disease in the world after malaria. It affects 201.5 million cases in Africa alone. The aim of this research was to explore alternative vaccination strategies against experimental schistosomiasis mansoni. We assessed the effect of cercarial transformation fluid (CTF) singly and in combination with crude cercarial antigen (CCA) using alum as an adjuvant. The combined antigens gave the best results, as evidenced by a significant reduction in the worm load (62.07%), tissue egg count (78.16%, 86.46%) in liver and intestine respectively, and hepatic granuloma size (29.96%). Scanning electron microscopy revealed changes in the tegument, in the form of roughness and appearance of vesicles and furrows between the tegumental tubercles. Also, resorption of the ventral sucker and dimples replacing its spines were observed. The female tegument was irregular and its posterior end showed loss of spines and sensory bulbs. Moreover, there was a significant decrease in liver enzymes (alanine transaminase (ALT) and aspartate transaminase (AST)) compared to infected control mice. A significant elevation in CD4+T-lymphocytes, denoting amelioration of the immune status, in mice that received combined antigens was also observed. It can be concluded that combined antigens demonstrate potential as a vaccine against Schistosoma mansoni.

  3. 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 Central

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

    2016-01-01

    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

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. Experimental Infection with Schistosoma mansoni in CCR5-Deficient Mice Is Associated with Increased Disease Severity, as CCR5 Plays a Role in Controlling Granulomatous Inflammation▿

    PubMed Central

    Souza, Adriano L. S.; Souza, Patrícia R. S.; Pereira, Cíntia A.; Fernandes, Adriana; Guabiraba, Rodrigo; Russo, Remo C.; Vieira, Leda Q.; Corrêa, Ary; Teixeira, Mauro M.; Negrão-Corrêa, Deborah

    2011-01-01

    The plasma level of the chemokine CCL3 is elevated in patients with chronic severe schistosomiasis mansoni. We have previously shown that CCL3−/− mice with experimental infection showed diminished pathology and worm burden compared to those of wild-type (WT) mice. To elucidate further the role of CC chemokines during schistosomiasis mansoni infection, we evaluated the course of infection in C57BL/6J mice deficient in CCR5, one of the receptors for CCL3. The CCR5 deficiency proved to be remarkably deleterious to the host, since mortality rates reached 70% at 14 weeks postinfection in CCR5−/− mice and 19% in WT mice. The increased lethality was not associated with an increased parasite burden, since similar numbers of eggs and adult worms were found in mice from both groups. Liver granulomas of chronically infected CCR5−/− mice were larger and showed greater numbers of cells and collagen deposition than liver granulomas from WT mice. This was associated with higher levels of production of intereleukin-5 (IL-5), IL-13, CCL3, and CCL5 in infected CCR5−/− mice than in infected WT mice. Moreover, at 8 weeks after infection, just before changes in pathology and mortality, the numbers of FoxP3-positive cells were lower in liver granulomas of CCR5−/− mice than in WT mice. In conclusion, the CCR5 deletion is deleterious to mice infected with Schistosoma mansoni, and this is associated with enhanced fibrosis and granulomatous inflammation. PMID:21263020

  9. Intestinal Schistosomiasis among Primary Schoolchildren in Two On-Shore Communities in Rorya District, Northwestern Tanzania: Prevalence, Intensity of Infection and Associated Risk Factors

    PubMed Central

    Buza, Joram; Mpolya, Emmanuel A.; Kinung'hi, Safari M.

    2016-01-01

    In Tanzania, Schistosoma mansoni is of great public health importance. Understanding the prevalence and infection intensity is important for targeted, evidence-based control strategies. This study aimed at studying the prevalence, intensity, and risk factors of S. mansoni among schoolchildren in the study area. A cross-sectional study was conducted in Busanga and Kibuyi villages. Sampled 513 schoolchildren provided stool specimens which were examined using kato-katz method. Pretested questionnaire was used to collect sociodemographic data and associated risk factors. The prevalence of S. mansoni infection was 84.01%, with geometric mean egg intensity of 167.13 (95% CI: 147.19–189.79) eggs per gram of stool (epg). Other parasites detected were Ascaris lumbricoides (1.4%) and hookworms (1.4%). The geometric mean infection intensity in Busanga and Kibuyi were 203.70 (95% CI: 169.67–244.56) and 135.98 (95% CI: 114.33–161.73) epg, respectively. Light, moderate, and heavy infection intensities were 34.11%, 39.91%, and 25.99%, respectively. Village of residence, parent's level of education, toilet use, and treatment history were predictors of infection. The high prevalence and infection intensity in this study were associated with village, parent's level of education, inconsistent toilet use, and treatment history. To control the disease among at-risk groups, these factors need to be considered in designing integrated schistosomiasis control interventions. PMID:27822385

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

    PubMed Central

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

    2000-01-01

    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

  11. Thermostability of heterophile antibodies from human sera infected with Schistosoma mansoni and geo-helminths. An immuno-metric statistical analysis.

    PubMed

    Chamone, Munir; Atuncar, Gregorio S; Coelho, Paulo Marcos Zech

    2006-01-01

    Antibody in human sera that induces lysis of sheep erythrocytes in hemolytic assay was investigated. The present study showed that the presence in serum of the thermostable cytolytic anti-sheep red blood cells antibodies is dependent on the Schistosoma mansoni infection, and this is more frequent in adults than in children. The thermostable characteristic of hemolysins in normal sera was not dependent on the presence of Ascaris lumbricoides, Trichuris trichiura or hookworm geo-helminths. Further, thermostable complement-activating heterophile antibodies were noticed in children in association with massive number of S. mansoni eggs. The results were obtained by using the z- and the chi-square tests. The z-test allows us to formulate a one-sided alternative, i.e., a tendency of one of the attributes. On the other hand, the chi-square test analyzes the independence between attributes by using a contingency table. Besides the obtained results being interesting in the field of schistosomiasis mansoni, they can provide a new insight into the use of statistics in medical science.

  12. 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

  13. Bayesian spatial risk prediction of Schistosoma mansoni infection in western Côte d'Ivoire using a remotely-sensed digital elevation model.

    PubMed

    Beck-Wörner, Christian; Raso, Giovanna; Vounatsou, Penelope; N'Goran, Eliézer K; Rigo, Gergely; Parlow, Eberhard; Utzinger, Jürg

    2007-05-01

    An important epidemiologic feature of schistosomiasis is the focal distribution of the disease. Thus, the identification of high-risk communities is an essential first step for targeting interventions in an efficient and cost-effective manner. We used a remotely-sensed digital elevation model (DEM), derived hydrologic features (i.e., stream order, and catchment area), and fitted Bayesian geostatistical models to assess associations between environmental factors and infection with Schistosoma mansoni among more than 4,000 school children from the region of Man in western Côte d'Ivoire. At the unit of the school, we found significant correlations between the infection prevalence of S. mansoni and stream order of the nearest river, water catchment area, and altitude. In conclusion, the use of a freely available 90 m high-resolution DEM, geographic information system applications, and Bayesian spatial modeling facilitates risk prediction for S. mansoni, and is a powerful approach for risk profiling of other neglected tropical diseases that are pervasive in the developing world.

  14. Utility of Schistosoma bovis Adult Worm Antigens for Diagnosis of Human Schistosomiasis by Enzyme-Linked Immunosorbent Assay and Electroimmunotransfer Blot Techniques

    PubMed Central

    Pardo, J.; Carranza, C.; Turrientes, M. C.; Arellano, J. L. Pérez; Vélez, R. López; Ramajo, V.; Muro, A.

    2004-01-01

    Immunodiagnostic methods based on the detection of antibodies continue to be the most effective and practical methods for the diagnosis of imported schistosomiasis. Schistosoma bovis is a species whose final natural hosts are bovines, ovines, caprines, and small wild ruminants. Different studies have demonstrated the analogies existing between S. bovis and other Schistosoma species which affect humans. The objective of this work was to evaluate the utility of S. bovis adult worm antigens (AWA) for the diagnosis of imported human schistosomiasis by enzyme-linked immunosorbent assay (ELISA) and electroimmunotransfer blotting (EITB) techniques. By detecting eggs, the ELISA for S. bovis AWA was able to definitively detect imported cases with a sensitivity of 94%. The specificity of the ELISA for S. bovis AWA was 97%. There were no differences between the results of the S. bovis AWA ELISA for patients infected with Schistosoma mansoni and those infected with Schistosoma haematobium. The EITB technique showed bands of 85, 37, and 20 kDa, which are characteristic of infections with Schistosoma spp. Specific bands to indicate infection by different species of Schistosoma have not been detected. The combined use of the ELISA for S. bovis AWA and EITB increased the global sensitivity of the study to 97%. Our findings suggest that the ELISA for S. bovis AWA is a useful test for the immunodiagnosis of imported schistosomiasis and that EITB for detecting S. bovis AWA permits the confirmation of diagnosis when the ELISA for S. bovis AWA is positive. PMID:15539523

  15. Utility of Schistosoma bovis adult worm antigens for diagnosis of human schistosomiasis by enzyme-linked immunosorbent assay and electroimmunotransfer blot techniques.

    PubMed

    Pardo, J; Carranza, C; Turrientes, M C; Pérez Arellano, J L; López Vélez, R; Ramajo, V; Muro, A

    2004-11-01

    Immunodiagnostic methods based on the detection of antibodies continue to be the most effective and practical methods for the diagnosis of imported schistosomiasis. Schistosoma bovis is a species whose final natural hosts are bovines, ovines, caprines, and small wild ruminants. Different studies have demonstrated the analogies existing between S. bovis and other Schistosoma species which affect humans. The objective of this work was to evaluate the utility of S. bovis adult worm antigens (AWA) for the diagnosis of imported human schistosomiasis by enzyme-linked immunosorbent assay (ELISA) and electroimmunotransfer blotting (EITB) techniques. By detecting eggs, the ELISA for S. bovis AWA was able to definitively detect imported cases with a sensitivity of 94%. The specificity of the ELISA for S. bovis AWA was 97%. There were no differences between the results of the S. bovis AWA ELISA for patients infected with Schistosoma mansoni and those infected with Schistosoma haematobium. The EITB technique showed bands of 85, 37, and 20 kDa, which are characteristic of infections with Schistosoma spp. Specific bands to indicate infection by different species of Schistosoma have not been detected. The combined use of the ELISA for S. bovis AWA and EITB increased the global sensitivity of the study to 97%. Our findings suggest that the ELISA for S. bovis AWA is a useful test for the immunodiagnosis of imported schistosomiasis and that EITB for detecting S. bovis AWA permits the confirmation of diagnosis when the ELISA for S. bovis AWA is positive.

  16. Sm-p80-based schistosomiasis vaccine mediated epistatic interactions identified potential immune signatures for vaccine efficacy in mice and baboons

    PubMed Central

    Rojo, Juan U.; Melkus, Michael W.; Kottapalli, Kameswara Rao; Okiya, Oscar E.; Sudduth, Justin; Zhang, Weidong; Molehin, Adebayo J.; Carter, Darrick; Siddiqui, Afzal A.

    2017-01-01

    Schistosomiasis is a neglected parasitic disease of major public health concern as it affects over 250 million people in developing countries. Currently there is no licensed vaccine available against schistosomiasis. The Schistosoma mansoni calpain protein, Sm-p80, is a leading vaccine candidate now ready to move to clinical trials. In order to better assess Sm-p80 vaccine immunogenicity; here we used a systems biology approach employing RNA-sequencing to identify gene signatures and epistatic interactions following Sm-p80 vaccination in mouse and baboon models that may predict vaccine efficacy. Recombinant Sm-p80 + CpG-oligodeoxynucleotide (ODN) vaccine formulation induced both cellular and humoral immunity genes with a predominant TH1 response as well as TH2 and TH17 gene signatures. Early gene responses and gene-network interactions in mice immunized with rSm-p80 + ODN appear to be initiated through TLR4 signaling. CSF genes, S100A alarmin genes and TNFRSF genes appear to be a signature of vaccine immunogenicity/efficacy as identified by their participation in gene network interactions in both mice and baboons. These gene families may provide a basis for predicting desirable outcomes for vaccines against schistosomiasis leading to a better understanding of the immune system response to vaccination. PMID:28192534

  17. Sm-p80-based schistosomiasis vaccine mediated epistatic interactions identified potential immune signatures for vaccine efficacy in mice and baboons.

    PubMed

    Rojo, Juan U; Melkus, Michael W; Kottapalli, Kameswara Rao; Okiya, Oscar E; Sudduth, Justin; Zhang, Weidong; Molehin, Adebayo J; Carter, Darrick; Siddiqui, Afzal A

    2017-01-01

    Schistosomiasis is a neglected parasitic disease of major public health concern as it affects over 250 million people in developing countries. Currently there is no licensed vaccine available against schistosomiasis. The Schistosoma mansoni calpain protein, Sm-p80, is a leading vaccine candidate now ready to move to clinical trials. In order to better assess Sm-p80 vaccine immunogenicity; here we used a systems biology approach employing RNA-sequencing to identify gene signatures and epistatic interactions following Sm-p80 vaccination in mouse and baboon models that may predict vaccine efficacy. Recombinant Sm-p80 + CpG-oligodeoxynucleotide (ODN) vaccine formulation induced both cellular and humoral immunity genes with a predominant TH1 response as well as TH2 and TH17 gene signatures. Early gene responses and gene-network interactions in mice immunized with rSm-p80 + ODN appear to be initiated through TLR4 signaling. CSF genes, S100A alarmin genes and TNFRSF genes appear to be a signature of vaccine immunogenicity/efficacy as identified by their participation in gene network interactions in both mice and baboons. These gene families may provide a basis for predicting desirable outcomes for vaccines against schistosomiasis leading to a better understanding of the immune system response to vaccination.

  18. In vivo schistosomicidal activity of three novels 8-hydroxyquinoline derivatives against adult and immature worms of Schistosoma mansoni.

    PubMed

    Allam, Gamal; Eweas, Ahmad F; Abuelsaad, Abdelaziz S A

    2013-09-01

    Schistosomiasis control is widely dependent on a single drug, praziquantel (PZQ). The potential for development of resistance to PZQ has justified the search for new alternative chemotherapies. In a previous study, we have been reported that three of 8-hydroxyquinoline derivatives namely: 3-((8-hydroxyquinolin-5-yl) sulfonyl) pentane-2,4-dione (HQSP), 5-((2,4-diphenyl-3H-benzo[b][1,4]diazepin-3-yl) sulfonyl) quinolin-8-ol (HQBD), and 5-((2,4-diphenyl-3H-pyrido[3,4-b][1,4] diazepin-3-yl) sulfonyl) quinolin-8-ol (HQPD) possess a potent anti-schistosomal activity in vitro. The aim of the present study was to evaluate the in vivo schistosomicidal effect of these three compounds on adult and immature worms of Schistosoma mansoni and their induced pathology. Treatment of S. mansoni-infected mice with 1000, 250, 150, and 200 mg/kg body weight of PZQ, HQSP, HQBD, and HQPD, respectively, reduced adult and immature worm burden by 94.63 and 31.32%, 73.63 and 5.45%, 76.5 and 28.11%, and 81.25 and 56.84%, respectively, compared to infected untreated mice. Moreover, numbers of egg per gram liver and intestine were decreased by 84 and 95.51%, 47.84 and 46.28 %, 53.18 and 59.37 %, and 54.22 and 67.26 as a result of PZQ, HQSP, HQBD, and HQPD treatment, respectively. Hepatic granuloma volume was also reduced by 40.10, 42.96, 35.72, and 72.09% due to PZQ, HQSP, HQBD, and HQPD treatment, respectively. In addition, hepatic histopathological alterations and collagen fiber deposition that accompanied with S. mansoni infection were largely retrieved with different treatments, especially HQPD treatment. Furthermore, humoral immune response, especially IgG response against S. mansoni antigens, was augmented with different treatments. This study concluded that among the three tested 8-hydroxyquinoline derivatives, HQPD is the most effective compound against adult and pre-mature worms of S. mansoni and can be used for the development of a new schistosomicidal drug.

  19. Relationship between intensity of infection and immunomodulation in human schistosomiasis. I. Lymphocyte subpopulations and specific antibody responses.

    PubMed

    Feldmeier, H; Gastl, G A; Poggensee, U; Kortmann, C; Daffalla, A A; Peter, H H

    1985-05-01

    Cellular and humoral immune responsiveness in 44 Sudanese children with schistosomiasis was studied and related to the intensity of infection. The parasite load was quantitated by accurate assessment of the excretion of ova of S. mansoni and S. haematobium in stool and urine, respectively. Lymphocyte subpopulations (T3+, T4+, T8+, TAC+, HNK1+, Ia+, SIg+, LGL+, ANAE+) as well as specific IgE and IgG antibodies to adult schistosome antigens were determined. The relationships existing between intensity of infection and cellular and humoral immune responsiveness revealed a distinct pattern of anti-parasite immunity: The percentage of pan-T cells (T3+) and the T helper (T4+):T suppressor (T8+) ratio were inversely correlated to the intensity of infection. In contrast, the percentage of T suppressor cells positively correlated to the parasite load. Ia+, TAC+, HNK1+ and T4+ cell counts did not show a significant relationship to worm burden. Specific IgE and IgG antibodies to S. mansoni and S. haematobium adult worm antigen clearly increased with the parasite load. The dichotomy of decreased T cell parameters and increased antibody response in heavily infected individuals represents a unique feature in helminthic infections.

  20. 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)

  1. 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

  2. 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.

  3. Susceptibility of Biomphalaria straminea from Peixe Angical dam, Tocantins, Brazil to infection with three strains of Schistosoma mansoni.

    PubMed

    Fernandez, Monica Ammon; Thiengo, Silvana Carvalho

    2010-07-01

    Environmental changes from water resource developmental projects affect the epidemiology of water-associated diseases, as well as malaria and schistosomiasis. Aiming to investigate the occurrence and distribution of freshwater snails of medical and veterinary importance in the area of influence of the Peixe Angical hydroelectric dam, a survey has been conducted over four years (2004-2008). The study has revealed the occurrence of populations of Biomphalaria straminea (Dunker) in all municipalities surrounding the lake. Studies on parasite-mollusc compatibility were undertaken using 35 populations of B. straminea, descendants of specimens obtained from that area and three strains of Schistosoma mansoni (Sambon) (BH, CM and CMO). The main results are as follows: (i) among the 1,314 specimens used, eight had been infected (infection index of 0.6%) with only the BH strain, (ii) for B. straminea populations, the mortality index was 6.8% and, depending on the strain used, the indexes were 4.6%, 8.49% and 19% with BH, CM and CMO strains, respectively, (iii) the infection indexes varied according to the B. straminea populations, ranging from 0-12.5% and (iv) the duration of the precercarial period varied from 25-49 days. These results, in addition to environmental and social changes that took place in the Peixe Angical dam region, indicate the possibility of B. straminea emerging as a schistosomiasis vector in this area.

  4. Ultrastructural alterations in Schistosoma mansoni juvenile and adult male worms after in vitro incubation with primaquine

    PubMed Central

    Kamel, Reem Osama A; Bayaumy, Fatma El-Zahraa Anwar

    2017-01-01

    BACKGROUND Praziquantel has been cited as the only drug for treating schistosomiasis. However, concerns over drug resistance have encouraged the search for novel drug leads. The antimalarial drug primaquine possesses interesting anti-schistosmal properties. OBJECTIVES This study is the first to document the potential role of primaquine as a schistosomicide and the ultrastructural changes induced by primaquine on juvenile or adult male worms of Schistosoma mansoni. METHODS Ultrastructural alterations in the tegumental surface of 21-day-old juvenile and adult male worms of S. mansoni were demonstrated following primaquine treatment at different concentrations (2, 5, 10, 15, and 20 µg/mL) and incubation periods (1, 3, 6, 24, and 48 h) in vitro, using both scanning and transmission electron microscopy. FINDINGS At low concentrations (2, 5, and 10 µg/mL) both juvenile and adult male worms were alive after 24 h of incubation, whereas contraction, paralysis, and death of all worms were observed after 24 h of drug exposure at 20 µg/mL. The tegument of juvenile and adult male worms treated with primaquine exhibited erosion, peeling, and sloughing. Furthermore, extensive damage of both tegumental and subtegumental layers included embedded spines, and shrinkage of muscles with vacuoles. The in vitro results confirmed that primaquine has dose-dependent effects with 20 µg/mL as the most effective concentration in a short incubation period. MAIN CONCLUSIONS The schistosomicidal activity of primaquine indicates that this drug possesses moderate in vitro activity against juvenile and adult male worms, since it caused high mortality and tegumental alterations. This study confirmed that the antimalarial drug primaquine possesses anti-schistosomal activity. Further investigation is needed to elucidate its mechanism of action. PMID:28327785

  5. Expression of corticotropin-releasing factor and urocortins in the normal and Schistosoma mansoni-infected mouse ileum.

    PubMed

    Buckinx, Roeland; Bagyanszki, Maria; Avula, Leela Rani; Adriaensen, Dirk; Van Nassauw, Luc; Timmermans, Jean-Pierre

    2015-02-01

    Corticotropin-releasing factor (CRF) and urocortins (UCNs) are important ligands in the CRF signaling pathways, which are most known for their role in the hypothalamic-pituitary-adrenal stress axis. However, peripheral CRF signaling also has profound effects on gastrointestinal functions. Although the murine animal model is highly relevant for the exploration of this complexly balanced pathway via genetic manipulation, little is known about the expression of CRF and UCNs in the mouse intestine. This study aims to investigate the cellular localization of CRF and UCNs in the ileum and to explore whether and how this cellular expression is altered in conditions of intestinal Schistosoma mansoni-induced inflammation. The results show a distinct expression pattern for the different CRF receptor ligands in the ileum. CRF was located in nerve fibers and stromal cells. All UCNs were expressed in polymorphonuclear leukocytes. Furthermore, UCN2 and UCN3 were found in the musculature. During acute schistosomiasis, UCN1 showed an increased immunoreactivity in blood vessels and UCN3 was de novo expressed mainly in submucous neurons. Typical features of S. mansoni-inflamed ileum, such as nerve fiber sprouting, muscle layer thickening and granuloma formation thus all have an impact on the CRF signaling pathways. In conclusion, we outline for the first time the expression of CRF signaling ligands in the mouse ileum; our results point to important changes of this signaling system in S. mansoni-induced intestinal inflammation, which warrants further functional investigation with specific focus on CRF2, given the exclusive binding of UCN2 and UCN3 to this receptor.

  6. 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

  7. 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

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

    PubMed

    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.

  9. The Effect of Simulating Different Intermediate Host Snail Species on the Link between Water Temperature and Schistosomiasis Risk

    PubMed Central

    McCreesh, Nicky; Booth, Mark

    2014-01-01

    Introduction A number of studies have attempted to predict the effects of climate change on schistosomiasis risk. The importance of considering different species of intermediate host snails separately has never previously been explored. Methods An agent-based model of water temperature and Biomphalaria pfeifferi population dynamics and Schistosoma mansoni transmission was parameterised to two additional species of snail: B. glabrata and B. alexandrina. Results Simulated B. alexandrina populations had lower minimum and maximum temperatures for survival than B. pfeifferi populations (12.5–29.5°C vs. 14.0–31.5°C). B. glabrata populations survived over a smaller range of temperatures than either B. pfeifferi or B. alexandrina (17.0°C–29.5°C). Infection risk peaked at 16.5°C, 25.0°C and 19.0°C respectively when B. pfeifferi, B. glabrata and B. alexandrina were simulated. For all species, infection risk increased sharply once a minimum temperature was reached. Conclusions The results from all three species suggest that infection risk may increase dramatically with small increases in temperature in areas at or near the currents limits of schistosome transmission. The effect of small increases in temperature in areas where schistosomiasis is currently found will depend both on current temperatures and on the species of snail acting as intermediate host(s) in the area. In most areas where B. pfeifferi is the host, infection risk is likely to decrease. In cooler areas where B. glabrata is the host, infection risk may increase slightly. In cooler areas where B. alexandrina is the host, infection risk may more than double with only 2°C increase in temperature. Our results show that it is crucial to consider the species of intermediate host when attempting to predict the effects of climate change on schistosomiasis. PMID:24988377

  10. 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

  11. 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.

  12. [Natural environment and schistosomiasis transmission in Poyang Lake region].

    PubMed

    Lv, Shang-Biao; Lin, Dan-Dan

    2014-10-01

    Schistosomiasis is closely related to natural environmental factors. The changes of environmental factors, such as temperature, hydrology, vegetation, soil etc., all impact the scope and extent of schistosomiasis transmission. Poyang Lake is the largest freshwater lake and one of the major endemic areas with schistosomiasis in China. With global warming, the implementation of the Three Gorges Dam operation, and the Poyang Lake Ecological Economic Planning, the natural environment in Poyang Lake area has been and will continue to change, especially, the water environment and climate environment, which are more closely related to the schistosomiasis transmission. These changes, to some extent, have affected and will continue to affect the prevalence and transmission of schistosomiasis. This article reviews the relationship between the natural environment and its changes and schistosomiasis transmission in the Poyang Lake region.

  13. 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

  14. 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

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

    PubMed

    Milligan, John N; Jolly, Emmitt R

    2011-08-16

    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

  16. Efficacy and Safety of Moxidectin, Synriam, Synriam-Praziquantel versus Praziquantel against Schistosoma haematobium and S. mansoni Infections: A Randomized, Exploratory Phase 2 Trial

    PubMed Central

    Barda, Beatrice; Coulibaly, Jean T.; Puchkov, Maxim; Huwyler, Jörg; Hattendorf, Jan; Keiser, Jennifer

    2016-01-01

    Background Schistosomiasis affects millions of people, yet treatment options are limited. The antimalarial Synriam (piperaquine 150 mg/arterolane 750 mg) and the anthelminthic moxidectin revealed promising antischistosomal properties in preclinical or clinical studies. Methodology We conducted two single-blind, randomized exploratory Phase 2 trials in Schistosoma mansoni and S. haematobium-infected adolescents in northern and central Côte d’Ivoire. Our primary endpoints were cure rates (CRs) and egg reduction rates (ERRs) based on geometric mean and safety. Each subject was asked to provide two stool samples (S. mansoni trial) for Kato-Katz analysis or three urine samples (S. haematobium trial) for urine filtration and one finger prick for malaria screening at baseline and follow-up. Participants were randomly assigned to either moxidectin, Synriam, Synriam plus praziquantel or praziquantel. Principal Findings 128 adolescents (age: 12–17 years) were included in each study. Against S. haematobium moxidectin and Synriam revealed low efficacy. On the other hand, Synriam plus praziquantel and praziquantel yielded CRs of 60.0% and 38.5% and ERRs of 96.0% and 93.5%, respectively. CRs observed in the treatment of S. mansoni were 13.0%, 6.7%, 27.0%, and 27.6% for moxidectin, Synriam, Synriam plus praziquantel and praziquantel, respectively. ERRs ranged from 64.9% (Synriam) to 87.5% (praziquantel). Conclusion/Significance Synriam and moxidectin show low efficacy against S. haematobium, hence an ancillary benefit is not expected when these drugs are used for treating onchocerciasis and malaria in co-endemic settings. Further studies are needed to corroborate our findings that moxidectin and Synriam show moderate ERRs against S. mansoni. PMID:27636542

  17. The spatial and seasonal distribution of Bulinus truncatus, Bulinus forskalii and Biomphalaria pfeifferi, the intermediate host snails of schistosomiasis, in N'Djamena, Chad.

    PubMed

    Moser, Wendelin; Greter, Helena; Schindler, Christian; Allan, Fiona; Ngandolo, Bongo N R; Moto, Daugla D; Utzinger, Jürg; Zinsstag, Jakob

    2014-11-01

    There is a paucity of epidemiological and malacological data pertaining to schistosomiasis in Chad. In view of a recently articulated elimination agenda, a deeper understanding of the spatio-temporal distribution of schistosomiasis intermediate host snails is pivotal. We conducted cross-sectional malacological surveys during the dry season (April/May 2013) and after the short rainy season (October 2013) in N'Djamena, the capital of Chad. Snails were identified at the genus and species level using morphological keys and molecular DNA barcoding approaches. Those belonging to Bulinus and Biomphalaria were examined for cercarial shedding. Snail habitats were characterised and their predictive potential for the presence of schistosomiasis intermediate host snails explored. Seasonal patterns were studied using geographical information system and kriging in order to interpolate snail abundance data to make predictions at non-sampled locations across N'Djamena. Overall, 413 Bulinus truncatus, 369 Bulinus forskalii and 108 Biomphalaria pfeifferi snails were collected and subjected to cercarial shedding. During the dry season, one Bu. truncatus of 119 snails collected shed Schistosoma spp. cercariae (0.84%), while S. mansoni was shed by one of 108 Bi. pfeifferi snails (0.93%). None of the snails collected after the rainy season shed Schistosoma spp. cercariae. The abundance of Bu. truncatus and Bu. forskalii showed an inverse U-shape relationship with the square term of conductivity, i.e. low abundance at the lowest and highest levels of conductivity and high abundance at intermediate levels. Bi. pfeifferi showed a negative, linear association with pH in the dry seasons. It is planned to link these intermediate host snail data to infection data in human populations with the goal to draw a predictive risk map that can be utilised for control and elimination of schistosomiasis in N'Djamena.

  18. [Implementation of precision control to achieve the goal of schistosomiasis elimination in China].

    PubMed

    Zhou, Xiao-nong

    2016-02-01

    The integrated strategy for schistosomiasis control with focus on infectious source control, which has been implemented since 2004, accelerated the progress towards schistosomiasis control in China, and achieved transmission control of the disease across the country by the end of 2015, which achieved the overall objective of the Mid- and Long-term National Plan for Prevention and Control of Schistosomiasis (2004-2015) on schedule. Then, the goal of schistosomiasis elimination by 2025 was proposed in China in 2014. To achieve this new goal on schedule, we have to address the key issues, and implement precision control measures with more precise identification of control targets, so that we are able to completely eradicate the potential factors leading to resurgence of schistosomiasis transmission and enable the achievement of schistosomiasis elimination on schedule. Precision schistosomiasis control, a theoretical innovation of precision medicine in schistosomiasis control, will provide new insights into schistosomiasis control based on the conception of precision medicine. This paper describes the definition, interventions and the role of precision schistosomiasis control in the elimination of schistosomiasis in China, and demonstrates that sustainable improvement of professionals and integrated control capability at grass-root level is a prerequisite to the implementation of schistosomiasis control, precision schistosomiasis control is a key to the further implementation of the integrated strategy for schistosomiasis control with focus on infectious source control, and precision schistosomiasis control is a guarantee of curing schistosomiasis patients and implementing schistosomiasis control program and interventions.

  19. Proteasome stress responses in Schistosoma mansoni.

    PubMed

    de Paula, Renato Graciano; de Magalhães Ornelas, Alice Maria; Morais, Enyara Rezende; de Souza Gomes, Matheus; de Paula Aguiar, Daniela; Magalhães, Lizandra Guidi; Rodrigues, Vanderlei

    2015-05-01

    The proteasome proteolytic system is the major ATP-dependent protease in eukaryotic cells responsible for intracellular protein turnover. Schistosoma mansoni has been reported to contain an ubiquitin-proteasome proteolytic pathway, and many studies have suggested a biological role of proteasomes in the development of this parasite. Additionally, evidence has suggested diversity in proteasome composition under several cellular conditions, and this might contribute to the regulation of its function in this parasite. The proteasomal system has been considered important to support the protein homeostasis during cellular stress. In this study, we described in vitro effects of oxidative stress, heat shock, and chemical stress on S. mansoni adults. Our findings showed that chemical stress induced with curcumin, IBMX, and MG132 modified the gene expression of the proteasomal enzymes SmHul5 and SmUbp6. Likewise, the expression of these genes was upregulated during oxidative stress and heat shock. Analyses of the S. mansoni life cycle showed differential gene expression in sporocysts, schistosomulae, and miracidia. These results suggested that proteasome accessory proteins participate in stress response during the parasite development. The expression level of SmHul5 and SmUbp6 was decreased by 16-fold and 9-fold, respectively, by the chemical stress induced with IBMX, which suggests proteasome disassembly. On the other hand, curcumin, MG132, oxidative stress, and heat shock increased the expression of these genes. Furthermore, the gene expression of maturation proteasome protein (SmPOMP) was increased in stress conditions induced by curcumin, MG132, and H₂O₂, which could be related to the synthesis of new proteasomes. S. mansoni adult worms were found to utilize similar mechanisms to respond to different conditions of stress. Our results demonstrated that oxidative stress, heat shock, and chemical stress modified the expression profile of genes related to the ubiquitin

  20. TROPISTIC BEHAVIOR IN SCHISTOSOMIASIS: MIRACIDIA AND CERCARIAE PREDATORS.

    DTIC Science & Technology

    Biomphalaria glabrata and cercariae of Schistosoma mansoni were tagged by exposing infected snails to H275SeO3 or 75Se-methionine. Labeled cercariae... mansoni cercariae occur after exposure to emulsions of epoxygeranylgeraniol at concentrations as low as 1 ppm. Cercariae exposed to 4 ppm

  1. Data management in schistosomiasis control programmes.

    PubMed

    Dixon, H G

    1986-06-01

    Adequate data recording, processing, analysis and evaluation are all components of data management within schistosomiasis control programmes oriented towards reduction of morbidity. Without data management, the response to operational questions will remain subjective and vague. Different types of data related to the population and the environment are reviewed. Examples of data format and presentation are given. The importance of data management for proper short and long term evaluation of control measures is emphasized.

  2. Testing of Compounds for Efficacy Against Schistosomiasis

    DTIC Science & Technology

    1988-08-25

    infections in humans. These are praziquantel , active against all species of schistosomes infective to man; oxamniquine, active against one species of...that strains of S. haematobium resistant to metrifonate have emerged [8]. This leaves only one antischistosomal agent, praziquantel , with minimal...side effects for use in treatment of schistosomiasis at present. Studies to determine if praziquantel is capable of causing drug-resistant schistosomes

  3. Evidence for ryanodine receptors in Schistosoma mansoni.

    PubMed

    Silva, C L; Cunha, V M; Mendonça-Silva, D L; Noël, F

    1998-10-15

    The present study investigated the presence of ryanodine receptors in the trematode Schistosoma mansoni. [3H]Ryanodine specific binding sites were found in the four subcellular fractions of S. mansoni; however, more binding sites were recovered in the heterogeneous fraction P1 and the microsomal fraction P4, as was thapsigargin-sensitive (Ca2+-Mg2+)ATPase activity, marking the sarco/endoplasmic reticulum calcium ATPase (SERCA) pumps. This binding had an equilibrium dissociation constant (Kd) in the nanomolar range, an apparent maximal number of receptors (Bmax) of about 80 fmol/mg of protein, and was modulated by ions (Ca2+, Mg2+) and some pharmacological tools such as caffeine. Ryanodine was able to accelerate the rate of 45Ca2+ release from actively loaded vesicles, and also to induce a transient contraction of the whole worm. We conclude that ryanodine-sensitive Ca2+ release channels are present in S. mansoni, with properties very similar to the ones present in higher animals.

  4. [Oltipraz as brief treatment of schistosomiasis (comparison with niridazole) (author's transl)].

    PubMed

    Pieron, R; Lesobre, B; Mafart, Y; Lancastre, F

    1980-01-01

    161 patients affected by schistosomiasis due in most cases to S. haematobium, and less frequently to S. mansoni, received one day treatment with 4,5 g a day of oltipraz in a first group and, later on, 3 g a day in another group. A control after one year was possible for patients having received 4,5 g one day dosis. Urin control, rectal mucosa biopsy (R.M.B.) and indirect immunofluorescence test (I.I.F.) were performed in patients who did not return to infested areas during that period of time; in almost all cases, the urin control was negative; in 52 p. 100 of the cases the R.M.B. shown no live egg and I.I.F. test was significantly decreased with individual variations. -- These results are compared to those of a previous and similar study on the effects of niridazole. -- Side-effects, mostly digestive or nervous, are frequent with a 4,5 g dose and less frequent with 3 g. They rarely compel to discard the treatment and they never persist after the morning following the treatment is stopped. There is no electrocardiographic change. -- Doses below 3 g in one-day intake are presently studied in order to fix the minimal acting dosis.

  5. 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.

  6. 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

  7. New research tools for urogenital schistosomiasis.

    PubMed

    Rinaldi, Gabriel; Young, Neil D; Honeycutt, Jared D; Brindley, Paul J; Gasser, Robin B; Hsieh, Michael H

    2015-03-15

    Approximately 200,000,000 people have schistosomiasis (schistosome infection). Among the schistosomes, Schistosoma haematobium is responsible for the most infections, which are present in 110 million people globally, mostly in sub-Saharan Africa. This pathogen causes an astonishing breadth of sequelae: hematuria, anemia, dysuria, stunting, uremia, bladder cancer, urosepsis, and human immunodeficiency virus coinfection. Refined estimates of the impact of schistosomiasis on quality of life suggest that it rivals malaria. Despite S. haematobium's importance, relevant research has lagged. Here, we review advances that will deepen knowledge of S. haematobium. Three sets of breakthroughs will accelerate discoveries in the pathogenesis of urogenital schistosomiasis (UGS): (1) comparative genomics, (2) the development of functional genomic tools, and (3) the use of animal models to explore S. haematobium-host interactions. Comparative genomics for S. haematobium is feasible, given the sequencing of multiple schistosome genomes. Features of the S. haematobium genome that are conserved among platyhelminth species and others that are unique to S. haematobium may provide novel diagnostic and drug targets for UGS. Although there are technical hurdles, the integrated use of these approaches can elucidate host-pathogen interactions during this infection and can inform the development of techniques for investigating schistosomes in their human and snail hosts and the development of therapeutics and vaccines for the control of UGS.

  8. Evaluating the risk of Schistosoma mansoni transmission in mainland China.

    PubMed

    Qu, Guoli; Wang, Wei; Lu, Xiaomin; Dai, Jianrong; Li, Xiaoheng; Liang, Yousheng

    2016-12-01

    Biomphalaria straminea, an intermediate host of Schistosoma mansoni, is predominantly distributed in the South Americas and Caribbean; however, this snail, as an invasive species, was introduced to Shenzhen, southern China, in 1981, and recent epidemiologic surveys demonstrate that the distribution of B. straminea has expanded across the Zhujiang River Basin, South China. In the presence of continuous importation of S. mansoni-infected cases, there is a growing concern about the transmission of S. mansoni in China. To evaluate the risk of S. mansoni transmission in China, we tested the compatibility of B. straminea captured from the snail habitats in southern China with S. mansoni in laboratory. We detected no S. mansoni infections in B. straminea following exposure to the parasite larvae at snail/miracidium ratios of 1:5, 1:10, 1:20, 1:40, and 1:80, while 6.7 to 66.7 % infections occurred in the control Biomphalaria glabrata depending on the ratio. The results of the present study demonstrate that the invasive B. straminea snails seem to be incompatible with S. mansoni, suggesting a low risk of S. mansoni transmission in mainland China.

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

    PubMed Central

    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

    2016-01-01

    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

  10. Polyethyleneimine (PEI) Mediated siRNA Gene Silencing in the Schistosoma mansoni Snail Host, Biomphalaria glabrata

    PubMed Central

    Knight, Matty; Miller, Andre; Liu, Yijia; Scaria, Puthupparampil; Woodle, Martin; Ittiprasert, Wannaporn

    2011-01-01

    An in vivo, non-invasive technique for gene silencing by RNA interference (RNAi) in the snail, Biomphalaria glabrata, has been developed using cationic polymer polyethyleneimine (PEI) mediated delivery of long double-stranded (ds) and small interfering (si) RNA. Cellular delivery was evaluated and optimized by using a ‘mock’ fluorescent siRNA. Subsequently, we used the method to suppress expression of Cathepsin B (CathB) with either the corresponding siRNA or dsRNA of this transcript. In addition, the knockdown of peroxiredoxin (Prx) at both RNA and protein levels was achieved with the PEI-mediated soaking method. B. glabrata is an important snail host for the transmission of the parasitic digenean platyhelminth, Schistosoma mansoni that causes schistosomiasis in the neotropics. Progress is being made to realize the genome sequence of the snail and to uncover gene expression profiles and cellular pathways that enable the snail to either prevent or sustain an infection. Using PEI complexes, a convenient soaking method has been developed, enabling functional gene knockdown studies with either dsRNA or siRNA. The protocol developed offers a first whole organism method for host-parasite gene function studies needed to identify key mechanisms required for parasite development in the snail host, which ultimately are needed as points for disrupting this parasite mediated disease. PMID:21765961

  11. Fasciola hepatica and Schistosoma mansoni: identification of common proteins by comparative proteomic analysis.

    PubMed

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

    2011-10-01

    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.

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

    PubMed Central

    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.

    2015-01-01

    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

  13. Kicking in the Guts: Schistosoma mansoni Digestive Tract Proteins are Potential Candidates for Vaccine Development

    PubMed Central

    Figueiredo, Barbara Castro-Pimentel; Ricci, Natasha Delaqua; de Assis, Natan Raimundo Gonçalves; de Morais, Suellen Batistoni; Fonseca, Cristina Toscano; Oliveira, Sergio Costa

    2015-01-01

    Schistosomiasis is a debilitating disease that represents a major health problem in at least 74 tropical and subtropical countries. Current disease control strategies consist mainly of chemotherapy, which cannot prevent recurrent re-infection of people living in endemic area. In the last decades, many researchers made a remarkable effort in the search for an effective vaccine to provide long-term protection. Parasitic platyhelminthes of Schistosoma genus, which cause the disease, live in the blood vessels of definitive hosts where they are bathed in host blood for many years. Among the most promising molecules as vaccine candidates are the proteins present in the host–parasite interface, so numerous tegument antigens have been assessed and the achieved protection never got even close to 100%. Besides the tegument, the digestive tract is the other major site of host–parasite interface. Since parasites feed on blood, they need to swallow a considerable amount of blood for nutrient acquisition. Host blood ingested by schistosomes passes through the esophagus and reaches the gut where many peptidases catalyze the proteolysis of blood cells. Recent studies show the emergence of antigens related to the parasite blood feeding, such as esophageal gland proteins, proteases, and other proteins related to nutrient uptake. Herein, we review what is known about Schistosoma mansoni digestive tract proteins, emphasizing the ones described as potential vaccine candidates. PMID:25674091

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. Schistosoma mansoni Infection Can Jeopardize the Duration of Protective Levels of Antibody Responses to Immunizations against Hepatitis B and Tetanus Toxoid

    PubMed Central

    Riner, Diana K.; Ndombi, Eric M.; Carter, Jennifer M.; Omondi, Amos; Kittur, Nupur; Kavere, Emmy; Korir, Harrison K.; Flaherty, Briana; Karanja, Diana; Colley, Daniel G.

    2016-01-01

    Background Schistosomiasis is a disease of major public health importance in sub-Saharan Africa. Immunoregulation begins early in schistosome infection and is characterized by hyporesponsiveness to parasite and bystander antigens, suggesting that a schistosome infection at the time of immunization could negatively impact the induction of protective vaccine responses. This study examined whether having a Schistosoma mansoni infection at the time of immunization with hepatitis B and tetanus toxoid (TT) vaccines impacts an individual’s ability to achieve and maintain protective antibody levels against hepatitis B surface antigen or TT. Methods Adults were recruited from Kisumu Polytechnic College in Western Kenya. At enrollment, participants were screened for schistosomiasis and soil transmitted helminths (STHs) and assigned to groups based on helminth status. The vaccines were then administered and helminth infections treated a week after the first hepatitis B boost. Over an 8 month period, 3 blood specimens were obtained for the evaluation of humoral and cytokine responses to the vaccine antigens and for immunophenotyping. Results 146 individuals were available for final analysis and 26% were S. mansoni positive (Sm+). Schistosomiasis did not impede the generation of initial minimum protective antibody levels to either hepatitis B or TT vaccines. However, median hepatitis B surface antibody levels were significantly lower in the Sm+ group after the first boost and remained lower, but not significantly lower, following praziquantel (PZQ) treatment and final boost. In addition, 8 months following TT boost and 7 months following PZQ treatment, Sm+ individuals were more likely to have anti-TT antibody levels fall below levels considered optimal for long term protection. IL-5 levels in response to in vitro TT stimulation of whole blood were significantly higher in the Sm+ group at the 8 month time period as well. Conclusions Individuals with schistosomiasis at the

  19. Role of microRNAs in schistosomes and schistosomiasis.

    PubMed

    Zhu, Lihui; Liu, Jinming; Cheng, Guofeng

    2014-01-01

    Schistosomes, a class of parasitic trematode worms, cause schistosomiasis. Accumulating evidence suggests that microRNAs (miRNAs)-small, non-coding RNAs that are known to play critical regulatory roles in many organisms-may be involved in schistosome development and sexual maturation, as well as the pathogenesis of schistosomiasis. Schistosoma miRNAs, such as Bantam and miR-10, may be involved in the pathological processes of schistosomiasis, and recent studies suggest that schistosome-specific miRNAs (e.g., Bantam, miR-3479-3p) in the bloodstream of a final host could be used as biomarkers for schistosomiasis diagnosis. Furthermore, aberrant miRNAs, such as miR-223 and miR-454, can be produced by a host in response to schistosome infection, and these miRNAs may contribute to the pathogenesis of schistosomiasis-associated liver injury. Here, we summarize recent progress evaluating the relationship between schistosome miRNAs and schistosomiasis and discuss how these miRNAs can mediate the pathogenesis of schistosomiasis and be used as biomarkers for schistosomiasis diagnosis.

  20. Elucidation of the in vitro and in vivo activities of bridged 1,2,4-trioxolanes, bridged 1,2,4,5-tetraoxanes, tricyclic monoperoxides, silyl peroxides, and hydroxylamine derivatives against Schistosoma mansoni.

    PubMed

    Cowan, Noemi; Yaremenko, Ivan A; Krylov, Igor B; Terent'ev, Alexander O; Keiser, Jennifer

    2015-08-15

    Praziquantel is currently the only drug available to treat schistosomiasis. Since drug resistance would be a major barrier for the increasing global attempts to eliminate schistosomiasis as a public health problem, efforts should go hand in hand with the discovery of novel treatment options. Synthetic peroxides might offer a good direction since their antischistosomal activity has been demonstrated in the laboratory. We studied 19 bridged 1,2,4,5-tetraoxanes, 2 tricyclic monoperoxides, 11 bridged 1,2,4-trioxolanes, 12 silyl peroxides, and 4 hydroxylamine derivatives against newly transformed schistosomula (NTS) and adult Schistosoma mansoni in vitro. Schistosomicidal compounds were tested for cytotoxicity followed by in vivo studies of the most promising compounds. Tricyclic monoperoxides, trioxolanes, and tetraoxanes revealed the highest in vitro activity against NTS (IC50s 0.4-20.2 μM) and adult schistosomes (IC50s 1.8-22.8 μM). Tetraoxanes showed higher cytotoxicity than antischistosomal activity. Selected trioxolane and tricyclic monoperoxides were tested in mice harboring an adult S. mansoni infection. The highest activity was observed for two trioxolanes, which showed moderate worm burden reductions (WBR) of 44.3% and 42.9% (p>0.05). Complexation of the compounds with β-cyclodextrin with the aim to improve solubility and gastrointestinal absorption did not increase in vivo antischistosomal efficacy. The high in vitro antischistosomal activity of trioxolanes and tricyclic monoperoxides is a promising basis for future investigations, with the focus on improving in vivo efficacy.

  1. Non-necrotizing colonic granuloma induced by schistosomiasis

    PubMed Central

    Swe, Thein; Baqui, AAMA; Naing, Akari Thein; Baqui, Tajruba; Sherigar, Jagannath; Mansour, Mohamed

    2016-01-01

    Schistosomiasis is an important parasitic disease with various clinical presentations caused by trematode blood flukes. It can present with asymptomatic, chronic colonic ulcerations, strictures, or inflammatory mass causing bowel obstruction. Intestinal polyps are uncommon and induced by antigens released from the schistosome eggs that trigger a cell-mediated inflammatory response with granuloma formation involving T cells, macrophages, and necrosis. This is very relevant while evaluating chronic intermittent gastrointestinal symptoms and eosinophilia in an immigrant patient from endemic areas of schistosomiasis. Here, we describe a case of chronic intestinal schistosomiasis which was found to have schistosomiasis-induced colonic polyp with non-necrotizing granuloma. With increase in immigrant population from the endemic areas of schistosomiasis in the United States, physicians should be aware of this disease and its various manifestations. Gastroenterologist should keep this as one of the differentials for colonic polyps. Diagnosis and treatment in time prevents further progression of the disease and its complications. PMID:27987283

  2. [Discussion on abilities for a leader of station of schistosomiasis prevention and control at primary level].

    PubMed

    Tao, Bo; Zhang, Zhi-Jie

    2012-08-01

    Based on the actual situation of schistosomiasis prevention and control at the primary level and from the point of a leader of the local station of schistosomiasis prevention and control, we put forward the practical problems existed in the process of schistosomiasis-related work and the corresponding solutions. What responsibilities and abilities that a leader of the station of schistosomiasis prevention and control should have are discussed and some suggestions are also given for serving the work of schistosomiasis prevention and control.

  3. [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.

  4. Schistosomiasis, Soil-Transmitted Helminthiasis, and Sociodemographic Factors Influence Quality of Life of Adults in Côte d'Ivoire

    PubMed Central

    Fürst, Thomas; Silué, Kigbafori D.; Ouattara, Mamadou; N'Goran, Dje N.; Adiossan, Lukas G.; N'Guessan, Yao; Zouzou, Fabian; Koné, Siaka; N'Goran, Eliézer K.; Utzinger, Jürg

    2012-01-01

    Background Burden of disease estimates are widely used for priority setting in public health and disability-adjusted life years are a powerful “currency” nowadays. However, disability weights, which capture the disability incurred by a typical patient of a certain condition, are fundamental to such burden calculation and their determination remains a widely debated issue. Methodology A cross-sectional epidemiological survey was conducted in the recently established Taabo health demographic surveillance system (HDSS) in south-central Côte d'Ivoire, to provide new, population-based evidence on the disability caused by schistosomiasis and soil-transmitted helminthiasis. Parasitological results from stool, urine, and blood examinations were juxtaposed to quality of life (QoL) questionnaire results from 187 adults. A multivariable linear regression model with stepwise backward elimination was used to identify significant associations, considering also sociodemographic characteristics obtained from the Taabo HDSS database. Principal Findings Prevalences for hookworm, Plasmodium spp., Trichuris trichiura, Schistosoma haematobium and Schistosoma mansoni were 39.0%, 18.2%, 2.7%, 2.1% and 2.1%, respectively. S. mansoni and T. trichiura infections of any intensity reduced the participants' self-rated QoL by 16 points (95% confidence interval (CI): 4–29 points) and 13 points (95% CI: 1–24 points), respectively, on a scale from 0 (worst QoL) to 100 points (best QoL). The only other statistically significant effect was a 1-point (95% CI: 0.1–2 points) increase on the QoL scale per one unit increase in a calculated wealth index. Conclusions/Significance We found consistent and significant results on the negative effects of schistosomiasis and soil-transmitted helminthiasis on adults' self-rated QoL, also when taking sociodemographic characteristics into account. Our results warrant further investigation on the disability incurred by helmintic infections and the

  5. Coinfection with the intestinal nematode Heligmosomoides polygyrus markedly reduces hepatic egg-induced immunopathology and proinflammatory cytokines in mouse models of severe schistosomiasis.

    PubMed

    Bazzone, Lindsey E; Smith, Patrick M; Rutitzky, Laura I; Shainheit, Mara G; Urban, Joseph F; Setiawan, Tommy; Blum, Arthur M; Weinstock, Joel V; Stadecker, Miguel J

    2008-11-01

    Infection with the trematode helminth Schistosoma mansoni results in a parasite egg-induced, CD4 T-cell-mediated, hepatointestinal granulomatous and fibrosing inflammation that varies greatly in severity, with a higher frequency of milder forms typically occurring in regions where the disease is endemic. One possible explanation for this is that in these regions the degree of inflammation is lessened by widespread concurrent infection with gastrointestinal nematodes. We tested this hypothesis by establishing a murine coinfection model in which mice were infected with the intestinal nematode parasite Heligmosomoides polygyrus prior to infection with S. mansoni. In CBA mice that naturally display a severe form of schistosomiasis, preinfection with H. polygyrus resulted in a marked reduction in schistosome egg-induced hepatic immunopathology, which was associated with significant decreases in the levels of interleukin-17 (IL-17), gamma interferon, tumor necrosis factor alpha, IL-23, IL-6, and IL-1beta and with increases in the levels of IL-4, IL-5, IL-10, and transforming growth factor beta in mesenteric lymph node cells, purified CD4 T cells, and isolated liver granuloma cells. There also were increases in liver Ym1 and forkhead box P3 transcription factor expression. In another model of high-pathology schistosomiasis induced in C57BL/6 mice by immunization with schistosome egg antigens in complete Freund's adjuvant, coinfection with the nematodes also resulted in a marked inhibition of hepatic immunopathology accompanied by similar shifts in cytokine production. These findings demonstrate that intestinal nematodes prevent Th1- and Th17-cell-mediated inflammation by promoting a strong Th2-polarized environment associated with increases in the levels of alternatively activated macrophages and T regulatory cells, which result in significant amelioration of schistosome-induced immunopathology.

  6. 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.

  7. 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.

  8. The costs and a cost-benefit analysis of an S. mansoni control programme on an irrigated sugar estate in northern Tanzania

    PubMed Central

    Fenwick, A.

    1972-01-01

    On a sugar estate in northern Tanzania, an integrated control programme against Schistosoma mansoni was carried out during the three years 1968-70 inclusive. The costs of that programme are defined, the costs of future snail control in the same area are estimated, and an attempt is made to evaluate the cost—benefit ratio of schistosomiasis control in the estate. The total expenditure on snail control was US $23 538, of which US $17 371 was spent on molluscicides and US $5 135 on labour. This represents an annual expenditure of approximately US $1.31 per estate resident. In the mass diagnosis and treatment campaign the main items in the total expenditure of US $37 043 were labour (US $13 724), drugs (US $4 218), hospital charges (US $8 262), and lost working days (US $8 760). It is estimated that the recurrent annual expenditure necessary to keep S. mansoni at a low level in the future would be US $7 714 on snail control and US $1 832 on detecting and treating new cases; however, the institution of a snail control programme would reduce the need for chemotherapy and would result in recurrent annual savings of US $7 448. In addition, it was estimated from a productivity study that savings of about US $14 000 per year could result if treatment of infected workers raised productivity by 5%. The goodwill that resulted from the protection of wives and children against schistosomiasis would be a further benefit. When all factors are taken into account, snail control appears to be a feasible economic proposition. PMID:4540676

  9. 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

  10. Evaluation of circulating cathodic antigen (CCA) urine-cassette assay as a survey tool for Schistosoma mansoni in different transmission settings within Bugiri District, Uganda.

    PubMed

    Adriko, M; Standley, C J; Tinkitina, B; Tukahebwa, E M; Fenwick, A; Fleming, F M; Sousa-Figueiredo, J C; Stothard, J R; Kabatereine, N B

    2014-08-01

    Diagnosis of schistosomiasis at the point-of-care (POC) is a growing topic in neglected tropical disease research. There is a need for diagnostic tests which are affordable, sensitive, specific, user-friendly, rapid, equipment-free and delivered to those who need it, and POC is an important tool for disease mapping and guiding mass deworming. The aim of present study was to evaluate the relative diagnostic performance of two urine-circulating cathodic antigen (CCA) cassette assays, one commercially available and the other in experimental production, against results obtained using the standard Kato-Katz faecal smear method (six thick smears from three consecutive days), as a 'gold-standard', for Schistosoma mansoni infection in different transmission settings in Uganda. Our study was conducted among 500 school children randomly selected across 5 schools within Bugiri district, adjacent to Lake Victoria in Uganda. Considering results from the 469 pupils who provided three stool samples for the six Kato-Katz smears, 293 (76%) children had no infection, 109 (23%) were in the light intensity category, while 42 (9%) and 25 (5%) were in the moderate and heavy intensity categories respectively. Following performance analysis of CCA tests in terms of sensitivity, specificity, negative and positive predictive values, overall performance of the commercially available CCA test was more informative than single Kato-Katz faecal smear microscopy, the current operational field standard for disease mapping. The current CCA assay is therefore a satisfactory method for surveillance of S. mansoni in an area where disease endemicity is declining due to control interventions. With the recent resolution on schistosomiasis elimination by the 65th World Health Assembly, the urine POC CCA test is an attractive tool to augment and perhaps replace the Kato-Katz sampling within ongoing control programmes.

  11. 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

  12. Experience with schistosomiasis in Northern Ireland.

    PubMed

    Ingram, P J; Allen, D C; Irwin, S T

    1996-11-01

    Five cases of schistosomiasis have been recorded in the Belfast City Hospital Histopathology Laboratory over the last three years. The sites of infection have included the colon, bladder, uterus and seminal vesicles. All the infected individuals had visited Africa. Three of them were health care workers. The clinician must maintain a high index of suspicion when treating those with a history of travel and risk of exposure to this infection. Diagnosis is made even more critical as the condition is treatable, and serological markers can identify those with occult infection.

  13. Intensity of Schistosoma mansoni, hepatitis B, age, and sex predict levels of hepatic periportal thickening/fibrosis (PPT/F): a large-scale community-based study in Ethiopia.

    PubMed

    Berhe, Nega; Myrvang, Bjørn; Gundersen, Svein G

    2007-12-01

    To elucidate determinants of morbidity in schistosomiasis mansoni, a community-based study was undertaken involving 2,451 subjects (mean age, 18.8 +/- 15.3 [SD] years) from four endemic sites in Ethiopia. Overall prevalence of infection was 65.9%, reported blood in stools was 35.8%, and schistosomal periportal thickening/fibrosis (PPT/F) was 4.6%. Similarly, 43.2% were positive for at least one marker of hepatitis B virus (HBV), 5.3% were HBsAg positive, and 1.3% were anti-hepatitis C virus (HCV) positive. Prevalence of PPT/F increased significantly with increasing community prevalence and intensity of S. mansoni infection. In a multiple logistic regression analysis, intensity of egg excretion, markers of HBV infection, age, and male sex were significantly associated with PPT/F, whereas co-infection with other intestinal helminths was associated with lower odds for PPT/F. HCV was not associated with S. mansoni infection or with schistosomal PPT/F. In conclusion, integrated helminth control targeting school-aged children, who have the highest burden infection, should be used to substantially reduce the risk of periportal fibrosis.

  14. 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

  15. 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.

  16. A Rationale for Schistosomiasis Control in Elementary Schools of the Rainforest Zone of Pernambuco, Brazil

    PubMed Central

    Favre, Tereza C.; Pereira, Ana P. B.; Galvão, Aline F.; Zani, Luciana C.; Barbosa, Constança S.; Pieri, Otávio S.

    2009-01-01

    Background Since its beginning in 1999, the Schistosomiasis Control Program within the Unified Health System (PCE-SUS) has registered a cumulative coverage of just 20% of the population from the Rainforest Zone of Pernambuco (ZMP), northeast Brazil. This jeopardizes the accomplishment of the minimum goal of the Fifty-Fourth World Health Assembly, resolution WHA54.19, of providing treatment for schistosomiasis and soil-transmitted helminthiases (STH) to 75% of school-aged children at risk, which requires attending at least 166,000 residents in the 7–14 age range by year 2010 in that important endemic area. In the present study, secondary demographic and parasitological data from a representative municipality of the ZMP are analyzed to provide evidence that the current, community-based approach to control schistosomiasis and STH is unlikely to attain the WHA-54.19 minimum goal and to suggest that school-based control actions are also needed. Methodology/Principal Findings Data available on the PCE-SUS activities related to diagnosis and treatment of the population from the study municipality were obtained from the State Secretary of Health of Pernambuco (SES/PE) for 2002–2006, complemented by the Municipal Secretary of Health (SMS) for 2003–2004. Data from a school-based stool survey carried out by the Schistosomiasis Reference Service of the Oswaldo Cruz Foundation (SRE/Fiocruz) in 2004 were used to provide information on infection status variation among school-aged children (7–14 years). According to the SES, from 2004 to 2006, only 2,977 (19.5%) of the estimated 15,288 residents of all ages were examined, of which 396 (13.3%) were positive for Schistosoma mansoni. Among these, only 180 (45.5%) were treated. According to the SMS, of the 1,766 examined in the 2003–2004 population stool survey 570 (32.3%) were children aged 7–14 years. One year later, the SRE/Fiocruz school survey revealed that the infection status among those children remained unchanged

  17. Control of calcium homeostasis in Schistosoma mansoni.

    PubMed

    Noël, F; Cunha, V M; Silva, C L; Mendonça-Silva, D L

    2001-01-01

    Calcium signalling is fundamental for muscular contractility of Schistosoma mansoni. We have previously described the presence of transport ATPases (Na+,K+-ATPase and (Ca2+-Mg2+)-ATPase) and calcium channels (ryanodine receptors - RyR) involved in control of calcium homeostasis in this worm. Here we briefly review the main technics (ATPase activity, binding with specific radioligands, fluxes of 45Ca2+ and whole worm contractions) and results obtained in order to compare the distribution patterns of these proteins: thapsigargin-sensitive (Ca2+-Mg2+)-ATPase activity and RyR co-purified in P1 and P4 fractions mainly, which is compatible with a sarcoplasmic reticulum localization, while basal ATPase (along with Na+,K+-ATPase) and thapsigargin-resistant (Ca2+-Mg2+)-ATPase have a distinct distribution, indicative of their plasma membrane localization. Finally we attempt to integrate these contributions with data from other groups in order to propose the first synoptic model for control of calcium homeostasis in S. mansoni.

  18. 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.

  19. Geographical and socioeconomic factors relating to the distribution of Schistosoma mansoni infection in an urban area of north-east Brazil.

    PubMed Central

    Barreto, M. L.

    1991-01-01

    A study was carried out in Santo Antonio de Jesus, a town in Bahia State, north-east Brazil, to determine the relationship between various biological, socioeconomic, behavioural, and geographical factors and the prevalence and intensity of Schistosoma mansoni infection. The town's population was around 45,000 and the study was targeted at all children born in 1970-71 who were living in the town at the time of the survey (August-November 1984). An extensive questionnaire was used to collect information on each child and on family and household conditions; samples of stools were also taken for examination (Kato-Katz method). A survey of water snails was also carried out and information on the distribution of their breeding sites was plotted on a map of the area. The overall prevalence of S. mansoni infection was 31.0%. Several variables that reflected different aspects of the population's way of life were strongly associated with the prevalence and the intensity of infection. Some of the findings are valuable for understanding the mechanisms involved in the occurrence of schistosomiasis and its distribution in urban locations as well as for defining high-risk groups, all of which are important for planning control strategies. PMID:1905208

  20. Heterogeneity of ouabain binding sites in Schistosoma mansoni. First evidence for the presence of two (Na+ + K+)-ATPase isoforms in platyhelminths.

    PubMed

    Pardon, R S; Noël, F

    1994-01-20

    Binding experiments with [3H]ouabain were performed to investigate the presence of (Na+ + K+)-ATPase (EC3.6.1.3) isoforms in adult male Schistosoma mansoni, the trematode responsible for human schistosomiasis. Non-linear regression analysis of equilibrium experiments performed with homogenates in a Mg-Pi medium indicated the presence of about 10% (Bmax = 223 +/- 67 fmol/mg protein) high-affinity sites (KD = 0.285 +/- 0.045 microM) and 90% (Bmax = 2117 +/- 348 fmol/mg protein) sites with a 20-fold lower affinity (KD = 4.9 +/- 1.28 microM). This was confirmed by their-exponential decay of [3H]ouabain dissociation. Furthermore, determination of association and dissociation rate constants indicated that the two classes of binding sites differed by their dissociation rate constants for ouabain (k-1 = 0.0185 +/- 0.0019 min-1 and 0.0997 +/- 0.0528 min-1 for high- and low-affinity sites, respectively). Surprisingly, the association rate constant measured for ouabain binding to S. mansoni homogenate (0.038 microM-1.min-1) was lower (25- to 80-fold) than the one usually observed for mammalian enzymes. This is the first direct evidence for the existence of (Na+ + K+)-ATPase isoforms in platyhelminths, invertebrates of great importance from the phylogenetic point of view.

  1. Control of Biomphalaria pfeifferi population and schistosomiasis transmission in Ethiopia using the soap berry endod (Phytolacca dodecandra), with special emphasis on application methods.

    PubMed

    Abebe, F; Erko, B; Gemetchu, T; Gundersen, S G

    2005-10-01

    The endod (Phytolacca dodecandra)-based schistosomiasis mansoni control project was implemented in Ethiopia between 1994 and 1999. The aim was to develop an effective, cheap and sustainable method of controlling schistosomiasis. First, different formulations of the Ethiopian endod strain 44 (E-44) were compared for potency in the laboratory. Secondly, spray and drip-feeding methods were compared for simplicity and effectiveness in the field. Lastly, the efficacy of endod powder soap was compared with the endod spray method. In Bati stream, endod powder soap was distributed to the residents every weekend at laundry sites. In Worke stream, endod was sprayed along a 1-km stretch of the stream at 3-month intervals. No endod was applied in Harbu stream. The immediate and long-term effects of endod application on the snail population and schistosomal infection were determined. Using the spray method, 100% snail mortality could be obtained, and it was simpler and more effective than the drip-feeding method. Snail mortality ranged from 20 to 100% using endod soap. There was a progressive decline in the snail population and infection in Bati stream compared with Worke stream, mainly due to sustained use of endod soap. The advantages and disadvantages of the different endod delivery systems are discussed.

  2. Low genetic diversity in a snail intermediate host (Biomphalaria pfeifferi Krass, 1848) and schistosomiasis transmission in the Senegal River Basin.

    PubMed

    Campbell, G; Noble, L R; Rollinson, D; Southgate, V R; Webster, J P; Jones, C S

    2010-01-01

    Population genetic perturbations of intermediate hosts, often a consequence of human pressure on environmental resources, can precipitate unexpectedly severe disease outbreaks. Such disturbances are set to become increasingly common following range changes concomitant with climate shifts, dwindling natural resources and major infrastructure changes such as hydroprojects. Construction of the Diama dam in the Senegal River Basin (SRB) reduced river salinity, enabling the freshwater snail intermediate host Biomphalaria pfeifferi to rapidly expand its distribution. A serious public health problem ensued, with an epidemic of intestinal schistosomiasis occurring in the previously schistosome-free Richard-Toll region within 2 years. The current study aimed to assess the population variability of B. pfeifferi in the SRB, and speculate upon its subsequent impact on host-parasite interactions following such engineered ecological change. Genetic variation at nine polymorphic microsatellite loci revealed little population differentiation in SRB snails compared with those from natural habitats in Zimbabwe, where Schistosoma mansoni transmission is much lower. 'Open' SRB habitats are associated with greater water contact, smaller population sizes and less genetic diversity, with sites downstream of Richard-Toll showing greater inter- and intrapopulation variation, concomitant with less frequent human contact. These observations may be explained by rapid expansion into pristine habitat selecting for high fecundity genotypes at the expense of schistosome resistance, presenting S. mansoni with genetically homogenous highly fecund susceptible populations around the focal point, promoting development of a highly compatible host-parasite relationship. Longitudinal study of such systems may prove important in predicting public health risks engendered by future environmental engineering projects.

  3. The major parasite surface antigen associated with human resistance to schistosomiasis is a 37-kD glyceraldehyde-3P-dehydrogenase

    PubMed Central

    1989-01-01

    Schistosomiasis, due to Schistosoma mansoni, is a major health problem in many subtropical countries, and major efforts are being made to define a vaccine. In this regard, we have reported that sera from subjects with low susceptibility to infection by S. mansoni react with a major larval surface antigen (P-37), having an apparent molecular mass of 37 kD, against which sera of susceptible individuals show little reactivity. We have now cloned the cDNA for this antigen by screening a schistosome cDNA expression library with antibodies against the purified protein. The selected cDNAs encode a protein that is specifically identified by immune human sera containing antibodies against P-37, while sera exhibiting low or no reactivity toward P-37 fail to recognize the recombinant protein. The cloned cDNAs hybridize with a 1.2-kb RNA that is the transcript of a single copy gene. This RNA directs the synthesis of a 36.5-kD polypeptide that is precipitated by sera from the most resistant subjects. The amino acid sequence of the encoded polypeptide shows homology with the glycolytic enzyme Glyceraldehyde-3P-dehydrogenase (72.5% of positional identity with human Glyceraldehyde-3P-dehydrogenase). Antibodies against the recombinant protein identified P-37 on the larva. These findings, together with other reports, indicate that a number of conserved proteins may be major targets of host-protective immunity against S. mansoni. The hypothesis is discussed that genetic restriction of the immune response to these antigens may occur in heterogeneous human populations because of the limited number of T cell epitopes carried by these host-like proteins. Such genetic effects might allow parasite transmission through nonresponder (susceptible) individuals. This hypothesis and the protective properties of P-37 can now be tested using the recombinant protein and synthetic peptides derived from selected regions of the polypeptide chain. PMID:2584935

  4. [Evaluation of a program for the control of schistosomiasis in municipalities located on the basin of the Sao Francisco River, Minas Gerais, Brazil].

    PubMed

    Lima e Costa, M F; Guerra, H L; Pimenta, F G; Firmo, J O; Uchoa, E

    1996-01-01

    An evaluation of the control program on schistosomiasis (PCE/PCDEN) was performed in the region of São Francisco river in MInas Gerais. The study area comprises six municipalities, with 130,000 inhabitants and 916 localities situated in an area with 10,722 km2. The activities initiated in 1983-85 in four municipalities and in 1987 in the other two. The main measures of control were repeated treatment with oxamniquine and use of niclosamide. The prevalence of infection by Schistosoma mansoni in the first four municipalities, that was initially around 18 and 32%, dropped abruptly after the first intervention (1983/85) and remained in levels below the initial ones until the last assessment (1990-94); similar trends were observed for the proportion of infected snails. In these municipalities, the proportion of localities without infection or with prevalence below 5% increased in relation to those with higher prevalence. In the other two municipalities, with initial prevalence below 5%, there were no substantial changes in S. mansoni prevalence or proportion of infected snails; the cost benefit of the program in these municipalities need to be assessed and the priorities redirected to eradicate focal areas and prevent spread to non infected localities. The authors call attention to the difficulties in the long term of a control program based on repeated treatments. Information on factors associated with S. mansoni infection in each locality, or in groups of similar localities, would allow to develop additional measures to treatment that could last longer and be less dependent on the continuous use of chemotherapy.

  5. Evidence for Integrin - Venus Kinase Receptor 1 Alliance in the Ovary of Schistosoma mansoni Females Controlling Cell Survival.

    PubMed

    Gelmedin, Verena; Morel, Marion; Hahnel, Steffen; Cailliau, Katia; Dissous, Colette; Grevelding, Christoph G

    2017-01-01

    In metazoan integrin signaling is an important process of mediating extracellular and intracellular communication processes. This can be achieved by cooperation of integrins with growth factor receptors (GFRs). Schistosoma mansoni is a helminth parasite inducing schistosomiasis, an infectious disease of worldwide significance for humans and animals. First studies on schistosome integrins revealed their role in reproductive processes, being involved in spermatogenesis and oogenesis. With respect to the roles of eggs for maintaining the parasite´s life cycle and for inducing the pathology of schistosomiasis, elucidating reproductive processes is of high importance. Here we studied the interaction of the integrin receptor Smβ-Int1 with the venus kinase receptor SmVKR1 in S. mansoni. To this end we cloned and characterized SmILK, SmPINCH, and SmNck2, three putative bridging molecules for their role in mediating Smβ-Int1/SmVKR1 cooperation. Phylogenetic analyses showed that these molecules form clusters that are specific for parasitic platyhelminths as it was shown for integrins before. Transcripts of all genes colocalized in the ovary. In Xenopus oocytes germinal vesicle breakdown (GVBD) was only induced if all members were simultaneously expressed. Coimmunoprecipitation results suggest that a Smβ-Int1-SmILK-SmPINCH-SmNck2-SmVKR1 complex can be formed leading to the phosphorylation and activation of SmVKR1. These results indicate that SmVKR1 can be activated in a ligand-independent manner by receptor-complex interaction. RNAi and inhibitor studies to knock-down SmILK as a representative complex member concurrently revealed effects on the extracellular matrix surrounding the ovary and oocyte localization within the ovary, oocyte survival, and egg production. By TUNEL assays, confocal laser scanning microscopy (CLSM), Caspase-3 assay, and transcript profiling of the pro-apoptotic BCL-2 family members BAK/BAX we obtained first evidence for roles of this signaling

  6. Evidence for Integrin – Venus Kinase Receptor 1 Alliance in the Ovary of Schistosoma mansoni Females Controlling Cell Survival

    PubMed Central

    Gelmedin, Verena; Morel, Marion; Hahnel, Steffen; Cailliau, Katia; Dissous, Colette; Grevelding, Christoph G.

    2017-01-01

    In metazoan integrin signaling is an important process of mediating extracellular and intracellular communication processes. This can be achieved by cooperation of integrins with growth factor receptors (GFRs). Schistosoma mansoni is a helminth parasite inducing schistosomiasis, an infectious disease of worldwide significance for humans and animals. First studies on schistosome integrins revealed their role in reproductive processes, being involved in spermatogenesis and oogenesis. With respect to the roles of eggs for maintaining the parasite´s life cycle and for inducing the pathology of schistosomiasis, elucidating reproductive processes is of high importance. Here we studied the interaction of the integrin receptor Smβ-Int1 with the venus kinase receptor SmVKR1 in S. mansoni. To this end we cloned and characterized SmILK, SmPINCH, and SmNck2, three putative bridging molecules for their role in mediating Smβ-Int1/SmVKR1 cooperation. Phylogenetic analyses showed that these molecules form clusters that are specific for parasitic platyhelminths as it was shown for integrins before. Transcripts of all genes colocalized in the ovary. In Xenopus oocytes germinal vesicle breakdown (GVBD) was only induced if all members were simultaneously expressed. Coimmunoprecipitation results suggest that a Smβ-Int1-SmILK-SmPINCH-SmNck2-SmVKR1 complex can be formed leading to the phosphorylation and activation of SmVKR1. These results indicate that SmVKR1 can be activated in a ligand-independent manner by receptor-complex interaction. RNAi and inhibitor studies to knock-down SmILK as a representative complex member concurrently revealed effects on the extracellular matrix surrounding the ovary and oocyte localization within the ovary, oocyte survival, and egg production. By TUNEL assays, confocal laser scanning microscopy (CLSM), Caspase-3 assay, and transcript profiling of the pro-apoptotic BCL-2 family members BAK/BAX we obtained first evidence for roles of this signaling

  7. Changes in collagen and albumin mRNA in liver tissue of mice infected with Schistosoma mansoni as determined by in situ hybridization

    PubMed Central

    1983-01-01

    We have employed in situ hybridization to evaluate the molecular mechanisms responsible for hypoalbuminemia and increased liver collagen content in murine schistosomiasis. Results were compared using a simplified method of hybridizing isolated hepatocytes from Schistosoma mansoni-infected and normal mouse liver with mouse albumin (pmalb-2) and chick pro-alpha 2(l) collagen (pCg45) probes. Whereas hepatocytes from infected mice showed significantly less albumin mRNA than hepatocytes from control, there were more grains of procollagen mRNA in hepatocytes from infected as compared with control liver. Hybridization of infected liver tissue sections with the collagen probe showed more grains per field in granulomas than in liver regions, whereas with the albumin probe there was more hybridization in liver tissue than in granulomas. These results suggest that in murine schistosomiasis a reduction in albumin mRNA sequence content may be associated with decreased albumin synthesis and ultimately leads to hypoalbuminemia. In addition, although the granuloma seems to be the primary source of type I collagen synthesis, hepatocytes are also capable of synthesizing collagen, especially under fibrogenic stimulation. PMID:6619195

  8. 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.

  9. 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

  10. 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

  11. Countrywide Reassessment of Schistosoma mansoni Infection in Burundi Using a Urine-Circulating Cathodic Antigen Rapid Test: Informing the National Control Program

    PubMed Central

    Ortu, Giuseppina; Ndayishimiye, Onésime; Clements, Michelle; Kayugi, Donatien; Campbell, Carl H.; Lamine, Mariama Sani; Zivieri, Antonio; Magalhaes, Ricardo Soares; Binder, Sue; King, Charles H.; Fenwick, Alan; Colley, Daniel G.; Jourdan, Peter Mark

    2017-01-01

    Following implementation of the national control program, a reassessment of Schistosoma mansoni prevalence was conducted in Burundi to determine the feasibility of moving toward elimination. A countrywide cluster-randomized cross-sectional study was performed in May 2014. At least 25 schools were sampled from each of five eco-epidemiological risk zones for schistosomiasis. Fifty randomly selected children 13–14 years of age per school were included for a single urine-circulating cathodic antigen (CCA) rapid test and, in a subset of schools, for duplicate Kato-Katz slide preparation from a single stool sample. A total of 17,331 children from 347 schools were tested using CCA. The overall prevalence of S. mansoni infection, when CCA trace results were considered negative, was 13.5% (zone range [zr] = 4.6–17.8%), and when CCA trace results were considered positive, it was 42.8% (zr = 34.3–49.9%). In 170 schools, prevalence of this infection determined using Kato-Katz method was 1.5% (zr ==0–2.7%). The overall mean intensity of S. mansoni infection determined using Kato-Katz was 0.85 eggs per gram (standard deviation = 10.86). A majority of schools (84%) were classified as non-endemic (prevalence = 0) using Kato-Katz; however, a similar proportion of schools were classified as endemic when CCA trace results were considered negative (85%) and nearly all (98%) were endemic when CCA trace results were considered positive. The findings of this nationwide reassessment using a CCA rapid test indicate that Schistosoma infection is still widespread in Burundi, although its average intensity is probably low. Further evidence is now needed to determine the association between CCA rapid test positivity and low-intensity disease transmission. PMID:28115675

  12. Severe hepatic fibrosis in Schistosoma mansoni infection is controlled by a major locus that is closely linked to the interferon-gamma receptor gene.

    PubMed Central

    Dessein, A J; Hillaire, D; Elwali, N E; Marquet, S; Mohamed-Ali, Q; Mirghani, A; Henri, S; Abdelhameed, A A; Saeed, O K; Magzoub, M M; Abel, L

    1999-01-01

    Lethal disease due to hepatic periportal fibrosis occurs in 2%-10% of subjects infected by Schistosoma mansoni in endemic regions such as Sudan. It is unknown why few infected individuals present with severe disease, and inherited factors may play a role in fibrosis development. Schistosoma mansoni infection levels have been shown to be controlled by a locus that maps to chromosome 5q31-q33. To investigate the genetic control of severe hepatic fibrosis (assessed by ultrasound examination) causing portal hypertension, a segregation analysis was performed in 65 Sudanese pedigrees from the same village. Results provide evidence for a codominant major gene, with.16 as the estimated allele A frequency predisposing to advanced periportal fibrosis. For AA males, AA females, and Aa males a 50% penetrance is reached after, respectively, 9, 14, and 19 years of residency in the area, whereas for other subjects the penetrance remains <.02 after 20 years of exposure. Linkage analysis performed in four candidate regions shows that this major locus maps to chromosome 6q22-q23 and that it is closely linked (multipoint LOD score 3.12) to the IFN-gammaR1 gene encoding the receptor of the strongly antifibrogenic cytokine interferon-gamma. These results show that infection levels and advanced hepatic fibrosis in human schistosomiasis are controlled by distinct loci; they suggest that polymorphisms within the IFN-gammaR1 gene could determine severe hepatic disease due to S. mansoni infection and that the IFN-gammaR1 gene is a strong candidate for the control of abnormal fibrosis observed in other diseases. PMID:10441577

  13. Countrywide Reassessment of Schistosoma mansoni Infection in Burundi Using a Urine-Circulating Cathodic Antigen Rapid Test: Informing the National Control Program.

    PubMed

    Ortu, Giuseppina; Ndayishimiye, Onésime; Clements, Michelle; Kayugi, Donatien; Campbell, Carl H; Lamine, Mariama Sani; Zivieri, Antonio; Magalhaes, Ricardo Soares; Binder, Sue; King, Charles H; Fenwick, Alan; Colley, Daniel G; Jourdan, Peter Mark

    2017-01-23

    Following implementation of the national control program, a reassessment of Schistosoma mansoni prevalence was conducted in Burundi to determine the feasibility of moving toward elimination. A countrywide cluster-randomized cross-sectional study was performed in May 2014. At least 25 schools were sampled from each of five eco-epidemiological risk zones for schistosomiasis. Fifty randomly selected children 13-14 years of age per school were included for a single urine-circulating cathodic antigen (CCA) rapid test and, in a subset of schools, for duplicate Kato-Katz slides preparation from a single stool sample. A total of 17,331 children from 347 schools were tested using CCA. The overall prevalence of S. mansoni infection, when CCA trace results were considered negative, was 13.5% (zone range [zr] = 4.6-17.8%), and when CCA trace results were considered positive, it was 42.8% (zr = 34.3-49.9%). In 170 schools, prevalence of this infection determined using Kato-Katz method was 1.5% (zr ==0-2.7%). The overall mean intensity of S. mansoni infection determined using Kato-Katz was 0.85 eggs per gram (standard deviation = 10.86). A majority of schools (84%) were classified as non-endemic (prevalence = 0) using Kato-Katz; however, a similar proportion of schools were classified as endemic when CCA trace results were considered negative (85%) and nearly all (98%) were endemic when CCA trace results were considered positive. The findings of this nationwide reassessment using CCA rapid test indicate that Schistosoma infection is still widespread in Burundi, although its average intensity is probably low. Further evidence is now needed to determine the association between CCA rapid test positivity and low-intensity disease transmission.

  14. 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.

  15. Seeding experiments demonstrate poor performance of the hatching test for detecting small numbers of Schistosoma mansoni eggs in feces.

    PubMed

    Borges, Dieli Souza; de Souza, Juliana Schilling; Romanzini, Juliano; Graeff-Teixeira, Carlos

    2013-12-01

    Parasitological methods for the evaluation of schistosomiasis tend to be limited when parasitic burdens are low, which is a major characteristic of low intensity transmission areas. While the hatching test (HT) method has been considered to be "very sensitive", reports of its capacity to detect low numbers of eggs remain scarce in the published literature. Our main hypothesis is that HT has limitations and cannot be recommended for diagnosing light infections or as a control of cure. Hence, this study aims to describe the performance of HT in detail, with respect to seeding experiments for egg numbers in the range of 4 to 24 eggs per gram (epg) of feces. Different numbers of eggs of Schistosoma mansoni were seeded in normal human feces. The first set of experiments evaluated the amount of feces (higher than 0.5 g prevented hatching), the proximity of the light source (50 cm was preferred), and the observation time required for the detection of miracidia (more than 3h did not add to sensitivity). HT was subsequently performed with 12, 10, 8, 6, 4, and 2 eggs in 0.5 g of feces. The final set of experiments was performed to analyze the initial filtration step, in which surgical gauze versus a 500 μm nylon mesh was compared and demonstrated losses of eggs that occurred with washing and gauze (better with nylon) sieving steps. The proposed method was found to produce 100% positivity for up to 12 epg, with a sharp decrease to 33% for 8 epg and less. In conclusion, HT is not recommended for diagnosing intestinal schistosomiasis in populations with light infections, considering the complexity of the procedure and its lack of effectiveness with fecal amounts higher than 0.5 g even at optimized conditions.

  16. 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

  17. 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

  18. Involvement of a community in schistosomiasis control: a Kenyan experience.

    PubMed

    Katsivo, M N; Muthami, L N; Kimani, S; Karama, M; Kingori, F

    1993-08-01

    This paper illustrates how community participation was achieved in a study that was carried out between 1983-1988 whose general objective was to reduce the transmission of schistosomiasis in a rice irrigation scheme in Kenya. A community of 2,219 people was mobilized through health education, to effect changes in behaviour regarding water contact, water use and faecal disposal. Health education, alternative water sources, latrines and mass chemotherapy with praziquantel were the schistosomiasis control strategies utilized in this study. By the end of 2 years, the canals were cleared of their thick vegetation, water, sanitation, bathing and washing facilities were constructed, water contact with infective waters was reduced, faecal contamination of water was reduced, the people's knowledge on schistosomiasis increased and the rate and intensity of schistosomiasis infection was reduced. The study demonstrated that it is possible to fully involve the community in disease control efforts.

  19. 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.

  20. 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

  1. [Selection of government instruments in schistosomiasis control services].

    PubMed

    Yi, Ping; Li, Sheng-Ming; Franziska, Bieri; Yuan, Li-Ping; Zhao, Zheng-Yuan; He, Yong-Kang; Liu, Zong-Chuan; Zhou, Jie; He, Hong-Bin

    2011-06-01

    From the perspective of public administration and epidemiology, on the combination of the governance cases in the central and local government of China, the author explores ten modes of the provision of public goods and services in schistosomiasis control services, discusses seven main government instruments, and points out its pluralism, complexity and the slight changes of government' s preference. This paper also explores the approach to help the relevant government make schistosomiasis control work more practicable in field.

  2. Schistosomiasis and cancer in egypt: review.

    PubMed

    Khaled, Hussein

    2013-09-01

    Schistosomiasis is not known to be associated with any malignant disease other than bladder cancer. Bladder cancer is still the most common malignant tumor among males in Egypt and some African and Middle East countries. However, the frequency rate of bladder cancer has declined significantly during the last 25 years. This drop is mainly related to the control of Schistosomiasis. Many studies have elucidated the pathogenic events of Schistosomal-related bladder cancer with a suggested theory of pathogenesis. Furthermore, the disease presents with a distinct clinicopathologic profile that is quite different from bladder cancer elsewhere with younger age at presentation, more male predominance, more invasive stages, and occurrence of squamous cell carcinoma pathologic subtype. However, recent data suggest that this profile has been dramatically changed over the past 25 years leading to minimization of the differences between its features in Egypt and that in Western countries. Management of muscle-invasive localized disease is mainly surgery with 5-year survival rates of 30-50%. Although still a debatable issue, adjuvant and neoadjuvant chemotherapy and radiotherapy have improved treatment outcomes including survival and bladder preservation rates in most studies. This controversy emphasizes the need of individualized treatment options based on a prognostic index or other factors that can define the higher risk groups where more aggressive therapy is needed. The treatment for locally advanced and/or metastatic disease has passed through a series of clinical trials since 1970s. These phase II and III trials have included the use of single agent and combination of chemotherapy and radiotherapy regimens. The current standard of systemic chemotherapy of generally fit patients is now the gemcitabine-cisplatin combination. In conclusion, a changing pattern of bladder cancer in Egypt is clearly observed. This is mainly due to the success in the control of Schistosomiasis

  3. Pulmonary sparganosis mansoni: a case report from a non-endemic region.

    PubMed

    Cheng, Ke-Bin; Gao, Bei-Lan; Liu, Jin-Ming; Xu, Jin-Fu

    2014-06-01

    Sparganosis mansoni is a parasitic disease caused by the larva of Spirometra mansoni. It occurs worldwide, but only a few patients show pulmonary involvement. Here, we present a case of pulmonary sparganosis mansoni in a non-endemic region. A 32-year-old Chinese woman presented with intermittent bloody phlegm, peripheral blood eosinophilia, and migratory patch shadows in both lungs. She had been misdiagnosed with eosinophilic pneumonia. She had a history of eating raw frogs, and the sparganum mansoni antibody was positive in both her blood and bronchoalveolar lavage fluid. Several sparganum mansoni were found in a frog sample that the patient provided. Consequently, she was diagnosed with pulmonary sparganosis mansoni. After two oral courses of praziquantel were administered, her symptoms and radiological lesions improved significantly. To our knowledge, this is the first case of pulmonary sparganosis mansoni occuring in Shanghai. Oral praziquantel is effective for the treatment of sparganosis mansoni, although its course of therapy may need to be repeated.

  4. 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.

  5. 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

  6. 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

  7. 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

  8. [Appropriate technology: a driver to eliminate schistosomiasis in China. In- sights gained from the First Forum on Schistosomiasis Control in China].

    PubMed

    Hong, Qing-biao; Wen, Li-yong; Zhong, Bo; Yang, Hai-tao; Li, Shi-zhu; Liang, You-sheng; Zhang, Shi-qing; Ren, Guang-hui; Lin, Dan-dan; Sun, Le-ping; Zhou, Xiao-nong

    2015-10-01

    This paper described the First Forum on Schistosomiasis Control in China. With "Appropriate technology is essential to schistosomiasis prevention and control" as the topic, the forum shared the main interventions and experiences for schistosomiasis control and elimination, exhibited the recent achievements gained from the development of appropriate technology for schistosomiasis control, showed the technical support of appropriate technology for schistosomiasis elimination, and proposed the priority for the future research and development of appropriate technology for schistosomiasis control and elimination in China. It is considered that the forum builds a bridge for communicating information between the administrative sectors and specialized prevention and control institutions, between research institutions and manufactures, and between experts/professors and grassroots professional staff, and provides a platform to communicate the national schistosomiasis control knowledge of China.

  9. BASIC BIOLOGY AND TROPISTIC BEHAVIOR OF SCHISTOSOMA MANSONI CERCARIA RELATING TO CERCARICIDAL AGENTS AND CERCARIAL REPELLENTS.

    DTIC Science & Technology

    antigen a purified proteolytic fraction isolated from S. mansoni cercariae support the assumption of Lewert et al. that the cercarial enzyme inhibitor... mansoni cercariae, in contrast to farnesol which was found inactive. The active constituents of Vetiver and Fennel oils in protecting mice against the...infection by S. mansoni cercariae are being isolated and chemically identified. (Author)

  10. Schistosoma mansoni Stomatin Like Protein-2 Is Located in the Tegument and Induces Partial Protection against Challenge Infection

    PubMed Central

    Farias, Leonardo P.; Cardoso, Fernanda C.; Miyasato, Patricia A.; Montoya, Bogar O.; Tararam, Cibele A.; Roffato, Henrique K.; Kawano, Toshie; Gazzinelli, Andrea; Correa-Oliveira, Rodrigo; Coulson, Patricia S.; Wilson, R. Alan; Oliveira, Sérgio C.; Leite, Luciana C. C.

    2010-01-01

    Background Schistosomiasis affects more than 200 million individuals worldwide, with a further 650 million living at risk of infection, constituting a severe health problem in developing countries. Even though an effective treatment exists, it does not prevent re-infection, and the development of an effective vaccine still remains the most desirable means of control for this disease. Methodology/Principal Findings Herein, we report the cloning and characterization of a S. mansoni Stomatin-like protein 2 (SmStoLP-2). In silico analysis predicts three putative sites for palmitoylation (Cys11, Cys61 and Cys330), which could contribute to protein membrane association; and a putative mitochondrial targeting sequence, similar to that described for human Stomatin-like protein 2 (HuSLP-2). The protein was detected by Western blot with comparable levels in all stages across the parasite life cycle. Fractionation by differential centrifugation of schistosome tegument suggested that SmStoLP-2 displays a dual targeting to the tegument membranes and mitochondria; additionally, immunolocalization experiments confirm its localization in the tegument of the adult worms and, more importantly, in 7-day-old schistosomula. Analysis of the antibody isotype profile to rSmStoLP-2 in the sera of patients living in endemic areas for schistosomiasis revealed that IgG1, IgG2, IgG3 and IgA antibodies were predominant in sera of individuals resistant to reinfection as compared to those susceptible. Next, immunization of mice with rSmStoLP-2 engendered a 30%–32% reduction in adult worm burden. Protective immunity in mice was associated with specific anti-rSmStoLP-2 IgG1 and IgG2a antibodies and elevated production of IFN-γ and TNF-α, while no IL-4 production was detected, suggesting a Th1-predominant immune response. Conclusions/Significance Data presented here demonstrate that SmStoLP-2 is a novel tegument protein located in the host-parasite interface. It is recognized by different

  11. 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

  12. 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

  13. 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

  14. 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.

  15. The effects of 3-methylclonazepam on Schistosoma mansoni musculature are not mediated by benzodiazepine receptors.

    PubMed

    Thibaut, Jean Pierre Barros; Monteiro, Lidiane Mota; Leite, Lydia Christina Calcanho; Menezes, Carla Maria Souza; Lima, Lidia Moreira; Noël, François

    2009-03-15

    Schistosomiasis is one of the most prevalent infectious diseases worldwide and classified as a neglected disease for which there is an urgent need for searching new drug candidates. According to TDR/WHO, existing leads with proven schistosomicidal activity, like meclonazepam, might be the objects of further exploration. Here, we decided to investigate if the benzodiazepine binding sites that we recently characterized in adult Schistosoma mansoni could represent the molecular target of meclonazepam for its effect on worm motility and morphological appearance. The EC(50) of meclonazepam for its contracturant effect is 10-20 times lower than its IC(50) for binding to the worm benzodiazepine binding sites. On the contrary, benzodiazepines like flunitrazepam and diazepam have affinities at least 50 times higher than meclonazepam for these binding sites but did not induce contraction of the worms. We also confirmed the existence of a great similarity between the appearance, kinetics, Emax and external calcium dependency of the contractile effect of praziquantel and meclonazepam. Based on computer-aided molecular modeling calculations, we verified that a certain structural similarity exists between the active enantiomers of both drugs. We further proposed the hypothesis of common pharmacophoric elements including amide and imine subunits and the asymmetric carbons of S-(+)-meclozepam and R-(-)-praziquantel. As a whole, the present data indicate that the contracturant effect of meclonazepam is not a result of its binding to the worm benzodiazepine binding sites but that it shares some basic transduction pathway with praziquantel, even if not through identical molecular targets or binding sites.

  16. Characteristics of the Human Host Have Little Influence on Which Local Schistosoma mansoni Populations Are Acquired

    PubMed Central

    Barbosa, Lúcio M.; Silva, Luciano K.; Reis, Eliana A.; Azevedo, Theomira M.; Costa, Jackson M.; Blank, Walter A.; Reis, Mitermayer G.; Blanton, Ronald E.

    2013-01-01

    Background Brazil remains the country in the Americas with the highest prevalence of schistosomiasis. A combination of control efforts and development, however, has sharply reduced its intensity and distribution. The acquisition of specific schistosome populations may be dependent on host characteristics such as sex, age, geography, work, habits and culture. How these and other host characteristics align with parasite subpopulations may guide approaches to improve control. Methodology A cohort of more than 90% of the residents in two rural communities in Brazil participated in an epidemiologic survey of demographic, socio-economic and behavioral characteristics. The variables sex, age, intensity of infection, socio-economic index, % lifetime spent on site, previous infection, and trips outside the district were used to group parasites infecting individuals. Schistosoma mansoni infection status was determined by examination of stools submitted on 3 different days. The aggregate of eggs collected from the whole stool was used to determine degree of population differentiation from allele frequencies for 15 microsatellites. Conclusions/Significance Infection prevalence was 41% for these communities, and the epidemiologic characteristics were similar to many of the endemic areas of Brazil and the world. Parasite population structuring was observed between the two communities (Jost's D 0.046, CI95% 0.042–0.051), although separated by only 8 km and connected by a highway. No structuring was observed when infected individuals were stratified by host's biologic, demographic or epidemiologic characteristics. Those most heavily infected best reflected the communities' overall parasite diversity. The lack of differentiation within villages suggests that individuals are likely to get infected at the same sites or that the same parasite multilocus genotypes can be found at most sites. The geographic structuring between villages and the lack of structuring by age of the host

  17. [Application of high resolution remote sensing technology in research of schistosomiasis surveillance].

    PubMed

    Xue, Jing-bo; Zhang, Li-juan; Wang, Qiang; Lu, Yan-xin; Li, Shi-zhu

    2015-10-01

    Schistosomiasis is closely related to environmental factors, the changes of environmental factors, such as vegetation, temperature, hydrology and soil, could impact the transmission of the disease. The environmental factors associated with schistosomiasis could be extracted by remote sensing technology quickly and precisely, and be applied to monitor the schistosomiasis transmission. The studies on high resolution remote sensing technology applied in the research of schistosomiasis are reviewed in this paper.

  18. Spatiotemporal Patterns of Schistosomiasis-Related Deaths, Brazil, 2000-2011.

    PubMed

    Martins-Melo, Francisco Rogerlândio; Pinheiro, Marta Cristhiany Cunha; Ramos, Alberto Novaes; Alencar, Carlos Henrique; Bezerra, Fernando Schemelzer de Moraes; Heukelbach, Jorg

    2015-10-01

    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.

  19. 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.

  20. Spatial distribution of Schistosoma mansoni infection before and after chemotherapy with two praziquantel doses in a community of Pernambuco, Brazil.

    PubMed

    Galvão, Aline F; Favre, Tereza C; Guimarães, Ricardo J P S; Pereira, Ana P B; Zani, Luciana C; Felipe, Katariny T; Domingues, Ana Lúcia C; Carvalho, Omar S; Barbosa, Constança S; Pieri, Otávio S

    2010-07-01

    Praziquantel chemotherapy has been the focus of the Schistosomiasis Control Program in Brazil for the past two decades. Nevertheless, information on the impact of selective chemotherapy against Schistosoma mansoni infection under the conditions confronted by the health teams in endemic municipalities remains scarce. This paper compares the spatial pattern of infection before and after treatment with either a 40 mg/kg or 60 mg/kg dose of praziquantel by determining the intensity of spatial cluster among patients at 180 and 360 days after treatment. The spatial-temporal distribution of egg-positive patients was analysed in a Geographic Information System using the kernel smoothing technique. While all patients became egg-negative after 21 days, 17.9% and 30.9% reverted to an egg-positive condition after 180 and 360 days, respectively. Both the prevalence and intensity of infection after treatment were significantly lower in the 60 mg/kg than in the 40 mg/kg treatment group. The higher intensity of the kernel in the 40 mg/kg group compared to the 60 mg/kg group, at both 180 and 360 days, reflects the higher number of reverted cases in the lower dose group. Auxiliary, preventive measures to control transmission should be integrated with chemotherapy to achieve a more enduring impact.

  1. Fine-scale population structure and dispersal in Biomphalaria glabrata, the intermediate snail host of Schistosoma mansoni, in Venezuela.

    PubMed

    Mavárez, J; Amarista, M; Pointier, J-P; Jarne, P

    2002-05-01

    Biomphalaria glabrata is the main intermediate host of Schistosoma mansoni in America and one of the most intensely studied species of freshwater snails, yet very little is known about its population biology. Here, we used seven highly polymorphic microsatellite loci to analyse genetic diversity in the Valencia lake basin, which represents the core of the endemic area for schistosomiasis in Venezuela. Populations were sampled at short spatial scale (a few kilometres), both inside the lake and in ponds or rivers near the lake. Our results indicate that B. glabrata essentially cross-fertilizes, with little variation in selfing rates among populations. Our markers detected considerable genetic variation, with an average heterozygosity of 0.60. More diversity per population was found within than outside the lake, suggesting an influence of connectivity among populations on the levels of genetic diversity. A marked population structure was detected and lake populations were less structured than other populations. Most individuals were assigned to their population of origin using an assignment test. No strong demographic signal (e.g. bottleneck) was detected, though lake populations are likely to experience bottlenecks more frequently than the other populations analysed. Differences in gene flow therefore seem to play an important role in population differentiation and in the restoring of genetic diversity in demographically unstable populations.

  2. 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

  3. 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.

  4. Schistosoma mansoni infection enhances host portal vein contraction: role of potassium channels and p38 MAP kinase.

    PubMed

    Araujo, F P; Quintas, L E M; Noël, F; Silva, C L M

    2007-07-01

    Murine Schistosoma mansoni infection is related to an increased contraction of portal vein in response to 5-hydroxytryptamine (5-HT). The present study addressed a putative alteration of ion channels and enzymes involved in vascular contraction. In control group, either inhibition of K+ channels sensitive to ATP (K(ATP)) or Ca2+ (BK(Ca)) increased 5-HT-induced contraction, but the same did not occur in infected mice. On the other hand, inhibition of p38 MAP kinase markedly decreased the vascular contraction to 5-HT in the infected mice with minor effects in the control group. Accordingly, we observed a higher density of phospho-p38 MAP kinase, that refers to the fully active state of the enzyme, in portal veins from infected mice as compared to control animals. These results suggest that the reduced function of K(ATP) and BK(Ca) channels along with an increased contribution of p38 MAP kinase contribute to the increased contraction of portal veins to 5-HT observed in murine schistosomiasis.

  5. Reductions in genetic diversity of Schistosoma mansoni populations under chemotherapeutic pressure: the effect of sampling approach and parasite population definition.

    PubMed

    French, Michael D; Churcher, Thomas S; Basáñez, María-Gloria; Norton, Alice J; Lwambo, Nicholas J S; Webster, Joanne P

    2013-11-01

    Detecting potential changes in genetic diversity in schistosome populations following chemotherapy with praziquantel (PZQ) is crucial if we are to fully understand the impact of such chemotherapy with respect to the potential emergence of resistance and/or other evolutionary outcomes of interventions. Doing so by implementing effective, and cost-efficient sampling protocols will help to optimise time and financial resources, particularly relevant to a disease such as schistosomiasis currently reliant on a single available drug. Here we explore the effect on measures of parasite genetic diversity of applying various field sampling approaches, both in terms of the number of (human) hosts sampled and the number of transmission stages (miracidia) sampled per host for a Schistosoma mansoni population in Tanzania pre- and post-treatment with PZQ. In addition, we explore population structuring within and between hosts by comparing the estimates of genetic diversity obtained assuming a 'component population' approach with those using an 'infrapopulation' approach. We found that increasing the number of hosts sampled, rather than the number of miracidia per host, gives more robust estimates of genetic diversity. We also found statistically significant population structuring (using Wright's F-statistics) and significant differences in the measures of genetic diversity depending on the parasite population definition. The relative advantages, disadvantages and, hence, subsequent reliability of these metrics for parasites with complex life-cycles are discussed, both for the specific epidemiological and ecological scenario under study here and for their future application to other areas and schistosome species.

  6. Redox balance mechanisms in Schistosoma mansoni rely on peroxiredoxins and albumin and implicate peroxiredoxins as novel drug targets.

    PubMed

    Sayed, Ahmed A; Cook, Shawna K; Williams, David L

    2006-06-23

    Schistosoma mansoni, a causative agent of schistosomiasis, resides in the hepatic portal circulation of their human host up to 30 years without being eliminated by the host immune attack. Production of an antioxidant "firewall," which would neutralize the oxidative assault generated by host immune defenses, is one proposed survival mechanism of the parasite. Schistosomes lack catalase, the main H2O2-neutralizing enzyme of many organisms, and their glutathione peroxidases are in the phospholipid class with poor reactivity toward H2O2. Evidence implicates peroxiredoxins (Prx) as providing the main enzymatic activity to reduce H2O2 in the parasite. Quantitative monitoring of Prx mRNAs during parasite life cycle indicated that Prx proteins are differentially expressed, with highest expression occurring in adult stages (oxidative resistant stages). Incubation of schistosomula with Prx1 double-stranded RNA knocked down total Prx enzymatic activity and resulted in lowered survival of cultured parasites compared with controls demonstrating that Prx are essential parasite proteins. These results represent the first report of lethal gene silencing in Schistosoma. Investigation of downstream effects of Prx silencing revealed an abrupt increase of lipid peroxides and the generation of several oxidized proteins. Using mass spectrometry, parasite albumin and actin were identified as the main oxidized proteins. Gene expression analysis showed that schistosome albumin was induced by oxidative stress. This study highlights Prx proteins as essential parasite proteins and potential new targets for anti-schistosome drug development and albumin as a novel, sacrificial oxidant scavenging protein in parasite redox regulation.

  7. 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

  8. 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.

  9. Application of praziquantel in schistosomiasis japonica control strategies in China.

    PubMed

    Wu, Wei; Huang, Yixin

    2013-03-01

    Schistosomiasis remains a major public health problem with an estimated 200 million people infected in the world, and in China, schistosomiasis japonica is endemic in the south part of the country. In 1960s, before praziquantel was developed, there were about seven million patients. Praziquantel has a high efficacy against Schistosoma, few and transient side effects, simple administration and competitive cost, and is equally suited for both individual and large-scale treatment. Praziquantel has been widely used in the morbidity control, transmission control, and prevention of schistosomiasis japonica in China since 1980s. The schemes of praziquantel chemotherapy include the diagnostic selective chemotherapy, extensive chemotherapy, mass chemotherapy, stratified chemotherapy, phased chemotherapy, etc. Chemotherapy alone or combined with other control measure, such as Oncomelania snail control, health education, safety water supply, and so on, has achieved a great success, and there are only 0.33 million infected people now. This paper reviews the application of praziquantel in the schistosomiasis japonica control strategies in China so as to provide the rich experiences for reference of health workers of other countries where schistosomiasis is endemic.

  10. Urinary schistosomiasis and malaria associated anemia in Ethiopia

    PubMed Central

    Deribew, Ketema; Tekeste, Zinaye; Petros, Beyene

    2013-01-01

    Objective To assess the prevalence of anemia in children with urinary schistosomiasis, malaria and concurrent infections by the two diseases. Methods Urine and blood samples were collected from 387 children (216 males and 171 females) to examine urinary schistosomiasis and malaria and to determine hemoglobin concentration at Hassoba and Hassoba Buri village in Amibara woreda, Afar region, Ethiopia. Results The overall prevalence of urinary schistosomiasis and Plasmodium falciparum malaria was 24.54% and 6.20% respectively. Only 2.84% of children carried concurrent infections of both parasites. There was high percentage of anemic patients (81.81%) in the coinfected cases than in either malaria (33.3%) or schistosomiasis (38.94%) cases. There was significantly low mean hemoglobin concentration in concurrently infected children than non-infected and single infected (P<0.05). The mean hemoglobin concentration between Plasmodium falciparum and S. haematobium infected children showed no significant difference (P>0.05). The level of hemoglobin was negatively correlated with the number of S. haematobium eggs/10 mL urine (r=-0.6) and malaria parasitemia (r=-0.53). Conclusions The study showed that anemia is higher in concurrently infected children than non-infected and single infected. Furthermore, level of hemoglobin was negatively correlated with the number of S. haematobium eggs and malaria parsitemia. Therefore, examination of hemoglobin status in patients co-infected with malaria and schistosomiasis is important to reduce the risk of anemia and to improve health of the community. PMID:23620856

  11. Comparison of two Egyptian strains of Schistosoma mansoni in hamsters.

    PubMed

    Soliman, G N; el Assal, F M; Mansour, N S; Garo, K

    1986-01-01

    In human infection with Schistosoma mansoni from Beni-Suef, the eggs were encountered more frequently in the urine of patients than in infection with S. mansoni from Giza, where eggs were passed into the stool. A comparative study of the two strains of S. mansoni from Beni-Suef and Giza has been carried out in golden hamster. Consistent strain differences were observed. The Beni-Suef strain proved to have lower worm recovery and different egg distribution patterns in tissues of infected hamsters. Worms of both sexes of this strain were larger in size and required a longer period to reach maturity. Hence, the prepatent period was prolonged. Significant differences between the two strains were also noted in the number of eggs per worm. A lower mortality rate and a longer survival time were encountered in hamsters infected with the Beni-Suef strain.

  12. Evaluation of Lethal Giant Larvae as a Schistosomiasis Vaccine Candidate

    PubMed Central

    Cao, Yufan; Qiao, Hongbin; Shi, Yanli; Han, Yu; Liu, Jinming; Li, Hao; Lu, Ke; Lin, Jiaojiao

    2016-01-01

    Schistosomiasis is a neglected tropical disease of humans, and it is considered to be the second most devastating parasitic disease after malaria. Eggs produced by normally developed female worms are important in the transmission of the parasite, and they responsible for the pathogenesis of schistosomiasis. The tumor suppressor gene lethal giant larvae (lgl) has an essential function in establishing apical-basal cell polarity, cell proliferation, differentiation, and tissue organization. In our earlier study, downregulation of the lgl gene induced a significant reduction in the egg hatching rate of Schistosoma japonicum (Sj) eggs. In this study, the Sjlgl gene was used as a vaccine candidate against schistosomiasis, and vaccination achieved and maintained a stable reduction of the egg hatching rate, which is consistent with previous studies, in addition to reducing the worm burden and liver egg burden in some trials. PMID:27957496

  13. Towards control of schistosomiasis in sub-Saharan Africa.

    PubMed

    Southgate, V R; Rollinson, D; Tchuem Tchuenté, L A; Hagan, P

    2005-09-01

    Approximately 80% of the 200 million people infected with schistosomiasis inhabit sub-Saharan Africa, and the annual mortality is estimated to be 280,000. Praziquantel is the drug of choice in the treatment of schistosomiasis and pregnant women may now be treated. It was agreed at the World Health Assembly in 2001 that at least 75% of school-aged children in high burden areas should be treated for schistosomiasis and soil-transmitted helminth infections by 2010 to reduce morbidity. A grant from the Bill and Melinda Gates Foundation to the Schistosomiasis Control Initiative, Imperial College of Science, Technology and Medicine, London has enabled control programmes to be initiated in Uganda, Tanzania, Zambia, Burkina Faso, Niger and Mali. Additional programmes have recently commenced in Zanzibar with a grant from the Health Foundation to The Natural History Museum, London and in Cameroon. Combination treatment for schistosomiasis, gastrointestinal helminths and filariasis reduces costs of control programmes. The EC Concerted Action Group on 'Praziquantel: its central role in the chemotherapy of schistosome infection' met in Yaoundé Cameroon in 2004 to discuss recent developments in laboratory and field studies. The use of standard operating procedures will enable data on drug action on schistosomes produced in different laboratories to be compared. With the ever increasing use of praziquantel there is a possibility of the development of resistance by schistosomes to the drug, hence the necessity to explore the activities of other compounds. Artemether, unlike praziquantel, is effective against immature schistosomes. The effectiveness of mirazid, an extract of myrrh, is controversial as data from different laboratories are equivocal. It is suggested that an independent body such as the World Health Organization should determine whether mirazid should be used in the treatment of schistosomiasis.

  14. The Nephropathy of Experimental Hepatosplenic Schistosomiasis

    PubMed Central

    Cavallo, Tito; Galvanek, Eleonora G.; Ward, Peter A.; von Lichtenberg, Franz

    1974-01-01

    The glomerular lesions induced in 10 chimpanzees infected with variable numbers of Schistosoma japonicum cercariae were studied by means of light and electron microscopy and fluorescent antibody technic. Ten animals served as controls; 5 were uninfected and 5 were only lightly infected. The animals were observed for periods ranging from 3 to 17 months, and by the time of sacrifice, all had developed advanced liver fibrosis. In general, the degree of glomerular injury was related to infection intensity and degree and duration of portal liver fibrosis. Some animals had terminal BUN elevation and slight proteinuria. By light and electron microscopy, in the initial stages, only part of the glomeruli were involved and exhibited mesangial matrix expansion and mesangial cell proliferation with intracellular hyaline droplets. At later stages, a larger number of glomeruli were affected and exhibited diffuse hypercellularity, glomerular basement thickening, mesangial sclerosis and less often, focal necrosis, crescent formation, synechiae and global hyalinization. In addition, there were discrete electron-dense deposits localized in the mesangial area in some glomeruli. Immunofluorescent studies utilizing antisera to chimpanzee γ-globulin and complement (C3) and to human properdin disclosed only faint deposits of C3, apparently in mesangial areas. The association of hepatosplenic schistosomiasis and nephropathy, the possible role of schistosomal antigen and the mechanism(s) of such glomerular injuries are reviewed and compared with the disease in humans and other host species infected with Schistosoma. ImagesFig 1Fig 2Fig 3Fig 4Figs 5-8Fig 9Fig 10 PMID:4137991

  15. Possible eggshell protein gene from Schistosoma mansoni.

    PubMed

    Johnson, K S; Taylor, D W; Cordingley, J S

    1987-01-02

    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.

  16. Multivalent anthelminthic vaccine to prevent hookworm and schistosomiasis.

    PubMed

    Hotez, Peter J; Bethony, Jeffrey M; Oliveira, Sergio Costa; Brindley, Paul J; Loukas, Alex

    2008-08-01

    Hookworm infection and schistosomiasis are two of the world's most important human parasitic infections, affecting hundreds of millions of people in developing countries. Measured together in disability-adjusted life years, hookworm infection and schistosomiasis rank closely behind malaria as the most prevalent human parasitic diseases. A major approach for the control of these two helminth infections relies on periodic, mass chemotherapy with anthelminthics. However, high rates of post-treatment reinfection, the declining efficacy with repeated treatment, rebound morbidity (in the case of schistosomiasis) and the potential for the emergence of anthelminthic drug resistance threaten the sustainability of mass drug administration as the only form of control. Hence, there is a strong rationale for developing a vaccine that simultaneously targets both hookworms and schistosomes because of similarities in the pathobiology of both parasites, the ability of both helminths to cause anemia and their coendemicity in sub-Saharan Africa, Brazil and East Asia. A multivalent anthelminthic vaccine for hookworm infection and schistosomiasis would represent an important new tool for combating disease and poverty.

  17. Local and International Implications of Schistosomiasis Acquired in Corsica, France.

    PubMed

    Gautret, Philippe; 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

    2015-10-01

    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.

  18. [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.

  19. 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.…

  20. 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

    2016-02-16

    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.

  1. 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

  2. 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.

  3. Genitourinary schistosomiasis: life cycle and radiologic-pathologic findings.

    PubMed

    Shebel, Haytham M; Elsayes, Khaled M; Abou El Atta, Heba M; Elguindy, Yehia M; El-Diasty, Tarek A

    2012-01-01

    Genitourinary schistosomiasis is produced by Schistosoma haematobium, a species of fluke that is endemic to Africa and the Middle East, and causes substantial morbidity and mortality in those regions. It also may be seen elsewhere, as a result of travel or immigration. S haematobium, one of the five fluke species that account for most human cases of schistosomiasis, is the only species that infects the genitourinary system, where it may lead to a wide spectrum of clinical symptoms and signs. In the early stages, it primarily involves the bladder and ureters; later, the kidneys and genital organs are involved. It rarely infects the colon or lungs. A definitive diagnosis of genitourinary schistosomiasis is based on findings of parasite ova at microscopic urinalysis. Clinical manifestations and radiologic imaging features also may be suggestive of the disease, even at an early stage: Hematuria, dysuria, and hemospermia, early clinical signs of an established S haematobium infection, appear within 3 months after infection. At imaging, fine ureteral calcifications that appear as a line or parallel lines on abdominopelvic radiographs and as a circular pattern on axial images from computed tomography (CT) are considered pathognomonic of early-stage schistosomiasis. Ureteritis, pyelitis, and cystitis cystica, conditions that are characterized by air bubble-like filling defects representing ova deposited in the ureter, kidney, and bladder, respectively, may be seen at intravenous urography, intravenous ureteropyelography, and CT urography. Coarse calcification, fibrosis, and strictures are signs of chronic or late-stage schistosomiasis. Such changes may be especially severe in the bladder, creating a predisposition to squamous cell carcinoma. Genital involvement, which occurs more often in men than in women, predominantly affects the prostate and seminal vesicles.

  4. In vitro and in vivo anthelmintic activity of (-)-6,6'-dinitrohinokinin against schistosomula and juvenile and adult worms of Schistosoma mansoni.

    PubMed

    Pereira, Ana C; Silva, Márcio L A E; Souza, Julia Medeiros; Laurentiz, Rosangela S de; Rodrigues, Vanderlei; Januário, Ana H; Pauletti, Patrícia M; Tavares, Denise C; Filho, Ademar A Da Silva; Cunha, Wilson R; Bastos, Jairo K; Magalhães, Lizandra G

    2015-09-01

    The chemotherapy of schistosomiasis relies on the use of praziquantel. However, concerns over drug resistance have encouraged the search for new drug leads. This paper is the first report on the in vitro and in vivo activity of (-)-6,6'-dinitrohinokinin (DNK) against Schistosoma mansoni. In vitro, the lethal concentrations for 50% of parasites (LC50) of DNK against adult worms were 103.9±3.6 and 102.5±4.8μM at 24 and 72h, respectively. Scanning electron microscopy images showed extensive tegumental alterations such as peeling and smaller numbers of tubercles in the spine of adult worms. DNK also elicited high mortality of schistosomula, with LC50 values of 57.4±2.3, 32.5±0.9, and 20.4±1.2μM at 24, 48, and 72h, respectively. DNK displayed moderate activity against the juvenile liver parasite, with an LC50 value of 179.5±2.3 μM at 72h. This compound reduced the total number of eggs by over 83%, and it affected the development of eggs produced by adult worms. The selectivity index showed that at 24h, DNK was 8.5 and 15.4 times more toxic to the adult worms and schistosomula than to Chinese hamster lung fibroblast cells, respectively. Treatment of infected mice with DNK moderately decreased worm burden (33.8-52.3%), egg production (40.7-60.0%), and spleen and liver weights. Together, our results indicated that DNK presents moderate in vitro and in vivo activities against S. mansoni, and it might therefore be interesting to explore the structure-activity relationship of the antischistosomal activity of this compound.

  5. 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.

  6. 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.

  7. Naturally occurring CD4+Foxp3+ regulatory T cells are an essential, IL-10-independent part of the immunoregulatory network in Schistosoma mansoni egg-induced inflammation.

    PubMed

    Baumgart, Martin; Tompkins, Fae; Leng, Jin; Hesse, Matthias

    2006-05-01

    In acute and chronic schistosomiasis, survival of the host requires a carefully balanced immune response against highly immunogenic parasite eggs. We characterized the phenotype, distribution, and functional role of CD4(+)Foxp3(+) naturally occurring regulatory T cells (naTregs) in schistosome egg-induced inflammation. In adoptive transfer experiments and by intracellular staining for Foxp3, we demonstrate significant frequencies of naTregs in hepatic granulomas and draining lymphoid tissues of mice infected with the trematode Schistosoma mansoni. Strikingly, egg-induced inflammation does not change the normal ratio between naTregs and effector CD4(+) T cells at the inflammatory site or in lymphoid organs in acute or chronic disease. However, increasing frequencies of CD103-expressing cells in the naTreg compartment indicate a change in phenotype for naTregs with disease progression. Because CD103 was described recently as an activation marker for naTregs, we speculate that naTregs in chronic schistosomiasis are potentially more suppressive. Furthermore, we found that most naTregs do not contribute to egg-induced IL-4 and IL-10 production. Importantly, depletion of CD25(+) naTregs strongly enhances the frequency of IL-4-producing effector T cells in acute egg-induced inflammation. It does not change clonal expansion of activated CD4(+) T cells. This regulation of egg-induced cytokine production does not require the presence of IL-10. These data demonstrate that naTregs limit egg-induced effector-cytokine production in our model. Our results identify naTregs as an important, IL-10-independent part of the regulatory network in schistosome egg-induced inflammation.

  8. Susceptibility of Biomphalaria amazonica and Biomphalaria occidentalis from Manso Dam, Mato Grosso, Brazil to infection with three strains of Schistosoma mansoni.

    PubMed

    Fernandez, Monica Ammon; Thiengo, Silvana Carvalho

    2006-09-01

    As well as malaria and yellow fever, schistosomiasis is one of the main endemic diseases associated to environments which suffered some impact related to the development of great economic projects, as for example the construction of hydroelectric power stations. Aiming to investigate the occurrence and distribution of freshwater snails of medical and veterinary importance in the area which suffered impact from the Manso hydroelectric power station a survey was performed during the period of 2002 to 2003 and revealed the occurrence of populations of Biomphalaria amazonica and Biomphalaria occidentalis. Studies on parasite-mollusc compatibility were undertaken using five B. amazonica colonies (Barão de Melgaço, Poconé, Santo Antônio do Leverger, and Chapada dos Guimarães, in the Manso and Casca rivers), and four B. occidentalis colonies (Cuiabá, Santo Antônio do Leverger, and Chapada dos Guimarães, in the Agua Fria district and Casca river) were exposed to miracidia of Schistosoma mansoni. Of 257 snails of B. amazonica used, 17 became infected (infection index of 6.61%) and all specimens of B. occidentalis proved unsusceptible. According to the strains used, of the 158 snails exposed to BH miracidia, 6 became infected (3.79%); of the 44 exposed to SJ miracidia, 6 became infected (13.63%); and of the 55 snails of B. amazonica exposed to EC miracidia, 5 became infected (9.09%). These results point out the low possibility of introduction of schistosomiasis in those areas, but we believe it can not be discarded as due the presence of B. amazonica.

  9. Malacological survey and geographical distribution of vector snails for schistosomiasis within informal settlements of Kisumu City, western Kenya

    PubMed Central

    2011-01-01

    Background Although schistosomiasis is generally considered a rural phenomenon, infections have been reported within urban settings. Based on observations of high prevalence of Schistosoma mansoni infection in schools within the informal settlements of Kisumu City, a follow-up malacological survey incorporating 81 sites within 6 informal settlements of the City was conducted to determine the presence of intermediate host snails and ascertain whether active transmission was occurring within these areas. Methods Surveyed sites were mapped using a geographical information system. Cercaria shedding was determined from snails and species of snails identified based on shell morphology. Vegetation cover and presence of algal mass at the sites was recorded, and the physico-chemical characteristics of the water including pH and temperature were determined using a pH meter with a glass electrode and a temperature probe. Results Out of 1,059 snails collected, 407 (38.4%) were putatively identified as Biomphalaria sudanica, 425 (40.1%) as Biomphalaria pfeifferi and 227 (21.5%) as Bulinus globosus. The spatial distribution of snails was clustered, with few sites accounting for most of the snails. The highest snail abundance was recorded in Nyamasaria (543 snails) followed by Nyalenda B (313 snails). As expected, the mean snail abundance was higher along the lakeshore (18 ± 12 snails) compared to inland sites (dams, rivers and springs) (11 ± 32 snails) (F1, 79 = 38.8, P < 0.0001). Overall, 19 (1.8%) of the snails collected shed schistosome cercariae. Interestingly, the proportion of infected Biomphalaria snails was higher in the inland (2.7%) compared to the lakeshore sites (0.3%) (P = 0.0109). B. sudanica was more abundant in sites along the lakeshore whereas B. pfeifferi and B. globosus were more abundant in the inland sites. Biomphalaria and Bulinus snails were found at 16 and 11 out of the 56 inland sites, respectively. Conclusions The high abundance of Biomphalaria and

  10. The cercarial glycocalyx of Schistosoma mansoni

    PubMed Central

    1985-01-01

    Cercariae, the freshwater stage of Schistosoma mansoni infectious to man, are covered by a single unit membrane and an immunogenic glycocalyx. When cercariae penetrate the host skin, they transform to schistosomula by shedding tails, secreting mucous and enzymes, and forming microvilli over their surface. Here the loss of the glycocalyx from cercariae transforming in vitro was studied morphologically and biochemically. By scanning electron microscopy, the glycocalyx was a dense mesh composed of 15-30 nm fibrils that obscured spines on the cercarial surface. The glycocalyx was absent on organisms fixed without osmium and was partially lost when parasites aggregated in their own secretions before fixation. By transmission electron microscopy, a 1-2 microns thick mesh of 8-15-nm fibrils was seen on parasites incubated with anti-schistosomal antibodies or fixed in aldehydes containing tannic acid or ruthenium red. Cercariae transformed to schistosomula when tails were removed mechanically and parasites were incubated in saline. Within 5 min of transformation, organisms synchronously formed microvilli which elongated to 3-5 microns by 20 min and then were shed. However, considerable fibrillar material remained adherent to the double unit membrane surface of schistosomula. For biochemical labeling, parasites were treated with eserine sulfate, which blocked cercarial swimming, secretion, infectivity, and transformation to schistosomula. Material labeled by periodate oxidation and NaB3H4 was on the surface as shown by autoradiography and had an apparent molecular weight of greater than 10(6) by chromatography. Periodate- NaB3H4 glycocalyx had an isoelectric point of 5.0 +/- 0.4 and was precipitable with anti-schistosomal antibodies. More than 60% of the radiolabeled glycocalyx was released into the medium by transforming parasites in 3 h and was recovered as high molecular weight material. Parasites labeled with periodate and fluorescein-thiosemicarbazide and then

  11. [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.

  12. Additional Evaluation of the Point-of-Contact Circulating Cathodic Antigen Assay for Schistosoma mansoni Infection.

    PubMed

    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 elimination of

  13. 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

  14. Single Versus Double Dose Praziquantel Comparison on Efficacy and Schistosoma mansoni Re-Infection in Preschool-Age Children in Uganda: A Randomized Controlled Trial

    PubMed Central

    Nalugwa, Allen; Nuwaha, Fred; Tukahebwa, Edridah Muheki; Olsen, Annette

    2015-01-01

    Background Schistosoma mansoni infection is proven to be a major health problem of preschool-age children in sub-Saharan Africa, yet this age category is not part of the schistosomiasis control program. The objective of this study was to compare the impact of single and double dose praziquantel (PZQ) treatment on cure rates (CRs), egg reduction rates (ERRs) and re-infection rates 8 months later, in children aged 1-5 years living along Lake Victoria, Uganda. Methodology/Principal Findings Infected children (n= 1017) were randomized to receive either a single or double dose of PZQ. Initially all children were treated with a single standard oral dose 40 mg/kg body weight of PZQ. Two weeks later a second dose was administered to children in the double dose treatment arm. Side effects were monitored at 30 minutes to 24 hours after each treatment. Efficacy in terms of CRs and ERRs for the two treatments was assessed and compared 1 month after the second treatment. Re-infection with S. mansoni was assessed in the same children 8 months following the second treatment. CRs were non-significantly higher in children treated with two 40 mg/kg PZQ doses (85.5%; 290/339) compared to a single dose (83.2%; 297/357). ERRs were significantly higher in the double dose with 99.3 (95%CI: 99.2-99.5) compared with 98.9 (95%CI: 98.7-99.1) using a single dose, (P = 0.01). Side effects occurred more frequently during the first round of drug administration and were mild and short-lived; these included vomiting, abdominal pain and bloody diarrhea. Overall re-infection rate 8 months post treatment was 44.5%. Conclusions PZQ is efficacious and relatively safe to use in preschool-age children but there is still an unmet need to improve its formulation to suit small children. Two PZQ doses lead to significant reduction in egg excretion compared to a single dose. Re-infection rates with S. mansoni 8 months post treatment is the same among children irrespective of the treatment regimen. PMID

  15. Cloning the genes and DNA binding properties of High Mobility Group B1 (HMGB1) proteins from the human blood flukes Schistosoma mansoni and Schistosoma japonicum.

    PubMed

    de Oliveira, Francisco Meirelles Bastos; de Abreu da Silva, Isabel Caetano; Rumjanek, Franklin David; Dias-Neto, Emmanuel; Guimarães, Pedro Edson Moreira; Verjovski-Almeida, Sergio; Stros, Michal; Fantappié, Marcelo Rosado

    2006-08-01

    The parasitic helminth Schistosoma mansoni contains three HMGB proteins, HMGB1, HMGB2 and HMGB3, of primary amino acid sequences highly similar to vertebrate proteins. In this report we describe the characterization of the HMGB1 proteins and their genes from S. mansoni and Schistosoma japonicum. The deduced amino acid sequences of HMGB1 proteins from both schistosome species are identical, and comprise 176 residues. The proteins contain the two evolutionarily highly conserved HMG-box domains, A and B, exhibiting 60% similarity to mammalian HMGB1. Unlike the human HMGB1 which contains an unbroken run of 30 glutamic or aspartic residues, the SmHMGB1 or SjHMGB1 proteins possess unusually short acidic C-terminal tails (5 acidic residues interrupted by 2 serines). Southern hybridization and DNA sequencing revealed a single copy HMGB1 gene, composed of 3 exons and two introns, in S. mansoni. The exon/intron boundaries are identical to those of the human HMGB1 gene, with the exception that the second exon of the SmHMGB1 gene which is not split into two exons as in the human HMGB1 gene. RNA blot analysis revealed that the SmHMGB1 gene is constitutively expressed in similar levels both in male and female worms. The single-sized mRNA for SmHMGB1 is consistent with the size derived from the cDNA. Although DNA binding properties of SmHMGB1 (or SjHMGB1) protein seem to be similar to those previously reported with human HMGB1, i.e., preferential binding to supercoiled DNA over linear DNA, specific recognition of DNA four-way junctions, DNA-induced supercoiling in the presence of topoisomerase I, and DNA bending, we have observed two important differences relative to those observed with the human HMGB1: (i) the inability of the isolated SmHMGB1 domain A to bend DNA (as revealed by T4 ligase-mediated circularization assay), and (ii) higher DNA supercoiling and bending potential of the SmHMGB1 protein as compared to its human counterpart. The latter finding may indicate that the

  16. [Acute schistosomiasis: lessons learned from a cohort of 42 exposed travelers].

    PubMed

    Rochat, L; Bizzini, A; Bochud, P-Y; Senn, N; De Vallière, S; Genton, B

    2015-05-06

    Acute schistosomiasis is a regularly encountered disease in travelers. Because of the temporal delay, its unspecific presentation and the spontaneous resolution, acute schistosomiasis can easily remain unrecognized by physicians who are not familiar with tropical pathologies. In December 2011, a female traveler was admitted to the hospital with undetermined fever after having returned from Madagascar where she bathed in fresh water. Acute schistosomiasis was diagnosed and infection was suspected among other travelers of her group. Seroconversion was confirmed among 78% of participants. This article intends to clarify the preventive and diagnostic strategies based on the lessons learned from this cluster of 42 travelers exposed to schistosomiasis.

  17. 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

  18. Successful parasitism of vector snail Biomphalaria glabrata by the human blood fluke (trematode) Schistosoma mansoni: a 2009 assessment

    PubMed Central

    Bayne, Christopher J.

    2009-01-01

    Schistosomiasis, caused by infections by human blood flukes (Trematoda), continues to disrupt the lives of over 200,000,000 people in over 70 countries, inflicting misery and precluding the individuals’ otherwise reasonable expectations of productive lives. Infection requires contact with freshwater in which infected snails (the intermediate hosts of schistosomes) have released cercariae larvae. Habitats suitable for the host snails continue to expand as a consequence of water resource development. No vaccine is available, and the emergence and spread of resistance to the single licensed schistosomicide drug would be devastating. Since human infections would cease if parasite infections in snails were prevented, efforts are being made to discover requirements of intra-molluscan development of these parasites. Wherever blood flukes occur, naturally resistant conspecific snails are present. To understand the mechanisms used by parasites to ensure their survival in immunocompetent hosts, one must comprehend the internal defense mechanisms that are available to the host. For one intermediate host snail (Biomphalaria glabrata) and trematodes for which it serves as vector, molecular genetic and proteomic surveys for genes and proteins influencing the outcomes on infections are yielding lists of candidates. A comparative approach drawing on data from studies in divergent species provides a robust basis for hypothesis generation to drive decisions as to which candidates merit detailed further investigation. For example, reactive oxygen and nitrogen species are known mediators or effectors in battles between infectious agents and their hosts. An approach targeting genes involved in relevant pathways has been fruitful in the Schistosoma mansoni-B. glabrata parasitism, leading to discovery of a functionally relevant gene set (encoding enzymes responsible for the leukocyte respiratory burst) that associates significantly with host resistance phenotype. This review summarizes

  19. Functional and antigenic similarities between a 94-kD protein of Schistosoma mansoni (SCIP-1) and human CD59

    PubMed Central

    1994-01-01

    Schistosomiasis is a parasitic disease affecting approximately 200 million people, primarily in the third world. Schistosoma mansoni, one of the causative agents of this disease, parasitize the human mesenteric and portal blood systems while successfully evading host immune responses. During parasite penetration into the mammalian host and shortly afterwards, the larvae rapidly convert from being sensitive to being resistant to C-mediated killing. Treatment of the C-resistant parasitic forms with trypsin renders the parasite susceptible to C attack, thus indicating the presence of C inhibitory protein(s) on the parasite surface. We describe here an intrinsic schistosome C inhibitory protein (SCIP-1) that exhibits antigenic and functional similarities with the human C-inhibitor CD59. Like CD59, SCIP-1 is capable of inhibiting formation of the C membrane attack complex (MAC), probably by binding to C8 and C9 of the C terminal pathway. In addition, SCIP-1 is apparently also membrane-anchored via glycosyl phosphatidylinositol as it can be specifically released with phosphatidylinositol-specific phospholipase C. Soluble SCIP-1, partially purified from Nonidet P-40 extracts of schistosome tegument is capable of inhibiting hemolysis of sensitized sheep erythrocytes and of rabbit erythrocytes by human C. Anti-human CD59 antibodies block this activity of SCIP-1 and in addition, upon binding to intact parasites, render them vulnerable to killing by human and guinea pig C. SCIP-1 is located on the surface of C-resistant forms of the parasite, i.e., 24-h cultured mechanical schistosomula and in vivo-derived adult worms as revealed by immunofluorescence and immunogold electron microscopy studies. These results identify one of the mechanisms schistosomes use to escape immune attack. PMID:7513011

  20. Schistosoma mansoni: assessment of effects of oleic acid, cercarial age and water temperature on parasite-host attraction.

    PubMed

    Lee, Vivien S T; Burgess, Jefferey L; Sterling, Charles R; Lutz, Eric A

    2013-09-01

    Although the lifecycle of Schistosoma spp. and pathophysiology of schistosomiasis have been established, the mechanism by which cercariae find their host is not well understood. Speculatively, host infection by random and accidental host contact is not as biologically plausible as a biochemical mechanism of mammalian attraction. A few studies have indicated that biochemical cues and temperature gradients may play a role in host identification, attraction and attachment triggers. This study aimed to elucidate these mechanisms more specifically through evaluation of biochemical, age and temperature influences leading to Schistosoma mansoni cercariae attraction and attachment behaviors. Oleic acid, a common unsaturated free fatty acid in the outer layer of human skin, was tested for cercariae attraction across biologically relevant concentrations. Influence of media type (beeswax, nail varnish and agar), age-dependent behavior variability and environmentally appropriate temperatures (22 and 30 °C) were also evaluated. Results indicated that oleic acid at concentrations of 0.3, 0.9 and 1.8 g/mL in beeswax significantly increased median attachment to media (median attachment of 7.50%, 4.20% and 3.71%, respectively, P<0.001), compared with pla