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Sample records for malaria oocysts increases

  1. A Class of Tricyclic Compounds Blocking Malaria Parasite Oocyst Development and Transmission

    PubMed Central

    Eastman, Richard T.; Pattaradilokrat, Sittiporn; Raj, Dipak K.; Dixit, Saurabh; Deng, Bingbing; Miura, Kazutoyo; Yuan, Jing; Tanaka, Takeshi Q.; Johnson, Ronald L.; Jiang, Hongying; Huang, Ruili; Williamson, Kim C.; Lambert, Lynn E.; Long, Carole; Austin, Christopher P.; Wu, Yimin

    2013-01-01

    Malaria is a deadly infectious disease in many tropical and subtropical countries. Previous efforts to eradicate malaria have failed, largely due to the emergence of drug-resistant parasites, insecticide-resistant mosquitoes and, in particular, the lack of drugs or vaccines to block parasite transmission. ATP-binding cassette (ABC) transporters are known to play a role in drug transport, metabolism, and resistance in many organisms, including malaria parasites. To investigate whether a Plasmodium falciparum ABC transporter (Pf14_0244 or PfABCG2) modulates parasite susceptibility to chemical compounds or plays a role in drug resistance, we disrupted the gene encoding PfABCG2, screened the recombinant and the wild-type 3D7 parasites against a library containing 2,816 drugs approved for human or animal use, and identified an antihistamine (ketotifen) that became less active against the PfABCG2-disrupted parasite in culture. In addition to some activity against asexual stages and gametocytes, ketotifen was highly potent in blocking oocyst development of P. falciparum and the rodent parasite Plasmodium yoelii in mosquitoes. Tests of structurally related tricyclic compounds identified additional compounds with similar activities in inhibiting transmission. Additionally, ketotifen appeared to have some activity against relapse of Plasmodium cynomolgi infection in rhesus monkeys. Further clinical evaluation of ketotifen and related compounds, including synthetic new derivatives, in blocking malaria transmission may provide new weapons for the current effort of malaria eradication. PMID:23129054

  2. Increased efficacy of Eimeria oocysts delivery by gel beads or spray vaccination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Control of avian coccidiosis is increasingly being achieved by the administration of low doses of Eimeria oocysts to newly hatched chicks. The purpose of this study was to test the efficacy of gel-beads containing a mixture of E. acervulina, E. maxima, and E. tenella oocysts as a vaccine to protect ...

  3. Conservation Efforts May Increase Malaria Burden in the Brazilian Amazon

    PubMed Central

    Valle, Denis; Clark, James

    2013-01-01

    Background Large-scale forest conservation projects are underway in the Brazilian Amazon but little is known regarding their public health impact. Current literature emphasizes how land clearing increases malaria incidence, leading to the conclusion that forest conservation decreases malaria burden. Yet, there is also evidence that proximity to forest fringes increases malaria incidence, which implies the opposite relationship between forest conservation and malaria. We compare the effect of these environmental factors on malaria and explore its implications. Methods and Findings Using a large malaria dataset (∼1,300,000 positive malaria tests collected over ∼4.5 million km2), satellite imagery, permutation tests, and hierarchical Bayesian regressions, we show that greater forest cover (as a proxy for proximity to forest fringes) tends to be associated with higher malaria incidence, and that forest cover effect was 25 times greater than the land clearing effect, the often cited culprit of malaria in the region. These findings have important implications for land use/land cover (LULC) policies in the region. We find that cities close to protected areas (PA’s) tend to have higher malaria incidence than cities far from PA’s. Using future LULC scenarios, we show that avoiding 10% of deforestation through better governance might result in an average 2-fold increase in malaria incidence by 2050 in urban health posts. Conclusions Our results suggest that cost analysis of reduced carbon emissions from conservation efforts in the region should account for increased malaria morbidity, and that conservation initiatives should consider adopting malaria mitigation strategies. Coordinated actions from disparate science fields, government ministries, and global initiatives (e.g., Reduced Emissions from Deforestation and Degradation; Millenium Development Goals; Roll Back Malaria; and Global Fund to Fight AIDS, Tuberculosis and Malaria), will be required to decrease

  4. Structure and Function of a G-actin Sequestering Protein with a Vital Role in Malaria Oocyst Development inside the Mosquito Vector*

    PubMed Central

    Hliscs, Marion; Sattler, Julia M.; Tempel, Wolfram; Artz, Jennifer D.; Dong, Aiping; Hui, Raymond; Matuschewski, Kai; Schüler, Herwig

    2010-01-01

    Cyclase-associated proteins (CAPs) are evolutionary conserved G-actin-binding proteins that regulate microfilament turnover. CAPs have a modular structure consisting of an N-terminal adenylate cyclase binding domain, a central proline-rich segment, and a C-terminal actin binding domain. Protozoan parasites of the phylum Apicomplexa, such as Cryptosporidium and the malaria parasite Plasmodium, express small CAP orthologs with homology to the C-terminal actin binding domain (C-CAP). Here, we demonstrate by reverse genetics that C-CAP is dispensable for the pathogenic Plasmodium blood stages. However, c-cap(-) parasites display a complete defect in oocyst development in the insect vector. By trans-species complementation we show that the Cryptosporidium parvum ortholog complements the Plasmodium gene functions. Purified recombinant C. parvum C-CAP protein binds actin monomers and prevents actin polymerization. The crystal structure of C. parvum C-CAP shows two monomers with a right-handed β-helical fold intercalated at their C termini to form the putative physiological dimer. Our results reveal a specific vital role for an apicomplexan G-actin-binding protein during sporogony, the parasite replication phase that precedes formation of malaria transmission stages. This study also exemplifies how Plasmodium reverse genetics combined with biochemical and structural analyses of orthologous proteins can offer a fast track toward systematic gene characterization in apicomplexan parasites. PMID:20083609

  5. Malaria

    MedlinePlus

    Quartan malaria; Falciparum malaria; Biduoterian fever; Blackwater fever; Tertian malaria; Plasmodium ... Malaria is caused by a parasite that is passed to humans by the bite of infected Anopheles ...

  6. Increasing malaria hospital admissions in Uganda between 1999 and 2009

    PubMed Central

    2011-01-01

    Background Some areas of Africa are witnessing a malaria transition, in part due to escalated international donor support and intervention coverage. Areas where declining malaria rates have been observed are largely characterized by relatively low baseline transmission intensity and rapid scaling of interventions. Less well described are changing patterns of malaria burden in areas of high parasite transmission and slower increases in control and treatment access. Methods Uganda is a country predominantly characterized by intense, perennial malaria transmission. Monthly pediatric admission data from five Ugandan hospitals and their catchments have been assembled retrospectively across 11 years from January 1999 to December 2009. Malaria admission rates adjusted for changes in population density within defined catchment areas were computed across three time periods that correspond to periods where intervention coverage data exist and different treatment and prevention policies were operational. Time series models were developed adjusting for variations in rainfall and hospital use to examine changes in malaria hospitalization over 132 months. The temporal changes in factors that might explain changes in disease incidence were qualitatively examined sequentially for each hospital setting and compared between hospital settings Results In four out of five sites there was a significant increase in malaria admission rates. Results from time series models indicate a significant month-to-month increase in the mean malaria admission rates at four hospitals (trend P < 0.001). At all hospitals malaria admissions had increased from 1999 by 47% to 350%. Observed changes in intervention coverage within the catchments of each hospital showed a change in insecticide-treated net coverage from <1% in 2000 to 33% by 2009 but accompanied by increases in access to nationally recommended drugs at only two of the five hospital areas studied. Conclusions The declining malaria disease

  7. Malaria.

    PubMed

    White, Nicholas J; Pukrittayakamee, Sasithon; Hien, Tran Tinh; Faiz, M Abul; Mokuolu, Olugbenga A; Dondorp, Arjen M

    2014-02-22

    Although global morbidity and mortality have decreased substantially, malaria, a parasite infection of red blood cells, still kills roughly 2000 people per day, most of whom are children in Africa. Two factors largely account for these decreases; increased deployment of insecticide-treated bednets and increased availability of highly effective artemisinin combination treatments. In large trials, parenteral artesunate (an artemisinin derivative) reduced severe malaria mortality by 22·5% in Africa and 34·7% in Asia compared with quinine, whereas adjunctive interventions have been uniformly unsuccessful. Rapid tests have been an important addition to microscopy for malaria diagnosis. Chemopreventive strategies have been increasingly deployed in Africa, notably intermittent sulfadoxine-pyrimethamine treatment in pregnancy, and monthly amodiaquine-sulfadoxine-pyrimethamine during the rainy season months in children aged between 3 months and 5 years across the sub-Sahel. Enthusiasm for malaria elimination has resurfaced. This ambitious but laudable goal faces many challenges, including the worldwide economic downturn, difficulties in elimination of vivax malaria, development of pyrethroid resistance in some anopheline mosquitoes, and the emergence of artemisinin resistance in Plasmodium falciparum in southeast Asia. We review the epidemiology, clinical features, pathology, prevention, and treatment of malaria. PMID:23953767

  8. Does Iron Increase the Risk of Malaria in Pregnancy?

    PubMed

    Moya-Alvarez, Violeta; Cottrell, Gilles; Ouédraogo, Smaila; Accrombessi, Manfred; Massougbodgi, Achille; Cot, Michel

    2015-04-01

    Background.  Pregnancy-associated malaria (PAM) remains a significant health concern in sub-Saharan Africa. Cross-sectional studies report that iron might be associated with increased malaria morbidity, raising fears that current iron supplementation policies will cause harm in the present context of increasing resistance against intermittent preventive treatment in pregnancy (IPTp). Therefore, it is necessary to assess the relation of iron levels with malaria risk during the entire pregnancy. Methods.  To investigate the association of maternal iron levels on malaria risk in the context of an IPTp clinical trial, 1005 human immunodeficiency virus-negative, pregnant Beninese women were monitored throughout their pregnancy between January 2010 and May 2011. Multilevel models with random intercept at the individual levels and random slope for gestational age were used to analyze the factors associated with increased risk of a positive blood smear and increased Plasmodium falciparum density. Results.  During the follow-up, 29% of the women had at least 1 episode of malaria. On average, women had 0.52 positive smears (95% confidence interval [CI], 0.44-0.60). High iron levels (measured by the log10 of ferritin corrected on inflammation) were significantly associated with increased risk of a positive blood smear (adjusted odds ratio = 1.75; 95% CI, 1.46-2.11; P < .001) and high P falciparum density (beta estimate = 0.22; 95% CI, 0.18-0.27; P < .001) during the follow-up period adjusted on pregnancy parameters, comorbidities, environmental and socioeconomic indicators, and IPTp regime. Furthermore, iron-deficient women were significantly less likely to have a positive blood smear and high P falciparum density (P < .001 in both cases). Conclusions.  Iron levels were positively associated with increased PAM during pregnancy in the context of IPTp. Supplementary interventional studies are needed to determine the benefits and risks of differently dosed iron and

  9. Does Iron Increase the Risk of Malaria in Pregnancy?

    PubMed Central

    Moya-Alvarez, Violeta; Cottrell, Gilles; Ouédraogo, Smaila; Accrombessi, Manfred; Massougbodgi, Achille; Cot, Michel

    2015-01-01

    Background. Pregnancy-associated malaria (PAM) remains a significant health concern in sub-Saharan Africa. Cross-sectional studies report that iron might be associated with increased malaria morbidity, raising fears that current iron supplementation policies will cause harm in the present context of increasing resistance against intermittent preventive treatment in pregnancy (IPTp). Therefore, it is necessary to assess the relation of iron levels with malaria risk during the entire pregnancy. Methods. To investigate the association of maternal iron levels on malaria risk in the context of an IPTp clinical trial, 1005 human immunodeficiency virus-negative, pregnant Beninese women were monitored throughout their pregnancy between January 2010 and May 2011. Multilevel models with random intercept at the individual levels and random slope for gestational age were used to analyze the factors associated with increased risk of a positive blood smear and increased Plasmodium falciparum density. Results. During the follow-up, 29% of the women had at least 1 episode of malaria. On average, women had 0.52 positive smears (95% confidence interval [CI], 0.44–0.60). High iron levels (measured by the log10 of ferritin corrected on inflammation) were significantly associated with increased risk of a positive blood smear (adjusted odds ratio = 1.75; 95% CI, 1.46–2.11; P < .001) and high P falciparum density (beta estimate = 0.22; 95% CI, 0.18–0.27; P < .001) during the follow-up period adjusted on pregnancy parameters, comorbidities, environmental and socioeconomic indicators, and IPTp regime. Furthermore, iron-deficient women were significantly less likely to have a positive blood smear and high P falciparum density (P < .001 in both cases). Conclusions. Iron levels were positively associated with increased PAM during pregnancy in the context of IPTp. Supplementary interventional studies are needed to determine the benefits and risks of differently dosed iron and

  10. Malaria

    MedlinePlus

    MENU Return to Web version Malaria Overview What is malaria? Malaria is an infection of a part of the blood called the red blood cells. It is ... by mosquitoes that carry a parasite that causes malaria. If a mosquito carrying this parasite bites you, ...

  11. Increase in malaria cases imported from Pakistan to Germany in 2012.

    PubMed

    Stark, K; Schöneberg, I

    2012-01-01

    A significant increase of malaria cases imported to Germany from Pakistan was observed in 2012. As of 14 November, Pakistan was the country of infection in 32 out of 434 malaria cases in 2012, compared to zero to eight annual malaria cases (out of over 500 cases) in previous years. Physicians and public health authorities should consider malaria in febrile patients returning or migrating from Pakistan. PMID:23231855

  12. Malaria.

    ERIC Educational Resources Information Center

    Dupasquier, Isabelle

    1989-01-01

    Malaria, the greatest pandemia in the world, claims an estimated one million lives each year in Africa alone. While it may still be said that for the most part malaria is found in what is known as the world's poverty belt, cases are now frequently diagnosed in western countries. Due to resistant strains of malaria which have developed because of…

  13. Malaria

    MedlinePlus

    Malaria is a serious disease caused by a parasite. You get it when an infected mosquito bites you. Malaria is a major cause of death worldwide, but ... at risk. There are four different types of malaria caused by four related parasites. The most deadly ...

  14. Malaria

    PubMed Central

    Suh, Kathryn N.; Kain, Kevin C.; Keystone, Jay S.

    2004-01-01

    Malaria is a parasitic infection of global importance. Although relatively uncommon in developed countries, where the disease occurs mainly in travellers who have returned from endemic regions, it remains one of the most prevalent infections of humans worldwide. In endemic regions, malaria is a significant cause of morbidity and mortality and creates enormous social and economic burdens. Current efforts to control malaria focus on reducing attributable morbidity and mortality. Targeted chemoprophylaxis and use of insecticide-treated bed nets have been successful in some endemic areas. For travellers to malaria-endemic regions, personal protective measures and appropriate chemoprophylaxis can significantly reduce the risk of infection. Prompt evaluation of the febrile traveller, a high degree of suspicion of malaria, rapid and accurate diagnosis, and appropriate antimalarial therapy are essential in order to optimize clinical outcomes of infected patients. Additional approaches to malaria control, including genetic manipulation of mosquitoes and malaria vaccines, are areas of ongoing research. PMID:15159369

  15. Malaria

    MedlinePlus

    ... a parasite. You get it when an infected mosquito bites you. Malaria is a major cause of ... insect repellent with DEET Cover up Sleep under mosquito netting Centers for Disease Control and Prevention

  16. Malaria

    MedlinePlus

    ... Malaria can be carried by mosquitoes in temperate climates, but the parasite disappears over the winter. The ... a major disease hazard for travelers to warm climates. In some areas of the world, mosquitoes that ...

  17. Malaria in school-age children in Africa: an increasingly important challenge

    PubMed Central

    Nankabirwa, Joaniter; Brooker, Simon J; Clarke, Sian E; Fernando, Deepika; Gitonga, Caroline W; Schellenberg, David; Greenwood, Brian

    2014-01-01

    School-age children have attracted relatively little attention as a group in need of special measures to protect them against malaria. However, increasing success in lowering the level of malaria transmission in many previously highly endemic areas will result in children acquiring immunity to malaria later in life than has been the case in the past. Thus, it can be anticipated that in the coming years there will be an increase in the incidence of both uncomplicated and severe malaria in school-age children in many previously highly endemic areas. In this review, which focuses primarily on Africa, recent data on the prevalence of malaria parasitaemia and on the incidence of clinical malaria in African school-age children are presented and evidence that malaria adversely effects school performance is reviewed. Long-lasting insecticide treated bednets (LLIN) are an effective method of malaria control but several studies have shown that school-age children use LLINs less frequently than other population groups. Antimalarial drugs are being used in different ways to control malaria in school-age children including screening and treatment and intermittent preventive treatment. Some studies of chemoprevention in school-age children have shown reductions in anaemia and improved school performance but this has not been the case in all trials and more research is needed to identify the situations in which chemoprevention is likely to be most effective and, in these situations, which type of intervention should be used. In the longer term, malaria vaccines may have an important role in protecting this important section of the community from malaria. Regardless of the control approach selected, it is important this is incorporated into the overall programme of measures being undertaken to enhance the health of African school-age children. PMID:25145389

  18. The economic benefits of malaria elimination: do they include increases in tourism?

    PubMed Central

    2012-01-01

    Background Policy makers have speculated that one of the economic benefits of malaria elimination includes increases in foreign direct investment, particularly tourism. Methods This study examines the empirical relationship between the demand for travel and malaria cases in two countries with large tourism industries around the time in which they carried out malaria-elimination campaigns. In Mauritius, this analysis examines historical, yearly tourist arrivals and malaria cases from 1978–1999, accounting for the background secular trend of increasing international travel. In Dominican Republic, a country embarking upon malaria elimination, it employs a time-series analysis of the monthly, international tourist arrivals from 1998–2010 to determine whether the timing of significant deviations in tourist arrivals coincides with malaria outbreaks. Results While naïve relationships exist in both cases, the results show that the relationships between tourist arrivals and malaria cases are relatively weak and statistically insignificant once secular confounders are accounted for. Conclusions This suggests that any economic benefits from tourism that may be derived from actively pursuing elimination in countries that have high tourism potential are likely to be small when measured at a national level. Rather, tourism benefits are likely to be experienced with greater impact in more concentrated tourist areas within countries, and future studies should seek to assess these relationships at a regional or local level. PMID:22839351

  19. Flow cytometric detection of Cryptosporidium oocysts in human stool samples.

    PubMed Central

    Valdez, L M; Dang, H; Okhuysen, P C; Chappell, C L

    1997-01-01

    Cryptosporidium parvum is an important pathogen that causes diarrhea in virtually all human populations. Improved diagnostic methods are needed to understand the risk factors, modes of transmission, and impact of cryptosporidiosis. In the present study, we fluorescently labeled and counted C. parvum oocysts by flow cytometry (FC) and developed a simple and efficient method of processing human stool samples for FC analysis. Formed stool (suspended in phosphate-buffered saline) from an asymptomatic, healthy individual was seeded with known concentrations of oocysts, and oocysts were labeled with a cell wall-specific monoclonal antibody and detected by FC. The method described herein resulted in a mean oocyst recovery rate of 45% +/- 16% (median, 42%), which consistently yielded a fourfold increase in sensitivity compared to direct fluorescent-antibody assay of seeded stool samples. However, in many instances, FC detected as few as 10(3) oocysts per ml. Thus, FC provides a reproducible and sensitive method for C. parvum oocyst detection. PMID:9230372

  20. Decreased Endothelial Nitric Oxide Bioavailability, Impaired Microvascular Function, and Increased Tissue Oxygen Consumption in Children with Falciparum Malaria

    PubMed Central

    Yeo, Tsin W.; Lampah, Daniel A.; Kenangalem, Enny; Tjitra, Emiliana; Weinberg, J. Brice; Granger, Donald L.; Price, Ric N.; Anstey, Nicholas M.

    2014-01-01

    Endothelial nitric oxide (NO) bioavailability, microvascular function, and host oxygen consumption have not been assessed in pediatric malaria. We measured NO-dependent endothelial function by using peripheral artery tonometry to determine the reactive hyperemia index (RHI), and microvascular function and oxygen consumption (VO2) using near infrared resonance spectroscopy in 13 Indonesian children with severe falciparum malaria and 15 with moderately severe falciparum malaria. Compared with 19 controls, children with severe malaria and those with moderately severe malaria had lower RHIs (P = .03); 12% and 8% lower microvascular function, respectively (P = .03); and 29% and 25% higher VO2, respectively. RHIs correlated with microvascular function in all children with malaria (P < .001) and all with severe malaria (P < .001). Children with malaria have decreased endothelial and microvascular function and increased oxygen consumption, likely contributing to the pathogenesis of the disease. PMID:24879801

  1. Climate, environment and transmission of malaria.

    PubMed

    Rossati, Antonella; Bargiacchi, Olivia; Kroumova, Vesselina; Zaramella, Marco; Caputo, Annamaria; Garavelli, Pietro Luigi

    2016-06-01

    Malaria, the most common parasitic disease in the world, is transmitted to the human host by mosquitoes of the genus Anopheles. The transmission of malaria requires the interaction between the host, the vector and the parasite.The four species of parasites responsible for human malaria are Plasmodium falciparum, Plasmodium ovale, Plasmodium malariae and Plasmodium vivax. Occasionally humans can be infected by several simian species, like Plasmodium knowlesi, recognised as a major cause of human malaria in South-East Asia since 2004. While P. falciparum is responsible for most malaria cases, about 8% of estimated cases globally are caused by P. vivax. The different Plasmodia are not uniformly distributed although there are areas of species overlap. The life cycle of all species of human malaria parasites is characterised by an exogenous sexual phase in which multiplication occurs in several species of Anopheles mosquitoes, and an endogenous asexual phase in the vertebrate host. The time span required for mature oocyst development in the salivary glands is quite variable (7-30 days), characteristic of each species and influenced by ambient temperature. The vector Anopheles includes 465 formally recognised species. Approximately 70 of these species have the capacity to transmit Plasmodium spp. to humans and 41 are considered as dominant vector capable of transmitting malaria. The intensity of transmission is dependent on the vectorial capacity and competence of local mosquitoes. An efficient system for malaria transmission needs strong interaction between humans, the ecosystem and infected vectors. Global warming induced by human activities has increased the risk of vector-borne diseases such as malaria. Recent decades have witnessed changes in the ecosystem and climate without precedent in human history although the emphasis in the role of temperature on the epidemiology of malaria has given way to predisposing conditions such as ecosystem changes, political

  2. Hematological Indices in Malian Children Change Significantly During a Malaria Season and with Increasing Age: Implications for Malaria Epidemiological Studies.

    PubMed

    Diakite, Mahamadou; Miura, Kazutoyo; Diouf, Ababacar; Konate, Drissa; Keita, Abdoul S; Doumbia, Saibou; Diakite, Seidina; Traore, Karim; Doumbouya, Mory; Anderson, Jennifer M; Fairhurst, Rick M; Long, Carole A

    2016-08-01

    Standard hematological indices are commonly used in malaria epidemiological studies to measure anemia prevalence and calculate blood parasite densities. In Africa, few studies have investigated how these indices change during a malaria transmission season and with increasing age. To address these knowledge gaps, we collected blood from 169 healthy Malian children aged 3-12 years before (May 2010) and after (January 2011) a transmission season. Red blood cell (RBC) count, hemoglobin (Hb) level, hematocrit (Ht), white blood cell (WBC) count, and WBC subsets were measured in paired blood samples, and the data were stratified by month (May, January) and age group (3-5, 6-8, and 9-12 years). From May to January, RBC count (4.53-4.70 × 10(6)/μL; P < 0.0001), Hb level (11.5-11.9 g/dL; P < 0.0001), and Ht (37.1-39.2%; P < 0.0001) increased, and WBC count (6.46-5.96 × 10(3)/μL; P = 0.0006) decreased. From May to January, the prevalence of WBC subsets also changed: 35-43% neutrophils, 6.5-7.6% monocytes, and 53-45% lymphocytes (P < 0.001). These seasonal changes were not associated with the number of malaria episodes experienced in the interim or the presence of RBC polymorphisms. In May, Hb (11.2, 11.4, and 11.8 g/dL; P = 0.0013) and Ht (36.5%, 36.7%, and 38.1%; P = 0.0154) increased and WBC count (8.04, 6.43, and 5.76 × 10(3)/μL; P < 0.0001) decreased with age group; similar differences were observed in January. These data suggest that season- and age-based reference values for hematological indices are needed to better estimate anemia prevalence and parasite density in malaria epidemiological studies. PMID:27296389

  3. Plasma Circulating Nucleic Acids Levels Increase According to the Morbidity of Plasmodium vivax Malaria

    PubMed Central

    Franklin, Bernardo S.; Vitorino, Barbara L. F.; Coelho, Helena C.; Menezes-Neto, Armando; Santos, Marina L. S.; Campos, Fernanda M. F.; Brito, Cristiana F.; Fontes, Cor J.; Lacerda, Marcus V.; Carvalho, Luzia H.

    2011-01-01

    Background Given the increasing evidence of Plasmodium vivax infections associated with severe and fatal disease, the identification of sensitive and reliable markers for vivax severity is crucial to improve patient care. Circulating nucleic acids (CNAs) have been increasingly recognized as powerful diagnostic and prognostic tools for various inflammatory diseases and tumors as their plasma concentrations increase according to malignancy. Given the marked inflammatory status of P. vivax infection, we investigated here the usefulness of CNAs as biomarkers for malaria morbidity. Methods and Findings CNAs levels in plasma from twenty-one acute P. vivax malaria patients from the Brazilian Amazon and 14 malaria non-exposed healthy donors were quantified by two different methodologies: amplification of the human telomerase reverse transcriptase (hTERT) genomic sequence by quantitative real time PCR (qPCR), and the fluorometric dsDNA quantification by Pico Green. CNAs levels were significantly increased in plasma from P. vivax patients as compared to healthy donors (p<0.0001). Importantly, plasma CNAs levels were strongly associated with vivax morbidity (p<0.0001), including a drop in platelet counts (p = 0.0021). These findings were further sustained when we assessed CNAS levels in plasma samples from 14 additional P. vivax patients of a different endemic area in Brazil, in which CNAS levels strongly correlated with thrombocytopenia (p = 0.0072). We further show that plasma CNAs levels decrease and reach physiological levels after antimalarial treatment. Although we found both host and parasite specific genomic sequences circulating in plasma, only host CNAs clearly reflected the clinical spectrum of P. vivax malaria. Conclusions Here, we provide the first evidence of increased plasma CNAs levels in malaria patients and reveal their potential as sensitive biomarkers for vivax malaria morbidity. PMID:21611202

  4. Impaired Systemic Tetrahydrobiopterin Bioavailability and Increased Oxidized Biopterins in Pediatric Falciparum Malaria: Association with Disease Severity

    PubMed Central

    Rubach, Matthew P.; Mukemba, Jackson; Florence, Salvatore; Lopansri, Bert K.; Hyland, Keith; Volkheimer, Alicia D.; Yeo, Tsin W.; Anstey, Nicholas M.; Weinberg, J. Brice; Mwaikambo, Esther D.; Granger, Donald L.

    2015-01-01

    Decreased bioavailability of nitric oxide (NO) is a major contributor to the pathophysiology of severe falciparum malaria. Tetrahydrobiopterin (BH4) is an enzyme cofactor required for NO synthesis from L-arginine. We hypothesized that systemic levels of BH4 would be decreased in children with cerebral malaria, contributing to low NO bioavailability. In an observational study in Tanzania, we measured urine levels of biopterin in its various redox states (fully reduced [BH4] and the oxidized metabolites, dihydrobiopterin [BH2] and biopterin [B0]) in children with uncomplicated malaria (UM, n = 55), cerebral malaria (CM, n = 45), non-malaria central nervous system conditions (NMC, n = 48), and in 111 healthy controls (HC). Median urine BH4 concentration in CM (1.10 [IQR:0.55–2.18] μmol/mmol creatinine) was significantly lower compared to each of the other three groups — UM (2.10 [IQR:1.32–3.14];p<0.001), NMC (1.52 [IQR:1.01–2.71];p = 0.002), and HC (1.60 [IQR:1.15–2.23];p = 0.005). Oxidized biopterins were increased, and the BH4:BH2 ratio markedly decreased in CM. In a multivariate logistic regression model, each Log10-unit decrease in urine BH4 was independently associated with a 3.85-fold (95% CI:1.89–7.61) increase in odds of CM (p<0.001). Low systemic BH4 levels and increased oxidized biopterins contribute to the low NO bioavailability observed in CM. Adjunctive therapy to regenerate BH4 may have a role in improving NO bioavailability and microvascular perfusion in severe falciparum malaria. PMID:25764173

  5. Parasite Specific Antibody Increase Induced by an Episode of Acute P. falciparum Uncomplicated Malaria

    PubMed Central

    Kaddumukasa, Mark; Lwanira, Catherine; Lugaajju, Allan; Katabira, Elly; Persson, Kristina E. M.; Wahlgren, Mats; Kironde, Fred

    2015-01-01

    Introduction There is no approved vaccine for malaria, and precisely how human antibody responses to malaria parasite components and potential vaccine molecules are developed and maintained remains poorly defined. In this study, antibody anamnestic or memory response elicited by a single episode of P. falciparum infection was investigated. Methods This study involved 362 malaria patients aged between 6 months to 60 years, of whom 19% were early-diagnosed people living with HIV/AIDS (PLWHA). On the day malaria was diagnosed and 42 days later, blood specimens were collected. Parasite density, CD4+ cells, and antibodies specific to synthetic peptides representing antigenic regions of the P. falciparum proteins GLURP, MSP3 and HRPII were measured. Results On the day of malaria diagnosis, Immunoglobulin (IgG) antibodies against GLURP, MSP3 and HRP II peptides were present in the blood of 75%, 41% and 60% of patients, respectively. 42 days later, the majority of patients had boosted their serum IgG antibody more than 1.2 fold. The increase in level of IgG antibody against the peptides was not affected by parasite density at diagnosis. The median CD4+ cell counts of PLWHAs and HIV negative individuals were not statistically different, and median post-infection increases in anti-peptide IgG were similar in both groups of patients. Conclusion In the majority (70%) of individuals, an infection of P. falciparum elicits at least 20% increase in level of anti-parasite IgG. This boost in anti-P. falciparum IgG is not affected by parasite density on the day of malaria diagnosis, or by HIV status. PMID:25906165

  6. Impaired systemic tetrahydrobiopterin bioavailability and increased oxidized biopterins in pediatric falciparum malaria: association with disease severity.

    PubMed

    Rubach, Matthew P; Mukemba, Jackson; Florence, Salvatore; Lopansri, Bert K; Hyland, Keith; Volkheimer, Alicia D; Yeo, Tsin W; Anstey, Nicholas M; Weinberg, J Brice; Mwaikambo, Esther D; Granger, Donald L

    2015-03-01

    Decreased bioavailability of nitric oxide (NO) is a major contributor to the pathophysiology of severe falciparum malaria. Tetrahydrobiopterin (BH4) is an enzyme cofactor required for NO synthesis from L-arginine. We hypothesized that systemic levels of BH₄ would be decreased in children with cerebral malaria, contributing to low NO bioavailability. In an observational study in Tanzania, we measured urine levels of biopterin in its various redox states (fully reduced [BH₄] and the oxidized metabolites, dihydrobiopterin [BH₂] and biopterin [B₀]) in children with uncomplicated malaria (UM, n = 55), cerebral malaria (CM, n = 45), non-malaria central nervous system conditions (NMC, n = 48), and in 111 healthy controls (HC). Median urine BH4 concentration in CM (1.10 [IQR:0.55-2.18] μmol/mmol creatinine) was significantly lower compared to each of the other three groups - UM (2.10 [IQR:1.32-3.14];p<0.001), NMC (1.52 [IQR:1.01-2.71];p = 0.002), and HC (1.60 [IQR:1.15-2.23];p = 0.005). Oxidized biopterins were increased, and the BH4:BH2 ratio markedly decreased in CM. In a multivariate logistic regression model, each Log10-unit decrease in urine BH4 was independently associated with a 3.85-fold (95% CI:1.89-7.61) increase in odds of CM (p<0.001). Low systemic BH4 levels and increased oxidized biopterins contribute to the low NO bioavailability observed in CM. Adjunctive therapy to regenerate BH4 may have a role in improving NO bioavailability and microvascular perfusion in severe falciparum malaria. PMID:25764173

  7. Transport, fate, and infectivity of Cryptosporidium parvum oocysts released from manure and leached through macroporous soil

    NASA Astrophysics Data System (ADS)

    Boyer, Douglas G.; Kuczynska, Ewa; Fayer, Ron

    2009-09-01

    A major mode of transmission of Cryptosporidium parvum, a widespread waterborne pathogen, is via contaminated drinking and recreational waters. Oocyst transport to surface water can occur by deposition of manure directly in the water or by wash off in surface runoff. Oocyst transport to groundwater is less straightforward and requires that the oocysts move through soil and bedrock to reach the water table. The purpose of this study was to determine the relative concentration and infectivity of C. parvum oocysts released from manure and leached through columns of undisturbed, macroporous karst soil. Modeling the fate of oocysts in this system over time can provide baseline data for evaluating real world events. Substantially more oocysts leached from undisturbed soil columns than disturbed soil columns. Oocyst survival studies using BALB/c neonatal suckling mice showed that about 85% of oocysts were infective at the beginning of leaching experiments. The oocyst infectivity decreased to about 20% after 12 weeks of leaching from soil columns maintained at 10°C. Cool (10°C) temperatures appear to increase survivability and maintain infectivity of many oocysts for 3 months or longer. Cool temperatures also appear to increase rates of release of oocysts from manure and leaching through soil. This study demonstrated that leaching is an important mechanism of oocyst transport in karst soils where infiltration capacities are high and long, continuous macropores exist. Karst groundwater systems might be especially vulnerable to contamination by leached oocysts, because of the prevalence of shallow soils and rapid groundwater movement. Oocysts leaching from soils into the epikarst could accumulate and remain viable for months until hydrological conditions are right for flushing the oocysts into the conduit flow system.

  8. Survival of Cryptosporidium parvum oocysts in the presence of hydrated lime.

    PubMed

    Zintl, A; Keogh, B; Ezzaty-Mirhashemi, M; De Waal, T; Scholz, D; Mulcahy, G

    2010-03-01

    To investigate the effects of hydrated lime on the survival of Cryptosporidium oocysts, the percentage viability of oocysts was assessed using fluorescent in situ hybridisation. In the absence of lime and with lime at a concentration of 1 per cent, there was a gradual decline in oocyst viability during the 10-day trial. Although the addition of 5 or 10 per cent lime caused the total number of oocysts to decrease, there appeared to be an increase in the proportion of potentially viable oocysts. PMID:20208077

  9. The relevance and applicability of oocyst prevalence as a read-out for mosquito feeding assays

    NASA Astrophysics Data System (ADS)

    Stone, Will J. R.; Eldering, Maarten; van Gemert, Geert-Jan; Lanke, Kjerstin H. W.; Grignard, Lynn; van de Vegte-Bolmer, Marga G.; Siebelink-Stoter, Rianne; Graumans, Wouter; Roeffen, Will F. G.; Drakeley, Chris J.; Sauerwein, Robert W.; Bousema, Teun

    2013-12-01

    Mosquito feeding assays are important in evaluations of malaria transmission-reducing interventions. The proportion of mosquitoes with midgut oocysts is commonly used as an outcome measure, but in natural low intensity infections the effect of oocyst non-rupture on mosquito infectivity is unclear. By identifying ruptured as well as intact oocysts, we show that in low intensity P. falciparum infections i) 66.7-96.7% of infected mosquitoes experienced oocyst rupture between 11-21 days post-infection, ii) oocyst rupture led invariably to sporozoite release, iii) oocyst rupture led to salivary gland infections in 97.8% of mosquitoes, and iv) 1250 (IQR 313-2400) salivary gland sporozoites were found per ruptured oocyst. These data show that infectivity can be predicted with reasonable certainty from oocyst prevalence in low intensity infections. High throughput methods for detecting infection in whole mosquitoes showed that 18s PCR but not circumsporozoite ELISA gave a reliable approximation of mosquito infection rates on day 7 post-infection.

  10. Increase in cases of malaria in Mozambique, 2014: epidemic or new endemic pattern?

    PubMed Central

    Arroz, Jorge Alexandre Harrison

    2016-01-01

    ABSTRACT OBJECTIVE To describe the increase in cases of malaria in Mozambique. METHODS Cross-sectional study conducted in 2014, in Mozambique with national weekly epidemiological bulletin data. I analyzed the number of recorded cases in the 2009-2013 period, which led to the creation of an endemic channel using the quartile and C-Sum methods. Monthly incidence rates were calculated for the first half of 2014, making it possible to determine the pattern of endemicity. Months in which the incidence rates exceeded the third quartile or line C-sum were declared as epidemic months. RESULTS The provinces of Nampula, Zambezia, Sofala, and Inhambane accounted for 52.7% of all cases in the first half of 2014. Also during this period, the provinces of Nampula, Sofala and Tete were responsible for 54.9% of the deaths from malaria. The incidence rates of malaria in children, and in all ages, have showed patterns in the epidemic zone. For all ages, the incidence rate has peaked in April (2,573 cases/100,000 inhabitants). CONCLUSIONS The results suggest the occurrence of an epidemic pattern of malaria in the first half of 2014 in Mozambique. It is strategic to have a more accurate surveillance at all levels (central, provincial and district) to target prevention and control interventions in a timely manner. PMID:26982961

  11. Increase in cases of malaria in Mozambique, 2014: epidemic or new endemic pattern?

    PubMed

    Arroz, Jorge Alexandre Harrison

    2016-01-01

    OBJECTIVE To describe the increase in cases of malaria in Mozambique. METHODS Cross-sectional study conducted in 2014, in Mozambique with national weekly epidemiological bulletin data. I analyzed the number of recorded cases in the 2009-2013 period, which led to the creation of an endemic channel using the quartile and C-Sum methods. Monthly incidence rates were calculated for the first half of 2014, making it possible to determine the pattern of endemicity. Months in which the incidence rates exceeded the third quartile or line C-sum were declared as epidemic months. RESULTS The provinces of Nampula, Zambezia, Sofala, and Inhambane accounted for 52.7% of all cases in the first half of 2014. Also during this period, the provinces of Nampula, Sofala and Tete were responsible for 54.9% of the deaths from malaria. The incidence rates of malaria in children, and in all ages, have showed patterns in the epidemic zone. For all ages, the incidence rate has peaked in April (2,573 cases/100,000 inhabitants). CONCLUSIONS The results suggest the occurrence of an epidemic pattern of malaria in the first half of 2014 in Mozambique. It is strategic to have a more accurate surveillance at all levels (central, provincial and district) to target prevention and control interventions in a timely manner. PMID:26982961

  12. Methods to Increase the Sensitivity of High Resolution Melting Single Nucleotide Polymorphism Genotyping in Malaria.

    PubMed

    Daniels, Rachel; Hamilton, Elizabeth J; Durfee, Katelyn; Ndiaye, Daouda; Wirth, Dyann F; Hartl, Daniel L; Volkman, Sarah K

    2015-01-01

    Despite decades of eradication efforts, malaria remains a global burden. Recent renewed interest in regional elimination and global eradication has been accompanied by increased genomic information about Plasmodium parasite species responsible for malaria, including characteristics of geographical populations as well as variations associated with reduced susceptibility to anti-malarial drugs. One common genetic variation, single-nucleotide polymorphisms (SNPs), offers attractive targets for parasite genotyping. These markers are useful not only for tracking drug resistance markers but also for tracking parasite populations using markers not under drug or other selective pressures. SNP genotyping methods offer the ability to track drug resistance as well as to fingerprint individual parasites for population surveillance, particularly in response to malaria control efforts in regions nearing elimination status. While informative SNPs have been identified that are agnostic to specific genotyping technologies, high-resolution melting (HRM) analysis is particularly suited to field-based studies. Compared to standard fluorescent-probe based methods that require individual SNPs in a single labeled probe and offer at best 10% sensitivity to detect SNPs in samples that contain multiple genomes (polygenomic), HRM offers 2-5% sensitivity. Modifications to HRM, such as blocked probes and asymmetric primer concentrations as well as optimization of amplification annealing temperatures to bias PCR towards amplification of the minor allele, further increase the sensitivity of HRM. While the sensitivity improvement depends on the specific assay, we have increased detection sensitivities to less than 1% of the minor allele. In regions approaching malaria eradication, early detection of emerging or imported drug resistance is essential for prompt response. Similarly, the ability to detect polygenomic infections and differentiate imported parasite types from cryptic local reservoirs

  13. Methods to Increase the Sensitivity of High Resolution Melting Single Nucleotide Polymorphism Genotyping in Malaria

    PubMed Central

    Daniels, Rachel; Hamilton, Elizabeth J.; Durfee, Katelyn; Ndiaye, Daouda; Wirth, Dyann F.; Hartl, Daniel L.; Volkman, Sarah K.

    2015-01-01

    Despite decades of eradication efforts, malaria remains a global burden. Recent renewed interest in regional elimination and global eradication has been accompanied by increased genomic information about Plasmodium parasite species responsible for malaria, including characteristics of geographical populations as well as variations associated with reduced susceptibility to anti-malarial drugs. One common genetic variation, single-nucleotide polymorphisms (SNPs), offers attractive targets for parasite genotyping. These markers are useful not only for tracking drug resistance markers but also for tracking parasite populations using markers not under drug or other selective pressures. SNP genotyping methods offer the ability to track drug resistance as well as to fingerprint individual parasites for population surveillance, particularly in response to malaria control efforts in regions nearing elimination status. While informative SNPs have been identified that are agnostic to specific genotyping technologies, high-resolution melting (HRM) analysis is particularly suited to field-based studies. Compared to standard fluorescent-probe based methods that require individual SNPs in a single labeled probe and offer at best 10% sensitivity to detect SNPs in samples that contain multiple genomes (polygenomic), HRM offers 2-5% sensitivity. Modifications to HRM, such as blocked probes and asymmetric primer concentrations as well as optimization of amplification annealing temperatures to bias PCR towards amplification of the minor allele, further increase the sensitivity of HRM. While the sensitivity improvement depends on the specific assay, we have increased detection sensitivities to less than 1% of the minor allele. In regions approaching malaria eradication, early detection of emerging or imported drug resistance is essential for prompt response. Similarly, the ability to detect polygenomic infections and differentiate imported parasite types from cryptic local reservoirs

  14. Critical processes affecting Cryptosporidium oocyst survival in the environment.

    PubMed

    King, B J; Monis, P T

    2007-03-01

    Cryptosporidium are parasitic protozoans that cause gastrointestinal disease and represent a significant risk to public health. Cryptosporidium oocysts are prevalent in surface waters as a result of human, livestock and native animal faecal contamination. The resistance of oocysts to the concentrations of chlorine and monochloramine used to disinfect potable water increases the risk of waterborne transmission via drinking water. In addition to being resistant to commonly used disinfectants, it is thought that oocysts can persist in the environment and be readily mobilized by precipitation events. This paper will review the critical processes involved in the inactivation or removal of oocysts in the terrestrial and aquatic environments and consider how these processes will respond in the context of climate change. PMID:17096874

  15. Toxoplasma oocysts as a public health problem.

    PubMed

    Torrey, E Fuller; Yolken, Robert H

    2013-08-01

    Waterborne outbreaks of Toxoplasma gondii have focused attention on the importance of oocysts shed in the feces of infected cats. Cat feces deposited annually into the environment in the United States total approximately 1.2 million metric tons. The annual oocyst burden measured in community surveys is 3 to 434 oocysts per square foot and is greater in areas where cats selectively defecate. Because a single oocyst can possibly cause infection, this oocyst burden represents a major potential public health problem. The proper disposal of cat litter, keeping cats indoors, reducing the feral cat population, and protecting the play areas of children might potentially reduce the oocyst burden. PMID:23849140

  16. DETECTION OF CRYPTOSPORIDIUM OOCYSTS IN WATER MATRICES

    EPA Science Inventory

    Since the advent and recognition of waterborne outbreaks of cryptosporidiosis great effort has been expended on development of methods for detecting Cryptosporidium oocysts in water. Oocysts recovery rates using a method originally developed for detecting Giardia cysts ranged fr...

  17. Localisation of laminin within Plasmodium berghei oocysts and the midgut epithelial cells of Anopheles stephensi

    PubMed Central

    Nacer, Adéla; Walker, Karen; Hurd, Hilary

    2008-01-01

    Background Oocysts of the malaria parasite form and develop in close proximity to the mosquito midgut basal lamina and it has been proposed that components of this structure play a crucial role in the development and maturation of oocysts that produce infective sporozoites. It is further suggested that oocysts incorporate basal lamina proteins into their capsule and that this provides them with a means to evade recognition by the mosquito's immune system. The site of production of basal lamina proteins in insects is controversial and it is still unclear whether haemocytes or midgut epithelial cells are the main source of components of the mosquito midgut basal lamina. Of the multiple molecules that compose the basal lamina, laminin is known to interact with a number of Plasmodium proteins. In this study, the localisation of mosquito laminin within the capsule and cytoplasm of Plasmodium berghei oocysts and in the midgut epithelial cells of Anopheles stephensi was investigated. Results An ultrastructural examination of midgut sections from infected and uninfected An. stephensi was performed. Post-embedded immunogold labelling demonstrated the presence of laminin within the mosquito basal lamina. Laminin was also detected on the outer surface of the oocyst capsule, incorporated within the capsule and associated with sporozoites forming within the oocysts. Laminin was also found within cells of the midgut epithelium, providing support for the hypothesis that these cells contribute towards the formation of the midgut basal lamina. Conclusion We suggest that ookinetes may become coated in laminin as they pass through the midgut epithelium. Thereafter, laminin secreted by midgut epithelial cells and/or haemocytes, binds to the outer surface of the oocyst capsule and that some passes through and is incorporated into the developing oocysts. The localisation of laminin on sporozoites was unexpected and the importance of this observation is less clear. PMID:18808667

  18. Preferential Flow and Transport of Cryptosporidium Parvum Oocysts Through Vadose Zone: Experiments and Modeling

    NASA Astrophysics Data System (ADS)

    Darnault, C. J.; Darnault, C. J.; Garnier, P.; Kim, Y.; Oveson, K.; Jenkins, M.; Ghiorse, W.; Baveye, P.; Parlange, J.; Steenhuis, T.

    2001-12-01

    long exponential tailing. The spatial distribution of oocysts suggest a close relationship between oocyst retention and the extent of gas-water interfaces; sharp increases in oocyst numbers are consistently observed in regions of the sand where the water content has steep gradients, and therefore where one expects capillary meniscii to have maximal extent. These observations imply that oocyst transport in the vadose zone is likely to be very limited in the absence of preferential flow. However, experimental results suggest that the transport of oocysts in the subsurface via preferential flow may create a significant risk of groundwater contamination in some situations.

  19. Impaired Systemic Tetrahydrobiopterin Bioavailability and Increased Dihydrobiopterin in Adult Falciparum Malaria: Association with Disease Severity, Impaired Microvascular Function and Increased Endothelial Activation

    PubMed Central

    Yeo, Tsin W.; Lampah, Daniel A.; Kenangalem, Enny; Tjitra, Emiliana; Price, Ric N.; Weinberg, J. Brice; Hyland, Keith; Granger, Donald L.; Anstey, Nicholas M.

    2015-01-01

    Tetrahydrobiopterin (BH4) is a co-factor required for catalytic activity of nitric oxide synthase (NOS) and amino acid-monooxygenases, including phenylalanine hydroxylase. BH4 is unstable: during oxidative stress it is non-enzymatically oxidized to dihydrobiopterin (BH2), which inhibits NOS. Depending on BH4 availability, NOS oscillates between NO synthase and NADPH oxidase: as the BH4/BH2 ratio decreases, NO production falls and is replaced by superoxide. In African children and Asian adults with severe malaria, NO bioavailability decreases and plasma phenylalanine increases, together suggesting possible BH4 deficiency. The primary three biopterin metabolites (BH4, BH2 and B0 [biopterin]) and their association with disease severity have not been assessed in falciparum malaria. We measured pterin metabolites in urine of adults with severe falciparum malaria (SM; n=12), moderately-severe malaria (MSM, n=17), severe sepsis (SS; n=5) and healthy subjects (HC; n=20) as controls. In SM, urinary BH4 was decreased (median 0.16 ¼mol/mmol creatinine) compared to MSM (median 0.27), SS (median 0.54), and HC (median 0.34)]; p<0.001. Conversely, BH2 was increased in SM (median 0.91 ¼mol/mmol creatinine), compared to MSM (median 0.67), SS (median 0.39), and HC (median 0.52); p<0.001, suggesting increased oxidative stress and insufficient recycling of BH2 back to BH4 in severe malaria. Overall, the median BH4/BH2 ratio was lowest in SM [0.18 (IQR: 0.04-0.32)] compared to MSM (0.45, IQR 0.27-61), SS (1.03; IQR 0.54-2.38) and controls (0.66; IQR 0.43-1.07); p<0.001. In malaria, a lower BH4/BH2 ratio correlated with decreased microvascular reactivity (r=0.41; p=0.03) and increased ICAM-1 (r=-0.52; p=0.005). Decreased BH4 and increased BH2 in severe malaria (but not in severe sepsis) uncouples NOS, leading to impaired NO bioavailability and potentially increased oxidative stress. Adjunctive therapy to regenerate BH4 may have a role in improving NO bioavailability and microvascular

  20. Acute Kidney Injury Is Common in Pediatric Severe Malaria and Is Associated With Increased Mortality.

    PubMed

    Conroy, Andrea L; Hawkes, Michael; Elphinstone, Robyn E; Morgan, Catherine; Hermann, Laura; Barker, Kevin R; Namasopo, Sophie; Opoka, Robert O; John, Chandy C; Liles, W Conrad; Kain, Kevin C

    2016-03-01

    Background.  Acute kidney injury (AKI) is a well recognized complication of severe malaria in adults, but the incidence and clinical importance of AKI in pediatric severe malaria (SM) is not well documented. Methods.  One hundred eighty children aged 1 to 10 years with SM were enrolled between 2011 and 2013 in Uganda. Kidney function was monitored daily for 4 days using serum creatinine (Cr). Acute kidney injury was defined using the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. Blood urea nitrogen (BUN) and Cr were assessed using i-STAT, and cystatin C (CysC) was measured by enzyme-linked immunosorbent assay. Results.  Eighty-one (45.5%) children had KDIGO-defined AKI in the study: 42 (51.9%) stage 1, 18 (22.2%) stage 2, and 21 (25.9%) stage 3. Acute kidney injury evolved or developed in 50% of children after admission of hospital. There was an increased risk of AKI in children randomized to inhaled nitric oxide (iNO), with 47 (54.0%) of children in the iNO arm developing AKI compared with 34 (37.4%) in the placebo arm (relative risk, 1.36; 95% confidence interval [CI], 1.03-1.80). Duration of hospitalization increased across stages of AKI (P = .002). Acute kidney injury was associated with neurodisability at discharge in the children receiving placebo (25% in children with AKI vs 1.9% in children with no AKI, P = .002). Mortality increased across stages of AKI (P = .006) in the placebo arm, reaching 37.5% in stage 3 AKI. Acute kidney injury was not associated with neurodisability or mortality at discharge in children receiving iNO (P > .05 for both). Levels of kidney biomarkers were predictive of mortality with areas under the curves (AUCs) of 0.80 (95% CI, .65-.95; P = .006) and 0.72 (95% CI, .57-.87; P < .001), respectively. Admission levels of CysC and BUN were elevated in children who died by 6 months (P < .0001 and P = .009, respectively). Conclusions.  Acute kidney injury is an underrecognized complication in young children with SM

  1. Acute Kidney Injury Is Common in Pediatric Severe Malaria and Is Associated With Increased Mortality

    PubMed Central

    Conroy, Andrea L.; Hawkes, Michael; Elphinstone, Robyn E.; Morgan, Catherine; Hermann, Laura; Barker, Kevin R.; Namasopo, Sophie; Opoka, Robert O.; John, Chandy C.; Liles, W. Conrad; Kain, Kevin C.

    2016-01-01

    Background. Acute kidney injury (AKI) is a well recognized complication of severe malaria in adults, but the incidence and clinical importance of AKI in pediatric severe malaria (SM) is not well documented. Methods. One hundred eighty children aged 1 to 10 years with SM were enrolled between 2011 and 2013 in Uganda. Kidney function was monitored daily for 4 days using serum creatinine (Cr). Acute kidney injury was defined using the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. Blood urea nitrogen (BUN) and Cr were assessed using i-STAT, and cystatin C (CysC) was measured by enzyme-linked immunosorbent assay. Results. Eighty-one (45.5%) children had KDIGO-defined AKI in the study: 42 (51.9%) stage 1, 18 (22.2%) stage 2, and 21 (25.9%) stage 3. Acute kidney injury evolved or developed in 50% of children after admission of hospital. There was an increased risk of AKI in children randomized to inhaled nitric oxide (iNO), with 47 (54.0%) of children in the iNO arm developing AKI compared with 34 (37.4%) in the placebo arm (relative risk, 1.36; 95% confidence interval [CI], 1.03–1.80). Duration of hospitalization increased across stages of AKI (P = .002). Acute kidney injury was associated with neurodisability at discharge in the children receiving placebo (25% in children with AKI vs 1.9% in children with no AKI, P = .002). Mortality increased across stages of AKI (P = .006) in the placebo arm, reaching 37.5% in stage 3 AKI. Acute kidney injury was not associated with neurodisability or mortality at discharge in children receiving iNO (P > .05 for both). Levels of kidney biomarkers were predictive of mortality with areas under the curves (AUCs) of 0.80 (95% CI, .65–.95; P = .006) and 0.72 (95% CI, .57–.87; P < .001), respectively. Admission levels of CysC and BUN were elevated in children who died by 6 months (P < .0001 and P = .009, respectively). Conclusions. Acute kidney injury is an underrecognized complication in young children with SM

  2. Prevalence and concentration of Cryptosporidium oocysts in beef cattle paddock soils and forage.

    PubMed

    Boyer, Douglas G; Kuczynska, Ewa

    2010-08-01

    Cryptosporidium is a parasitic protozoan of great interest because of its widespread occurrence in surface waters, high degree of infectivity, and difficulty of risk management associated with its presence and control. Information about environmental loading and seasonal prevalence of Cryptosporidium oocysts is important for development of watershed management plans to protect public health. Healthy adult beef cattle are known to shed oocysts into the environment, and Cryptosporidium oocysts are often present all year in streams and groundwater in livestock agriculture areas. Surface soil and forage samples from 12 Virginia, United States, paddocks were analyzed bimonthly over 3 years for the presence and concentrations of Cryptosporidium oocysts. Half of the paddocks were grazed by stocker beef from November to September. The other half were managed for hay, but were grazed for a few days by the same animals in late fall and early spring to clean up late fall forage regrowth. Annual mean oocyst prevalences in soil were 57.9% and 48.4% in pasture and hay paddocks, respectively. Mean annual oocyst prevalences on forage were 52.4% and 40.5% in pasture and hay paddocks, respectively. Prevalence and concentration of oocysts on hay forage was highest in summer. Oocyst concentrations increased with increasing prevalences in both management systems. Wild animals appeared to be efficient vectors for oocyst distribution among paddocks. Canopy management, short-cycle rotational grazing, and control of wildlife are potential strategies for reduction of Cryptosporidium oocysts in pasture and lessening risk of contamination of water supplies, but further studies are needed before recommendations can be made. PMID:20353289

  3. Transmission-blocking activity is determined by transmission-reducing activity and number of control oocysts in Plasmodium falciparum standard membrane-feeding assay.

    PubMed

    Miura, Kazutoyo; Swihart, Bruce J; Deng, Bingbing; Zhou, Luwen; Pham, Thao P; Diouf, Ababacar; Burton, Timothy; Fay, Michael P; Long, Carole A

    2016-07-29

    Malaria transmission-blocking vaccines (TBVs) are potentially helpful tools for malaria eradication. The standard membrane-feeding assay (SMFA) is considered one of the "gold standard" assays for TBV development. However, lack of consensus in reporting results from SMFA has made it very challenging to compare results from different studies. Two main readouts, % inhibition in mean oocyst count per mosquito (TRA) and % inhibition in prevalence of infected mosquitoes (TBA), have been used widely. In this study, we statistically modeled the oocyst data in SMFA using data from 105 independent feeding experiments including 9804 mosquitoes. The model was validated using an independent data set that included 10,790 mosquitoes from 110 feeding studies. The model delineates a relationship between TRA, the mean oocyst count in the control mosquitoes (mo-contl), and TBA. While TRA was independent from mo-contl, TBA values changed depending on mo-contl. Regardless of monoclonal or polyclonal antibodies tested, there were strong concordances between observed TBA and predicted TBA based on the model using mo-contl and observed TRA. Simulations showed that SMFA with lower true control means had increased uncertainty in TRA estimates. The strong linkage between TBA, TRA and mo-contl inspired creation of a standardized TBA, a model-based TBA standardized to a target control mean, which allows comparison across multiple feeds regardless of mo-contl. This is the first study showing that the observed TBA can be reasonably predicted by mo-contl and the TRA of the test antibody using independent experimental data. This study indicates that TRA should be used to compare results from multiple feeds with different levels of mo-contl. If a measure of TBA is desired, it is better to report standardized TBA rather than observed TBA. These recommendations support rational comparisons of results from different studies, thus benefiting future TBV development. PMID:27372156

  4. ENHANCED PRODUCTION OF CRYPTOSPORIDIUM PARVUM OOCYSTS IN IMMUNOSUPPRESSED MICE

    EPA Science Inventory

    Recently there has been an increase in the need for fresh C. parvum oocysts for engineering and biomedical research applications. In our laboratory the emphsis has shifted from the use of dairy calves to inbred C57BL/67n mice, primarily for reasons of ease of collection and proce...

  5. Poor housing construction associated with increased malaria incidence in a cohort of young Ugandan children.

    PubMed

    Snyman, Katherine; Mwangwa, Florence; Bigira, Victor; Kapisi, James; Clark, Tamara D; Osterbauer, Beth; Greenhouse, Bryan; Sturrock, Hugh; Gosling, Roly; Liu, Jenny; Dorsey, Grant

    2015-06-01

    Despite the use of accepted interventions to combat malaria, such as insecticide-treated bed nets and artemisinin-based combination therapy, malaria remains a leading cause of morbidity and mortality in Uganda. We investigated associations between household factors and malaria incidence in a cohort of children living in a highly endemic region of Uganda. Living in a modern house, defined as the use of non-earth floors, non-thatched roofs, and non-mud walls, was associated with approximately half malaria incidence compared with living in a traditional home (incidence rate ratio [IRR] = 0.54, P = 0.001). Other factors found to be associated with a lower incidence of malaria included living in town versus rural setting; sleeping in a room with openings to the outside (windows, eaves, and airbricks); and having an older and more educated primary caregiver. This study adds to the growing body of evidence that improved house construction may be associated with a lower risk of malaria. PMID:25870429

  6. Poor Housing Construction Associated with Increased Malaria Incidence in a Cohort of Young Ugandan Children

    PubMed Central

    Snyman, Katherine; Mwangwa, Florence; Bigira, Victor; Kapisi, James; Clark, Tamara D.; Osterbauer, Beth; Greenhouse, Bryan; Sturrock, Hugh; Gosling, Roly; Liu, Jenny; Dorsey, Grant

    2015-01-01

    Despite the use of accepted interventions to combat malaria, such as insecticide-treated bed nets and artemisinin-based combination therapy, malaria remains a leading cause of morbidity and mortality in Uganda. We investigated associations between household factors and malaria incidence in a cohort of children living in a highly endemic region of Uganda. Living in a modern house, defined as the use of non-earth floors, non-thatched roofs, and non-mud walls, was associated with approximately half malaria incidence compared with living in a traditional home (incidence rate ratio [IRR] = 0.54, P = 0.001). Other factors found to be associated with a lower incidence of malaria included living in town versus rural setting; sleeping in a room with openings to the outside (windows, eaves, and airbricks); and having an older and more educated primary caregiver. This study adds to the growing body of evidence that improved house construction may be associated with a lower risk of malaria. PMID:25870429

  7. Combination therapy counteracts the enhanced transmission of drug-resistant malaria parasites to mosquitoes.

    PubMed

    Hallett, Rachel L; Sutherland, Colin J; Alexander, Neal; Ord, Rosalynn; Jawara, Musa; Drakeley, Chris J; Pinder, Margaret; Walraven, Gijs; Targett, Geoffrey A T; Alloueche, Ali

    2004-10-01

    Malaria parasites carrying genes conferring resistance to antimalarials are thought to have a selective advantage which leads to higher rates of transmissibility from the drug-treated host. This is a likely mechanism for the increasing prevalence of parasites with resistance to chloroquine (CQ) and sulfadoxine-pyrimethamine in sub-Saharan Africa. Combination therapy is the key strategy being implemented to reduce the impact of resistance, but its effect on the transmission of genetically resistant parasites from treated patients to mosquito vectors has not been measured directly. In a trial comparing CQ monotherapy to the combination CQ plus artesunate (AS) in Gambian children with uncomplicated falciparum malaria, we measured transmissibility by feeding Anopheles gambiae mosquitoes with blood from 43 gametocyte-positive patients through a membrane. In the CQ-treated group, gametocytes from patients carrying parasites with the CQ resistance-associated allele pfcrt-76T prior to treatment produced infected mosquitoes with 38 times higher Plasmodium falciparum oocyst burdens than mosquitoes fed on gametocytes from patients infected with sensitive parasites (P < 0.001). Gametocytes from parasites carrying the resistance-associated allele pfmdr1-86Y produced 14-fold higher oocyst burdens than gametocytes from patients infected with sensitive parasites (P = 0.011). However, parasites carrying either of these resistance-associated alleles pretreatment were not associated with higher mosquito oocyst burdens in the CQ-AS-treated group. Thus, combination therapy overcomes the transmission advantage enjoyed by drug-resistant parasites. PMID:15388456

  8. Cannabidiol increases survival and promotes rescue of cognitive function in a murine model of cerebral malaria.

    PubMed

    Campos, A C; Brant, F; Miranda, A S; Machado, F S; Teixeira, A L

    2015-03-19

    Cerebral malaria (CM) is a severe complication resulting from Plasmodium falciparum infection that might cause permanent neurological deficits. Cannabidiol (CBD) is a nonpsychotomimetic compound of Cannabis sativa with neuroprotective properties. In the present work, we evaluated the effects of CBD in a murine model of CM. Female mice were infected with Plasmodium berghei ANKA (PbA) and treated with CBD (30mg/kg/day - 3 or 7days i.p.) or vehicle. On 5th day-post-infection (dpi), at the peak of the disease), animals were treated with single or repeated doses of Artesunate, an antimalarial drug. All groups were tested for memory impairment (Novel Object Recognition or Morris Water Maze) and anxiety-like behaviors (Open field or elevated plus maze test) in different stages of the disease (at the peak or after the complete clearance of the disease). Th1/Th2 cytokines and neurotrophins (brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF)) were measured in the prefrontal cortex and hippocampus of experimental groups. PbA-infected mice displayed memory deficits and exhibited increase in anxiety-like behaviors on the 5dpi or after the clearance of the parasitemia, effects prevented by CBD treatment. On 5dpi, TNF-α and IL-6 increased in the hippocampus, while only IL-6 increased in the prefrontal cortex. CBD treatment resulted in an increase in BDNF expression in the hippocampus and decreased levels of proinflammatory cytokines in the hippocampus (TNF-α) and prefrontal cortex (IL-6). Our results indicate that CBD exhibits neuroprotective effects in CM model and might be useful as an adjunctive therapy to prevent neurological symptoms following this disease. PMID:25595981

  9. Increase of malaria attacks among children presenting concomitant infection by Schistosoma mansoni in Senegal

    PubMed Central

    Sokhna, Cheikh; Le Hesran, Jean-Yves; Mbaye, Pape A; Akiana, Jean; Camara, Pape; Diop, Mamadou; Ly, Abdoulaye; Druilhe, Pierre

    2004-01-01

    Helminthic infections concomitant with malaria are common in inter-tropical areas. A recent study showed that mice co-infected with Schistosoma mansoni and Plasmodium chabaudi develop higher P. chabaudi parasitaemia and had a higher mortality rate. This important observation deserved to be further investigated among human populations. Malaria attacks were recorded in 512 children aged 6–15 years living in Richard Toll (Northern Senegal) among whom 336 were infected by S. mansoni, and 175 were not. The incidence rate of malaria attacks was significantly higher among S. mansoni-infected individuals, particularly those carrying the highest worm loads, as compared to uninfected subjects (26.6% versus 16,4 %). In contrast, the rate of malaria attacks was lower, without reaching significance, in medium grade S. mansoni infections. Thus, infection by S. mansoni affects susceptibility to malaria, but this can vary according to the intensity of parasite load. The immunological mechanisms underlying this dual effect need to be further explored. PMID:15544703

  10. IDENTIFICATION OF 'CRYPTOSPORIDIUM' OOCYSTS IN RIVER WATER

    EPA Science Inventory

    Water samples were collected from four rivers in Washington State and two rivers in California and examined for the presence of Cryptosporidium oocysts. Oocyst-sized particles were concentrated from 20-liter samples of water by membrane filtration, centrifugation, and differentia...

  11. RESEARCH NOTE: AUTOFLUORESCENCE OF TOXOPLASMA GONDII OOCYSTS

    EPA Science Inventory

    This is the first report of a blue autofluorescence as a useful characteristic in the microscopic identification of Toxoplasma gondii oocysts. This autofluorescence appears to be of high intensity. Similar to the autofluorescence of related coccidia, the oocysts glow pale blue ...

  12. Influence of temperature on Cryptosporidium parvum oocyst infectivity in river water samples as detected by tissue culture assay.

    PubMed

    Pokorny, Nicholas J; Weir, Susan C; Carreno, Ramon A; Trevors, Jack T; Lee, Hung

    2002-06-01

    Cryptosporidium parvum oocysts were stored in 1-ml aliquots of filtered river water at -20, 4, 10, and 21-23 C in the dark. Oocysts were also added to filter-sterilized river water samples and stored at 21-23 C. The infectivity of oocysts stored under different conditions was assayed at weekly intervals through infection of human adenocarcinoma ileocecal (HCT-8) cell monolayers. Wells containing between 10 and 100 foci of infection were enumerated by immunofluorescent microscopy, and the number of infective oocysts was calculated. No infectious oocysts were detected after 1 wk at -20 C. The number of infective oocysts stored at 4 C decreased 5-fold, and the number of those stored at 10 C decreased 2.5-fold after 14 wk. The infectivity of oocysts stored in potassium dichromate (positive control) at 4 C decreased 2-fold over 14 wk. The number of infective oocysts in filter-sterilized and non-filter-sterilized river water stored at 21-23 C decreased by 3.3 and 2.6 log units, respectively, over 12 wk, and no foci of infection were detected at 14 wk. The results show that as temperature increased from 4 to 23 C, the duration of oocyst infectivity decreased. PMID:12099446

  13. Inactivation of Cryptosporidium parvum oocysts using medium- and low-pressure ultraviolet radiation.

    PubMed

    Craik, S A; Weldon, D; Finch, G R; Bolton, J R; Belosevic, M

    2001-04-01

    The effect of ultraviolet radiation from low- and medium-pressure mercury arc lamps on Cryptosporidium parvum oocysts was studied using a collimated beam apparatus. Experiments were conducted using parasites suspended in both filtered surface water and phosphate buffered laboratory water. Inactivation of oocysts was measured as reduction in infectivity using a CD-1 neonatal mouse model and was found to be a non-linear function of UV dose over the range of germicidal doses tested (0.8-119 mJ/cm2). Oocyst inactivation increased rapidly with UV dose at doses less than 25 mJ/cm2 with two and three log-units inactivation at approximately 10 and 25 mJ/cm2, respectively. The cause of significant leveling-off and tailing in the UV inactivation curve at higher doses was not determined. Maximum measured oocyst inactivation ranged from 3.4 to greater than 4.9 log-units and was dependent on different batches of parasites. Water type and temperature, the concentration of oocysts in the suspension, and the UV irradiance did not have significant impacts on oocyst inactivation. When compared on the basis of germicidal UV dose, the oocysts were equally sensitive to low- and medium-pressure UV radiation. With respect to Cryptosporidium, both low- and medium-pressure ultraviolet radiation are attractive alternatives to conventional chemical disinfection methods in drinking water treatment. PMID:11317885

  14. SMS messages increase adherence to rapid diagnostic test results among malaria patients: results from a pilot study in Nigeria

    PubMed Central

    2014-01-01

    Background The World Health Organization now recommends parasitological confirmation for malaria case management. Rapid diagnostic tests (RDTs) for malaria are an accurate and simple diagnostic to confirm parasite presence in blood. However, where they have been deployed, adherence to RDT results has been poor, especially when the test result is negative. Few studies have examined adherence to RDTs distributed or purchased through the private sector. Methods The Rapid Examination of Malaria and Evaluation of Diagnostic Information (REMEDI) study assessed the acceptability of and adherence to RDT results for patients seeking care from private sector drug retailers in two cities in Oyo State in south-west Nigeria. In total, 465 adult participants were enrolled upon exit from a participating drug shop having purchased anti-malaria drugs for themselves. Participants were given a free RDT and the appropriate treatment advice based on their RDT result. Short Message Service (SMS) text messages reiterating the treatment advice were sent to a randomly selected half of the participants one day after being tested. Participants were contacted via phone four days after the RDT was conducted to assess adherence to the RDT information and treatment advice. Results Adherence to RDT results was 14.3 percentage points (P-val <0.001) higher in the treatment group who were sent the SMS. The higher adherence in the treatment group was robust to several specification tests and the estimated difference in adherence ranged from 9.7 to 16.1 percentage points. Further, the higher adherence to the treatment advice was specific to the treatment advice for anti-malarial drugs and not other drugs purchased to treat malaria symptoms in the RDT-negative participants who bought both anti-malarial and symptom drugs. There was no difference in adherence for the RDT-positive participants who were sent the SMS. Conclusions SMS text messages substantially increased adherence to RDT results for

  15. Erythropoietin Levels Increase during Cerebral Malaria and Correlate with Heme, Interleukin-10 and Tumor Necrosis Factor-Alpha in India

    PubMed Central

    Dalko, Esther; Tchitchek, Nicolas; Pays, Laurent; Herbert, Fabien; Cazenave, Pierre-André; Ravindran, Balachandran; Sharma, Shobhona; Nataf, Serge; Das, Bidyut; Pied, Sylviane

    2016-01-01

    Cerebral malaria (CM) caused by Plasmodium falciparum parasites often leads to the death of infected patients or to persisting neurological sequelae despite anti-parasitic treatments. Erythropoietin (EPO) was recently suggested as a potential adjunctive treatment for CM. However diverging results were obtained in patients from Sub-Saharan countries infected with P. falciparum. In this study, we measured EPO levels in the plasma of well-defined groups of P. falciparum-infected patients, from the state of Odisha in India, with mild malaria (MM), CM, or severe non-CM (NCM). EPO levels were then correlated with biological parameters, including parasite biomass, heme, tumor necrosis factor (TNF)-α, interleukin (IL)-10, interferon gamma-induced protein (IP)-10, and monocyte chemoattractant protein (MCP)-1 plasma concentrations by Spearman’s rank and multiple correlation analyses. We found a significant increase in EPO levels with malaria severity degree, and more specifically during fatal CM. In addition, EPO levels were also found correlated positively with heme, TNF-α, IL-10, IP-10 and MCP-1 during CM. We also found a significant multivariate correlation between EPO, TNF-α, IL-10, IP-10 MCP-1 and heme, suggesting an association of EPO with a network of immune factors in CM patients. The contradictory levels of circulating EPO reported in CM patients in India when compared to Africa highlights the need for the optimization of adjunctive treatments according to the targeted population. PMID:27441662

  16. Erythropoietin Levels Increase during Cerebral Malaria and Correlate with Heme, Interleukin-10 and Tumor Necrosis Factor-Alpha in India.

    PubMed

    Dalko, Esther; Tchitchek, Nicolas; Pays, Laurent; Herbert, Fabien; Cazenave, Pierre-André; Ravindran, Balachandran; Sharma, Shobhona; Nataf, Serge; Das, Bidyut; Pied, Sylviane

    2016-01-01

    Cerebral malaria (CM) caused by Plasmodium falciparum parasites often leads to the death of infected patients or to persisting neurological sequelae despite anti-parasitic treatments. Erythropoietin (EPO) was recently suggested as a potential adjunctive treatment for CM. However diverging results were obtained in patients from Sub-Saharan countries infected with P. falciparum. In this study, we measured EPO levels in the plasma of well-defined groups of P. falciparum-infected patients, from the state of Odisha in India, with mild malaria (MM), CM, or severe non-CM (NCM). EPO levels were then correlated with biological parameters, including parasite biomass, heme, tumor necrosis factor (TNF)-α, interleukin (IL)-10, interferon gamma-induced protein (IP)-10, and monocyte chemoattractant protein (MCP)-1 plasma concentrations by Spearman's rank and multiple correlation analyses. We found a significant increase in EPO levels with malaria severity degree, and more specifically during fatal CM. In addition, EPO levels were also found correlated positively with heme, TNF-α, IL-10, IP-10 and MCP-1 during CM. We also found a significant multivariate correlation between EPO, TNF-α, IL-10, IP-10 MCP-1 and heme, suggesting an association of EPO with a network of immune factors in CM patients. The contradictory levels of circulating EPO reported in CM patients in India when compared to Africa highlights the need for the optimization of adjunctive treatments according to the targeted population. PMID:27441662

  17. Long-term survival of Cryptosporidium parvum oocysts in seawater and in experimentally infected mussels (Mytilus galloprovincialis).

    PubMed

    Tamburrini, A; Pozio, E

    1999-05-01

    Transmission of infectious oocysts of Cryptosporidium parvum via surface- and drinking-water supplies has been reported and many surface waters flow into the sea, potentially causing runoff of animal-infected faeces. Eating raw mussels is a common practice in many countries, increasing the public's risk of acquiring enteric pathogens. The aims of the present study were to estimate how long C. parvum oocysts remain infectious in artificial seawater, to determine if the oocysts are retained in mussel tissues (Mytilus galloprovincialis), and how long they maintain their infectivity. Oocysts were incubated in artificial seawater at 6-8 degrees C under moderate oxygenation and the infectivity of oocysts was tested five times, over a 12 month period after incubation in seawater, in BALB/c mice. Each pup was inoculated per os with 10(5) oocysts and killed 5 days p.i. Oocysts remained infectious for 1 year. Forty mussels held in an aquarium containing artificial seawater filtered out more than 4 x 10(8) oocysts in a 24 h period. Oocysts were detected in the gill washing up to 3 days p.i., in the haemolymph up to 7 days p.i., and in the intestinal tract up to 14 days p.i. Oocysts collected from the gut of mussels 7 and 14 days p.i. were observed to have infected mice. These results suggest that C. parvum oocysts can survive in seawater for at least 1 year and can be filtered out by benthic mussels, retaining their infectivity up to 14 days, so seawater and molluscs are a potential source of C. parvum infection for humans. PMID:10404265

  18. INACTIVATION OF CRYPTOSPORIDIUM PARVUM OOCYSTS WITH OZONE

    EPA Science Inventory

    Ozone inactivation rates for Cryptosporidium parvum (C. parvum) oocysts were determined with an in-vitro excystation method based on excysted sporozoite counts. Results were consistent with published animal infectivity data for the same C. parvum strain. The inactivation kinetics...

  19. Malaria Research

    MedlinePlus

    ... Malaria > Research Malaria Understanding Research NIAID Role Basic Biology Prevention and Control Strategies Strategic Partnerships and Research ... the malaria parasite. Related Links Global Research​ Vector Biology International Centers of Excellence for Malaria Research (ICEMR) ...

  20. Land use and soil contamination with Toxoplasma gondii oocysts in urban areas.

    PubMed

    Gao, Xiang; Wang, Hongbin; Wang, Huan; Qin, Hongyu; Xiao, Jianhua

    2016-10-15

    Because soil contaminated with Toxoplasma gondii oocysts is increasingly recognized as a major source of infection for humans, in this study, we investigated the spatial pattern of soil contamination with T. gondii oocysts in urban area of northeastern Mainland China. From April 2014 to May 2015, more than 9000 soil samples were collected. Detection of T. gondii oocysts was performed applying real-time quantitative PCR. Sensitivity was improved by analyzing four replicates for each sampling point. T. gondii was detected in 30.3% of all samples. Subsequently, a maximum entropy model was used to evaluate the effect of land use and intrinsic soil properties on the risk of contamination with oocysts. Jackknife analysis revealed that the likelihood for positive results is significantly enhanced in soil originating from foci of human habitation, wood land and grass land. Furthermore, soil temperature and humidity significantly influence the probability of contamination with T. gondii oocysts. Our findings indicate that land use may affect distribution of T. gondii oocysts in urban areas. PMID:27373378

  1. Transport of Cryptosporidium oocysts in porous media: Role of straining and physicochemical filtration

    USGS Publications Warehouse

    Tufenkji, N.; Miller, G.F.; Ryan, J.N.; Harvey, R.W.; Elimelech, M.

    2004-01-01

    The transport and filtration behavior of Cryptosporidium parvum oocysts in columns packed with quartz sand was systematically examined under repulsive electrostatic conditions. An increase in solution ionic strength resulted in greater oocyst deposition rates despite theoretical predictions of a significant electrostatic energy barrier to deposition. Relatively high deposition rates obtained with both oocysts and polystyrene latex particles of comparable size at low ionic strength (1 mM) suggest that a physical mechanism may play a key role in oocyst removal. Supporting experiments conducted with latex particles of varying sizes, under very low ionic strength conditions where physicochemical filtration is negligible, clearly indicated that physical straining is an important capture mechanism. The results of this study indicate that irregularity of sand grain shape (verified by SEM imaging) contributes considerably to the straining potential of the porous medium. Hence, both straining and physicochemical filtration are expected to control the removal of C. parvum oocysts in settings typical of riverbank filtration, soil infiltration, and slow sand filtration. Because classic colloid filtration theory does not account for removal by straining, these observations have important implications with respect to predictions of oocyst transport.

  2. Comparison of two methods for detection of Giardia cysts and Cryptosporidium oocysts in water.

    PubMed

    Nieminski, E C; Schaefer, F W; Ongerth, J E

    1995-05-01

    The steps of two immunofluorescent-antibody-based detection methods were evaluated for their efficiencies in detecting Giardia cysts and Cryptosporidium oocysts. The two methods evaluated were the American Society for Testing and Materials proposed test method for Giardia cysts and Cryptosporidium oocysts in low-turbidity water and a procedure employing sampling by membrane filtration, Percoll-Percoll step gradient, and immunofluorescent staining. The membrane filter sampling method was characterized by higher recovery rates in all three types of waters tested: raw surface water, partially treated water from a flocculation basin, and filtered water. Cyst and oocyst recovery efficiencies decreased with increasing water turbidity regardless of the method used. Recoveries of seeded Giardia cysts exceeded those of Cryptosporidium oocysts in all types of water sampled. The sampling step in both methods resulted in the highest loss of seeded cysts and oocysts. Furthermore, much higher recovery efficiencies were obtained when the flotation step was avoided. The membrane filter method, using smaller tubes for flotation, was less time-consuming and cheaper. A serious disadvantage of this method was the lack of confirmation of presumptive cysts and oocysts, leaving the potential for false-positive Giardia and Cryptosporidium counts when cross-reacting algae are present in water samples. PMID:7646008

  3. Estimating malaria transmission from humans to mosquitoes in a noisy landscape.

    PubMed

    Reiner, Robert C; Guerra, Carlos; Donnelly, Martin J; Bousema, Teun; Drakeley, Chris; Smith, David L

    2015-10-01

    A basic quantitative understanding of malaria transmission requires measuring the probability a mosquito becomes infected after feeding on a human. Parasite prevalence in mosquitoes is highly age-dependent, and the unknown age-structure of fluctuating mosquito populations impedes estimation. Here, we simulate mosquito infection dynamics, where mosquito recruitment is modelled seasonally with fractional Brownian noise, and we develop methods for estimating mosquito infection rates. We find that noise introduces bias, but the magnitude of the bias depends on the 'colour' of the noise. Some of these problems can be overcome by increasing the sampling frequency, but estimates of transmission rates (and estimated reductions in transmission) are most accurate and precise if they combine parity, oocyst rates and sporozoite rates. These studies provide a basis for evaluating the adequacy of various entomological sampling procedures for measuring malaria parasite transmission from humans to mosquitoes and for evaluating the direct transmission-blocking effects of a vaccine. PMID:26400195

  4. Estimating malaria transmission from humans to mosquitoes in a noisy landscape

    PubMed Central

    Reiner, Robert C.; Guerra, Carlos; Donnelly, Martin J.; Bousema, Teun; Drakeley, Chris; Smith, David L.

    2015-01-01

    A basic quantitative understanding of malaria transmission requires measuring the probability a mosquito becomes infected after feeding on a human. Parasite prevalence in mosquitoes is highly age-dependent, and the unknown age-structure of fluctuating mosquito populations impedes estimation. Here, we simulate mosquito infection dynamics, where mosquito recruitment is modelled seasonally with fractional Brownian noise, and we develop methods for estimating mosquito infection rates. We find that noise introduces bias, but the magnitude of the bias depends on the ‘colour' of the noise. Some of these problems can be overcome by increasing the sampling frequency, but estimates of transmission rates (and estimated reductions in transmission) are most accurate and precise if they combine parity, oocyst rates and sporozoite rates. These studies provide a basis for evaluating the adequacy of various entomological sampling procedures for measuring malaria parasite transmission from humans to mosquitoes and for evaluating the direct transmission-blocking effects of a vaccine. PMID:26400195

  5. Reduced erythrocyte susceptibility and increased host clearance of young parasites slows Plasmodium growth in a murine model of severe malaria

    NASA Astrophysics Data System (ADS)

    Khoury, David S.; Cromer, Deborah; Best, Shannon E.; James, Kylie R.; Sebina, Ismail; Haque, Ashraful; Davenport, Miles P.

    2015-05-01

    The best correlate of malaria severity in human Plasmodium falciparum (Pf) infection is the total parasite load. Pf-infected humans could control parasite loads by two mechanisms, either decreasing parasite multiplication, or increasing parasite clearance. However, few studies have directly measured these two mechanisms in vivo. Here, we have directly quantified host clearance of parasites during Plasmodium infection in mice. We transferred labelled red blood cells (RBCs) from Plasmodium infected donors into uninfected and infected recipients, and tracked the fate of donor parasites by frequent blood sampling. We then applied age-based mathematical models to characterise parasite clearance in the recipient mice. Our analyses revealed an increased clearance of parasites in infected animals, particularly parasites of a younger developmental stage. However, the major decrease in parasite multiplication in infected mice was not mediated by increased clearance alone, but was accompanied by a significant reduction in the susceptibility of RBCs to parasitisation.

  6. Plasmodium P-Type Cyclin CYC3 Modulates Endomitotic Growth during Oocyst Development in Mosquitoes

    PubMed Central

    Ferguson, David J. P.; Kaindama, Mbinda L.; Brusini, Lorenzo; Joshi, Nimitray; Rchiad, Zineb; Brady, Declan; Guttery, David S.; Wheatley, Sally P.; Yamano, Hiroyuki; Holder, Anthony A.; Pain, Arnab; Wickstead, Bill; Tewari, Rita

    2015-01-01

    Cell-cycle progression and cell division in eukaryotes are governed in part by the cyclin family and their regulation of cyclin-dependent kinases (CDKs). Cyclins are very well characterised in model systems such as yeast and human cells, but surprisingly little is known about their number and role in Plasmodium, the unicellular protozoan parasite that causes malaria. Malaria parasite cell division and proliferation differs from that of many eukaryotes. During its life cycle it undergoes two types of mitosis: endomitosis in asexual stages and an extremely rapid mitotic process during male gametogenesis. Both schizogony (producing merozoites) in host liver and red blood cells, and sporogony (producing sporozoites) in the mosquito vector, are endomitotic with repeated nuclear replication, without chromosome condensation, before cell division. The role of specific cyclins during Plasmodium cell proliferation was unknown. We show here that the Plasmodium genome contains only three cyclin genes, representing an unusual repertoire of cyclin classes. Expression and reverse genetic analyses of the single Plant (P)-type cyclin, CYC3, in the rodent malaria parasite, Plasmodium berghei, revealed a cytoplasmic and nuclear location of the GFP-tagged protein throughout the lifecycle. Deletion of cyc3 resulted in defects in size, number and growth of oocysts, with abnormalities in budding and sporozoite formation. Furthermore, global transcript analysis of the cyc3-deleted and wild type parasites at gametocyte and ookinete stages identified differentially expressed genes required for signalling, invasion and oocyst development. Collectively these data suggest that cyc3 modulates oocyst endomitotic development in Plasmodium berghei. PMID:26565797

  7. Plasmodium P-Type Cyclin CYC3 Modulates Endomitotic Growth during Oocyst Development in Mosquitoes.

    PubMed

    Roques, Magali; Wall, Richard J; Douglass, Alexander P; Ramaprasad, Abhinay; Ferguson, David J P; Kaindama, Mbinda L; Brusini, Lorenzo; Joshi, Nimitray; Rchiad, Zineb; Brady, Declan; Guttery, David S; Wheatley, Sally P; Yamano, Hiroyuki; Holder, Anthony A; Pain, Arnab; Wickstead, Bill; Tewari, Rita

    2015-11-01

    Cell-cycle progression and cell division in eukaryotes are governed in part by the cyclin family and their regulation of cyclin-dependent kinases (CDKs). Cyclins are very well characterised in model systems such as yeast and human cells, but surprisingly little is known about their number and role in Plasmodium, the unicellular protozoan parasite that causes malaria. Malaria parasite cell division and proliferation differs from that of many eukaryotes. During its life cycle it undergoes two types of mitosis: endomitosis in asexual stages and an extremely rapid mitotic process during male gametogenesis. Both schizogony (producing merozoites) in host liver and red blood cells, and sporogony (producing sporozoites) in the mosquito vector, are endomitotic with repeated nuclear replication, without chromosome condensation, before cell division. The role of specific cyclins during Plasmodium cell proliferation was unknown. We show here that the Plasmodium genome contains only three cyclin genes, representing an unusual repertoire of cyclin classes. Expression and reverse genetic analyses of the single Plant (P)-type cyclin, CYC3, in the rodent malaria parasite, Plasmodium berghei, revealed a cytoplasmic and nuclear location of the GFP-tagged protein throughout the lifecycle. Deletion of cyc3 resulted in defects in size, number and growth of oocysts, with abnormalities in budding and sporozoite formation. Furthermore, global transcript analysis of the cyc3-deleted and wild type parasites at gametocyte and ookinete stages identified differentially expressed genes required for signalling, invasion and oocyst development. Collectively these data suggest that cyc3 modulates oocyst endomitotic development in Plasmodium berghei. PMID:26565797

  8. ISOLATION OF PURIFIED OOCYST WALLS AND SPOROCYSTS FROM TOXOPLASMA GONDII

    EPA Science Inventory

    Toxaplasma gondii is a parasitic protozoan that infects a wide range of vertebrates, including humans. This report describes methods that have been developed for separation of oocyst components starting with the mechanical fragmentation of oocysts. Use of iodixoanol gradients a...

  9. Use of a Sentinel System for Field Measurements of Cryptosporidium parvum Oocyst Inactivation in Soil and Animal Waste

    PubMed Central

    Jenkins, M. B.; Walker, M. J.; Bowman, D. D.; Anthony, L. C.; Ghiorse, W. C.

    1999-01-01

    A small-volume sentinel chamber was developed to assess the effects of environmental stresses on survival of sucrose-Percoll-purified Cryptosporidium parvum oocysts in soil and animal wastes. Chambers were tested for their ability to equilibrate with external chemical and moisture conditions. Sentinel oocysts were then exposed to stresses of the external environment that affected their viability (potential infectivity), as indicated by results of a dye permeability assay. Preliminary laboratory experiments indicated that temperatures between 35 and 50°C and decreases in soil water potential (−0.003 to −3.20 MPa) increased oocyst inactivation rates. The effects of two common animal waste management practices on oocyst survival were investigated on three dairy farms in Delaware County, N.Y., within the New York City watershed: (i) piling wastes from dairy youngstock (including neonatal calves) and (ii) spreading wastes as a soil amendment on an agricultural field. Sentinel containers filled with air-dried and sieved (2-mm mesh) youngstock waste or field soil were wetted and inoculated with 2 million oocysts in an aqueous suspension and then placed in waste piles on two different farms and in soil within a cropped field on one farm. Controls consisted of purified oocysts in either phosphate-buffered saline or distilled water contained in sealed microcentrifuge tubes. Two microdata loggers recorded the ambient temperature at each field site. Sentinel experiments were conducted during the fall and winter (1996 to 1997) and winter (1998). Sentinel containers and controls were removed at 2- to 4-week intervals, and oocysts were extracted and tested by the dye permeability assay. The proportions of potentially infective oocysts exposed to the soil and waste pile material decreased more rapidly than their counterpart controls exposed to buffer or water, indicating that factors other than temperature affected oocyst inactivation in the waste piles and soil. The effect

  10. Rapid Response to Selection, Competitive Release and Increased Transmission Potential of Artesunate-Selected Plasmodium chabaudi Malaria Parasites

    PubMed Central

    Pollitt, Laura C.; Huijben, Silvie; Sim, Derek G.; Salathé, Rahel M.; Jones, Matthew J.; Read, Andrew F.

    2014-01-01

    The evolution of drug resistance, a key challenge for our ability to treat and control infections, depends on two processes: de-novo resistance mutations, and the selection for and spread of resistant mutants within a population. Understanding the factors influencing the rates of these two processes is essential for maximizing the useful lifespan of drugs and, therefore, effective disease control. For malaria parasites, artemisinin-based drugs are the frontline weapons in the fight against disease, but reports from the field of slower parasite clearance rates during drug treatment are generating concern that the useful lifespan of these drugs may be limited. Whether slower clearance rates represent true resistance, and how this provides a selective advantage for parasites is uncertain. Here, we show that Plasmodium chabaudi malaria parasites selected for resistance to artesunate (an artemisinin derivative) through a step-wise increase in drug dose evolved slower clearance rates extremely rapidly. In single infections, these slower clearance rates, similar to those seen in the field, provided fitness advantages to the parasite through increased overall density, recrudescence after treatment and increased transmission potential. In mixed infections, removal of susceptible parasites by drug treatment led to substantial increases in the densities and transmission potential of resistant parasites (competitive release). Our results demonstrate the double-edged sword for resistance management: in our initial selection experiments, no parasites survived aggressive chemotherapy, but after selection, the fitness advantage for resistant parasites was greatest at high drug doses. Aggressive treatment of mixed infections resulted in resistant parasites dominating the pool of gametocytes, without providing additional health benefits to hosts. Slower clearance rates can evolve rapidly and can provide a strong fitness advantage during drug treatment in both single and mixed strain

  11. Rapid response to selection, competitive release and increased transmission potential of artesunate-selected Plasmodium chabaudi malaria parasites.

    PubMed

    Pollitt, Laura C; Huijben, Silvie; Sim, Derek G; Salathé, Rahel M; Jones, Matthew J; Read, Andrew F

    2014-04-01

    The evolution of drug resistance, a key challenge for our ability to treat and control infections, depends on two processes: de-novo resistance mutations, and the selection for and spread of resistant mutants within a population. Understanding the factors influencing the rates of these two processes is essential for maximizing the useful lifespan of drugs and, therefore, effective disease control. For malaria parasites, artemisinin-based drugs are the frontline weapons in the fight against disease, but reports from the field of slower parasite clearance rates during drug treatment are generating concern that the useful lifespan of these drugs may be limited. Whether slower clearance rates represent true resistance, and how this provides a selective advantage for parasites is uncertain. Here, we show that Plasmodium chabaudi malaria parasites selected for resistance to artesunate (an artemisinin derivative) through a step-wise increase in drug dose evolved slower clearance rates extremely rapidly. In single infections, these slower clearance rates, similar to those seen in the field, provided fitness advantages to the parasite through increased overall density, recrudescence after treatment and increased transmission potential. In mixed infections, removal of susceptible parasites by drug treatment led to substantial increases in the densities and transmission potential of resistant parasites (competitive release). Our results demonstrate the double-edged sword for resistance management: in our initial selection experiments, no parasites survived aggressive chemotherapy, but after selection, the fitness advantage for resistant parasites was greatest at high drug doses. Aggressive treatment of mixed infections resulted in resistant parasites dominating the pool of gametocytes, without providing additional health benefits to hosts. Slower clearance rates can evolve rapidly and can provide a strong fitness advantage during drug treatment in both single and mixed strain

  12. Purification of Toxoplasma gondii oocysts by cesium chloride gradient.

    PubMed

    Dumètre, Aurélien; Dardé, Marie-Laure

    2004-03-01

    We describe the use of a cesium chloride (CsCl) gradient as an improvement for the purification of Toxoplasma gondii oocysts from concentrated suspensions. After concentration by sucrose flotation, this technique gives a > 96% recovery of very pure unsporulated or sporulated oocysts, but requires "fresh" oocysts (< or = 10 weeks of age). This material is suitable for biochemical and immunological analyses of environmentally resistant T. gondii oocysts. PMID:14967234

  13. Epidemiology of malaria and predictions of retransmission in Babylon Governorate, Iraq.

    PubMed

    Al-Ghoury, A A; El-Hashimi, W K; Abul-Hab, J

    2006-01-01

    After the 1997-98 malaria epidemic in Babylon governorate, Iraq, malaria transmission in this area was successfully interrupted. A parasitological survey in 2002 identified no malaria cases but an entomological survey found both Anopheles stephensi and A. pulcherrimus in high densities. The highest density was recorded in September and the lowest in December and January. Despite the high density of Anopheles, no parasite sporozoites or oocysts were found in dissected mosquitoes. Nevertheless, malaria transmission could recur if A. stephensi indoor resting density exceeds the critical threshold and imported malaria cases are not monitored. PMID:17037694

  14. Mechanics of the Toxoplasma gondii oocyst wall

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ability of microorganisms to survive under extreme conditions is closely related to the physicochemical properties of their wall. In the ubiquitous protozoan parasite Toxoplasma gondii, the oocyst stage possesses a bilayered wall that protects the dormant but potentially infective parasites from...

  15. Regulation of Plasmodium yoelii Oocyst Development by Strain- and Stage-Specific Small-Subunit rRNA

    PubMed Central

    Qi, Yanwei; Zhu, Feng; Eastman, Richard T.; Fu, Young; Zilversmit, Martine; Pattaradilokrat, Sittiporn; Hong, Lingxian; Liu, Shengfa; McCutchan, Thomas F.; Pan, Weiqing; Xu, Wenyue

    2015-01-01

    ABSTRACT One unique feature of malaria parasites is the differential transcription of structurally distinct rRNA (rRNA) genes at different developmental stages: the A-type genes are transcribed mainly in asexual stages, whereas the S-type genes are expressed mostly in sexual or mosquito stages. Conclusive functional evidence of different rRNAs in regulating stage-specific parasite development, however, is still absent. Here we performed genetic crosses of Plasmodium yoelii parasites with one parent having an oocyst development defect (ODD) phenotype and another producing normal oocysts to identify the gene(s) contributing to the ODD. The parent with ODD—characterized as having small oocysts and lacking infective sporozoites—was obtained after introduction of a plasmid with a green fluorescent protein gene into the parasite genome and subsequent passages in mice. Quantitative trait locus analysis of genome-wide microsatellite genotypes of 48 progeny from the crosses linked an ~200-kb segment on chromosome 6 containing one of the S-type genes (D-type small subunit rRNA gene [D-ssu]) to the ODD. Fine mapping of the plasmid integration site, gene expression pattern, and gene knockout experiments demonstrated that disruption of the D-ssu gene caused the ODD phenotype. Interestingly, introduction of the D-ssu gene into the same parasite strain (self), but not into a different subspecies, significantly affected or completely ablated oocyst development, suggesting a stage- and subspecies (strain)-specific regulation of oocyst development by D-ssu. This study demonstrates that P. yoelii D-ssu is essential for normal oocyst and sporozoite development and that variation in the D-ssu sequence can have dramatic effects on parasite development. PMID:25759501

  16. Malaria Diagnosis: A Brief Review

    PubMed Central

    Duangdee, Chatnapa; Wilairatana, Polrat; Krudsood, Srivicha

    2009-01-01

    Malaria is a major cause of death in tropical and sub-tropical countries, killing each year over 1 million people globally; 90% of fatalities occur in African children. Although effective ways to manage malaria now exist, the number of malaria cases is still increasing, due to several factors. In this emergency situation, prompt and effective diagnostic methods are essential for the management and control of malaria. Traditional methods for diagnosing malaria remain problematic; therefore, new technologies have been developed and introduced to overcome the limitations. This review details the currently available diagnostic methods for malaria. PMID:19488414

  17. Improved Risk Analysis by Dual Direct Detection of Total and Infectious Cryptosporidium Oocysts on Cell Culture in Combination with Immunofluorescence Assay▿

    PubMed Central

    Lalancette, Cindy; Di Giovanni, George D.; Prévost, Michèle

    2010-01-01

    The inactivation of Cryptosporidium oocysts is a main driver in the selection of water treatment disinfection strategies, and microbial risk analysis provides a sound basis for optimizing water treatment processes. U.S. Environmental Protection Agency method 1622/23 provides an estimate of the total oocyst count; however, it cannot be used directly for risk assessment, as it does not determine the fraction of infectious oocysts. Improved assessment of the risk for designated sources or in treated water requires evaluation of the total number of oocysts and an estimate of their infectivity. We developed a dual direct detection method using differential immunofluorescent staining that allows detection of both oocysts and cell culture infection foci for each sample. Using Cryptosporidium parvum oocysts, various pH levels, proteases, and gastroenteric compounds and substrates were assessed to determine their abilities to enhance the number of infection foci. The results showed that the key trigger for oocyst stimulation was acidification. Addition of a low concentration of d-glucose (50 mM) to the infection media increased rates of infectivity, while a higher dose (300 mM) was inhibitory. The total number of oocysts in each sample was determined by counting the oocysts remaining on a cell monolayer and the oocysts recovered from cell monolayer washes during processing using a simple filtration technique. With the dual direct detection on cell culture with immunofluorescence assay method, it is now possible to determine the numbers of total and infectious oocysts for a given sample in a single analysis. Direct percentages of infectivity are then calculated, which allows more accurate assessments of risk. PMID:19933339

  18. Variation in susceptibility of African Plasmodium falciparum malaria parasites to TEP1 mediated killing in Anopheles gambiae mosquitoes.

    PubMed

    Eldering, Maarten; Morlais, Isabelle; van Gemert, Geert-Jan; van de Vegte-Bolmer, Marga; Graumans, Wouter; Siebelink-Stoter, Rianne; Vos, Martijn; Abate, Luc; Roeffen, Will; Bousema, Teun; Levashina, Elena A; Sauerwein, Robert W

    2016-01-01

    Anopheles gambiae s.s. mosquitoes are efficient vectors for Plasmodium falciparum, although variation exists in their susceptibility to infection. This variation depends partly on the thioester-containing protein 1 (TEP1) and TEP depletion results in significantly elevated numbers of oocysts in susceptible and resistant mosquitoes. Polymorphism in the Plasmodium gene coding for the surface protein Pfs47 modulates resistance of some parasite laboratory strains to TEP1-mediated killing. Here, we examined resistance of P. falciparum isolates of African origin (NF54, NF165 and NF166) to TEP1-mediated killing in a susceptible Ngousso and a refractory L3-5 strain of A. gambiae. All parasite clones successfully developed in susceptible mosquitoes with limited evidence for an impact of TEP1 on transmission efficiency. In contrast, NF166 and NF165 oocyst densities were strongly reduced in refractory mosquitoes and TEP1 silencing significantly increased oocyst densities. Our results reveal differences between African P. falciparum strains in their capacity to evade TEP1-mediated killing in resistant mosquitoes. There was no significant correlation between Pfs47 genotype and resistance of a given P. falciparum isolate for TEP1 killing. These data suggest that polymorphisms in this locus are not the sole mediators of immune evasion of African malaria parasites. PMID:26861587

  19. Variation in susceptibility of African Plasmodium falciparum malaria parasites to TEP1 mediated killing in Anopheles gambiae mosquitoes

    PubMed Central

    Eldering, Maarten; Morlais, Isabelle; van Gemert, Geert-Jan; van de Vegte-Bolmer, Marga; Graumans, Wouter; Siebelink-Stoter, Rianne; Vos, Martijn; Abate, Luc; Roeffen, Will; Bousema, Teun; Levashina, Elena A.; Sauerwein, Robert W.

    2016-01-01

    Anopheles gambiae s.s. mosquitoes are efficient vectors for Plasmodium falciparum, although variation exists in their susceptibility to infection. This variation depends partly on the thioester-containing protein 1 (TEP1) and TEP depletion results in significantly elevated numbers of oocysts in susceptible and resistant mosquitoes. Polymorphism in the Plasmodium gene coding for the surface protein Pfs47 modulates resistance of some parasite laboratory strains to TEP1-mediated killing. Here, we examined resistance of P. falciparum isolates of African origin (NF54, NF165 and NF166) to TEP1-mediated killing in a susceptible Ngousso and a refractory L3–5 strain of A. gambiae. All parasite clones successfully developed in susceptible mosquitoes with limited evidence for an impact of TEP1 on transmission efficiency. In contrast, NF166 and NF165 oocyst densities were strongly reduced in refractory mosquitoes and TEP1 silencing significantly increased oocyst densities. Our results reveal differences between African P. falciparum strains in their capacity to evade TEP1-mediated killing in resistant mosquitoes. There was no significant correlation between Pfs47 genotype and resistance of a given P. falciparum isolate for TEP1 killing. These data suggest that polymorphisms in this locus are not the sole mediators of immune evasion of African malaria parasites. PMID:26861587

  20. The endothelial protein C receptor rs867186-GG genotype is associated with increased soluble EPCR and could mediate protection against severe malaria.

    PubMed

    Shabani, Estela; Opoka, Robert O; Bangirana, Paul; Park, Gregory S; Vercellotti, Gregory M; Guan, Weihua; Hodges, James S; Lavstsen, Thomas; John, Chandy C

    2016-01-01

    The endothelial protein C receptor (EPCR) appears to play an important role in Plasmodium falciparum endothelial cell binding in severe malaria (SM). Despite consistent findings of elevated soluble EPCR (sEPCR) in other infectious diseases, field studies to date have provided conflicting data about the role of EPCR in SM. To better define this role, we performed genotyping for the rs867186-G variant, associated with increased sEPCR levels, and measured sEPCR levels in two prospective studies of Ugandan children designed to understand immunologic and genetic factors associated with neurocognitive deficits in SM including 551 SM children, 71 uncomplicated malaria (UM) and 172 healthy community children (CC). The rs867186-GG genotype was more frequent in CC (4.1%) than SM (0.6%, P = 0.002). The rs867186-G variant was associated with increased sEPCR levels and sEPCR was lower in children with SM than CC (P < 0.001). Among SM children, those who had a second SM episode showed a trend toward lower plasma sEPCR both at initial admission and at 6-month follow-up compared to those without repeated SM (P = 0.06 for both). The study findings support a role for sEPCR in severe malaria pathogenesis and emphasize a distinct role of sEPCR in malaria as compared to other infectious diseases. PMID:27255786

  1. The endothelial protein C receptor rs867186-GG genotype is associated with increased soluble EPCR and could mediate protection against severe malaria

    PubMed Central

    Shabani, Estela; Opoka, Robert O.; Bangirana, Paul; Park, Gregory S.; Vercellotti, Gregory M.; Guan, Weihua; Hodges, James S.; Lavstsen, Thomas; John, Chandy C.

    2016-01-01

    The endothelial protein C receptor (EPCR) appears to play an important role in Plasmodium falciparum endothelial cell binding in severe malaria (SM). Despite consistent findings of elevated soluble EPCR (sEPCR) in other infectious diseases, field studies to date have provided conflicting data about the role of EPCR in SM. To better define this role, we performed genotyping for the rs867186-G variant, associated with increased sEPCR levels, and measured sEPCR levels in two prospective studies of Ugandan children designed to understand immunologic and genetic factors associated with neurocognitive deficits in SM including 551 SM children, 71 uncomplicated malaria (UM) and 172 healthy community children (CC). The rs867186-GG genotype was more frequent in CC (4.1%) than SM (0.6%, P = 0.002). The rs867186-G variant was associated with increased sEPCR levels and sEPCR was lower in children with SM than CC (P < 0.001). Among SM children, those who had a second SM episode showed a trend toward lower plasma sEPCR both at initial admission and at 6-month follow-up compared to those without repeated SM (P = 0.06 for both). The study findings support a role for sEPCR in severe malaria pathogenesis and emphasize a distinct role of sEPCR in malaria as compared to other infectious diseases. PMID:27255786

  2. High Prevalence of Malaria in Zambezia, Mozambique: The Protective Effect of IRS versus Increased Risks Due to Pig-Keeping and House Construction

    PubMed Central

    Temu, Emmanuel A.; Coleman, Mike; Abilio, Ana Paula; Kleinschmidt, Immo

    2012-01-01

    Background African countries are scaling up malaria interventions, especially insecticide treated nets (ITN) and indoor residual spraying (IRS), for which ambitious coverage targets have been set. In spite of these efforts infection prevalence remains high in many parts of the continent. This study investigated risk factors for malaria infection in children using three malaria indicator surveys from Zambezia province, Mozambique. The impact of IRS and ITNs, the effects of keeping farm animals and of the construction material of roofs of houses and other potential risk factors associated with malaria infection in children were assessed. Methods Cross-sectional community-based surveys were conducted in October of 2006, 2007 and 2008. A total of 8338 children (ages 1–15 years) from 2748 households were included in the study. All children were screened for malaria by rapid diagnostic tests. Caregiver interviews were used to assess household demographic and wealth characteristics and ITN and IRS coverage. Associations between malaria infection, vector control interventions and potential risk factors were assessed. Results Overall, the prevalence of malaria infection was 47.8% (95%CI: 38.7%–57.1%) in children 1–15 years of age, less than a quarter of children (23.1%, 95%CI: 19.1%–27.6%) were sleeping under ITN and almost two thirds were living in IRS treated houses (coverage 65.4%, 95%CI: 51.5%–77.0%). Protective factors that were independently associated with malaria infection were: sleeping in an IRS house without sleeping under ITN (Odds Ratio (OR)  = 0.6; 95%CI: 0.4–0.9); additional protection due to sleeping under ITN in an IRS treated house (OR = 0.5; 95%CI: 0.3–0.7) versus sleeping in an unsprayed house without a ITN; and parental education (primary/secondary: OR = 0.6; 95%CI: 0.5–0.7) versus parents with no education. Increased risk of infection was associated with: current fever (OR = 1.2; 95%CI: 1.0–1.5) versus no fever; pig

  3. Absorption and deposition of xanthophylls in broilers challenged with three dosages of Eimeria acervulina oocysts.

    PubMed

    Hernández-Velasco, X; Chapman, H D; Owens, C M; Kuttappan, V A; Fuente-Martínez, B; Menconi, A; Latorre, J D; Kallapura, G; Bielke, L R; Rathinam, T; Hargis, B M; Tellez, G

    2014-01-01

    1. An experiment was designed to evaluate the effect of different doses of oocysts of Eimeria acervulina on intestinal absorption and skin deposition of xanthophylls (XAs) in broilers. 2. A total of 192 broiler chickens were randomly assigned to 4 groups: an uninfected control group and three groups inoculated with either 1 × 10(2), 1 × 10(4) or 1 × 10(5) sporulated oocysts of E. acervulina by gavaging at 21 d. There were 4 replicate pens (2 male and 2 female) per group. 3. Plasma xanthophyll (PX) and skin yellowness (SY) were measured in live birds weekly. At 42 d of age, SY was measured in the breast and abdomen after chilling and in the breast 24 h post-processing on refrigerated carcasses. 4. In general, in all challenged treatments, and for the duration of the study, the average PX decreased by 0.02 μg/ml (R(2) = 61.6%) for every 1000 inoculated oocysts, whereas PX increased by 1.26 μg/ml/d in uninfected birds. 5. The average SY in live birds from 21 to 42 d of age decreased by 0.019 b*/every 1000 oocysts administered, while SY of uninfected controls increased by 0.57 b*/d. It was also noted that in all treatments females had a greater SY (6.17 b*) than males for the duration of the study. The SY of the breast and abdomen was correlated (r = 0.76) in chilled carcasses. Breast SY in 24 h refrigerated carcasses was greater in the control group and for female birds. 6. Oocyst excretion was different between inoculated treatments only on 7 d post-inoculation (PI). Coccidia lesion scores in the duodenum averaged 1+ in infected birds and 2+ in birds given the highest oocyst dose. PMID:24720798

  4. Transport of Cryptosporidium parvum Oocysts in a Silicon Micromodel

    SciTech Connect

    Liu, Yuanyuan; Zhang, Changyong; Hilpert, Markus; Kuhlenschmidt, Mark S.; Kuhlenschmidt, Theresa B.; Nguyen, Thanh H.

    2012-02-01

    Effective removal of Cryptosporidium parvum oocysts by granular filtration requires the knowledge of oocyst transport and deposition mechanisms, which can be obtained based on real time microscopic observation of oocyst transport in porous media. Attachment of oocysts to silica surface in a radial stagnation point flow (RSPF) cell and in a micromodel, which has 2-dimensional (2-D) microscopic pore structures consisting of an array of cylindrical collectors, was studied and compared. Real time transport of oocysts in the micromodel was recorded to determine the attached oocyst distributions in transversal and longitudinal directions. In the micromodel, oocysts attached to the forward portion of clean collectors, where the flow velocity was lowest. After initial attachment, oocysts attached onto already attached oocysts. As a result, the collectors ripened and the region available for flow was reduced. Results of attachment and detachment experiments suggest that surface charge heterogeneity allowed for oocyst attachment. In addition to experiments, Lattice-Boltzmann simulations helped understanding the slightly non-uniform flow field and explained differences in the removal efficiency in the transversal direction. However, the hydrodynamic modeling could not explain differences in attachment in the longitudinal direction.

  5. Surface properties of Toxoplasma gondii oocysts and surrogate microspheres.

    PubMed

    Shapiro, Karen; Largier, John; Mazet, Jonna A K; Bernt, William; Ell, John R; Melli, Ann C; Conrad, Patricia A

    2009-02-01

    The physical properties that govern the waterborne transmission of Toxoplasma gondii oocysts from land to sea were evaluated and compared to the properties of carboxylated microspheres, which could serve as surrogates for T. gondii oocysts in transport and water treatment studies. The electrophoretic mobilities of T. gondii oocysts, lightly carboxylated Dragon Green microspheres, and heavily carboxylated Glacial Blue microspheres were determined in ultrapure water, artificial freshwater with and without dissolved organic carbon, artificial estuarine water, and artificial seawater. The surface wettabilities of oocysts and microspheres were determined using a water contact angle approach. Toxoplasma gondii oocysts and microspheres were negatively charged in freshwater solutions, but their charges were neutralized in estuarine water and seawater. Oocysts, Glacial Blue microspheres, and unwashed Dragon Green microspheres had low contact angles, indicating that they were hydrophilic; however, once washed, Dragon Green microspheres became markedly hydrophobic. The hydrophilic nature and negative charge of T. gondii oocysts in freshwater could facilitate widespread contamination of waterways. The loss of charge observed in saline waters may lead to flocculation and subsequent accumulation of T. gondii oocysts in locations where freshwater and marine water mix, indicating a high risk of exposure for humans and wildlife in estuarine habitats with this zoonotic pathogen. While microspheres did not have surface properties identical to those of T. gondii, similar properties shared between each microsphere type and oocysts suggest that their joint application in transport and fate studies could provide a range of transport potentials in which oocysts are likely to behave. PMID:19060174

  6. Increased Oxidative Stress and Inflammation Independent of Body Adiposity in Diabetic and Nondiabetic Controls in falciparum Malaria

    PubMed Central

    Acquah, Samuel; Boampong, Johnson Nyarko; Eghan Jnr, Benjamin Ackon

    2016-01-01

    Information on the extent to which oxidative stress and inflammation occur in the presence of falciparum malaria and type 2 diabetes mellitus in the same individual is limited. This study sought to investigate the extent of inflammation and oxidative stress in adult uncomplicated malaria by measuring fasting levels of lipid peroxides, C-reactive protein (CRP), and total antioxidant power (TAP) before and during falciparum malaria, in 100 respondents with type 2 diabetes and 100 age-matched controls in the Cape Coast metropolis of Ghana. Also, body adiposity index, body mass index, and waist-to-hip ratio were computed. Before and during falciparum malaria, diabetes patients exhibited higher (P < 0.05) levels of CRP and peroxides than controls but TAP and BAI were comparable (P > 0.05) between the two groups. Baseline CRP correlated positively (r = 0.341, P = 0.002) with peroxide only in the diabetic group. During malaria, TAP level in both study groups declined (P < 0.05) by 80% of their baseline levels. CRP correlated negatively (r = −0.352, P = 0.011) with TAP in the control but not the diabetic group. Uncomplicated falciparum malaria elevated inflammation and peroxidation but decreased antioxidant power independent of adiposity. This finding may have implication on cardiovascular health. PMID:27298824

  7. Functional Characterization of Anopheles Matrix Metalloprotease 1 Reveals Its Agonistic Role during Sporogonic Development of Malaria Parasites

    PubMed Central

    Sidén-Kiamos, I.; Loukeris, Thanasis G.

    2014-01-01

    The ability to invade tissues is a unique characteristic of the malaria stages that develop/differentiate within the mosquitoes (ookinetes and sporozoites). On the other hand, tissue invasion by many pathogens has often been associated with increased matrix metalloprotease (MMP) activity in the invaded tissues. By employing cell biology and reverse genetics, we studied the expression and explored putative functions of one of the three MMPs encoded in the genome of the malaria vector Anopheles gambiae, namely, the Anopheles gambiae MMP1 (AgMMP1) gene, during the processes of blood digestion, midgut epithelium invasion by Plasmodium ookinetes, and oocyst development. We show that AgMMP1 exists in two alternative isoforms resulting from alternative splicing; one secreted (S-MMP1) and associated with hemocytes, and one membrane type (MT-MMP1) enriched in the cell attachment sites of the midgut epithelium. MT-MMP1 showed a remarkable response to ookinete midgut invasion manifested by increased expression, enhanced zymogen maturation, and subcellular redistribution, all indicative of an implication in the midgut epithelial healing that accompanies ookinete invasion. Importantly, RNA interference (RNAi)-mediated silencing of the AgMMP1 gene revealed a postinvasion protective function of AgMMP1 during oocyst development. The combined results link for the first time an MMP with vector competence and mosquito-Plasmodium interactions. PMID:25183733

  8. Dispersion and Transport of Cryptosporidium Oocysts from Fecal Pats under Simulated Rainfall Events

    PubMed Central

    Davies, Cheryl M.; Ferguson, Christobel M.; Kaucner, Christine; Krogh, Martin; Altavilla, Nanda; Deere, Daniel A.; Ashbolt, Nicholas J.

    2004-01-01

    The dispersion and initial transport of Cryptosporidium oocysts from fecal pats were investigated during artificial rainfall events on intact soil blocks (1,500 by 900 by 300 mm). Rainfall events of 55 mm h−1 for 30 min and 25 mm h−1 for 180 min were applied to soil plots with artificial fecal pats seeded with approximately 107 oocysts. The soil plots were divided in two, with one side devoid of vegetation and the other left with natural vegetation cover. Each combination of event intensity and duration, vegetation status, and degree of slope (5° and 10°) was evaluated twice. Generally, a fivefold increase (P < 0.05) in runoff volume was generated on bare soil compared to vegetated soil, and significantly more infiltration, although highly variable, occurred through the vegetated soil blocks (P < 0.05). Runoff volume, event conditions (intensity and duration), vegetation status, degree of slope, and their interactions significantly affected the load of oocysts in the runoff. Surface runoff transported from 100.2 oocysts from vegetated loam soil (25-mm h−1, 180-min event on 10° slope) to up to 104.5 oocysts from unvegetated soil (55-mm h−1, 30-min event on 10° slope) over a 1-m distance. Surface soil samples downhill of the fecal pat contained significantly higher concentrations of oocysts on devegetated blocks than on vegetated blocks. Based on these results, there is a need to account for surface soil vegetation coverage as well as slope and rainfall runoff in future assessments of Cryptosporidium transport and when managing pathogen loads from stock grazing near streams within drinking water watersheds. PMID:14766600

  9. The CD14+CD16+ Inflammatory Monocyte Subset Displays Increased Mitochondrial Activity and Effector Function During Acute Plasmodium vivax Malaria

    PubMed Central

    Antonelli, Lis R. V.; Leoratti, Fabiana M. S.; Costa, Pedro A. C.; Rocha, Bruno C.; Diniz, Suelen Q.; Tada, Mauro S.; Pereira, Dhelio B.; Teixeira-Carvalho, Andrea; Golenbock, Douglas T.; Gonçalves, Ricardo; Gazzinelli, Ricardo T.

    2014-01-01

    Infection with Plasmodium vivax results in strong activation of monocytes, which are important components of both the systemic inflammatory response and parasite control. The overall goal of this study was to define the role of monocytes during P. vivax malaria. Here, we demonstrate that P. vivax–infected patients display significant increase in circulating monocytes, which were defined as CD14+CD16− (classical), CD14+CD16+ (inflammatory), and CD14loCD16+ (patrolling) cells. While the classical and inflammatory monocytes were found to be the primary source of pro-inflammatory cytokines, the CD16+ cells, in particular the CD14+CD16+ monocytes, expressed the highest levels of activation markers, which included chemokine receptors and adhesion molecules. Morphologically, CD14+ were distinguished from CD14lo monocytes by displaying larger and more active mitochondria. CD14+CD16+ monocytes were more efficient in phagocytizing P. vivax-infected reticulocytes, which induced them to produce high levels of intracellular TNF-α and reactive oxygen species. Importantly, antibodies specific for ICAM-1, PECAM-1 or LFA-1 efficiently blocked the phagocytosis of infected reticulocytes by monocytes. Hence, our results provide key information on the mechanism by which CD14+CD16+ cells control parasite burden, supporting the hypothesis that they play a role in resistance to P. vivax infection. PMID:25233271

  10. The CD14+CD16+ inflammatory monocyte subset displays increased mitochondrial activity and effector function during acute Plasmodium vivax malaria.

    PubMed

    Antonelli, Lis R V; Leoratti, Fabiana M S; Costa, Pedro A C; Rocha, Bruno C; Diniz, Suelen Q; Tada, Mauro S; Pereira, Dhelio B; Teixeira-Carvalho, Andrea; Golenbock, Douglas T; Gonçalves, Ricardo; Gazzinelli, Ricardo T

    2014-09-01

    Infection with Plasmodium vivax results in strong activation of monocytes, which are important components of both the systemic inflammatory response and parasite control. The overall goal of this study was to define the role of monocytes during P. vivax malaria. Here, we demonstrate that P. vivax-infected patients display significant increase in circulating monocytes, which were defined as CD14(+)CD16- (classical), CD14(+)CD16(+) (inflammatory), and CD14loCD16(+) (patrolling) cells. While the classical and inflammatory monocytes were found to be the primary source of pro-inflammatory cytokines, the CD16(+) cells, in particular the CD14(+)CD16(+) monocytes, expressed the highest levels of activation markers, which included chemokine receptors and adhesion molecules. Morphologically, CD14(+) were distinguished from CD14lo monocytes by displaying larger and more active mitochondria. CD14(+)CD16(+) monocytes were more efficient in phagocytizing P. vivax-infected reticulocytes, which induced them to produce high levels of intracellular TNF-α and reactive oxygen species. Importantly, antibodies specific for ICAM-1, PECAM-1 or LFA-1 efficiently blocked the phagocytosis of infected reticulocytes by monocytes. Hence, our results provide key information on the mechanism by which CD14(+)CD16(+) cells control parasite burden, supporting the hypothesis that they play a role in resistance to P. vivax infection. PMID:25233271

  11. Development of a sensitive method to extract and detect low numbers of Cryptosporidium oocysts from adult cattle faecal samples.

    PubMed

    Wells, B; Thomson, S; Ensor, H; Innes, E A; Katzer, F

    2016-08-30

    Cryptosporidium transmission studies to date have concluded that adult cattle are not a significant source of oocysts contributing to clinical cryptosporidiosis in calves on farm. However current methods of sample processing have been optimised for calf faecal samples and may be less sensitive when used on adult samples due to lower numbers of oocysts and larger size of samples. A modified and novel method of oocyst extraction and concentration was developed and applied in an experiment involving spiking adult cattle faecal samples with known concentrations of Cryptosporidium oocysts. The results showed an increased sensitivity of detection from 100oocysts/g of faecal sample using conventional protocols to 5oocysts/g using the newly developed method. As it is important to be able to accurately assess the contribution of adult ruminants to the transmission of Cryptosporidium, both on farm and in the environment, the development of the techniques described here is likely to make an important contribution to Cryptosporidium transmission studies in future and in subsequent control strategies aimed at the reduction of Cryptosporidium infection in calves on farm. PMID:27523933

  12. Sporulation and survival of Toxoplasma gondii oocysts in seawater

    USGS Publications Warehouse

    Lindsay, D.S.; Collins, M.V.; Mitchell, S.M.; Cole, R.A.; Flick, G.J.; Wetch, C.N.; Lindquist, A.; Dubey, J.P.

    2003-01-01

    We have been collaborating since 1992 in studies on southern sea otters (Enhdyra lutris nereis) as part of a program to define factors, which may be responsible for limiting the growth of the southern sea otter population. We previously demonstrated Toxoplasma gondii in sea otters. We postulated that cat feces containing oocysts could be entering the marine environment through storm run-off or through municipal sewage since cat feces are often disposed down toilets by cat owners. The present study examined the sporulation of T. gondii oocysts in seawater and the survival of sporulated oocysts in seawater. Unsporulated oocysts were placed in 15 ppt artificial seawater, 32 ppt artificial seawater or 2% sulfuric acid (positive control) at 24 C in an incubator. Samples were examined daily for 3 days and development monitored by counting 100 oocysts from each sample. From 75 to 80% of the oocysts were sporulated by 3 days post-inoculation under all treatment conditions. Groups of 2 mice were fed 10,000 oocysts each from each of the 3 treatment groups. All inoculated mice developed toxoplasmosis indicating that oocysts were capable of sporulating in seawater. Survival of sporulated oocysts was examined by placing sporulated T. gondii oocysts in 15 ppt seawater at room temperature 22a??24 C (RT) or in a refrigerator kept at 4 C. Mice fed oocysts that had been stored at 4C or RT for 6 months became infected. These results indicate that T. gondii oocysts can sporulate and remain viable in seawater for several months.

  13. Can Rapid Diagnostic Testing for Malaria Increase Adherence to Artemether-Lumefantrine?: A Randomized Controlled Trial in Uganda.

    PubMed

    Saran, Indrani; Yavuz, Elif; Kasozi, Howard; Cohen, Jessica

    2016-04-01

    Most patients with suspected malaria do not receive diagnostic confirmation before beginning antimalarial treatment. We investigated the extent to which uncertainty about malaria diagnosis contributes to patient nonadherence to artemether-lumefantrine (AL) treatment through a randomized controlled trial in central Uganda. Among 1,525 patients purchasing a course of AL at private drug shops, we randomly offered 37.6% a free malaria rapid diagnostic test (RDT) and then assessed adherence through home visits 3 days later. Of these subjects, 68.4% tested positive for malaria and 65.8% adhered overall. Patients who tested positive did not have significantly higher odds of adherence than those who were not offered the test (adjusted odds ratio [OR]: 1.07, 95% confidence interval [CI]: 0.734-1.57,P= 0.719). Patients who received a positive malaria test had 0.488 fewer pills remaining than those not offered the test (95% CI: -1.02 to 0.043,P= 0.072). We found that patients who felt relatively healthy by the second day of treatment had lower odds of completing treatment (adjusted OR: 0.532, 95% CI: 0.394-0.719,P< 0.001). Our results suggest that diagnostic testing may not improve artemisinin-based combination therapy adherence unless efforts are made to persuade patients to continue taking the full course of drugs even if symptoms have resolved. PMID:26928828

  14. Vivax malaria

    PubMed Central

    Price, Ric N; Tjitra, Emiliana; Guerra, Carlos A; Yeung, Shunmay; White, Nicholas J; Anstey, Nicholas M

    2009-01-01

    Plasmodium vivax threatens almost 40% of the world’s population, resulting in 132 - 391 million clinical infections each year. Most of these cases originate from South East Asia and the Western Pacific, although a significant number also occur in Africa and South America. Although often regarded as causing a benign and self-limiting infection, there is increasing evidence that the overall burden, economic impact and severity of disease from P. vivax have been underestimated. Malaria control strategies have had limited success and are confounded by the lack of access to reliable diagnosis, emergence of multidrug resistant isolates and the parasite’s ability to transmit early in the course of disease and relapse from dormant liver stages at varying time intervals after the initial infection. Progress in reducing the burden of disease will require improved access to reliable diagnosis and effective treatment of both blood-stage and latent parasites, and more detailed characterization of the epidemiology, morbidity and economic impact of vivax malaria. Without these, vivax malaria will continue to be neglected by ministries of health, policy makers, researchers and funding bodies. PMID:18165478

  15. EFFECTS OF OZONE, CHLORINE DIOXIDE, CHLORINE, AND MONOCHLORAMINE ON CRYTOSPORIDIUM PARVUM OOCYST VIABILITY

    EPA Science Inventory

    Purified Cryptosporiodium parvum oocysts were exposed to ozone, chlorine dioxide, chlorine, and monochloramine. Excystation and mouse infectivity were compareatively evaluated to assess oocyst viability. Ozone and chlorine dioxide more effectively inactivated oocysts than chlor...

  16. EFFECTS OF OZONE, CHLORINE DIOXIDE, CHLORINE, AND MONOCHLORAMINE ON CRYPTOSPORIDIUM PARVUM OOCYST VIABILITY

    EPA Science Inventory

    Purified Cryptosporidium parvum oocysts were exposed to ozone, chlorine dioxide, chlorine, and monochloramine. xcystation and mouse infectivity were comparatively evaluated to assess oocyst viability. zone and chlorine dioxide more effectively inactivated oocysts than chlorine an...

  17. Heterosis Increases Fertility, Fecundity, and Survival of Laboratory-Produced F1 Hybrid Males of the Malaria Mosquito Anopheles coluzzii

    PubMed Central

    Ekechukwu, Nkiru E.; Baeshen, Rowida; Traorè, Sékou F.; Coulibaly, Mamadou; Diabate, Abdoulaye; Catteruccia, Flaminia; Tripet, Frédéric

    2015-01-01

    The success of vector control strategies aiming to decrease disease transmission via the release of sterile or genetically-modified male mosquitoes critically depends on mating between laboratory-reared males and wild females. Unfortunately, mosquito colonization, laboratory rearing, and genetic manipulations can all negatively affect male competitiveness. Heterosis is commonly used to produce domestic animals with enhanced vigor and homogenous genetic background and could therefore potentially improve the mating performance of mass-reared male mosquitoes. Here, we produced enhanced hybrid males of the malaria mosquito Anopheles coluzzii by crossing two strains colonized >35 and 8 years ago. We compared the amount of sperm and mating plug proteins they transferred to females, as well as their insemination rate, reproductive success and longevity under various experimental conditions. Across experiments, widespread adaptations to laboratory mating were detected in the older strain. In large-group mating experiments, no overall hybrid advantage in insemination rates and the amount of sperm and accessory gland proteins transferred to females was detected. Despite higher sperm activity, hybrid males did not appear more fecund. However, individual-male mating and laboratory-swarm experiments revealed that hybrid males, while inseminating fewer females than older inbred males, were significantly more fertile, producing larger mating plugs and drastically increasing female fecundity. Heterotic males also showed increased longevity. These results validate the use of heterosis for creating hybrid males with improved fitness from long-established inbred laboratory strains. Therefore, this simple approach could facilitate disease control strategies based on male mosquito releases with important ultimate benefits to human health. PMID:26497140

  18. Fatal Pediatric Cerebral Malaria Is Associated with Intravascular Monocytes and Platelets That Are Increased with HIV Coinfection

    PubMed Central

    Hochman, Sarah E.; Madaline, Theresa F.; Wassmer, Samuel C.; Mbale, Emmie; Choi, Namjong; Seydel, Karl B.; Whitten, Richard O.; Varughese, Julie; Grau, Georges E. R.; Kamiza, Steve; Molyneux, Malcolm E.; Taylor, Terrie E.; Lee, Sunhee; Milner, Danny A.

    2015-01-01

    ABSTRACT  Cerebral malaria (CM) is a major contributor to malaria deaths, but its pathophysiology is not well understood. While sequestration of parasitized erythrocytes is thought to be critical, the roles of inflammation and coagulation are controversial. In a large series of Malawian children hospitalized with CM, HIV coinfection was more prevalent than in pediatric population estimates (15% versus 2%, P < 0.0001, chi-square test), with higher mortality than that seen in HIV-uninfected children (23% versus 17%, P = 0.0178, chi-square test). HIV-infected (HIV+) children with autopsy-confirmed CM were older than HIV-uninfected children (median age, 99 months versus 32 months, P = 0.0007, Mann-Whitney U test) and appeared to lack severe immunosuppression. Because HIV infection is associated with dysregulated inflammation and platelet activation, we performed immunohistochemistry analysis for monocytes, platelets, and neutrophils in brain tissue from HIV+ and HIV-uninfected children with fatal CM. Children with autopsy-confirmed CM had significantly (>9 times) more accumulations of intravascular monocytes and platelets, but not neutrophils, than did children with nonmalarial causes of coma. The monocyte and platelet accumulations were significantly (>2-fold) greater in HIV+ children than in HIV-uninfected children with autopsy-confirmed CM. Our findings indicate that HIV is a risk factor for CM and for death from CM, independent of traditional measures of HIV disease severity. Brain histopathology supports the hypotheses that inflammation and coagulation contribute to the pathogenesis of pediatric CM and that immune dysregulation in HIV+ children exacerbates the pathological features associated with CM. Importance  There are nearly 1 million malaria deaths yearly, primarily in sub-Saharan African children. Cerebral malaria (CM), marked by coma and sequestered malaria parasites in brain blood vessels, causes half of these deaths, although the mechanisms

  19. Comparative susceptibility of introduced forest-dwelling mosquitoes in Hawai'i to avian malaria, Plasmodium relictum

    USGS Publications Warehouse

    Lapointe, D.A.; Goff, M.L.; Atkinson, C.T.

    2005-01-01

    To identify potential vectors of avian malaria in Hawaiian native forests, the innate susceptibility of Aedes albopictus, Wyeomyia mitchellii, and Culex quinquefasciatus from 3 geographical sites along an altitudinal gradient was evaluated using local isolates of Plasmodium relictum. Mosquitoes were dissected 5-8 and 9-13 days postinfective blood meal and microscopically examined for oocysts and salivary-gland sporozoites. Sporogony was completed in all 3 species, but prevalence between species varied significantly. Oocysts were detected in 1-2% and sporozoites in 1-7% of Aedes albopictus that fed on infected ducklings. Wyeomyia mitchellii was slightly more susceptible, with 7-19% and 7% infected with oocysts and sporozoites, respectively. In both species, the median oocyst number was 5 or below. This is only the second Wyeomyia species reported to support development of a malarial parasite. Conversely, Culex quinquefasciatus from all 3 sites proved very susceptible. Prevalence of oocysts and sporozoites consistently exceeded 70%, regardless of gametocytemia or origin of the P. relictum isolate. In trials for which a maximum 200 oocysts were recorded, the median number of oocysts ranged from 144 to 200. It was concluded that Culex quinquefasciatus is the primary vector of avian malaria in Hawai'i. ?? American Society of Parasitologists 2005.

  20. Malaria Facts

    MedlinePlus

    ... a CDC Malaria Branch clinician. malaria@cdc.gov File Formats Help: How do I view different file formats (PDF, DOC, PPT, MPEG) on this site? Adobe PDF file Microsoft PowerPoint file Microsoft Word file Microsoft Excel ...

  1. CONTROL OF CRYPTOSPORIDIUM OOCYSTS BY STEADY-STATE CONVENTIONAL TREATMENT

    EPA Science Inventory

    Pilot-scale experiments have been performed to assess the ability of conventional treatment to control Cryptosporidium oocysts under steady-state conditions. The work was performed with a pilot plant that was designed to minimize flow rates and, as a result, the number of oocyst...

  2. Gene expression during excystation of Cryptosporidium parvum oocysts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The present study describes transcription of mRNA from genes encoding metabolic or structural proteins during excystation of Cryptosporidium parvum oocysts. RNA was harvested from C. parvum oocysts before excystation, and at 5, 10, and 15 min during excystation. Subtractive cDNA libraries were pre...

  3. Toxoplasma gondii oocyst-specific antibodies and sources of infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sources of post-natal infection with T. gondii include consumption of undercooked meat containing tissue cysts or ingestion of oocysts in contaminated food or environment. This study quantified the risk of acquiring infection from oocysts versus meat in pregnant women from the Valdivia Province, Chi...

  4. ISOLATION OF PURIFIED OOCYST WALLS AND SPOROCYSTS FROM TOXOPLASMA GONDII

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii oocysts are environmentally resistant and can infect virtually all warm-blooded hosts, including humans and livestock. Little is known about the biochemical basis for this resistance of oocysts, and mechanism for excystation of T. gondii sporozoites. The objective of the present...

  5. Detection of viable Cryptosporidium parvum oocysts by PCR.

    PubMed Central

    Wagner-Wiening, C; Kimmig, P

    1995-01-01

    PCR was used to detect and specifically identify a gene fragment from Cryptosporidium parvum. An 873-bp region of a 2,359-bp DNA fragment encoding a repetitive oocyst protein of C. parvum was shown to be specifically amplified in C. parvum. An excystation protocol before DNA extraction allowed the differentiation between live and dead Cryptosporidium parvum oocysts. PMID:8534121

  6. UTILITY OF SURROGATES FOR MEASURING CRYPTOSPORIDIUM OOCYST INFECTIVITY

    EPA Science Inventory

    The water industry must assess whether Cryptosporidium oocysts detected in source and finished water are viable and/or infectious. Initial approaches measuring the infectious nature of C. parvum oocysts have focused on in vitro excystation and in vitro vital dye staining. Recen...

  7. UTILITY OF SURROGATES FOR MEASURING CRYPTOSPORIDIUM OOCYSTS INFECTIVITY

    EPA Science Inventory

    The water industry must assess whether Cryptosporidium oocysts detected in source and finished water are viable and/or infectious. Initial approaches measuring the infectious nature of C. parvum oocysts have focused on in vitro excystation and in vitro vital dye staining. Recen...

  8. Migration and Malaria in Europe

    PubMed Central

    Monge-Maillo, Begoña; López-Vélez, Rogelio

    2012-01-01

    The proportion of imported malaria cases due to immigrants in Europe has increased during the lasts decades, with higher rates associated with settled immigrants who travel to visit friends and relatives (VFRs) in their country of origin. Cases are mainly due to P. falciparum and Sub-Saharan Africa is the most common origin. Clinically, malaria in immigrants is characterised by a mild clinical presentation including asymptomatic or delayed malaria cases and low parasitic levels. These characteristics may be explained by a semi-immunity acquired after long periods of time exposed to stable malaria transmission. Malaria cases among immigrants, even asymptomatic patients with sub-microscopic parasitemia, could increase the risk of transmission and cause the reintroduction of malaria in certain areas that have adequate vectors and climate conditions. Moreover, imported malaria cases in immigrants can also play an important role in the non-vector transmission out of endemic areas, through blood transfusions, organ transplantation or congenital transmission or occupational exposures. Consequently, outside of endemic areas, malaria screening should be carried out among recently arrived immigrants coming from malaria endemic countries. The aim of screening is to reduce the risk of clinical malaria in the individual as well as to prevent autochthonous transmission of malaria in areas where it has been eradicated. PMID:22536477

  9. [Malaria in Algerian Sahara].

    PubMed

    Hammadi, D; Boubidi, S C; Chaib, S E; Saber, A; Khechache, Y; Gasmi, M; Harrat, Z

    2009-08-01

    Thanks to the malaria eradication campaign launched in Algeria in 1968, the number of malaria cases fell down significantly from 95,424 cases in 1960 to 30 cases in 1978. At that time the northern part of the country was declared free of Plasmodium falciparum. Only few cases belonging to P. vivax persisted in residual foci in the middle part of the country. In the beginning of the eighties, the south of the country was marked by an increase of imported malaria cases. The resurgence of the disease in the oases coincided with the opening of the Trans-Saharan road and the booming trade with the neighbouring southern countries. Several authors insisted on the risk of introduction of malaria or its exotic potential vectors in Algeria via this new road. Now, the totality of malaria autochthonous cases in Algeria are located in the south of the country where 300 cases were declared during the period (1980-2007). The recent outbreak recorded in 2007 at the borders with Mall and the introduction of Anopheles gambiae into the Algerian territory show the vulnerability of this area to malaria which is probably emphasized by the local environmental changes. The authors assess the evolution of malaria in the Sahara region and draw up the distribution of the anopheles in this area. PMID:19739417

  10. Malaria (For Parents)

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy Malaria KidsHealth > For Parents > Malaria Print A A A ... Prevention Diagnosis and Treatment en español Malaria About Malaria Malaria is a common infection in hot, tropical ...

  11. Environmental inactivation of Cryptosporidium parvum oocysts in waste stabilization ponds.

    PubMed

    Reinoso, Roberto; Bécares, Eloy

    2008-11-01

    The survival of Cryptosporidium parvum oocysts in a waste stabilization pond system in northwestern Spain and the effects of sunlight and the depth and type of pond on oocyst viability were evaluated using an assay based on the exclusion or inclusion of two fluorogenic vital dyes, 4',6-diamidino-2-phenylindole (DAPI) and propidium iodide (PI). All tested factors had significant effects (P < 0.01) over time on C. parvum oocyst viability. Sunlight exposure was the most influential factor for oocyst inactivation. A 40% reduction was observed after 4 days exposure to sunlight conditions compared with dark conditions. The type of pond also caused a significant reduction in C. parvum oocyst viability (P < 0.01). Inactivation rates reflected that the facultative pond was the most aggressive environment for oocysts placed both at the surface (presence of sunlight) and at the bottom (absence of sunlight) of the pond, followed by the maturation pond and the anaerobic pond. The mean inactivation rates of oocysts in the ponds ranged from 0.0159 to 0.3025 day(-1). PMID:18345476

  12. Development of Plasmodium berghei ookinetes to young oocysts in vitro.

    PubMed

    Syafruddin; Arakawa, R; Kamimura, K; Kawamoto, F

    1992-01-01

    The mosquito stage of Plasmodium berghei was cultivated in vitro, with special attention to ookinete transformation into early oocyst. The ookinetes were obtained by in vitro culture of gametocytes taken from infected mice, purified by density gradient of metrizoic acid or a lymphocyte separation medium, and incubated either in acellular culture or in co-cultivations with mosquito cells. In acellular culture, the ookinetes were found to aggregate with each other and transformed from banana to round shapes. Their inner pellicular membranes and subpellicular microtubules partially disappeared, indicating that development to early oocyst had occurred. Co-cultivation wtih Aedes albopictus cells (C6/36 clone) revealed that ookinetes transformed into early oocyst in the medium, or invaded the cells and then transformed to early oocysts within the cell cytoplasm as well. However all of these transformed cells failed to develop further, i.e., neither deposition of the oocyst capsule nor nuclear division was observed. Many ookinetes which failed to penetrate the Aedes cells were phagocytized within three days of culture. A significant difference between invaded and transformed oocysts and phagocytized ookinetes was seen in that the former lacked vacuole membrane. Co-cultivation with Toxorhynchites amboinensis cells (TRA-284-SFG clone) permitted transformation of ookinetes into early oocysts in the medium as in the acellular culture, but no ookinete invasion nor phagocytosis by the cell was observed. PMID:1578408

  13. Parasite Killing in Malaria Non-Vector Mosquito Anopheles culicifacies Species B: Implication of Nitric Oxide Synthase Upregulation

    PubMed Central

    Vijay, Sonam; Rawat, Manmeet; Adak, Tridibes; Dixit, Rajnikant; Nanda, Nutan; Srivastava, Harish; Sharma, Joginder K.; Prasad, Godavarthi B. K. S.; Sharma, Arun

    2011-01-01

    Background Anopheles culicifacies, the main vector of human malaria in rural India, is a complex of five sibling species. Despite being phylogenetically related, a naturally selected subgroup species B of this sibling species complex is found to be a poor vector of malaria. We have attempted to understand the differences between vector and non-vector Anopheles culicifacies mosquitoes in terms of transcriptionally activated nitric oxide synthase (AcNOS) physiologies to elucidate the mechanism of refractoriness. Identification of the differences between genes and gene products that may impart refractory phenotype can facilitate development of novel malaria transmission blocking strategies. Methodology/Principal Findings We conducted a study on phylogenetically related susceptible (species A) and refractory (species B) sibling species of An. culicifacies mosquitoes to characterize biochemical and molecular differences in AcNOS gene and gene elements and their ability to inhibit oocyst growth. We demonstrate that in species B, AcNOS specific activity and nitrite/nitrates in mid-guts and haemolymph were higher as compared to species A after invasion of the mid-gut by P. vivax at the beginning and during the course of blood feeding. Semiquantitative RT-PCR and real time PCR data of AcNOS concluded that this gene is more abundantly expressed in midgut of species B than in species A and is transcriptionally upregulated post blood meals. Dietary feeding of L-NAME along with blood meals significantly inhibited midgut AcNOS activity leading to an increase in oocyst production in An. culicifacies species B. Conclusions/Significance We hypothesize that upregulation of mosquito innate cytotoxicity due to NOS in refractory strain to Plasmodium vivax infection may contribute to natural refractoriness in An. culicifacies mosquito population. This innate capacity of refractory mosquitoes could represent the ancestral function of the mosquito immune system against the parasite and

  14. Interaction between Cryptosporidium oocysts and water treatment coagulants.

    PubMed

    Bustamante, H A; Shanker, S R; Pashley, R M; Karaman, M E

    2001-09-01

    The electrokinetic properties of gamma-irradiated Cryptosporidium oocysts in the presence of coagulants (ferric chloride and alum) and coagulant aids (DADMAC based cationic polyelectrolytes) have been studied. The zeta potential of the oocysts was unaffected by the addition of ferric chloride at all pH values (3-10) studied. Addition of alum resulted in reversal of the oocysts charge, which suggests that the initial stage in the coagulation process leading to floc formation proceeds via the adsorption of hydrolysed aluminium species. The cationic polyelectrolyte Magnafloc LT35 was adsorbed onto iron flocs at doses of 0.1 mg/L even against an electrostatic barrier. The cationic polyelectrolyte only adsorbed and caused charge reversal at the oocyst surface at around 0.4 mg/L, suggesting a lower affinity for this surface. These results indicate that the oocysts, unlike inorganic colloidal materials such as metal oxides, appear to possess a lower surface density of active or charged sites. The lower density of sites, combined with the rapid precipitation of iron salts, may be responsible for the lack of specific adsorption of either hydroxylated ferric species or primary iron hydroxide particles on the oocysts. Further, this suggests that a process of sweep flocculation, where oocysts are engulfed in flocs during coagulation and floc formation, is the more likely mechanism involved. By comparison, it is likely that the specific interaction of hydrolysed aluminium species with the oocysts surface would result in a stronger link at the oocyst-floc interface and that the flocculation process may initially proceed via charge neutralisation. PMID:11487115

  15. Eimeriid oocysts from archaeological samples in Patagonia, Argentina.

    PubMed

    Fugassa, M H; Sardella, N H; Taglioretti, V; Reinhard, K; Araújo, A

    2008-12-01

    Oocysts attributable to E. macusaniensis Guerrero et al. 1971, were found in coprolites and in archaeological sediments dating to the Holocene of Patagonia, Argentina. By means of a non-parametric regression using a generalized additive model, a significant relationship was found between the size of the oocysts and their antiquity. Specifically, a reduction in oocyst size over time was discovered, probably due to a parasite response to host replacement, to an extinct eimeriid species common during the Pliestocene-Holocene transition, or to environmental changes known for the Holocene. Explanations regarding coevolution between parasites, hosts and paleoenvironmental conditions are discussed herein. PMID:18576839

  16. [Prospects for malaria elimination in Azerbaijan].

    PubMed

    Kondrashin, A V; Baranova, A M; Mammedov, S; Gasimov, É; Morozova, L F; Stepanova, E V

    2011-01-01

    Epidemiological analysis of the malaria in the Republic of Azerbaijan has revealed that: 1. In the past year, malaria problem has considerably improved in reducing morbidity and the number of active foci of malaria in the republic. 2. All active foci of malaria have been in its endemic area. 3. Despite the presence of favorable climatic preconditions for malaria in a large part of the republic, socioeconomic preconditions are considerably decreased, causing the malariogenic potential to substantially reduce. 4. All sets a favorable stage for possible interruption of local malaria transmission on the whole territory of the republic provided that financial support for the national malaria elimination program will be increased from the country's government and other sources in conjunction with the implementation of revised malaria control strategy and with the use of current methods for the detection, diagnosis, treatment, and prevention of malaria. PMID:21476253

  17. Malaria on the move: human population movement and malaria transmission.

    PubMed Central

    Martens, P.; Hall, L.

    2000-01-01

    Reports of malaria are increasing in many countries and in areas thought free of the disease. One of the factors contributing to the reemergence of malaria is human migration. People move for a number of reasons, including environmental deterioration, economic necessity, conflicts, and natural disasters. These factors are most likely to affect the poor, many of whom live in or near malarious areas. Identifying and understanding the influence of these population movements can improve prevention measures and malaria control programs. PMID:10756143

  18. Geographic coincidence of increased malaria transmission hazard and vulnerability occurring at the periphery of two Tanzanian villages

    PubMed Central

    2013-01-01

    Background The goal of malaria elimination necessitates an improved understanding of any fine-scale geographic variations in transmission risk so that complementary vector control tools can be integrated into current vector control programmes as supplementary measures that are spatially targeted to maximize impact upon residual transmission. This study examines the distribution of host-seeking malaria vectors at households within two villages in rural Tanzania. Methods Host-seeking mosquitoes were sampled from 72 randomly selected households in two villages on a monthly basis throughout 2008 using CDC light-traps placed beside occupied nets. Spatial autocorrelation in the dataset was examined using the Moran’s I statistic and the location of any clusters was identified using the Getis-Ord Gi* statistic. Statistical associations between the household characteristics and clusters of mosquitoes were assessed using a generalized linear model for each species. Results For both Anopheles gambiae sensu lato and Anopheles funestus, the density of host-seeking females was spatially autocorrelated, or clustered. For both species, houses with low densities were clustered in the semi-urban village centre while houses with high densities were clustered in the periphery of the villages. Clusters of houses with low or high densities of An. gambiae s.l. were influenced by the number of residents in nearby houses. The occurrence of high-density clusters of An. gambiae s.l. was associated with lower elevations while An. funestus was also associated with higher elevations. Distance from the village centre was also positively correlated with the number of household occupants and having houses constructed with open eaves. Conclusion The results of the current study highlight that complementary vector control tools could be most effectively targeted to the periphery of villages where the households potentially have a higher hazard (mosquito densities) and vulnerability (open eaves and

  19. Malaria: prevention in travellers

    PubMed Central

    Croft, Ashley

    2000-01-01

    Definition Malaria is caused by a protozoan infection of red blood cells with one of four species of the genus plasmodium: P falciparum, P vivax, P ovale, or P malariae.1 Clinically, malaria may present in different ways, but it is usually characterised by fever (which may be swinging), tachycardia, rigors, and sweating. Anaemia, hepatosplenomegaly, cerebral involvement, renal failure, and shock may occur. Incidence/prevalence Each year there are 300-500 million clinical cases of malaria. About 40% of the world's population is at risk of acquiring the disease.23 Each year 25-30 million people from non-tropical countries visit areas in which malaria is endemic,4 of whom between 10 000 and 30 000 contract malaria.5 Aetiology/risk factors Malaria is mainly a rural disease, requiring standing water nearby. It is transmitted by bites6 from infected female anopheline mosquitoes,7 mainly at dusk and during the night.18 In cities, mosquito bites are usually from female culicene mosquitoes, which are not vectors of malaria.9 Malaria is resurgent in most tropical countries and the risk to travellers is increasing.10 Prognosis Ninety per cent of travellers who contract malaria do not become ill until after they return home.5 “Imported malaria” is easily treated if diagnosed promptly, and it follows a serious course in only about 12% of people.1112 The most severe form of the disease is cerebral malaria, with a case fatality rate in adult travellers of 2-6%,3 mainly because of delays in diagnosis.5 Aims To reduce the risk of infection; to prevent illness and death. Outcomes Rates of malarial illness and death, and adverse effects of treatment. Proxy measures include number of mosquito bites and number of mosquitoes in indoor areas. We found limited evidence linking number of mosquito bites and risk of malaria.13 Methods Clinical Evidence search and appraisal in November 1999. We reviewed all identified systematic reviews and randomised controlled trials (RCTs

  20. Transcriptional silencing and activation of paternal DNA during P lasmodium berghei zygotic development and transformation to oocyst

    PubMed Central

    Ukegbu, Chiamaka V.; Cho, Jee‐Sun; Christophides, George K.

    2015-01-01

    Summary The malaria parasite develops sexually in the mosquito midgut upon entry with the ingested blood meal before it can invade the midgut epithelium and embark on sporogony. Recent data have identified a number of distinct transcriptional programmes operating during this critical phase of the parasite life cycle. We aimed at characterizing the parental contribution to these transcriptional programmes and establish the genetic framework that would guide further studies of P lasmodium zygotic development and ookinete‐to‐oocyst transition. To achieve this we used in vitro and in vivo cross‐fertilization experiments of various parasite lines expressing fluorescent reporters under the control of constitutive and stage‐specific promoters. The results revealed that the zygote/ookinete stage exhibits a maternal phenotype with respect to constitutively expressed reporters, which is derived from either maternal mRNA inheritance or transcription of the maternal allele. The respective paternal alleles are silenced in the zygote/ookinete but reactivated after midgut invasion and transformation to oocyst. Transcripts specifically produced in the zygote/ookinete are synthesized de novo by both parental alleles. These findings highlight a putative role of epigenetic regulation of P lasmodium zygotic development and add substantially to the emerging picture of the molecular mechanisms regulating this important stage of malaria transmission. PMID:25728487

  1. Effect of ferric oxyhydroxide grain coatings on the transport of bacteriophage PRD1 and Cryptosporidium parvum oocysts in saturated porous media

    USGS Publications Warehouse

    Abudalo, R.A.; Bogatsu, Y.G.; Ryan, J.N.; Harvey, R.W.; Metge, D.W.; Elimelech, M.

    2005-01-01

    To test the effect of geochemical heterogeneity on microorganism transport in saturated porous media, we measured the removal of two microorganisms, the bacteriophage PRD1 and oocysts of the protozoan parasite Cryptosporidium parvum, in flow-through columns of quartz sand coated by different amounts of a ferric oxyhydroxide. The experiments were conducted over ranges of ferric oxyhydroxide coating fraction of ?? = 0-0.12 for PRD1 and from ?? = 0-0.32 for the oocysts at pH 5.6-5.8 and 10-4 M ionic strength. To determine the effect of pH on the transport of the oocysts, experiments were also conducted over a pH range of 5.7-10.0 at a coating fraction of ?? = 0.04. Collision (attachment) efficiencies increased as the fraction of ferric oxyhydroxide coated quartz sand increased, from ?? = 0.0071 to 0.13 over ?? = 0-0.12 for PRD1 and from ?? = 0.059 to 0.75 over ?? = 0-0.32 for the oocysts. Increasing the pH from 5.7 to 10.0 resulted in a decrease in the oocyst collision efficiency as the pH exceeded the expected point of zero charge of the ferric oxyhydroxide coatings. The collision efficiencies correlated very well with the fraction of quartz sand coated by the ferric oxyhydroxide for PRD1 but not as well for the oocysts. ?? 2005 American Chemical Society.

  2. Influence of organic matter on the transport of Cryptosporidium parvum oocysts in a ferric oxyhydroxide-coated quartz sand saturated porous medium

    USGS Publications Warehouse

    Abudalo, R.A.; Ryan, J.N.; Harvey, R.W.; Metge, D.W.; Landkamer, L.

    2010-01-01

    To assess the effect of organic matter on the transport of Cryptosporidium parvum oocysts in a geochemically heterogeneous saturated porous medium, we measured the breakthrough and collision efficiencies of oocysts as a function of dissolved organic matter concentration in a flow-through column containing ferric oxyhydroxide-coated sand. We characterized the surface properties of the oocysts and ferric oxyhydroxide-coated sand using microelectrophoresis and streaming potential, respectively, and the amount of organic matter adsorbed on the ferric oxyhydroxide-coated sand as a function of the concentration of dissolved organic matter (a fulvic acid isolated from Florida Everglades water). The dissolved organic matter had no significant effect on the zeta potential of the oocysts. Low concentrations of dissolved organic matter were responsible for reversing the charge of the ferric oxyhydroxide-coated sand surface from positive to negative. The charge reversal and accumulation of negative charge on the ferric oxyhydroxide-coated sand led to increases in oocyst breakthrough and decreases in oocyst collision efficiency with increasing dissolved organic matter concentration. The increase in dissolved organic matter concentration from 0 to 20 mg L-1 resulted in a two-fold decrease in the collision efficiency. ?? 2009 Elsevier Ltd.

  3. Surface binding properties of aged and fresh (recently excreted) Toxoplasma gondii oocysts.

    PubMed

    Harito, Jemere Bekele; Campbell, Andrew T; Prestrud, Kristin W; Dubey, J P; Robertson, Lucy J

    2016-06-01

    The surfaces of aged (10 years) and fresh (recently excreted) oocysts of Toxoplasma gondii were investigated using monoclonal antibody (mAb) and lectin-binding assays. Fresh oocysts bound a wall-specific mAb labelled with fluorescein isothiocyanate while aged oocysts did not. In contrast, the walls of aged oocysts bound a lectin (wheat germ agglutinin, WGA), but not the walls of fresh oocysts. Exposure of oocysts to detergent solutions or trypsin did not affect the binding properties of the walls of the oocysts. However, exposure of fresh oocysts to acidified pepsin enabled labelling of the walls with WGA, presumably due to the relevant moieties on the oocyst walls becoming exposed. WGA binding, but not mAb binding, was partially abrogated with periodate exposure. These findings reveal a significant difference in the binding properties of oocyst walls from "aged" and "fresh" oocysts. The results are of relevance when considering technologies for isolating or detecting T. gondii oocysts in environmental samples based on oocyst surface properties, as used for other protozoan parasites. Our results suggest the possibility of developing a WGA-based separation procedure for isolating Toxoplasma oocysts from environmental matrices, in which pepsin pre-treatment would be included to ensure that both fresh and aged oocysts were isolated. PMID:27003461

  4. High plasma levels of soluble endothelial protein C receptor are associated with increased mortality among children with cerebral malaria in Benin.

    PubMed

    Moussiliou, Azizath; Alao, Maroufou J; Denoeud-Ndam, Lise; Tahar, Rachida; Ezimegnon, Sem; Sagbo, Gratien; Amoussou, Annick; Luty, Adrian J F; Deloron, Philippe; Tuikue Ndam, Nicaise

    2015-05-01

    Loss of endothelial protein C receptor (EPCR) occurs at the sites of Plasmodium falciparum-infected erythrocyte sequestration in patients with or who died from cerebral malaria. In children presenting with different clinical syndromes of malaria, we assessed the relationships between endogenous plasma soluble EPCR (sEPCR) levels and clinical presentation or mortality. After adjustment for age, for treatment before admission, and for a known genetic factor, sEPCR level at admission was positively associated with cerebral malaria (P = .011) and with malaria-related mortality (P = .0003). Measuring sEPCR levels at admission could provide an early biological marker of the outcome of cerebral malaria. PMID:25425698

  5. Molecular-Based Detection Systems for Cryptosporidium Oocysts

    EPA Science Inventory

    The presentation describes on-going studies in collaboration with US EPA Region 2, 3, and the CDC on identifying sources of Cryptosporidium oocyst contamination in source waters using conventional and real-time PCR approaches.

  6. “Sexual” Population Structure and Genetics of the Malaria Agent P. falciparum

    PubMed Central

    Mzilahowa, Themba; McCall, Philip J.; Hastings, Ian M.

    2007-01-01

    The population genetics and structure of P. falciparum determine the rate at which malaria evolves in response to interventions such as drugs and vaccines. This has been the source of considerable recent controversy, but here we demonstrate the organism to be essentially sexual, in an area of moderately high transmission in the Lower Shire Valley, Malawi. Seven thousand mosquitoes were collected and dissected, and genetic data were obtained on 190 oocysts from 56 infected midguts. The oocysts were genotyped at three microsatellite loci and the MSP1 locus. Selfing rate was estimated as 50% and there was significant genotypic linkage disequilibrium (LD) in the pooled oocysts. A more appropriate analysis searching for genotypic LD in outcrossed oocysts and/or haplotypic LD in the selfed oocysts found no evidence for LD, indicating that the population was effectively sexual. Inbreeding estimates at MSP1 were higher than at the microsatellites, possibly indicative of immune action against MSP1, but the effect was confounded by the probable presence of null mutations. Mating appeared to occur at random in mosquitoes and evidence regarding whether malaria clones in the same host were related (presumably through simultaneous inoculation in the same mosquito bite) was ambiguous. This is the most detailed genetic analysis yet of P. falciparum sexual stages, and shows P. falciparum to be a sexual organism whose genomes are in linkage equilibrium, which acts to slow the emergence of drug resistance and vaccine insensitivity, extending the likely useful therapeutic lifespan of drugs and vaccines. PMID:17637829

  7. Detection of Toxoplasma gondii oocysts in different water resources by Loop Mediated Isothermal Amplification (LAMP).

    PubMed

    Gallas-Lindemann, Carmen; Sotiriadou, Isaia; Mahmoodi, Mohammad Reza; Karanis, Panagiotis

    2013-02-01

    Human toxoplasmosis is potentially contracted due to consumption of contaminated drinking water and represents an increasing public health risk worldwide. Toxoplasma gondii oocysts can be resistant to standard disinfection processes, including UV radiation. Increased awareness of the risk of waterborne toxoplasmosis outbreaks has led to an increase in research interest in the detection of oocysts in environmental water systems. Ninety-five environmental water samples from the Lower Rhine area in Germany have been included in the study and examined for the presence of Toxoplasma. Water samples were filtered or flocculated by aluminum sulfate and purified by sucrose density gradient. DNA was then extracted, and the DNA samples were then examined by LAMP analysis. T. gondii DNA was detected in eight out of 83 (9.6%) influent and effluent samples obtained from wastewater treatment plants. All samples (n=12) from the surface, ground, raw and tap waters tested negative. The purpose of this work was to investigate the occurrence and distribution of Toxoplasma oocysts on the Lower Rhine in Germany. Our study provides evidence that the assay is a sensitive, specific, rapid and cost effective method for the detection of T. gondii and is useful for both the investigations of cases of waterborne outbreaks and for identifying the source of contamination. PMID:23088835

  8. Eradicating malaria.

    PubMed

    Breman, Joel G

    2009-01-01

    The renewed interest in malaria research and control is based on the intolerable toll this disease takes on young children and pregnant women in Africa and other vulnerable populations; 150 to 300 children die each hour from malaria amounting to 1 to 2 million deaths yearly. Malaria-induced neurologic impairment, anemia, hypoglycemia, and low birth weight imperil normal development and survival. Resistance of Plasmodium falciparum to drugs and Anopheles mosquitoes to insecticides has stimulated discovery and development of artemisinin-based combination treatments (ACTs) and other drugs, long-lasting insecticide-treated bednets (with synthetic pyrethroids) and a search for non-toxic, long-lasting, affordable insecticides for indoor residual spraying (IRS). Malaria vaccine development and testing are progressing rapidly and a recombinant protein (RTS,S/AS02A) directed against the circumsporozoite protein is soon to be in Phase 3 trials. Support for malaria control, research, and advocacy through the Global Fund for HIV/AIDS, Tuberculosis and Malaria, the U.S. President's Malaria Initiative, the Bill & Melinda Gates Foundation, WHO and other organizations is resulting in decreasing morbidity and mortality in many malarious countries. Sustainability of effective programs through training and institution strengthening will be the key to malaria elimination coupled with improved surveillance and targeted research. PMID:19544698

  9. Deposition of Cryptosporidium parvum oocysts in porous media: a synthesis of attachment efficiencies measured under varying environmental conditions.

    PubMed

    Park, Yeonjeong; Atwill, E Robert; Hou, Lingling; Packman, Aaron I; Harter, Thomas

    2012-09-01

    An extensive set of column experiments was performed with freshly harvested Cryptosporidium parvum oocysts to evaluate the effects of solution chemistry, surface coatings, interactions with other suspended particles, and pore fluid velocity on the fate and transport of this widely occurring waterborne pathogen in sandy porous media. We synthesized our data set with a comprehensive literature survey of similar experiments, to compute attachment (collision) efficiencies (α) used in colloid filtration theory (CFT) using three models for the single collector efficiency (η) across a wide range of experimental conditions. Most prior experiments have observed the transport of surface-treated, sterile C. parvum oocyst in porous media. Our column data confirm for freshly harvested oocysts that the presence of iron coatings on the sand medium and the presence of suspended illite clay drastically enhance oocyst deposition. Increasing ionic strength and decreasing pH also systematically enhance the attachment efficiency. Attachment efficiency decreases only at a very high ionic strength, most likely as a result of steric repulsion and possibly other changes in oocyst surface properties. Attachment efficiencies vary with fluid flow rate but without showing specific trends. We found that the computed attachment efficiency across all reported experiments could be reliably estimated using a regression model based on parameters related to ionic strength and pH. The regression model performed better with the Nelson-Ginn η model and Tufenkji-Elimelech η model than with the Rajagopalan-Tien η model. When CFT is used in environmental assessments, the proposed regression model provides a practical estimator for attachment efficiencies of C. parvum oocyst deposition in porous media for a variety of environmental conditions unfavorable to attachment. PMID:22861686

  10. Occurrence of Giardia and Cryptosporidium (oo)cysts in the river water of two recreational areas in Selangor, Malaysia.

    PubMed

    Azman, J; Init, I; Wan Yusoff, W S

    2009-12-01

    This study is the first report on the occurrence of Giardia and Cryptosporidium (oo)cysts in recreational rivers water from Malaysia. It was carried out in water samples at two rivers, 'Sungai Congkak' and 'Sungai Batu', located in Selangor State. The occurrence of both Giardia lamblia and Cryptosporidium parvum (oo)cysts was higher in Sungai Congkak (50% or 15/30 and 10% or 3/30 respectively) than Sungai Batu (16% or 5/30 and 3.3% or 1/30 respectively). The mean density of cysts/L was 0.72 in Sungai Congkak and 0.023 in Sungai Batu, and that of oocysts/L was 0.023 in Sungai Congkak and 0.0033 in Sungai Batu, showing that the occurrence of Giardia was higher and more frequent than Cryptosporidium in both rivers. Sungai Congkak also showed higher faecal coliforms count (ranging from 0.48x10³ to 73x10³ CFU/100 mL) than Sungai Batu (0.41x10³ to 16x10³ CFU/100 mL). On the other hand, the Giardia and Cryptosporidium (oo)cysts and faecal coliforms were more concentrated at the downstream station, followed by midstream and upstream stations which might be due to human factors where settlements and recreation areas were located around and between midstream and downstream stations. The (oo)cysts and faecal coliforms also increased during public holidays due to the significantly higher number of visitors (bathers) compared with the week days. All the parameters (physical, faecal coliforms and rainfall) did not show consistent significant correlation (based on r values of Pearson correlation analysis) with both protozoa, therefore these parameters are not suitable as indicator for the presence of Giardia and Cryptosporidium (oo)cysts in both rivers. PMID:20237443

  11. Re-description of a genetically typed, single oocyst line of the turkey coccidium, Eimeria adenoeides Moore and Brown, 1951.

    PubMed

    El-Sherry, S; Ogedengbe, M E; Hafeez, M A; Sayf-Al-Din, M; Gad, N; Barta, J R

    2014-11-01

    The Guelph strain of Eimeria adenoeides was obtained from a commercial turkey flock in Ontario, Canada, in 1985. Single oocyst derived lines of E. adenoeides were propagated, and one of them used to re-describe biological and morphological features of E. adenoeides in the turkey. Oocysts of this strain are within the lower size ranges in the original species description reported by Moore and Brown (1951); oocysts of the Guelph strain averaged 18.7 ± 1.4 μm (16.7-22.5) by 14.3 ± 0.9 μm (13-16.2, n = 30) with a shape index (SI) of 1.3 ± 0.1. It is possible that the original species description was based, at least in part, on a mixed culture of two or more Eimeria species. Immature first-generation meronts of E. adenoeides Guelph strain were observed histologically at 32 h post-infection in the ileum and cecal neck. Early studies reported only two asexual generations suggested that first asexual cycle observed at 32 h post-infection was overlooked. In the present study, three asexual generations were observed before the start of gametogony. The Guelph strain is also characterized by a prepatent period of 112 h. The Guelph strain of E. adenoeides is a highly pathogenic coccidium that forms classic cecal lesions, including prominent caseous cecal cores, during moderate to severe infections. The maximum output of oocysts (1.77 × 10(7) per bird) was obtained from birds inoculated with 1 × 10(3) oocysts; maximum fecundity (1.55 × 10(5) oocyst shed per oocyst inoculated) was obtained with an inoculation of 1 × 10(2) oocysts, but fecundity dropped dramatically as the inoculation dose increased. To promote stability of the E. adenoeides species concept, neotype specimens (a parahapantotype slides series and phototype) have been designated and deposited for future reference. PMID:25127734

  12. Mapping residual transmission for malaria elimination.

    PubMed

    Reiner, Robert C; Le Menach, Arnaud; Kunene, Simon; Ntshalintshali, Nyasatu; Hsiang, Michelle S; Perkins, T Alex; Greenhouse, Bryan; Tatem, Andrew J; Cohen, Justin M; Smith, David L

    2015-01-01

    Eliminating malaria from a defined region involves draining the endemic parasite reservoir and minimizing local malaria transmission around imported malaria infections . In the last phases of malaria elimination, as universal interventions reap diminishing marginal returns, national resources must become increasingly devoted to identifying where residual transmission is occurring. The needs for accurate measures of progress and practical advice about how to allocate scarce resources require new analytical methods to quantify fine-grained heterogeneity in malaria risk. Using routine national surveillance data from Swaziland (a sub-Saharan country on the verge of elimination), we estimated individual reproductive numbers. Fine-grained maps of reproductive numbers and local malaria importation rates were combined to show 'malariogenic potential', a first for malaria elimination. As countries approach elimination, these individual-based measures of transmission risk provide meaningful metrics for planning programmatic responses and prioritizing areas where interventions will contribute most to malaria elimination. PMID:26714110

  13. Using Quantitative Reverse Transcriptase PCR and Cell Culture Plaque Assays to Determine Resistance of Toxoplasma gondii Oocysts to Chemical Sanitizers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii oocysts are highly resistant to many chemical sanitizers. Current methods used to determine oocyst infectivity have relied exclusively on mouse, chicken, and feline bioassays. Although considered gold standards, they only provide a qualitative assessment of oocyst infectivity. I...

  14. A fast method for detecting Cryptosporidium parvum oocysts in real world samples

    NASA Astrophysics Data System (ADS)

    Stewart, Shona; McClelland, Lindy; Maier, John

    2005-04-01

    Contamination of drinking water with pathogenic microorganisms such as Cryptosporidium has become an increasing concern in recent years. Cryptosporidium oocysts are particularly problematic, as infections caused by this organism can be life threatening in immunocompromised patients. Current methods for monitoring and analyzing water are often laborious and require experts to conduct. In addition, many of the techniques require very specific reagents to be employed. These factors add considerable cost and time to the analytical process. Raman spectroscopy provides specific molecular information on samples, and offers advantages of speed, sensitivity and low cost over current methods of water monitoring. Raman spectroscopy is an optical method that has demonstrated the capability to identify and differentiate microorganisms at the species and strain levels. In addition, this technique has exhibited sensitivities down to the single organism detection limit. We have employed Raman spectroscopy and Raman Chemical Imaging, in conjunction with chemometric techniques, to detect small numbers of oocysts in the presence of interferents derived from real-world water samples. Our investigations have also indicated that Raman Chemical Imaging may provide chemical and physiological information about an oocyst sample which complements information provided by the traditional methods. This work provides evidence that Raman imaging is a useful technique for consideration in the water quality industry.

  15. [Malaria in the Americas].

    PubMed

    Carme, B; Venturin, C

    1999-01-01

    In 1996, malaria involving Plasmodium vivax, Plasmodium falciparum, and, to a lesser extent, Plasmodium malariae was endemic in 21 countries in the Americas. The Amazon river basin and bordering areas including the Guyanas were the most affected zones. Until the mid 1970s, endemic malaria appeared to be under control. However in the ensuing 15 year period, the situation deteriorated drastically. Although trends varied depending on location, aggregate indexes indicated a twofold increase with recrudescence in previously settled areas and emergence in newly populated zones. Since 1990, the situation has worsened further in some areas where increased incidences have been associated with a high levels of drug-resistant Plasmodium falciparum. However this species remains in minority except in the Guyanas where the highest annual incidences (100 to 500 cases per 1000) and the most drug-resistant Plasmodium have been reported. The causes underlying this deterioration are numerous and complex. In regions naturally prone to transmission of the disease, outbreaks have been intensified by unrestrained settlement. The resulting deforestation has created new breeding areas for Anopheles darlingi, the main vector of malaria in the Americas. Migration of poor populations to newly opened farming and mining areas has created highly exposed areas for malaria infection. Implementation of adequate medical care and prevention measures has been hindered by a lack of money and sociopolitical unrest. Climatic phenomenon related the El Nino have also been favorable to the return of malaria to the region. Except with regard to financial resources and political unrest, the same risk factors for malaria are present in French Guiana. PMID:10701211

  16. The treatment of malaria.

    PubMed

    White, N J

    1996-09-12

    Increasing drug resistance in Plasmodium falciparum and a resurgence of malaria in tropical areas have effected a change in treatment of malaria in the last two decades. Symptoms of malaria are fever, chills, headache, and malaise. The prognosis worsens as the parasite counts, counts of mature parasites, and counts of neutrophils containing pigment increase. Treatment depends on severity, age of patient, degree of background immunity, likely pattern of susceptibility to antimalarial drugs, and the cost and availability of drugs. Chloroquine should be used for P. vivax, P. malariae, and P. ovale. P. vivax has shown high resistance to chloroquine in Oceania, however. Primaquine may be needed to treat P. vivax and P. ovale to rid the body of hypnozoites that survive in the liver. Chloroquine can treat P. falciparum infections acquired in North Africa, Central America north of the Panama Canal, Haiti, or the Middle East but not in most of Africa and some parts of Asia and South America. In areas of low grade resistance to chloroquine, amodiaquine can be used to effectively treat falciparum malaria. A combination of sulfadoxine-pyrimethamine is responsive to falciparum infections with high grade resistance to chloroquine. Mefloquine, halofantrine, or quinine with tetracycline can be used to treat multidrug-resistant P. falciparum. Derivatives of artemisinin obtained from qinghao or sweet wormwood developed as pharmaceuticals in China are the most rapidly acting of all antimalarial drugs. Children tend to tolerate antimalarial drugs well. Children who weigh less than 15 kg should not be given mefloquine. Health workers should not prescribe primaquine to pregnant women or newborns due to the risk of hemolysis. Chloroquine, sulfadoxine-pyrimethamine, quinine, and quinidine can be safely given in therapeutic doses throughout pregnancy. Clinical manifestations of severe malaria are hypoglycemia, convulsions, severe anemia, acute renal failure, jaundice, pulmonary edema

  17. Exchange Transfusion in Severe Falciparum Malaria

    PubMed Central

    Khatib, Khalid Ismail

    2016-01-01

    Malaria is endemic in India with the incidence of P. falciparum Malaria increasing gradually over the last decade. Severe malaria is an acute disease, caused by P. falciparum, but increasingly also by P. vivax with major signs of organ dysfunction and/or high levels of parasitaemia (>10%) in blood smear. Use of exchange transfusion with antimalarial drug therapy as an additional modality of treatment in severe Falciparum malaria is controversial and is unclear. We report a case of severe malaria complicated by multiorgan failure and ARDS. Patient responded well to manual exchange transfusion with standard artesunate-based chemotherapy. PMID:27042503

  18. Effect of dissolved organic carbon on the transport and attachment behaviors of Cryptosporidium parvum oocysts and carboxylate-modified microspheres advected through temperate humic and tropical volcanic agricultural soil.

    PubMed

    Mohanram, Arvind; Ray, Chittaranjan; Metge, David W; Barber, Larry B; Ryan, Joseph N; Harvey, Ronald W

    2012-02-21

    Transport of Cryptosporidium parvum oocysts and microspheres in two disparate (a clay- and Fe-rich, volcanic and a temperate, humic) agricultural soils were studied in the presence and absence of 100 mg L(-1) of sodium dodecyl benzene sulfonate (SDBS), and Suwannee River Humic Acid (SRHA) at pH 5.0-6.0. Transport of carboxylate-modified, 1.8 μm microspheres in soil columns was highly sensitive to the nature of the dissolved organic carbon (DOC), whereas oocysts transport was more affected by soil mineralogy. SDBS increased transport of microspheres from 48% to 87% through the tropical soil and from 43% to 93% in temperate soil. In contrast, SRHA reduced transport of microspheres from 48% to 28% in tropical soil and from 43% to 16% in temperate soil. SDBS also increased oocysts transport through the temperate soil 5-fold, whereas no oocyst transport was detected in tropical soil. SRHA had only a nominal effect in increasing oocysts transport in tropical soil, but caused a 6-fold increase in transport through the temperate soil. Amendments of only 4 mg L(-1) SRHA and SDBS decreased oocyst hydrophobicity from 66% to 20% and from 66% to 5%, respectively. However, SDBS increased microsphere hydrophobicity from 16% to 33%. Soil fines, which includes clays, and SRHA, both caused the oocysts zeta potential (ζ) to become more negative, but caused the highly hydrophilic microspheres to become less negatively charged. The disparate behaviors of the two colloids in the presence of an ionic surfactant and natural organic matter suggest that microspheres may not be suitable surrogates for oocysts in certain types of soils. These results indicate that whether or not DOC inhibits or promotes transport of oocysts and microspheres in agricultural soils and by how much, depends not only on the surface characteristics of the colloid, but the nature of the DOC and the soil mineralogy. PMID:21711011

  19. Malaria vaccine.

    PubMed

    1994-05-01

    Some have argued that the vaccine against malaria developed by Manuel Pattaroyo, a Colombian scientist, is being tested prematurely in humans and that it is unlikely to be successful. While the Pattaroyo vaccine has been shown to confer protection against the relatively mild malaria found in Colombia, doubts exist over whether it will be effective in Africa. Encouraging first results, however, are emerging from field tests in Tanzania. The vaccine triggered a strong new immune response, even in individuals previously exposed to malaria. Additional steps must be taken to establish its impact upon mortality and morbidity. Five major trials are underway around the world. The creator estimates that the first ever effective malaria vaccine could be available for widespread use within five years and he has no intention of securing a patent for the discovery. In another development, malaria specialists from 35 African countries convened at an international workshop in Zimbabwe to compare notes. Participants disparaged financial outlays for the fight against malaria equivalent to 2% of total AIDS funding as insufficient; noted intercountry differences in prevention, diagnosis, and treatment; and found information exchange between anglophone and francophone doctors to be generally poor. PMID:12287671

  20. GENOTYPING CRYPTOSPORIDIUM OOCYSTS IN WATER SAMPLES AS A TOOL FOR THE IDENTIFICATION OF CONTAMINATION SOURCES

    EPA Science Inventory

    The identification of Cryptosporidium oocysts in environmental samples is largely made by the use of an immunofluorescent assay (IFA). Because IFA detects oocysts from all Cryptosporidium parasites, the species distribution and source of Cryptosporidium parasites in environmental...

  1. OCCURRENCE OF 'CRYPTOSPORIDIUM' OOCYSTS IN SEWAGE EFFLUENTS AND SELECTED SURFACE WATERS

    EPA Science Inventory

    An existing method for the detection of Cryptosporidium oocysts in water was modified to investigate oocyst prevalence in large volumes of water. Surface waters and sewage effluents were filtered, eluted from the filter, and concentrated using centrifugation. The resultant pellet...

  2. Sporulation dynamics of poultry Eimeria oocysts in Chennai.

    PubMed

    Venkateswara Rao, P; Raman, M; Gomathinayagam, S

    2015-12-01

    The infective form of Eimeria is the highly resistant oocyst, which is shed in the faeces of infected animals. Present study was carried out to understand the sporulation dynamics of six Eimeria oocysts viz. E. acervulina, E. brunetti, E. maxima, E. mitis, E. necatrix and E. tenella in Chennai. Faecal samples of poultry were collected from various poultry farms located in and around Tamil Nadu. Oocysts of various Eimeria species were examined microscopically for sporulation on a 6 h interval basis till complete sporulation is acheived. The sporulation time recorded was 168, 120, 216, 192, 96 and 96 h for E. acervulina, E. brunetti, E. maxima, E. mitis, E. necatrix and E. tenella respectively. It can be concluded on comparison with previous studies that humid weather conditions delay the sporulation time and dry weather and wet litter is the ideal condition for rapid sporulation. PMID:26688635

  3. Effects of pH and magnetic material on immunomagnetic separation of Cryptosporidium oocysts from concentrated water samples.

    PubMed

    Kuhn, Ryan C; Rock, Channah M; Oshima, Kevin H

    2002-04-01

    In this study, we examined the effect that magnetic materials and pH have on the recoveries of Cryptosporidium oocysts by immunomagnetic separation (IMS). We determined that particles that were concentrated on a magnet during bead separation have no influence on oocyst recovery; however, removal of these particles did influence pH values. The optimal pH of the IMS was determined to be 7.0. The numbers of oocysts recovered from deionized water at pH 7.0 were 26.3% higher than those recovered from samples that were not at optimal pH. The results indicate that the buffers in the IMS kit did not adequately maintain an optimum pH in some water samples. By adjusting the pH of concentrated environmental water samples to 7.0, recoveries of oocysts increased by 26.4% compared to recoveries from samples where the pH was not adjusted. PMID:11916735

  4. Effects of pH and Magnetic Material on Immunomagnetic Separation of Cryptosporidium Oocysts from Concentrated Water Samples

    PubMed Central

    Kuhn, Ryan C.; Rock, Channah M.; Oshima, Kevin H.

    2002-01-01

    In this study, we examined the effect that magnetic materials and pH have on the recoveries of Cryptosporidium oocysts by immunomagnetic separation (IMS). We determined that particles that were concentrated on a magnet during bead separation have no influence on oocyst recovery; however, removal of these particles did influence pH values. The optimal pH of the IMS was determined to be 7.0. The numbers of oocysts recovered from deionized water at pH 7.0 were 26.3% higher than those recovered from samples that were not at optimal pH. The results indicate that the buffers in the IMS kit did not adequately maintain an optimum pH in some water samples. By adjusting the pH of concentrated environmental water samples to 7.0, recoveries of oocysts increased by 26.4% compared to recoveries from samples where the pH was not adjusted. PMID:11916735

  5. Influence of Surface Characteristics on the Stability of Cryptosporidium parvum Oocysts

    PubMed Central

    Butkus, Michael A.; Bays, J. Timothy; Labare, Michael P.

    2003-01-01

    Microelectrophoresis is a common technique for probing the surface chemistry of the Cryptosporidium parvum oocyst. Results of previous studies of the electrophoretic mobility of C. parvum oocysts in which microelectrophoresis was used are incongruent. In this work we demonstrated that capillary electrophoresis may also be used to probe the surface characteristics of C. parvum oocysts, and we related the surface chemistry of C. parvum oocysts to their stability in water. Capillary electrophoresis results indicated that oocysts which were washed in a phosphate buffer solution had neutrally charged surfaces. Inactivation of oocysts with formalin did not influence their electrophoretic mobility, while oocyst populations that were washed in distilled water consisted of cells with both neutral and negative surface charges. These results indicate that washing oocysts in low-ionic-strength distilled water can impart a negative charge to a fraction of the oocysts in the sample. Rapid coagulation experiments indicated that oocysts did not aggregate in a 0.5 M NaCl solution; oocyst stability in the salt solution may have been the result of Lewis acid-base forces, steric stabilization, or some other factor. The presence of sucrose and Percoll could not be readily identified on the surface of C. parvum oocysts by attenuated total reflectance-Fourier transform infrared spectroscopy, suggesting that these purification reagents may not be responsible for the stability of the uncharged oocysts. These findings imply that precipitate enmeshment may be the optimal mechanism of coagulation for removal of oocysts in water treatment systems. The results of this work may help elucidate the causes of variation in oocyst surface characteristics, may ultimately lead to improved removal efficiencies in full-scale water treatment systems, and may improve fate and transport predictions for oocysts in natural systems. PMID:12839749

  6. Effects of Artemisia annua extracts on sporulation of Eimeria oocysts.

    PubMed

    Fatemi, Ahmadreza; Razavi, Seyyed Mostafa; Asasi, Keramat; Goudarzi, Majid Torabi

    2015-03-01

    The present study aimed to compare the effect of different Artemisia annua extracts on sporulation rate of mixed oocysts of Eimeria acervulina, Eimeria necatrix, and Eimeria tenella. Three types of A. annua extracts including petroleum ether (PE), ethanol 96° (E), and water (W) extracts were prepared. Artemisinin, a sesquiterpene lactone endoperoxide derived from the A. annua analysis of each extract was done by high-performance liquid chromatography with ultraviolet detection (HPLC-UV). Fresh fecal samples containing three Eimeria species were floated and counted, and the oocysts were transferred into 50 tubes, each containing 10(5) oocysts per milliliter. Five tubes were control. Each of the other 45 tubes contained one of three doses (1 part per thousand (ppt), 2 ppt, and 5 ppt) and one of three extracts (PE, E, and W extracts) with five replications. The tubes were incubated for 48 h at 25-29 °C and aerated. Sporulation inhibition assay was used to evaluate the activity of extracts. The results showed that the E and PE extracts inhibit sporulation in 2 and 5 ppt concentrations, but the W extract stimulates it in all concentrations. The proportions of oocyst inhibition relative to control were 31 % (5 ppt) and 29 % (2 ppt) for PE and 34 % (5 ppt) and 46 % (2 ppt) for E extract. Furthermore, many oocysts in PE and E groups were wrinkled and contained abnormal sporocysts. The proportions of sporulation stimulation relative to control were 22 % (5 ppt), 24 % (2 ppt), and 27 % (1 ppt) in W extract. Our study is the first to demonstrate that all types of A. annua extracts do not necessarily have a similar activity, and the interaction of all contents and their relative concentrations is an important factor for sporulation stimulation or inhibition. It seems, some parts of unmetabolized excreted PE and E extracts could inhibit oocyst sporulation and eventually affect infection transmission. PMID:25700644

  7. Malaria parasite colonisation of the mosquito midgut--placing the Plasmodium ookinete centre stage.

    PubMed

    Angrisano, Fiona; Tan, Yan-Hong; Sturm, Angelika; McFadden, Geoffrey I; Baum, Jake

    2012-05-15

    Vector-borne diseases constitute an enormous burden on public health across the world. However, despite the importance of interactions between infectious pathogens and their respective vector for disease transmission, the biology of the pathogen in the insect is often less well understood than the forms that cause human infections. Even with the global impact of Plasmodium parasites, the causative agents of malarial disease, no vaccine exists to prevent infection and resistance to all frontline drugs is emerging. Malaria parasite migration through the mosquito host constitutes a major population bottleneck of the lifecycle and therefore represents a powerful, although as yet relatively untapped, target for therapeutic intervention. The understanding of parasite-mosquito interactions has increased in recent years with developments in genome-wide approaches, genomics and proteomics. Each development has shed significant light on the biology of the malaria parasite during the mosquito phase of the lifecycle. Less well understood, however, is the process of midgut colonisation and oocyst formation, the precursor to parasite re-infection from the next mosquito bite. Here, we review the current understanding of cellular and molecular events underlying midgut colonisation centred on the role of the motile ookinete. Further insight into the major interactions between the parasite and the mosquito will help support the broader goal to identify targets for transmission-blocking therapies against malarial disease. PMID:22406332

  8. Spatial distribution of Toxoplasma gondii oocysts in soil in a rural area: Influence of cats and land use.

    PubMed

    Gotteland, Cécile; Gilot-Fromont, Emmanuelle; Aubert, Dominique; Poulle, Marie-Lazarine; Dupuis, Emilie; Dardé, Marie-Laure; Forin-Wiart, Marie-Amélie; Rabilloud, Muriel; Riche, Benjamin; Villena, Isabelle

    2014-10-15

    Toxoplasma gondii is the protozoan parasite responsible for toxoplasmosis, one of the most prevalent zoonoses worldwide. T. gondii infects humans through the ingestion of meat containing bradyzoites or through soil, food or water contaminated with oocysts. Soil contamination with oocysts is increasingly recognized as a major source of infection for humans, but has rarely been quantified directly. In this study, we investigated the spatial pattern of soil contamination with T. gondii over an area of 2.25 km(2) in a rural area of eastern France. The frequency and spatial distribution of T. gondii in soil was analyzed in relation with the factors that could influence the pattern of contamination: cats' frequency and spatial distribution and land use. According to a stratified random sampling Scheme 243 soil samples were collected. The detection of T. gondii oocysts was performed using a recent sensitive method based on concentration and quantitative PCR. Sensitivity was improved by analyzing four replicates at each sampling point. T. gondii was detected in 29.2% of samples. Soil contamination decreased with increasing distance from the core areas of cat home ranges (households and farms). However, it remained high at the periphery of the study site, beyond the boundaries of the largest cat home ranges, and was not related to land use. This pattern of contamination strongly supports the role of inhabited areas which concentrate cat populations as sources of risk for oocyst-induced infection for both humans and animals. Moreover, soil contamination was not restricted to areas of high cat density suggesting a large spatial scale of environmental contamination, which could result from T. gondii oocysts dissemination through rain washing or other mechanisms. PMID:25178554

  9. Sporulation and survival of Toxoplasma gondii oocysts in different types of commercial cat litters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii oocysts are environmentally resistant and can survive outdoors for months in the dry and cold climates. In the present study, sporulation and survival of T. gondii oocysts was studied in different types of cat litters commercially available in the US. Oocysts sporulated within 2-...

  10. Determining UV Inactivation of Toxoplasma gondii Oocysts by Using Cell Culture and a Mouse Bioassay

    EPA Science Inventory

    The effect of UV exposure on Toxoplasma gondii oocysts has not been completely defined for use in water disinfection. This study evaluated UV irradiated oocysts by three assays: a SCID mouse bioassay, an in vitro T. gondii oocyst plaque assay (TOP-assay), and a quantitative reve...

  11. Determining Resistance of Toxoplasma gondii Oocysts to UV Disinfection Using Cell Culture and a Mouse Bioassay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of UV exposure on Toxoplasma gondii oocysts has not been completely defined for use in water disinfection. This study evaluated irradiated oocysts by three assays: a SCID mouse biassay, an in vitro T. gondii oocyst plaque assay (TOP-assay), and a quantitative reverse-transcriptase real-t...

  12. The Applicability of TaqMan-Based Quantitative Real-Time PCR Assays for Detecting and Enumerating Cryptosporidium spp. Oocysts in the Environment

    PubMed Central

    Staggs, Sarah E.; Beckman, Erin M.; Keely, Scott P.; Mackwan, Reena; Ware, Michael W.; Moyer, Alan P.; Ferretti, James A.; Sayed, Abu; Xiao, Lihua; Villegas, Eric N.

    2013-01-01

    Quantitative real-time polymerase chain reaction (qPCR) assays to detect Cryptosporidium oocysts in clinical samples are increasingly being used to diagnose human cryptosporidiosis, but a parallel approach for detecting and identifying Cryptosporidium oocyst contamination in surface water sources has yet to be established for current drinking water quality monitoring practices. It has been proposed that Cryptosporidium qPCR-based assays could be used as viable alternatives to current microscopic-based detection methods to quantify levels of oocysts in drinking water sources; however, data on specificity, analytical sensitivity, and the ability to accurately quantify low levels of oocysts are limited. The purpose of this study was to provide a comprehensive evaluation of TaqMan-based qPCR assays, which were developed for either clinical or environmental investigations, for detecting Cryptosporidium oocyst contamination in water. Ten different qPCR assays, six previously published and four developed in this study were analyzed for specificity and analytical sensitivity. Specificity varied between all ten assays, and in one particular assay, which targeted the Cryptosporidium 18S rRNA gene, successfully detected all Cryptosporidium spp. tested, but also cross-amplified T. gondii, fungi, algae, and dinoflagellates. When evaluating the analytical sensitivity of these qPCR assays, results showed that eight of the assays could reliably detect ten flow-sorted oocysts in reagent water or environmental matrix. This study revealed that while a qPCR-based detection assay can be useful for detecting and differentiating different Cryptosporidium species in environmental samples, it cannot accurately measure low levels of oocysts that are typically found in drinking water sources. PMID:23805235

  13. Plasmodium vivax: ookinete destruction and oocyst development arrest are responsible for Anopheles albimanus resistance to circumsporozoite phenotype VK247 parasites.

    PubMed

    Gonzalez-Ceron, L; Rodriguez, M H; Santillan, F; Chavez, B; Nettel, J A; Hernandez-Avila, J E; Kain, K C

    2001-07-01

    Anopheles albimanus and An. pseudopunctipennis differ in their susceptibilities to Plasmodium vivax circumsporozoite phenotypes. An. pseudopunctipennis is susceptible to phenotype VK247 but almost refractory to VK210. In contrast, An. albimanus is almost refractory to VK247 but susceptible to VK210. To investigate the site in the mosquito and the parasite stage at which resistance mechanisms affect VK247 development in An. albimanus, parasite development was followed in a series of experiments in which both mosquitoes species were simultaneously infected with blood from patients. Parasite phenotype was determined in mature oocysts and salivary gland sporozoites by use of immunofluorescence and Western blot assays and/or gene identification. Ookinete maturation and their densities within the bloodmeal bolus were similar in both mosquito species. Ookinete densities on the internal midgut surface of An. albimanus were 4.7 times higher than those in An. pseudopunctipennis; however, the densities of developing oocysts on the external midgut surface were 6.12 times higher in the latter species. Electron microscopy observation of ookinetes in An. albimanus midgut epithelium indicated severe parasite damage. These results indicate that P. vivax VK247 parasites are destroyed at different parasite stages during migration in An. albimanus midguts. A portion, accumulated on the internal midgut surface, is probably destroyed by the mosquito's digestive enzymes and another portion is most likely destroyed by mosquito defense molecules within the midgut epithelium. A third group, reaching the external midgut surface, initiates oocyst development, but over 90% of them interrupt their development and die. The identification of mechanisms that participate in parasite destruction could provide new elements to construct transgenic mosquitoes resistant to malaria parasites. PMID:11527438

  14. Malaria in the WHO Southeast Asia region.

    PubMed

    Kondrashin, A V

    1992-09-01

    Malaria endemic countries in the southeast Asia region include Bangladesh, Bhutan, India, Indonesia, Maldives, Myanmar, Nepal, Sri Lanka, and Thailand. Population movement and rapid urbanization, both largely caused by unemployment, and environmental deterioration change the malaria pattern. They also increase the incidence of drug-resistant malaria, especially resistance to 4-aminoquinolines. In India, Plasmodium falciparum is linked to the density and distribution of tribals, and, in southern Thailand, rubber tappers have the highest malaria incidence rate (46.29%). Since the population is young and the young are highly sensitive to malaria infection, the region has low community immunity. High malaria priority areas are forests, forested hills, forest fringe areas, developmental project sites, and border areas. High risk groups include infants, young children, pregnant women, and mobile population groups. Malaria incidence is between 2.5-2.8 million cases, and the slide positivity rate is about 3%. P. falciparum constitutes 40% for all malaria cases. In 1988 in India, there were 222 malaria deaths. Malaria is the 7th most common cause of death in Thailand. 3 of the 19 Anopheline species are resistant to at least 1 insecticide, particularly DDT. Posteradication epidemics surfaced in the mid-1970s. Malaria control programs tend to use the primary health care and integration approach to malaria control. Antiparasite measures range from a single-dose of an antimalarial to mass drug administration. Residual spraying continues to be the main strategy of vector control. Some other vector control measures are fish feeding on mosquito larvae, insecticide impregnated mosquito nets, and repellents. Control programs also have health education activities. India allocates the highest percentage of its total health budget to malaria control (21.54%). Few malariology training programs exist in the region. Slowly processed surveillance data limit the countries' ability to

  15. Effects of Developmental Temperature on Gametocysts and Oocysts of Two Species of Gregarines Blabericola migrator and Blabericola cubensis (Apicomplexa: Eugregarinida: Blabericolidae) Parasitizing Blaberid Cockroaches (Dictyoptera: Blaberidae).

    PubMed

    Kolman, Jon A; Clopton, Richard E; Clopton, Debra T

    2015-12-01

    Abiotic environmental conditions, especially temperature and humidity, have profound effects on the growth and development of gregarines, but these effects remain largely undocumented. Quantifying the effects of environmental conditions on the growth and development of exogenous gregarine ontogenetic stages is an important first step in understanding the transmission, population dynamics, and environmental persistence of gregarine infection. In this study, we examined the effect of 6 environmental temperatures (10, 18, 22, 27, 35, and 40 C) at constant humidity (0 mmHg vapor pressure deficit) on gametocyst development and oocyst viability in 2 gregarine species: Blabericola migrator and Blabericola cubensis parasitizing the Tiger-striped Hissing Cockroach, Princisia vanwaerebecki, and the Discoid Cockroach, Blaberus discoidalis, respectively. Temperature has a significant effect on gametocyst development and oocyst viability for both gregarine species. Gametocyst development for both gregarine species displays a similar threshold response to environmental temperature: 10 and 40 C represent extremes outside their developmental range, but within these extremes, the relationship between gametocyst development and temperature is weakly direct. Dehiscence increased with temperature from 68% at 18 C to 93% at 22 C and remained at that level through 35 C. Developmental temperature also has a meaningful but inverse effect on oocyst viability of both B. migrator and B. cubensis. For both species, oocyst viability is highest at 18 and 22 C and is significantly reduced at 27 and 35 C. Thus oocyst production and sporozoite viability are linked but environmentally independent phenomena. Overall, there is an acceptable developmental temperature zone for B. migrator and B. cubensis that ranges from 18 to 27 C, but production of viable sporozoites is greatest in a relatively narrow zone around 22 C. Prior studies have postulated that mechanisms that concentrate oocysts and hosts

  16. Managing malaria in the intensive care unit

    PubMed Central

    Marks, M.; Gupta-Wright, A.; Doherty, J. F.; Singer, M.; Walker, D.

    2014-01-01

    The number of people travelling to malaria-endemic countries continues to increase, and malaria remains the commonest cause of serious imported infection in non-endemic areas. Severe malaria, mostly caused by Plasmodium falciparum, often requires intensive care unit (ICU) admission and can be complicated by cerebral malaria, respiratory distress, acute kidney injury, bleeding complications, and co-infection. The mortality from imported malaria remains significant. This article reviews the manifestations, complications and principles of management of severe malaria as relevant to critical care clinicians, incorporating recent studies of anti-malarial and adjunctive treatment. Effective management of severe malaria includes prompt diagnosis and early institution of effective anti-malarial therapy, recognition of complications, and appropriate supportive management in an ICU. All cases should be discussed with a specialist unit and transfer of the patient considered. PMID:24946778

  17. Clinical Aspects of Uncomplicated and Severe Malaria

    PubMed Central

    Bartoloni, Alessandro; Zammarchi, Lorenzo

    2012-01-01

    The first symptoms of malaria, common to all the different malaria species, are nonspecific and mimic a flu-like syndrome. Although fever represents the cardinal feature, clinical findings in malaria are extremely diverse and may range in severity from mild headache to serious complications leading to death, particularly in falciparum malaria. As the progression to these complications can be rapid, any malaria patient must be assessed and treated rapidly, and frequent observations are needed to look for early signs of systemic complications. In fact, severe malaria is a life threatening but treatable disease. The protean and nonspecific clinical findings occurring in malaria (fever, malaise, headache, myalgias, jaundice and sometimes gastrointestinal symptoms of nausea, vomiting and diarrhoea) may lead physicians who see malaria infrequently to a wrong diagnosis, such as influenza (particularly during the seasonal epidemic flu), dengue, gastroenteritis, typhoid fever, viral hepatitis, encephalitis. Physicians should be aware that malaria is not a clinical diagnosis but must be diagnosed, or excluded, by performing microscopic examination of blood films. Prompt diagnosis and appropriate treatment are then crucial to prevent morbidity and fatal outcomes. Although Plasmodium falciparum malaria is the major cause of severe malaria and death, increasing evidence has recently emerged that Plasmodium vivax and Plasmodium knowlesi can also be severe and even fatal. PMID:22708041

  18. Cryptosporidium parvum oocysts in zebra mussels (Dreissena polymorpha): evidence from the St Lawrence River.

    PubMed

    Graczyk, T K; Marcogliese, D J; de Lafontaine, Y; Da Silva, A J; Mhangami-Ruwende, B; Pieniazek, N J

    2001-03-01

    Molluscan shellfish can recover and concentrate environmentally derived waterborne pathogens and can be used for the sanitary assessment of water quality. Oocysts of Cryptosporidium parvum (genotype 1) were identified in zebra mussels (Dreissena polymorpha) from the St. Lawrence River, Quebec. Approximately 67 oocysts/ml of hemolymph and 129 oocysts/g of soft tissue were recovered. The adjusted concentration of oocysts per gram of tissue was 2.2 x 10(2), and approximately 4.4 x 10(2) oocysts were recovered from a single mussel. Zebra mussels can serve as biological indicators of waterborne contamination with Cryptosporidium. PMID:11293571

  19. Methods to produce and safely work with large numbers of Toxoplasma gondii oocysts and bradyzoite cysts

    PubMed Central

    Fritz, H.; Barr, B.; Packham, A.; Melli, A.; Conrad, P.A.

    2012-01-01

    Two major obstacles to conducting studies with Toxoplasma gondii oocysts are the difficulty in reliably producing large numbers of this life stage and safety concerns because the oocyst is the most environmentally resistant stage of this zoonotic organism. Oocyst production requires oral infection of the definitive feline host with adequate numbers of T. gondii organisms to obtain unsporulated oocysts that are shed in the feces for 3-10 days after infection. Since the most successful and common mode of experimental infection of kittens with T. gondii is by ingestion of bradyzoite tissue cysts, the first step in successful oocyst production is to ensure a high bradyzoite tissue cyst burden in the brains of mice that can be used for the oral inoculum. We compared two methods for producing bradyzoite brain cysts in mice, by infecting them either orally or subcutaneously with oocysts. In both cases, oocysts derived from a low passage T. gondii Type II strain (M4) were used to infect eight-ten week-old Swiss Webster mice. First the number of bradyzoite cysts that were purified from infected mouse brains was compared. Then to evaluate the effect of the route of oocyst inoculation on tissue cyst distribution in mice, a second group of mice was infected with oocysts by one of each route and tissues were examined by histology. In separate experiments, brains from infected mice were used to infect kittens for oocyst production. Greater than 1.3 billion oocysts were isolated from the feces of two infected kittens in the first production and greater than 1.8 billion oocysts from three kittens in the second production. Our results demonstrate that oral delivery of oocysts to mice results in both higher cyst loads in the brain and greater cyst burdens in other tissues examined as compared to those of mice that received the same number of oocysts subcutaneously. The ultimate goal in producing large numbers of oocysts in kittens is to generate adequate amounts of starting material

  20. A COMPARISON OF ENUMERATION TECHNIQUES FOR CRYPTOSPORIDIUM PARVUM OOCYSTS

    EPA Science Inventory

    A variety of methods have been used to enumerate Cryptosporidium parvum oocysts from source or drinking waters. The reliability of these counting methods varies, in part, with suspension density, sample purity, and other factors. Frequently, the method of determination of suspens...

  1. DETECTION OF CRYPTOSPORIDIUM OOCYSTS IN SOURCE AND FINISHED WATERS

    EPA Science Inventory

    Numerous waterborne outbreaks of cryptosporidiosis have occurred with the most notable being the 1993 episode in Milwaukee. As a result, the past decade has seen a massive effort expended on the development of methods to detect Cryptosporidium parvum oocysts in source and finish...

  2. Metam sodium reduces viability and infectivity of Eimeria oocysts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Metam sodium (MS, sodium N-methyldithiocarbamate) is a widely used soil pesticide. Fumigation or chemical sterilization of poultry litter containing infectious oocysts could be an effective strategy to block the transmission of avian coccidia. In the current study the effect of MS on the viability ...

  3. A sensitive method for detecting and genotyping Cryptosporidium parvum oocysts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cryptosporidium parvum oocysts represent a considerable health risk to humans and animals because the parasite has a low infectious dose and usually exists in low numbers in environmental samples, which makes detection problematic. The purpose of this study was to evaluate Cryspovirus as a target f...

  4. IMMUNOFLUORESCENCE DETECTION OF 'CRYPTOSPORIDIUM' OOCYSTS IN FECAL SMEARS

    EPA Science Inventory

    An indirect fluorescent antibody (IFA) procedure was developed for the detection of Cryptosporidium sp. oocysts in human, nonhuman primate, and bovine fecal smears. The procedure, which takes about 90 min to perform, involves the use of a rabbit antiserum against Cryptosporidium ...

  5. Vivax malaria.

    PubMed

    Baker, P B; Dronen, S C

    1986-01-01

    Malaria occurs in the United States infrequently and is found exclusively among immigrants and travelers returning from areas where the disease is endemic. Cases of acute relapses of Plasmodium vivax infection can present to the emergency department. Patients are often immigrants from developing countries who were symptom-free in this country for weeks or months preceding their illness. The clinical presentation and current treatment of malaria are reviewed. Malarial infection may become apparent months after leaving endemic areas despite adherence to prophylactic regimens. The disease usually responds to appropriate drug therapy with rapid and often dramatic results, but it can be fatal if unrecognized. PMID:3511922

  6. Seasonal Retention and Release of Cryptosporidium parvum Oocysts by Environmental Biofilms in the Laboratory ▿

    PubMed Central

    Wolyniak, E. A.; Hargreaves, B. R.; Jellison, K. L.

    2010-01-01

    Cryptosporidium is a genus of waterborne protozoan parasites that causes significant gastrointestinal disease in humans. These parasites can accumulate in environmental biofilms and be subsequently released to contaminate water supplies. Natural microbial assemblages were collected each season from an eastern Pennsylvania stream and used to grow biofilms in laboratory microcosms in which influx, efflux, and biofilm retention were determined from daily oocyst counts. For each seasonal biofilm, oocysts attached to the biofilm quickly during oocyst dosing. Upon termination of oocyst dosing, the percentage of oocysts retained within the biofilm decreased to a new steady state within 5 days. Seasonal differences in biofilm retention of oocysts were observed. The spring biofilm retained the greatest percentage of oocysts, followed (in decreasing order) by the winter, summer, and fall biofilms. There was no statistically significant correlation between the percentage of oocysts attached to the biofilm and (i) any measured stream water quality parameter (including temperature, pH, conductivity, and dissolved organic carbon concentration) or (ii) experimental temperature. Seasonal differences in oocyst retention persisted when biofilms were tested with stream water from a different season. These data suggest that seasonal variation in the microbial community and resulting biofilm architecture may be more important to oocyst transport in this stream site than water quality. The biofilm attachment and detachment dynamics of C. parvum oocysts have implications for public health, and the drinking water industry should recognize that the potential exists for pathogen-free water to become contaminated during the distribution process as a result of biofilm dynamics. PMID:20023100

  7. Transport of Cryptosporidium parvum oocysts in soil columns following applications of raw and separated liquid slurries.

    PubMed

    Petersen, Heidi H; Enemark, Heidi L; Olsen, Annette; Amin, M G Mostofa; Dalsgaard, Anders

    2012-09-01

    The potential for the transport of viable Cryptosporidium parvum oocysts through soil to land drains and groundwater was studied using simulated rainfall and intact soil columns which were applied raw slurry or separated liquid slurry. Following irrigation and weekly samplings over a 4-week period, C. parvum oocysts were detected from all soil columns regardless of slurry type and application method, although recovery rates were low (<1%). Soil columns with injected liquid slurry leached 73 and 90% more oocysts compared to columns with injected and surface-applied raw slurries, respectively. Among leachate samples containing oocysts, 44/72 samples yielded viable oocysts as determined by a dye permeability assay (DAPI [4',6'-diamidino-2-phenylindole]/propidium iodide) with the majority (41%) of viable oocysts found in leachate from soil columns with added liquid slurry. The number of viable oocysts was positively correlated (r = 0.63) with the total number of oocysts found. Destructively sampling of the soil columns showed that type of slurry and irrigation played a role in the vertical distribution of oocysts, with more oocysts recovered from soil columns added liquid slurry irrespective of the irrigation status. Further studies are needed to determine the effectiveness of different slurry separation technologies to remove oocysts and other pathogens, as well as whether the application of separated liquid slurry to agricultural land may represent higher risks for groundwater contamination compared to application of raw slurry. PMID:22706058

  8. Effects of clopidol on sporulation and infectivity of Eimeria tenella oocysts.

    PubMed

    Arakawa, A; Tanaka, Y; Baba, E; Fukata, T

    1991-01-01

    Feed additive anticoccidials currently used in Japan were examined for possible effects on oocyst sporulation of Eimeria tenella. Monensin, salinomycin, lasalocid, amprolium plus ethpabate, amporolium plus ethopabate plus sulfaquinoxaline, clopidol, or nicarbazin were given to chickens continuously via the feed at the recommended use level or one-half of that level. Oocysts discharged in feces 7-8 days post inoculation (PI) were collected and aerated for sporulation. Low sporulation rate was noted, when clopidol at 62.5 mg kg-1 was given from 4 to 7 days PI. These oocysts were as infective as oocysts from controls, based on weight gain, feed efficiency, gross lesion score of cecae, and oocyst count 7 days PI. The results of the study indicated that the second schizogony and gametogony are vulnerable to clopidol, as evidenced by oocyst sporulation, but infectivity of these sporulated oocysts was not affected. PMID:2024430

  9. Viability staining and animal infectivity of Cryptosporidium andersoni oocysts after long-term storage.

    PubMed

    Kvác, Martin; Kvetonová, Dana; Salát, Jirí; Ditrich, Oleg

    2007-01-01

    Preservation of biological properties of oocysts during the storage is critical for experimental work. Stomach species of cryptosporidia are less resistant against external influences, and their infectivity decreases rapidly in comparison with intestinal cryptosporidia. Cryptosporidium andersoni oocysts lost their infectivity for gerbil (Meriones unguiculatus) after 7 months storage in deionised water (DW) or in 2.5% potassium dichromate solution (PDS). Evaluation of oocyst viability by flow cytometry indicates higher percentage of viable oocysts stored in PDS than in DW, particularly after 6 months of storage. However, direct counting using fluorescent microscope revealed that these results are false and are influenced by the change of staining properties during the storage in PDS. Moreover, the examination of oocyst integrity by flow cytometry revealed that oocysts preserved in PDS kept their wall integrity longer than those stored in DW, and this fact should be taken into consideration during quantification of oocyst survival. PMID:17024363

  10. Urbanization and the global malaria recession

    PubMed Central

    2013-01-01

    Background The past century has seen a significant contraction in the global extent of malaria transmission, resulting in over 50 countries being declared malaria free, and many regions of currently endemic countries eliminating the disease. Moreover, substantial reductions in transmission have been seen since 1900 in those areas that remain endemic today. Recent work showed that this malaria recession was unlikely to have been driven by climatic factors, and that control measures likely played a significant role. It has long been considered, however, that economic development, and particularly urbanization, has also been a causal factor. The urbanization process results in profound socio-economic and landscape changes that reduce malaria transmission, but the magnitude and extent of these effects on global endemicity reductions are poorly understood. Methods Global data at subnational spatial resolution on changes in malaria transmission intensity and urbanization trends over the past century were combined to examine the relationships seen over a range of spatial and temporal scales. Results/Conclusions A consistent pattern of increased urbanization coincident with decreasing malaria transmission and elimination over the past century was found. Whilst it remains challenging to untangle whether this increased urbanization resulted in decreased transmission, or that malaria reductions promoted development, the results point to a close relationship between the two, irrespective of national wealth. The continuing rapid urbanization in malaria-endemic regions suggests that such malaria declines are likely to continue, particularly catalyzed by increasing levels of direct malaria control. PMID:23594701

  11. An Open Source Business Model for Malaria

    PubMed Central

    Årdal, Christine; Røttingen, John-Arne

    2015-01-01

    Greater investment is required in developing new drugs and vaccines against malaria in order to eradicate malaria. These precious funds must be carefully managed to achieve the greatest impact. We evaluate existing efforts to discover and develop new drugs and vaccines for malaria to determine how best malaria R&D can benefit from an enhanced open source approach and how such a business model may operate. We assess research articles, patents, clinical trials and conducted a smaller survey among malaria researchers. Our results demonstrate that the public and philanthropic sectors are financing and performing the majority of malaria drug/vaccine discovery and development, but are then restricting access through patents, ‘closed’ publications and hidden away physical specimens. This makes little sense since it is also the public and philanthropic sector that purchases the drugs and vaccines. We recommend that a more “open source” approach is taken by making the entire value chain more efficient through greater transparency which may lead to more extensive collaborations. This can, for example, be achieved by empowering an existing organization like the Medicines for Malaria Venture (MMV) to act as a clearing house for malaria-related data. The malaria researchers that we surveyed indicated that they would utilize such registry data to increase collaboration. Finally, we question the utility of publicly or philanthropically funded patents for malaria medicines, where little to no profits are available. Malaria R&D benefits from a publicly and philanthropically funded architecture, which starts with academic research institutions, product development partnerships, commercialization assistance through UNITAID and finally procurement through mechanisms like The Global Fund to Fight AIDS, Tuberculosis and Malaria and the U.S.’ President’s Malaria Initiative. We believe that a fresh look should be taken at the cost/benefit of patents particularly related to new

  12. An open source business model for malaria.

    PubMed

    Årdal, Christine; Røttingen, John-Arne

    2015-01-01

    Greater investment is required in developing new drugs and vaccines against malaria in order to eradicate malaria. These precious funds must be carefully managed to achieve the greatest impact. We evaluate existing efforts to discover and develop new drugs and vaccines for malaria to determine how best malaria R&D can benefit from an enhanced open source approach and how such a business model may operate. We assess research articles, patents, clinical trials and conducted a smaller survey among malaria researchers. Our results demonstrate that the public and philanthropic sectors are financing and performing the majority of malaria drug/vaccine discovery and development, but are then restricting access through patents, 'closed' publications and hidden away physical specimens. This makes little sense since it is also the public and philanthropic sector that purchases the drugs and vaccines. We recommend that a more "open source" approach is taken by making the entire value chain more efficient through greater transparency which may lead to more extensive collaborations. This can, for example, be achieved by empowering an existing organization like the Medicines for Malaria Venture (MMV) to act as a clearing house for malaria-related data. The malaria researchers that we surveyed indicated that they would utilize such registry data to increase collaboration. Finally, we question the utility of publicly or philanthropically funded patents for malaria medicines, where little to no profits are available. Malaria R&D benefits from a publicly and philanthropically funded architecture, which starts with academic research institutions, product development partnerships, commercialization assistance through UNITAID and finally procurement through mechanisms like The Global Fund to Fight AIDS, Tuberculosis and Malaria and the U.S.' President's Malaria Initiative. We believe that a fresh look should be taken at the cost/benefit of patents particularly related to new malaria

  13. Recovery of Waterborne Cryptosporidium parvum Oocysts by Freshwater Benthic Clams (Corbicula fluminea)

    PubMed Central

    Graczyk, Thaddeus K.; Fayer, Ronald; Cranfield, Michael R.; Conn, David Bruce

    1998-01-01

    Asian freshwater clams, Corbicula fluminea, exposed for 24 h to 38 liters of water contaminated with infectious Cryptosporidium parvum oocysts (1.00 × 106 oocysts/liter; approximately 1.9 × 105 oocysts/clam) were examined (hemolymph, gills, gastrointestinal [GI] tract, and feces) on days 1, 2, 3, 7, and 14 postexposure (PE). No oocysts were detected in the water 24 h after the contamination event. The percentage of oocyst-containing clams varied from 20 to 100%, depending on the type of tissue examined and the technique used—acid-fast stain (AFS) or immunofluorescent antibody (IFA). The oocysts were found in clam tissues and feces on days 1 through 14 PE; the oocysts extracted from the tissues on day 7 PE were infectious for neonatal BALB/c mice. Overall, the highest number of positive samples was obtained when gills and GI tracts were processed with IFA (prevalence, 97.5%). A comparison of the relative oocyst numbers indicated that overall, 58.3% of the oocysts were found in clam tissues and 41.7% were found in feces when IFA was used; when AFS was used, the values were 51.9 and 48.1%, respectively. Clam-released oocysts were always surrounded by feces; no free oocysts or oocysts disassociated from fecal matter were observed. The results indicate that these benthic freshwater clams are capable of recovery and sedimentation of waterborne C. parvum oocysts. To optimize the detection of C. parvum oocysts in C. fluminea tissue, it is recommended that gill and GI tract samples be screened with IFA (such as that in the commercially available MERIFLUOR test kit). PMID:9464376

  14. The history of 20th century malaria control in Peru

    PubMed Central

    2013-01-01

    Malaria has been part of Peruvian life since at least the 1500s. While Peru gave the world quinine, one of the first treatments for malaria, its history is pockmarked with endemic malaria and occasional epidemics. In this review, major increases in Peruvian malaria incidence over the past hundred years are described, as well as the human factors that have facilitated these events, and concerted private and governmental efforts to control malaria. Political support for malaria control has varied and unexpected events like vector and parasite resistance have adversely impacted morbidity and mortality. Though the ready availability of novel insecticides like DDT and efficacious medications reduced malaria to very low levels for a decade after the post eradication era, malaria reemerged as an important modern day challenge to Peruvian public health. Its reemergence sparked collaboration between domestic and international partners towards the elimination of malaria in Peru. PMID:24001096

  15. Co-infection with Plasmodium berghei and Trypanosoma brucei increases severity of malaria and trypanosomiasis in mice.

    PubMed

    Ademola, Isaiah Oluwafemi; Odeniran, Paul Olalekan

    2016-07-01

    Individuals in natural populations may be infected with multiple different parasites at a time. These parasites may interact with each other or act independently in the host, and this may result to varying outcomes on host health and survival. This study therefore aimed at investigating the health impact of co-infection of mice with Plasmodium berghei and Trypanosoma brucei. Forty Swiss albino mice (14-17g) were divided into four groups of ten. Mice in groups A and B received 10(6)P. berghei and groups B and C 10(5)T. brucei, while group D were uninfected. The co-infected mice had higher P. berghei and T. brucei parasitaemia, compared with the mono-infected mice. The co-infected mice had significantly (p<0.05) lower survival rate compared with the mono-infected mice. Co-infection of mice with P. berghei and T. brucei resulted in rapid P. berghei and T. brucei development and increased parasitaemia. The leukocyte numbers significantly (p<0.05) reduced on days 12 and 15 post infection among P. berghei infected mice, in the presence or absence of T. brucei. Anaemia and hypoglycaemia was more severe in the co-infected mice. Therefore, co-infection of mice with P. berghei and T. brucei may increase pathologic impact to the host by increasing parasitaemia. PMID:27021269

  16. Investigating Attachment Behaviors of Cryptosporidium Parvum Oocysts Using Collision Efficiency in Laboratory Column Experiments

    NASA Astrophysics Data System (ADS)

    Park, Y.; Hou, L.; Atwill, R.; Packman, A. I.; Harter, T.

    2009-12-01

    Cryptosporidium is one of the most common enteric parasites of humans and domestic animals, and a number of outbreaks of Cryprosporidiosis, a diarrheal disease caused by Cryptosporidium have been reported worldwide. Natural porous media has been demonstrated to be an effective filter for removing Cryptosporidium parvum from contaminated water and the amount of Cryptosporidium filtered is known to be highly dependent on physical and chemical conditions of the porous media and the water. Cryptosporidium deposition in saturated porous media involves two main steps: approach and attachment. In contrast to the approach mechanisms, attachment processes have not been systematically described to predict a priori because theories that represent attachment behavior (colloid stability) such as DLVO are insufficient to explain experimental data. For this reason, attachment efficiency is calculated based on empirical data, typically experimental breakthrough curves in laboratory columns or field experiments. In this study, collision (attachment) efficiencies (α) of C. parvum oocyst were calculated to test the effect of chemical property changes on the association of oocysts with sand grains. The breakthrough curve data obtained from twelve column experiments and three models were employed to calculate single collector efficiency (η) and α. The first ten experiments were conducted by changing ionic strength and pH, and mixing with natural sediments under the same physical properties (same η). Our experiment results show that iron coating or clay/suspended solids mixture drastically enhanced oocyst deposition. The experiments also showed that increase in ionic strength and decrease in pH enhanced the attachment efficiency. However, the experiment with 100mM NaCl resulted in low attachment efficiency and the experiment with pH 8.5 showed similar attachment efficiency to the one at pH 7. Based on the results from two additional experiments with different flow velocities, it

  17. Lymphocyte Perturbations in Malawian Children with Severe and Uncomplicated Malaria

    PubMed Central

    Mandala, Wilson L.; Msefula, Chisomo L.; Gondwe, Esther N.; Gilchrist, James J.; Graham, Stephen M.; Pensulo, Paul; Mwimaniwa, Grace; Banda, Meraby; Taylor, Terrie E.; Molyneux, Elizabeth E.; Drayson, Mark T.; Ward, Steven A.; Molyneux, Malcolm E.

    2015-01-01

    Lymphocytes are implicated in immunity and pathogenesis of severe malaria. Since lymphocyte subsets vary with age, assessment of their contribution to different etiologies can be difficult. We immunophenotyped peripheral blood from Malawian children presenting with cerebral malaria, severe malarial anemia, and uncomplicated malaria (n = 113) and healthy aparasitemic children (n = 42) in Blantyre, Malawi, and investigated lymphocyte subset counts, activation, and memory status. Children with cerebral malaria were older than those with severe malarial anemia. We found panlymphopenia in children presenting with cerebral malaria (median lymphocyte count, 2,100/μl) and uncomplicated malaria (3,700/μl), which was corrected in convalescence and was absent in severe malarial anemia (5,950/μl). Median percentages of activated CD69+ NK (73%) and γδ T (60%) cells were higher in cerebral malaria than in other malaria types. Median ratios of memory to naive CD4+ lymphocytes were higher in cerebral malaria than in uncomplicated malaria and low in severe malarial anemia. The polarized lymphocyte subset profiles of different forms of severe malaria are independent of age. In conclusion, among Malawian children cerebral malaria is characterized by lymphocyte activation and increased memory cells, consistent with immune priming. In contrast, there are reduced memory cells and less activation in severe malaria anemia. Further studies are required to understand whether these immunological profiles indicate predisposition of some children to one or another form of severe malaria. PMID:26581890

  18. Malaria Prophylaxis: A Comprehensive Review

    PubMed Central

    Castelli, Francesco; Odolini, Silvia; Autino, Beatrice; Foca, Emanuele; Russo, Rosario

    2010-01-01

    The flow of international travellers to and from malaria-endemic areas, especially Africa, has increased in recent years. Apart from the very high morbidity and mortality burden imposed on malaria-endemic areas, imported malaria is the main cause of fever possibly causing severe disease and death in travellers coming from tropical and subtropical areas, particularly Sub-Saharan Africa. The importance of behavioural preventive measures (bed nets, repellents, etc.), adequate chemoprophylaxis and, in selected circumstances, stand-by emergency treatment may not be overemphasized. However, no prophylactic regimen may offer complete protection. Expert advice is needed to tailor prophylactic advice according to traveller (age, baseline clinical conditions, etc.) and travel (destination, season, etc.) characteristics in order to reduce malaria risk.

  19. Malaria ecology and climate change

    NASA Astrophysics Data System (ADS)

    McCord, G. C.

    2016-05-01

    Understanding the costs that climate change will exact on society is crucial to devising an appropriate policy response. One of the channels through while climate change will affect human society is through vector-borne diseases whose epidemiology is conditioned by ambient ecology. This paper introduces the literature on malaria, its cost on society, and the consequences of climate change to the physics community in hopes of inspiring synergistic research in the area of climate change and health. It then demonstrates the use of one ecological indicator of malaria suitability to provide an order-of-magnitude assessment of how climate change might affect the malaria burden. The average of Global Circulation Model end-of-century predictions implies a 47% average increase in the basic reproduction number of the disease in today's malarious areas, significantly complicating malaria elimination efforts.

  20. ‘Manipulation’ without the parasite: altered feeding behaviour of mosquitoes is not dependent on infection with malaria parasites

    PubMed Central

    Cator, Lauren J.; George, Justin; Blanford, Simon; Murdock, Courtney C.; Baker, Thomas C.; Read, Andrew F.; Thomas, Matthew B.

    2013-01-01

    Previous studies have suggested that Plasmodium parasites can manipulate mosquito feeding behaviours such as probing, persistence and engorgement rate in order to enhance transmission success. Here, we broaden analysis of this ‘manipulation phenotype’ to consider proximate foraging behaviours, including responsiveness to host odours and host location. Using Anopheles stephensi and Plasmodium yoelii as a model system, we demonstrate that mosquitoes with early stage infections (i.e. non-infectious oocysts) exhibit reduced attraction to a human host, whereas those with late-stage infections (i.e. infectious sporozoites) exhibit increased attraction. These stage-specific changes in behaviour were paralleled by changes in the responsiveness of mosquito odourant receptors, providing a possible neurophysiological mechanism for the responses. However, we also found that both the behavioural and neurophysiological changes could be generated by immune challenge with heat-killed Escherichia coli and were thus not tied explicitly to the presence of malaria parasites. Our results support the hypothesis that the feeding behaviour of female mosquitoes is altered by Plasmodium, but question the extent to which this is owing to active manipulation by malaria parasites of host behaviour. PMID:23698008

  1. Prevalence of Enteric Protozoan Oocysts with Special Reference to Sarcocystis cruzi among Fecal Samples of Diarrheic Immunodeficient Patients in Iran

    PubMed Central

    Agholi, Mahmoud; Shahabadi, Shahrbanou Naderi; Motazedian, Mohammad Hossein; Hatam, Gholam Reza

    2016-01-01

    The genus Sarcocystis is not usually considered as an important enteric pathogen in immune compromised patients. It might be expected that species for which humans are the final host (Sarcocystis hominis and Sarcocystis suihominis as well as possibly others) would be encountered increasingly often in immunodeficient persons. This study aimed to address how to detect and differentiate Sarcocystis oocysts and/or sporocysts from enteric protozoans in the diarrheal samples of immunodeficient patients in Shiraz, Iran. Diarrheal samples of 741 immunodeficient patients with recurrent persistent or chronic diarrhea were examined by microscopy and molecular biological analysis. Oocysts-positive samples were 68 Cryptosporidium spp., 9 Cystoisospora belli (syn. Isospora belli), 2 Cyclospora cayetanensis, and 15 microsporidia (Enterocytozoon bieneusi). Sarcocystis-like sporocysts found from a woman were identified as Sarcocystis cruzi through 18S rDNA amplification and phylogenetic analysis. To the best of our knowledge, this is the first report of S. cruzi from a human. PMID:27417091

  2. Inhibition of Malaria Infection in Transgenic Anopheline Mosquitoes Lacking Salivary Gland Cells.

    PubMed

    Yamamoto, Daisuke S; Sumitani, Megumi; Kasashima, Katsumi; Sezutsu, Hideki; Matsuoka, Hiroyuki

    2016-09-01

    Malaria is an important global public health challenge, and is transmitted by anopheline mosquitoes during blood feeding. Mosquito vector control is one of the most effective methods to control malaria, and population replacement with genetically engineered mosquitoes to block its transmission is expected to become a new vector control strategy. The salivary glands are an effective target tissue for the expression of molecules that kill or inactivate malaria parasites. Moreover, salivary gland cells express a large number of molecules that facilitate blood feeding and parasite transmission to hosts. In the present study, we adapted a functional deficiency system in specific tissues by inducing cell death using the mouse Bcl-2-associated X protein (Bax) to the Asian malaria vector mosquito, Anopheles stephensi. We applied this technique to salivary gland cells, and produced a transgenic strain containing extremely low amounts of saliva. Although probing times for feeding on mice were longer in transgenic mosquitoes than in wild-type mosquitoes, transgenic mosquitoes still successfully ingested blood. Transgenic mosquitoes also exhibited a significant reduction in oocyst formation in the midgut in a rodent malaria model. These results indicate that mosquito saliva plays an important role in malaria infection in the midgut of anopheline mosquitoes. The dysfunction in the salivary glands enabled the inhibition of malaria transmission from hosts to mosquito midguts. Therefore, salivary components have potential in the development of new drugs or genetically engineered mosquitoes for malaria control. PMID:27598328

  3. Effects of ozone, chlorine dioxide, chlorine, and monochloramine on Cryptosporidium parvum oocyst viability.

    PubMed Central

    Korich, D G; Mead, J R; Madore, M S; Sinclair, N A; Sterling, C R

    1990-01-01

    Purified Cryptosporidium parvum oocysts were exposed to ozone, chlorine dioxide, chlorine, and monochloramine. Excystation and mouse infectivity were comparatively evaluated to assess oocyst viability. Ozone and chlorine dioxide more effectively inactivated oocysts than chlorine and monochloramine did. Greater than 90% inactivation as measured by infectivity was achieved by treating oocysts with 1 ppm of ozone (1 mg/liter) for 5 min. Exposure to 1.3 ppm of chlorine dioxide yielded 90% inactivation after 1 h, while 80 ppm of chlorine and 80 ppm of monochloramine required approximately 90 min for 90% inactivation. The data indicate that C. parvum oocysts are 30 times more resistant to ozone and 14 times more resistant to chlorine dioxide than Giardia cysts exposed to these disinfectants under the same conditions. With the possible exception of ozone, the use of disinfectants alone should not be expected to inactivate C. parvum oocysts in drinking water. PMID:2339894

  4. Effects of ozone, chlorine dioxide, chlorine, and monochloramine on Cryptosporidium parvum oocyst viability

    SciTech Connect

    Korich, D.G.; Mead, J.R.; Madore, M.S.; Sinclair, N.A.; Sterling, C.R. )

    1990-05-01

    Purified Cryptosporidium parvum oocysts were exposed to ozone, chlorine dioxide, chlorine, and monochloramine. Excystation and mouse infectivity were comparatively evaluated to assess oocyst viability. Ozone and chlorine dioxide more effectively inactivated oocysts than chlorine and monochloramine did. Greater than 90% inactivation as measured by infectivity was achieved by treating oocysts with 1 ppm of ozone (1 mg/liter) for 5 min. Exposure to 1.3 ppm of chlorine dioxide yielded 90% inactivation after 1 h, while 80 ppm of chlorine and 80 ppm of monochloramine required approximately 90 min for 90% inactivation. The data indicate that C. parvum oocysts are 30 times more resistant to ozone and 14 times more resistant to chlorine dioxide than Giardia cysts exposed to these disinfectants under the same conditions. With the possible exception of ozone, the use of disinfectants alone should not be expected to inactivate C. parvum oocysts in drinking water.

  5. Molecules to modeling: Toxoplasma gondii oocysts at the human–animal–environment interface

    PubMed Central

    VanWormer, Elizabeth; Fritz, Heather; Shapiro, Karen; Mazet, Jonna A.K.; Conrad, Patricia A.

    2013-01-01

    Environmental transmission of extremely resistant Toxoplasma gondii oocysts has resulted in infection of diverse species around the world, leading to severe disease and deaths in human and animal populations. This review explores T. gondii oocyst shedding, survival, and transmission, emphasizing the importance of linking laboratory and landscape from molecular characterization of oocysts to watershed-level models of oocyst loading and transport in terrestrial and aquatic systems. Building on discipline-specific studies, a One Health approach incorporating tools and perspectives from diverse fields and stakeholders has contributed to an advanced understanding of T. gondii and is addressing transmission at the rapidly changing human–animal–environment interface. PMID:23218130

  6. Uptake and transmission of Toxoplasma gondii oocysts by migratory, filter-feeding fish.

    PubMed

    Massie, Gloeta N; Ware, Michael W; Villegas, Eric N; Black, Michael W

    2010-05-11

    From bottlenose dolphins, to walruses, to sea otters, the parasitic protozoan Toxoplasma gondii is infecting marine mammals around the world. Whereas the terrestrial transmission pathways of T. gondii are well-described, the transmission pathway by which marine mammals are being infected is unknown. We hypothesize that migratory filter feeders, specifically northern anchovies (Engraulis mordax) and Pacific sardines (Sardinops sagax), are serving as biotic vectors for T. gondii within the marine environment. By filtering oocysts from seawater, these fishes could be transporting the oocysts from nearshore to pelagic environments. In this study, we experimentally exposed northern anchovies and Pacific sardines to T. gondii oocysts under laboratory conditions. Following exposure, the fishes' alimentary canals were harvested and assayed for the presence of T. gondii by PCR. Fish exposed to as few as 1197 oocysts/L seawater tested positive for T. gondii by PCR. In total, the PCR assay detected T. gondii DNA in 66% (40/61) of the exposed fishes. Oocyst infectivity was confirmed by mouse bioassay: 30% (7/23) of mice developed toxoplasmosis when fed fish exposed to 100,000 oocysts/L. This study demonstrates that both northern anchovies and Pacific sardines can filter T. gondii oocysts out of seawater under experimental conditions. Our experiments with anchovies demonstrated that the oocysts persisted in the fish for at least 8h post-exposure and our experiments with sardines demonstrated that the oocysts remained infectious inside the fish's alimentary canals. PMID:20097009

  7. A novel, simplified technique to amplify Eimeria (Coccidia: Apicomplexa) DNA from oocysts.

    PubMed

    Gerhold, R W; McDougald, L R; Beckstead, R B

    2015-02-01

    A new method to amplify coccidia DNA by polymerase chain reaction (PCR) was developed by placing freeze-thawed oocysts in Ready-to-Go PCR bead tubes and using a 5-min initial heat denaturation step. Positive PCR reactions were found in 3 of 3 samples containing 20 or 50 oocysts; when ≤5 oocysts were used, 1 of 3 samples was positive. This technique shows potential for effectively and efficiently detecting and identifying oocysts from soil, feces, and other matter. PMID:25019284

  8. Use of aerobic spores as a surrogate for cryptosporidium oocysts in drinking water supplies.

    PubMed

    Headd, Brendan; Bradford, Scott A

    2016-03-01

    Waterborne illnesses are a growing concern among health and regulatory agencies worldwide. The United States Environmental Protection Agency has established several rules to combat the contamination of water supplies by cryptosporidium oocysts, however, the detection and study of cryptosporidium oocysts is hampered by methodological and financial constraints. As a result, numerous surrogates for cryptosporidium oocysts have been proposed by the scientific community and efforts are underway to evaluate many of the proposed surrogates. The purpose of this review is to evaluate the suitability of aerobic bacterial spores to serve as a surrogate for cryptosporidium oocysts in identifying contaminated drinking waters. To accomplish this we present a comparison of the biology and life cycles of aerobic spores and oocysts and compare their physical properties. An analysis of their surface properties is presented along with a review of the literature in regards to the transport, survival, and prevalence of aerobic spores and oocysts in the saturated subsurface environment. Aerobic spores and oocysts share many commonalities with regard to biology and survivability, and the environmental prevalence and ease of detection make aerobic spores a promising surrogate for cryptosporidium oocysts in surface and groundwater. However, the long-term transport and release of aerobic spores still needs to be further studied, and compared with available oocyst information. In addition, the surface properties and environmental interactions of spores are known to be highly dependent on the spore taxa and purification procedures, and additional research is needed to address these issues in the context of transport. PMID:26734779

  9. Malaria zoonoses.

    PubMed

    Baird, J Kevin

    2009-09-01

    The genus Plasmodium includes many species that naturally cause malaria among apes and monkeys. The 2004 discovery of people infected by Plasmodium knowlesi in Malaysian Borneo alerted to the potential for non-human species of plasmodia to cause human morbidity and mortality. Subsequent work revealed what appears to be a surprisingly high risk of infection and relatively severe disease, including among travelers to Southeast Asia. The biology and medicine of this zoonosis is reviewed here, along with an examination of the spectrum of Plasmodium species that may cause infection of humans. PMID:19747661

  10. From malaria control to eradication: The WHO perspective.

    PubMed

    Mendis, Kamini; Rietveld, Aafje; Warsame, Marian; Bosman, Andrea; Greenwood, Brian; Wernsdorfer, Walther H

    2009-07-01

    Efforts to control malaria have been boosted in the past few years with increased international funding and greater political commitment. Consequently, the reported malaria burden is being reduced in a number of countries throughout the world, including in some countries in tropical Africa where the burden of malaria is greatest. These achievements have raised new hopes of eradicating malaria. This paper summarizes the outcomes of a World Health Organization's expert meeting on the feasibility of such a goal. Given the hindsight and experience of the Global Malaria Eradication Programme of the 1950s and 1960s, and current knowledge of the effectiveness of antimalarial tools and interventions, it would be feasible to effectively control malaria in all parts of the world and greatly reduce the enormous morbidity and mortality of malaria. It would also be entirely feasible to eliminate malaria from countries and regions where the intensity of transmission is low to moderate, and where health systems are strong. Elimination of malaria requires a re-orientation of control activity, moving away from a population-based coverage of interventions, to one based on a programme of effective surveillance and response. Sustained efforts will be required to prevent the resurgence of malaria from where it is eliminated. Eliminating malaria from countries where the intensity of transmission is high and stable such as in tropical Africa will require more potent tools and stronger health systems than are available today. When such countries have effectively reduced the burden of malaria, the achievements will need to be consolidated before a programme re-orientation towards malaria elimination is contemplated. Malaria control and elimination are under the constant threat of the parasite and vector mosquito developing resistance to medicines and insecticides, which are the cornerstones of current antimalarial interventions. The prospects of malaria eradication, therefore, rest heavily

  11. Cerebral malaria.

    PubMed

    Postels, Douglas G; Birbeck, Gretchen L

    2013-01-01

    Malaria, the most significant parasitic disease of man, kills approximately one million people per year. Half of these deaths occur in those with cerebral malaria (CM). The World Health Organization (WHO) defines CM as an otherwise unexplained coma in a patient with malarial parasitemia. Worldwide, CM occurs primarily in African children and Asian adults, with the vast majority (greater than 90%) of cases occurring in children 5 years old or younger in sub-Saharan Africa. The pathophysiology of the disease is complex and involves infected erythrocyte sequestration, cerebral inflammation, and breakdown of the blood-brain barrier. A recently characterized malarial retinopathy is visual evidence of Plasmodium falciparum's pathophysiological processes occurring in the affected patient. Treatment consists of supportive care and antimalarial administration. Thus far, adjuvant therapies have not been shown to improve mortality rates or neurological outcomes in children with CM. For those who survive CM, residual neurological abnormalities are common. Epilepsy, cognitive impairment, behavioral disorders, and gross neurological deficits which include motor, sensory, and language impairments are frequent sequelae. Primary prevention strategies, including bed nets, vaccine development, and chemoprophylaxis, are in varied states of development and implementation. Continuing efforts to find successful primary prevention options and strategies to decrease neurological sequelae are needed. PMID:23829902

  12. [Current malaria situation in Turkey].

    PubMed

    Gockchinar, T; Kalipsi, S

    2001-01-01

    Geographically, Turkey is situated in an area where malaria is very risky. The climatic conditions in the region are suitable for the malaria vector to proliferate. Due to agricultural infrastructural changes, GAP and other similar projects, insufficient environmental conditions, urbanization, national and international population moves, are a key to manage malaria control activities. It is estimated that malaria will be a potential danger for Turkey in the forthcoming years. The disease is located largely in south-eastern Anatolia. The Diyarbakir, Batman, Sanliurfa, Siirt, and Mardin districts are the most affected areas. In western districts, like Aydin and Manisa, an increase in the number of indigenous cases can be observed from time to time. This is due to workers moving from malaria districts to western parts to final work. Since these workers cannot be controlled, the population living in these regions get infected from indigenous cases. There were 84,345 malaria cases in 1994 and 82,096 in 1995, they decreased to 60,884 in 1996 and numbered 35,456 in 1997. They accounted for 36,842 and 20,963 in 1998 and 1999, respectively. In Turkey there are almost all cases of P. vivax malaria. There are also P. vivax and P. falciparum malaria cases coming from other countries: There were 321 P. vivax cases, including 2 P. falciparum ones, arriving to Turkey from Iraq in 1995. The P. vivax malaria cases accounted for 229 in 1996, and 67, cases P. vivax including 12 P. falciparum cases, in 1997, and 4 P. vivax cases in 1998 that came from that country. One P. vivax case entered Turkey from Georgia in 1998. The cause of higher incidence of P. vivax cases in 1995, it decreasing in 1999, is the lack of border controls over workers coming to Turkey. The other internationally imported cases are from Syria, Sudan, Pakistan, Afghanistan, Nigeria, India, Azerbaijan, Malaysia, Ghana, Indonesia, Yemen. Our examinations have shown that none of these internationally imported cases

  13. Hot topic or hot air? Climate change and malaria resurgence in East African highlands

    PubMed Central

    Hay, Simon I.; Rogers, David J.; Randolph, Sarah E.; Stern, David I.; Cox, Jonathan; Shanks, G. Dennis; Snow, Robert W.

    2011-01-01

    Climate has a significant impact on malaria incidence and we have predicted that forecast climate changes might cause some modifications to the present global distribution of malaria close to its present boundaries. However, it is quite another matter to attribute recent resurgences of malaria in the highlands of East Africa to climate change. Analyses of malaria time-series at such sites have shown that malaria incidence has increased in the absence of co-varying changes in climate. We find the widespread increase in resistance of the malaria parasite to drugs and the decrease in vector control activities to be more likely driving forces behind the malaria resurgence. PMID:12482536

  14. Comparison of Routine Health Management Information System Versus Enhanced Inpatient Malaria Surveillance for Estimating the Burden of Malaria Among Children Admitted to Four Hospitals in Uganda

    PubMed Central

    Mpimbaza, Arthur; Miles, Melody; Sserwanga, Asadu; Kigozi, Ruth; Wanzira, Humphrey; Rubahika, Denis; Nasr, Sussann; Kapella, Bryan K.; Yoon, Steven S.; Chang, Michelle; Yeka, Adoke; Staedke, Sarah G.; Kamya, Moses R.; Dorsey, Grant

    2015-01-01

    The primary source of malaria surveillance data in Uganda is the Health Management Information System (HMIS), which does not require laboratory confirmation of reported malaria cases. To improve data quality, an enhanced inpatient malaria surveillance system (EIMSS) was implemented with emphasis on malaria testing of all children admitted in select hospitals. Data were compared between the HMIS and the EIMSS at four hospitals over a period of 12 months. After the implementation of the EIMSS, over 96% of admitted children under 5 years of age underwent laboratory testing for malaria. The HMIS significantly overreported the proportion of children under 5 years of age admitted with malaria (average absolute difference = 19%, range = 8–27% across the four hospitals) compared with the EIMSS. To improve the quality of the HMIS data for malaria surveillance, the National Malaria Control Program should, in addition to increasing malaria testing rates, focus on linking laboratory test results to reported malaria cases. PMID:25422396

  15. Malaria in Brazil: an overview

    PubMed Central

    2010-01-01

    Malaria is still a major public health problem in Brazil, with approximately 306 000 registered cases in 2009, but it is estimated that in the early 1940s, around six million cases of malaria occurred each year. As a result of the fight against the disease, the number of malaria cases decreased over the years and the smallest numbers of cases to-date were recorded in the 1960s. From the mid-1960s onwards, Brazil underwent a rapid and disorganized settlement process in the Amazon and this migratory movement led to a progressive increase in the number of reported cases. Although the main mosquito vector (Anopheles darlingi) is present in about 80% of the country, currently the incidence of malaria in Brazil is almost exclusively (99,8% of the cases) restricted to the region of the Amazon Basin, where a number of combined factors favors disease transmission and impair the use of standard control procedures. Plasmodium vivax accounts for 83,7% of registered cases, while Plasmodium falciparum is responsible for 16,3% and Plasmodium malariae is seldom observed. Although vivax malaria is thought to cause little mortality, compared to falciparum malaria, it accounts for much of the morbidity and for huge burdens on the prosperity of endemic communities. However, in the last few years a pattern of unusual clinical complications with fatal cases associated with P. vivax have been reported in Brazil and this is a matter of concern for Brazilian malariologists. In addition, the emergence of P. vivax strains resistant to chloroquine in some reports needs to be further investigated. In contrast, asymptomatic infection by P. falciparum and P. vivax has been detected in epidemiological studies in the states of Rondonia and Amazonas, indicating probably a pattern of clinical immunity in both autochthonous and migrant populations. Seropidemiological studies investigating the type of immune responses elicited in naturally-exposed populations to several malaria vaccine candidates in

  16. Avian malaria in a boreal resident species: long-term temporal variability, and increased prevalence in birds with avian keratin disorder.

    PubMed

    Wilkinson, Laura C; Handel, Colleen M; Van Hemert, Caroline; Loiseau, Claire; Sehgal, Ravinder N M

    2016-04-01

    The prevalence of vector-borne parasitic diseases is widely influenced by biological and ecological factors. Environmental conditions such as temperature and precipitation can have a marked effect on haemosporidian parasites (Plasmodium spp.) that cause malaria and those that cause other malaria-like diseases in birds. However, there have been few long-term studies monitoring haemosporidian infections in birds in northern latitudes, where weather conditions can be highly variable and the effects of climate change are becoming more pronounced. We used molecular methods to screen more than 2,000 blood samples collected from black-capped chickadees (Poecile atricapillus), a resident passerine bird. Samples were collected over a 10 year period, mostly during the non-breeding season, at seven sites in Alaska, USA. We tested for associations between Plasmodium prevalence and local environmental conditions including temperature, precipitation, site, year and season. We also evaluated the relationship between parasite prevalence and individual host factors of age, sex and presence or absence of avian keratin disorder. This disease, which causes accelerated keratin growth in the beak, provided a natural study system in which to test the interaction between disease state and malaria prevalence. Prevalence of Plasmodium infection varied by year, site, age and individual disease status but there was no support for an effect of sex or seasonal period. Significantly, birds with avian keratin disorder were 2.6 times more likely to be infected by Plasmodium than birds without the disorder. Interannual variation in the prevalence of Plasmodium infection at different sites was positively correlated with summer temperatures at the local but not statewide scale. Sequence analysis of the parasite cytochrome b gene revealed a single Plasmodium spp. lineage, P43. Our results demonstrate associations between prevalence of avian malaria and a variety of biological and ecological factors

  17. Averting a malaria disaster: will insecticide resistance derail malaria control?

    PubMed

    Hemingway, Janet; Ranson, Hilary; Magill, Alan; Kolaczinski, Jan; Fornadel, Christen; Gimnig, John; Coetzee, Maureen; Simard, Frederic; Roch, Dabiré K; Hinzoumbe, Clément Kerah; Pickett, John; Schellenberg, David; Gething, Peter; Hoppé, Mark; Hamon, Nicholas

    2016-04-23

    World Malaria Day 2015 highlighted the progress made in the development of new methods of prevention (vaccines and insecticides) and treatment (single dose drugs) of the disease. However, increasing drug and insecticide resistance threatens the successes made with existing methods. Insecticide resistance has decreased the efficacy of the most commonly used insecticide class of pyrethroids. This decreased efficacy has increased mosquito survival, which is a prelude to rising incidence of malaria and fatalities. Despite intensive research efforts, new insecticides will not reach the market for at least 5 years. Elimination of malaria is not possible without effective mosquito control. Therefore, to combat the threat of resistance, key stakeholders need to rapidly embrace a multifaceted approach including a reduction in the cost of bringing new resistance management methods to market and the streamlining of associated development, policy, and implementation pathways to counter this looming public health catastrophe. PMID:26880124

  18. Use of Mosquito Preventive Measures Is Associated with Increased RBC CR1 Levels in a Malaria Holoendemic Area of Western Kenya

    PubMed Central

    King, Christine; Du, Ping; Otieno, Walter; Stoute, José A.

    2015-01-01

    Malaria is responsible for close to 1 million deaths each year, mostly among African children. Red blood cells (RBCs) of children with severe malarial anemia show loss of complement regulatory proteins such as complement receptor 1 (CR1). We carried out this study to identify socio-economic, environmental, and biological factors associated with the loss of RBC CR1. A cross-sectional study was conducted in a malaria holoendemic area of western Kenya. Twelve socioeconomic, environmental, and biological factors were examined for a relationship with RBC CR1 level using bivariate linear regression followed by creation of a multivariate linear regression model. A significant positive relationship between RBC CR1 level and use of mosquito countermeasures was found. However, there was no evidence of a significant relationship between RBC CR1 level and malaria infection or parasitemia level. Reducing mosquito exposure may aid in the prevention of severe malarial anemia by reducing the number of infections and thus preserving RBC CR1. PMID:25385855

  19. RNA Extraction Methods for Real-Time PCR and Microarray Analyses of Cryptosporidium and Toxoplasma gondii Oocysts - 2nd Presentation

    EPA Science Inventory

    The ability of infectious oocyst forms of Toxoplasma gondii and Cryptosporidium spp. to resist disinfection treatments and cause disease may have significant public health implications. Currently, little is known about oocyst-specific factors involved during host cell invasion pr...

  20. RNA Extraction Methods for Reverse Transcriptase Real-Time PCR and Microarray Analysis of Cryptosporidium and Toxoplasma gondii Oocysts

    EPA Science Inventory

    The ability of infectious oocyst forms of Toxoplasma gondii and Cryptosporidium spp. to resist disinfection treatments and cause disease may have significant public health implications. Currently, little is known about oocyst-specific factors involved during host cell invasion p...

  1. Sensitive and Rapid Detection of Viable Giardia Cysts and Cryptosporidium parvum Oocysts in Large-Volume Water Samples with Wound Fiberglass Cartridge Filters and Reverse Transcription-PCR

    PubMed Central

    Kaucner, Christine; Stinear, Timothy

    1998-01-01

    We recently described a reverse transcription-PCR (RT-PCR) for detecting low numbers of viable Cryptosporidium parvum oocysts spiked into clarified environmental water concentrates. We have now modified the assay for direct analysis of primary sample concentrates with simultaneous detection of viable C. parvum oocysts, Giardia cysts, and a novel type of internal positive control (IPC). The IPC was designed to assess both efficiency of mRNA isolation and potential RT-PCR inhibition. Sensitivity testing showed that low numbers of organisms, in the range of a single viable cyst and oocyst, could be detected when spiked into 100-μl packed pellet volumes of concentrates from creek and river water samples. The RT-PCR was compared with an immunofluorescence (IF) assay by analyzing 29 nonspiked environmental water samples. Sample volumes of 20 to 1,500 liters were concentrated with a wound fiberglass cartridge filter. Frequency of detection for viable Giardia cysts increased from 24% by IF microscopy to 69% by RT-PCR. Viable C. parvum oocysts were detected only once by RT-PCR (3%) in contrast to detection of viable Cryptosporidium spp. in four samples by IF microscopy (14%), suggesting that Cryptosporidium species other than C. parvum were present in the water. This combination of the large-volume sampling method with RT-PCR represents a significant advance in terms of protozoan pathogen monitoring and in the wider application of PCR technology to this field of microbiology. PMID:9572946

  2. Adjunctive therapy for cerebral malaria and other severe forms of Plasmodium falciparum malaria

    PubMed Central

    John, Chandy C; Kutamba, Elizabeth; Mugarura, Keith; Opoka, Robert O

    2010-01-01

    Severe malaria due to Plasmodium falciparum causes more than 800,000 deaths every year. Primary therapy with quinine or artesunate is generally effective in controlling P. falciparum parasitemia, but mortality from cerebral malaria and other forms of severe malaria remains unacceptably high. Long-term cognitive impairment is also common in children with cerebral malaria. Of the numerous adjunctive therapies for cerebral malaria and severe malaria studied over the past five decades, only one (albumin) was associated with a reduction in mortality. In this article, we review past and ongoing studies of adjunctive therapy, and examine the evidence of efficacy for newer therapies, including inhibitors of cytoadherence (e.g., levamisole), immune modulators (e.g., rosiglitazone), agents that increase nitric oxide levels (e.g., arginine) and neuroprotective agents (e.g., erythropoietin). PMID:20818944

  3. Maternally supplied S-acyl-transferase is required for crystalloid organelle formation and transmission of the malaria parasite.

    PubMed

    Santos, Jorge M; Duarte, Neuza; Kehrer, Jessica; Ramesar, Jai; Avramut, M Cristina; Koster, Abraham J; Dessens, Johannes T; Frischknecht, Friedrich; Chevalley-Maurel, Séverine; Janse, Chris J; Franke-Fayard, Blandine; Mair, Gunnar R

    2016-06-28

    Transmission of the malaria parasite from the mammalian host to the mosquito vector requires the formation of adequately adapted parasite forms and stage-specific organelles. Here we show that formation of the crystalloid-a unique and short-lived organelle of the Plasmodium ookinete and oocyst stage required for sporogony-is dependent on the precisely timed expression of the S-acyl-transferase DHHC10. DHHC10, translationally repressed in female Plasmodium berghei gametocytes, is activated translationally during ookinete formation, where the protein is essential for the formation of the crystalloid, the correct targeting of crystalloid-resident protein LAP2, and malaria parasite transmission. PMID:27303037

  4. Malaria situation in the Greater Mekong Subregion.

    PubMed

    Hewitt, Sean; Delacollette, Charles; Chavez, Irwin

    2013-01-01

    The epidemiology of malaria in the Greater Mekong Subregion is complex and rapidly evolving. Malaria control and elimination efforts face a daunting array of challenges including multidrug-resistant parasites. This review presents secondary data collected by the national malaria control programs in the six countries between 1998 and 2010 and examines trends over the last decade. This data has a number of limitations: it is derived exclusively from public sector health facilities; falciparum-specific and then pan-specific rapid diagnostic tests were introduced during the period under review; and, recently there has been a massive increase in case detection capability as a result of increased funding. It therefore requires cautious interpretation. A series of maps are presented showing trends in incidence, mortality and proportion of cases caused by Plasmodium falciparum over the last decade. A brief overview of institutional and implementation arrangements, historical background, demographics and key issues affecting malaria epidemiology is provided for each country. National malaria statistics for 2010 are presented and their robustness discussed in terms of the public sector's share of cases and other influencing factors such as inter-country variations in risk stratification, changes in diagnostic approach and immigration. Targets are presented for malaria control and where appropriate for elimination. Each country's artemisinin resistance status is described. The epidemiological trends presented reflect the improvement in the malaria situation, however the true malaria burden is as yet unknown. There is a need for continuing strengthening and updating of surveillance and response systems. PMID:24159830

  5. Effect of Lot Variability on Ultraviolet Radiation Inactivation Kinetics of Cryptosporidium parvum Oocysts

    EPA Science Inventory

    Numerous studies have demonstrated the efficiency of ultraviolet (UV) radiation for the inactivation of oocysts of Cryptosporidium parvum. In these studies inactivation is measured as reduction in oocysts. A primary goal is to estimate the UV radiation required to achiev...

  6. Different susceptibilities of Eimeria acervulina, Eimeria maxima, and Eimeria tenella oocysts to dessication

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Outbreaks of avian coccidiosis may occur when susceptible chickens are raised on litter containing high concentrations of viable Eimeria oocysts. The purpose of this study was to compare the relative sensitivities of E. acervulina, E. maxima, and E. tenella oocysts to dessication. Sporulated E. ac...

  7. Fate of Cryptosporidium parvum oocysts within soil, water, and plant environment.

    PubMed

    McLaughlin, Stephen J; Kalita, Prasanta K; Kuhlenschmidt, Mark S

    2013-12-15

    Vegetative Filter Strips (VFS) have long been used to control the movement of agricultural nutrients and prevent them from reaching receiving waters. Earlier studies have shown that VFS also dramatically reduce both the kinetics and extent of Cryptosporidium parvum (C. parvum) oocysts overland transport. In this study, we investigated possible mechanisms responsible for the ability of VFS to reduce oocyst overland transport. Measurement of the kinetics of C. parvum adhesion to individual sand, silt, and clay soil particles revealed that oocysts associate over time, albeit relatively slow, with clay but not silt or sand particles. Measurement of oocyst overland transport kinetics, soil infiltration depth, distance of travel, and adhesion to vegetation on bare and vegetated soil surfaces indicate that oocysts move more slowly, and penetrate the soil profile to a greater extent on a vegetated surface than on a bare soil surface. Furthermore, we demonstrate a small fraction of the oocysts become attached to vegetation at the soil-vegetation interface on VFS. These results suggest VFS function to reduce oocyst overland transport by primarily decreasing oocyst surface flow enough to allow penetration within the soil profile followed by subsequent adhesion to or entrapment within clay particle aggregates, and to a lesser extent, adhesion to the surface vegetation. PMID:24157412

  8. EFFECT OF LOT VARIABILITY ON ULTRAVIOLET RADIATION INACTIVATION KINETICS OF CRYPTOSPORIDIUM PARVUM OOCYSTS

    EPA Science Inventory

    The primary goal of this paper is to account for the effect of lot variability in determining the required ultraviolet (UV) radiation to inactivate Cryptosporidium parvum oocysts in mouse infectivity studies. The number of infectious oocysts (infective dose) per mouse is estima...

  9. Evaluation of an experimental irradiated oocysts vaccine to protect broiler chicks against avian coccidosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The current study investigates the use of irradiated oocysts to protect broiler chicks, raised on litter, from infection with multiple species of Eimeria. In order to determine the optimum radiation dose for each Eimeria species, day- old chicks were immunized with oocysts of E. maxima, E. acervulin...

  10. A RAPID METHOD FOR PRODUCTION OF HIGH NUMBERS OF PURIFIED CRYPTOSPORIDIUM PARVUM OOCYSTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most procedures that have been described for purifying Cryptosporidium parvum oocysts are designed to either identify the parasites in clinical specimens or isolate oocysts from a small volume of feces from infected animals. The present study describes a rapid method for purifying high numbers of C...

  11. Improved Cryptosporidium parvum oocysts propagation using dexamethasone suppressed CF-1 mice

    EPA Science Inventory

    This study evaluates Cryptosporidium parvum oocyst production in dexamethasone suppressed CF-1 and C57BL/6 mice. Both models can yield 1 x 109 total oocysts over a 20 day production period; however, only 20 CF-1 mice are required to reliably achieve this goal compared...

  12. EXAMINATION OF ATTACHMENT AND SURVIVAL OF TOXOPLASMA GONDII OOCYSTS ON RASPBERRIES AND BLUEBERRIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The consumption of Toxoplasma gondii oocysts on fresh produce may be a means of its transmission to humans. Cats can shed T. gondii oocysts that contaminate produce directly or contaminate water sources for agricultural irrigation, pesticide and fertilizer application. Cyclospora cayetanesis is a ...

  13. Spinacia oleracea L. leaf stomata harboring Cryptosporidium parvum oocysts: A potential threat for food safety

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Scientific literature documents the prevalence of Cryptosporidium oocysts in irrigation waters and on fresh produce. In the present study spinach leaves were experimentally exposed to Cryptosporidium oocysts which were subsequently irrigated with clean water daily for 5 days. As determined by confoc...

  14. Transport, Fate, and Infectivity of Cryptosporidium parvum Oocysts Released from Manure and Leached through Macroporous Soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A major mode of transmission of Cryptosporidium parvum, a widespread waterborne pathogen, is via contaminated drinking and recreational waters. Oocyst transport to surface water can occur by deposition of manure directly in the water or by wash off in surface runoff. Oocyst transport to groundwater ...

  15. Unrecognized ingestion of Toxoplasma gondii oocysts causes congenital toxoplasmosis and epidemics in North America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Undetected contamination of food and water by T. gondii oocysts frequently causes infection of humans in North America.Risks are often unrecognized by those infected. Demographic factors did not identify those with oocysts infections. Thus, although education programs describing hygienic measures ma...

  16. Obtaining Highly Purified Toxoplasma gondii Oocysts by a Discontinuous Cesium Chloride Gradient

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii is an obligate intracellular protozoan pathogen that commonly infects humans. To date, research on understanding the prevalence of T. gondii oocysts in the water and environment are limited due to the lack of tools to detect oocysts in the environment. This is primarily due to the...

  17. EFFECTS OF HIGH PRESSURE PROCESSING ON TOXOPLASMA GONDII OOCYSTS ON RASPBERRIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oocysts of Toxoplasma gondii are environmentally resistant stages. Humans can become infected by accidentally ingesting the oocysts in water or on contaminated produce. Severe disease can occur in immunocompromised individuals and non-immune pregnant women can infect their offspring. Chronic infect...

  18. Effects of ozone and UV radiation treatments on the infectivity of Toxoplasma gondii oocysts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Clinical toxoplasmosis in humans has been epidemiologically-linked to the consumption of drinking water contaminated by Toxoplasma gondii oocysts. We evaluated killing of T. gondii oocysts after ultraviolet (UV) or ozone treatments by bioassay in mice and/or cell culture. A 4-log inactivation of the...

  19. Prophylaxis of Malaria

    PubMed Central

    Schwartz, Eli

    2012-01-01

    Malaria prevention in travelers to endemic areas remains dependent principally on chemoprophylaxis. Although malaria chemoprophylaxis refers to all malaria species, a distinction should be drawn between falciparum malaria prophylaxis and the prophylaxis of the relapsing malaria species (vivax & ovale). While the emergence of drug resistant strains, as well as the costs and adverse reactions to medications, complicate falciparum prophylaxis use, there are virtually no drugs available for vivax prophylaxis, beside of primaquine. Based on traveler’s malaria data, a revised recommendation for using chemoprophylaxis in low risk areas should be considered. PMID:22811794

  20. Comparison of selected methods for recovery of Giardia spp. cysts and Cryptosporidium spp. oocysts in wastewater.

    PubMed

    Medeiros, Raphael Corrêa; Daniel, Luiz Antonio

    2015-09-01

    More precise methods are needed to recover Giardia and Cryptosporidium (oo)cysts from wastewater in order to advance research related to their inactivation, removal, quantification, and species differentiation. This study applied different methods to recover the maximum number of (oo)cysts from wastewater samples using ColorSeed®. Immunomagnetic separation assisted in capturing oocysts mainly in samples with medium and low turbidity. A triple centrifugation method reached recovery rates of 85% and 20%, for Giardia cysts and Cryptosporidium oocysts, respectively, in raw wastewater, and 62.5 and 17.5% in secondary-treated effluent. For low turbidity-treated effluent, membrane filtration reached 67.5% recovery for Giardia cysts and 22.5% for Cryptosporidium oocysts. Simple, quick and low-cost methods do not involve much handling of the samples and could be useful, particularly in developing countries. PMID:26322766

  1. Cryptosporidium sp. infections in green turtles, Chelonia mydas, as a potential source of marine waterborne oocysts in the Hawaiian Islands

    USGS Publications Warehouse

    Graczyk, T.K.; Balazs, G.H.; Work, T.M.; Aguirre, A.A.; Ellis, D.M.; Murakawa, S.K.K.; Morris, R.

    1997-01-01

    For the first time, Cryptosporidium sp. oocysts were identified in fecal and intestinal samples from free-ranging marine turtles, Chelonia mydas, from the Hawaiian Islands. The oocysts produced positive reactions with commercial test kits recommended for the detection of human-infectious waterborne oocysts of Cryptosporidium parvum.

  2. Cryptosporidium sp. Infections in Green Turtles, Chelonia mydas, as a Potential Source of Marine Waterborne Oocysts in the Hawaiian Islands

    PubMed Central

    Graczyk, T. K.; Balazs, G. H.; Work, T.; Aguirre, A. A.; Ellis, D. M.; Murakawa, S.; Morris, R.

    1997-01-01

    For the first time, Cryptosporidium sp. oocysts were identified in fecal and intestinal samples from free-ranging marine turtles, Chelonia mydas, from the Hawaiian Islands. The oocysts produced positive reactions with commercial test kits recommended for the detection of human-infectious waterborne oocysts of Cryptosporidium parvum. PMID:16535658

  3. Significance of wall structure, macromolecular composition, and surface polymers to the survival and transport of Cryptosporidium parvum Oocysts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The structure and composition of the oocyst wall are primary factors determining the survival of Cryptosporidium parvum oocysts outside the host. An external polymer matrix (glycocalyx) may mediate interactions with environmental surfaces and, thus, affect the transport of oocysts in water, soil, an...

  4. In vitro excystation of Cryptosporidium muris oocysts and viability of released sporozoites in different incubation media.

    PubMed

    Melicherová, Janka; Mazourová, Veronika; Valigurová, Andrea

    2016-03-01

    This study aimed to evaluate and document the excystation process of Cryptosporidium muris oocysts in various incubation media, and to monitor the behaviour of excysting and freshly excysted sporozoites. A test of oocyst viability, using fluorescent double staining with fluorescein diacetate and propidium iodide, was performed prior to each experimental assay. Light microscope observations confirmed that relatively often only three sporozoites were released; the fourth one either left the oocyst later together with a residual body or remained trapped within the oocyst wall. These results suggest that successful oocyst excystation is not limited by the viability of all four sporozoites. Darkening of oocysts to opaque and their specific movement (the so-called "oocyst dancing") preceded the final excystation and liberation of sporozoites, while the dormant oocysts appeared refractive. The process of excystation in C. muris is not gradual as generally described in cryptosporidia but very rapid in an eruptive manner. Experiments were performed using oocysts stored at 4 °C for various time periods, as well as oocysts freshly shed from host rodents (Mastomys coucha) of different ages. The most suitable medium supporting high excystation rate (76 %) and prolonged motility of sporozoites was RPMI 1640, enriched with 5 % bovine serum albumin (BSA). Our results emphasize that to reliably evaluate the success of in vitro excystation of cryptosporidia, not only the number of released sporozoites in a set time period should be taken into consideration but also their subsequent activity (motility), as it is expected to be essential for the invasion of host cells. PMID:26678654

  5. Anaemia of Plasmodium falciparum malaria.

    PubMed

    Phillips, R E; Pasvol, G

    1992-04-01

    The pathophysiology of the anaemia of falciparum malaria is both complex and multifactorial, and results in a condition which is a major cause of mortality and morbidity in patients, especially children and pregnant women, living in malarial endemic areas. The importance of anaemia as a cause of death in malaria may well be underestimated because of difficulty in diagnosis, especially where parasitaemia may be low and the clinical picture may be confused with other causes of anaemia. Two clinical presentations predominate: severe acute malaria in which anaemia supervenes, and severe anaemia in patients in whom there have been repeated attacks of malaria. The major mechanisms are those of red cell destruction and decreased red cell production. Potential causes of haemolysis include loss of infected cells by rupture or phagocytosis, removal of uninfected cells due to antibody sensitization or other physicochemical membrane changes, and increased reticuloendothelial activity, particularly in organs such as the spleen. Decreased production results from marrow hypoplasia seen in acute infections, and dyserythropoiesis, a morphological appearance, which in functional terms results in ineffective erythropoiesis. The role of parvovirus B19 as a possible cause of bone marrow aplasia in a few cases is postulated. Finally, there is now evidence which points to genetic factors, HLA associated, which may protect against the development of malarial anaemia and which has become common in areas endemic for malaria. PMID:1511178

  6. Risk behavior in malaria in Malaysia.

    PubMed

    Arasu, G D

    1992-01-01

    The risk behavior in malaria has been identified as one of the factors contributing to malaria in Malaysia. The occurrence of malaria among illegal immigrants and indigenous groups, staying in risk prone areas where conditions are favorable for transmission, highlights the behavior pattern of these groups. In these areas the usual anti-malarial activities are less effective and thus there is a need to identify control measures suited to that particular condition and environment and to community groups. Some of the determinants contributing to the increase in malaria cases like man-vector contact, non-compliance to drugs, complications of the disease, and factors interfering with malaria control measures, factors favoring transmission and proposals to modify risk behavior, which can be applied in an endeavor to control the diseases, have been discussed. PMID:1341845

  7. Mapping residual transmission for malaria elimination

    PubMed Central

    Reiner, Robert C; Le Menach, Arnaud; Kunene, Simon; Ntshalintshali, Nyasatu; Hsiang, Michelle S; Perkins, T Alex; Greenhouse, Bryan; Tatem, Andrew J; Cohen, Justin M; Smith, David L

    2015-01-01

    Eliminating malaria from a defined region involves draining the endemic parasite reservoir and minimizing local malaria transmission around imported malaria infections . In the last phases of malaria elimination, as universal interventions reap diminishing marginal returns, national resources must become increasingly devoted to identifying where residual transmission is occurring. The needs for accurate measures of progress and practical advice about how to allocate scarce resources require new analytical methods to quantify fine-grained heterogeneity in malaria risk. Using routine national surveillance data from Swaziland (a sub-Saharan country on the verge of elimination), we estimated individual reproductive numbers. Fine-grained maps of reproductive numbers and local malaria importation rates were combined to show ‘malariogenic potential’, a first for malaria elimination. As countries approach elimination, these individual-based measures of transmission risk provide meaningful metrics for planning programmatic responses and prioritizing areas where interventions will contribute most to malaria elimination. DOI: http://dx.doi.org/10.7554/eLife.09520.001 PMID:26714110

  8. Climate Change and Malaria in Canada: A Systems Approach

    PubMed Central

    Berrang-Ford, L.; MacLean, J. D.; Gyorkos, Theresa W.; Ford, J. D.; Ogden, N. H.

    2009-01-01

    This article examines the potential for changes in imported and autochthonous malaria incidence in Canada as a consequence of climate change. Drawing on a systems framework, we qualitatively characterize and assess the potential direct and indirect impact of climate change on malaria in Canada within the context of other concurrent ecological and social trends. Competent malaria vectors currently exist in southern Canada, including within this range several major urban centres, and conditions here have historically supported endemic malaria transmission. Climate change will increase the occurrence of temperature conditions suitable for malaria transmission in Canada, which, combined with trends in international travel, immigration, drug resistance, and inexperience in both clinical and laboratory diagnosis, may increase malaria incidence in Canada and permit sporadic autochthonous cases. This conclusion challenges the general assumption of negligible malaria risk in Canada with climate change. PMID:19277107

  9. Climate change and malaria in Canada: a systems approach.

    PubMed

    Berrang-Ford, L; Maclean, J D; Gyorkos, Theresa W; Ford, J D; Ogden, N H

    2009-01-01

    This article examines the potential for changes in imported and autochthonous malaria incidence in Canada as a consequence of climate change. Drawing on a systems framework, we qualitatively characterize and assess the potential direct and indirect impact of climate change on malaria in Canada within the context of other concurrent ecological and social trends. Competent malaria vectors currently exist in southern Canada, including within this range several major urban centres, and conditions here have historically supported endemic malaria transmission. Climate change will increase the occurrence of temperature conditions suitable for malaria transmission in Canada, which, combined with trends in international travel, immigration, drug resistance, and inexperience in both clinical and laboratory diagnosis, may increase malaria incidence in Canada and permit sporadic autochthonous cases. This conclusion challenges the general assumption of negligible malaria risk in Canada with climate change. PMID:19277107

  10. Malaria and Travelers

    MedlinePlus

    ... a CDC Malaria Branch clinician. malaria@cdc.gov File Formats Help: How do I view different file formats (PDF, DOC, PPT, MPEG) on this site? Adobe PDF file Microsoft PowerPoint file Microsoft Word file Microsoft Excel ...

  11. Malaria Treatment (United States)

    MedlinePlus

    ... a CDC Malaria Branch clinician. malaria@cdc.gov File Formats Help: How do I view different file formats (PDF, DOC, PPT, MPEG) on this site? Adobe PDF file Microsoft PowerPoint file Microsoft Word file Microsoft Excel ...

  12. Avian malaria in a boreal resident species: long-term temporal variability, and increased prevalence in birds with avian keratin disorder

    USGS Publications Warehouse

    Wilkinson, Laura C.; Handel, Colleen M.; Van Hemert, Caroline R.; Loiseau, Claire; Sehgal, Ravinder N. M.

    2016-01-01

    The prevalence of vector-borne parasitic diseases is widely influenced by biological and ecological factors. Environmental conditions such as temperature and precipitation can have a marked effect on haemosporidian parasites (Plasmodium spp.) that cause malaria and those that cause other malaria-like diseases in birds. However, there have been few long-term studies monitoring haemosporidian infections in birds in northern latitudes, where weather conditions can be highly variable and the effects of climate change are becoming more pronounced. We used molecular methods to screen more than 2,000 blood samples collected from black-capped chickadees (Poecile atricapillus), a resident passerine bird. Samples were collected over a 10 year period, mostly during the non-breeding season, at seven sites in Alaska, USA. We tested for associations between Plasmodium prevalence and local environmental conditions including temperature, precipitation, site, year and season. We also evaluated the relationship between parasite prevalence and individual host factors of age, sex and presence or absence of avian keratin disorder. This disease, which causes accelerated keratin growth in the beak, provided a natural study system in which to test the interaction between disease state and malaria prevalence. Prevalence of Plasmodium infection varied by year, site, age and individual disease status but there was no support for an effect of sex or seasonal period. Significantly, birds with avian keratin disorder were 2.6 times more likely to be infected by Plasmodium than birds without the disorder. Interannual variation in the prevalence of Plasmodium infection at different sites was positively correlated with summer temperatures at the local but not statewide scale. Sequence analysis of the parasite cytochrome b gene revealed a single Plasmodiumspp. lineage, P43. Our results demonstrate associations between prevalence of avian malaria and a variety of biological and

  13. Increased Access to Care and Appropriateness of Treatment at Private Sector Drug Shops with Integrated Management of Malaria, Pneumonia and Diarrhoea: A Quasi-Experimental Study in Uganda

    PubMed Central

    Awor, Phyllis; Wamani, Henry; Tylleskar, Thorkild; Jagoe, George; Peterson, Stefan

    2014-01-01

    Introduction Drug shops are a major source of care for children in low income countries but they provide sub-standard care. We assessed the feasibility and effect on quality of care of introducing diagnostics and pre-packaged paediatric-dosage drugs for malaria, pneumonia and diarrhoea at drug shops in Uganda. Methods We adopted and implemented the integrated community case management (iCCM) intervention within registered drug shops. Attendants were trained to perform malaria rapid diagnostic tests (RDTs) in each fever case and count respiratory rate in each case of cough with fast/difficult breathing, before dispensing recommended treatment. Using a quasi-experimental design in one intervention and one non-intervention district, we conducted before and after exit interviews for drug seller practices and household surveys for treatment-seeking practices in May–June 2011 and May–June 2012. Survey adjusted generalized linear models and difference-in-difference analysis was used. Results 3759 (1604 before/2155 after) household interviews and 943 (163 before/780 after) exit interviews were conducted with caretakers of children under-5. At baseline, no child at a drug shop received any diagnostic testing before treatment in both districts. After the intervention, while no child in the non-intervention district received a diagnostic test, 87.7% (95% CI 79.0–96.4) of children with fever at the intervention district drug shops had a parasitological diagnosis of malaria, prior to treatment. The prevalence ratios of the effect of the intervention on treatment of cough and fast breathing with amoxicillin and diarrhoea with ORS/zinc at the drug shop were 2.8 (2.0–3.9), and 12.8 (4.2–38.6) respectively. From the household survey, the prevalence ratio of the intervention effect on use of RDTs was 3.2 (1.9–5.4); Artemisinin Combination Therapy for malaria was 0.74 (0.65–0.84), and ORS/zinc for diarrhoea was 2.3 (1.2–4.7). Conclusion iCCM can be utilized to improve

  14. Molecular Approaches to Malaria 2000.

    PubMed

    Cowman, Alan F.; Cooke, Brian M.

    2000-04-01

    For more than 20 years now, Australia has been officially free of endemic malaria, but this devastating disease once again made a major impact on the continent in February 2000 when Melbourne hosted Australia's first major international conference on 'Molecular Approaches to Malaria' (Lorne, Australia, 2-5 February 2000). The global research effort toward our increased understanding of the pathogenesis and control of malaria in the post-genomics era was discussed and debated at length over 4 days packed with science encompassing molecular biology, cell biology, clinical studies, genomics, vaccines and pathogenic mechanisms. More than 260 researchers from 18 countries worldwide participated in this interdisciplinary meeting which comprised 57 oral presentations and 122 posters. Here we summarize some presentations pertinent to the field of drug action and resistance. Copyright 2000 Harcourt Publishers Ltd. PMID:11498369

  15. Prevalence of gestational, placental and congenital malaria in north-west Colombia

    PubMed Central

    2013-01-01

    Background The frequency of pregnancy-associated malaria is increasingly being documented in American countries. In Colombia, with higher frequency of Plasmodium vivax over Plasmodium falciparum infection, recent reports confirmed gestational malaria as a serious public health problem. Thick smear examination is the gold standard to diagnose malaria in endemic settings, but in recent years, molecular diagnostic methods have contributed to elucidate the dimension of the problem of gestational malaria. The study was aimed at exploring the prevalence of gestational, placental and congenital malaria in women who delivered at the local hospitals of north-west Colombia, between June 2008 and April 2011. Methods A group of 129 parturient women was selected to explore the prevalence of gestational, placental and congenital malaria in a descriptive, prospective and transversal (prevalence) design. Diagnosis was based on the simultaneous application of two independent diagnostic tests: microscopy of thick blood smears and a polymerase chain reaction assay (PCR). Results The prevalence of gestational malaria (thick smear /PCR) was 9.1%/14.0%; placental malaria was 3.3%/16.5% and congenital malaria was absent. A history of gestational malaria during the current pregnancy was significantly associated with gestational malaria at delivery. Plasmodium vivax caused 65% of cases of gestational malaria, whereas P. falciparum caused most cases of placental malaria. Conclusions Gestational and placental malaria are a serious problem in the region, but the risk of congenital malaria is low. A history of malaria during pregnancy may be a practical indicator of infection at delivery. PMID:24053184

  16. Hemiparesis post cerebral malaria

    PubMed Central

    Taiaa, Oumkaltoum; Amil, Touriya; Darbi, Abdelatif

    2015-01-01

    Cerebral malaria is one of the most serious complications in the Plasmodium falciparum infection. In endemic areas, the cerebral malaria interested mainly children. The occurrence in adults is very rare and most interested adult traveling in tropical zones. This case report describes a motor deficit post cerebral malaria in a young adult traveling in malaria endemic area. This complication has been reported especially in children and seems very rare in adults. PMID:25995798

  17. Pregnancy-associated malaria and malaria in infants: an old problem with present consequences.

    PubMed

    Moya-Alvarez, Violeta; Abellana, Rosa; Cot, Michel

    2014-01-01

    Albeit pregnancy-associated malaria (PAM) poses a potential risk for over 125 million women each year, an accurate review assessing the impact on malaria in infants has yet to be conducted. In addition to an effect on low birth weight (LBW) and prematurity, PAM determines foetal exposure to Plasmodium falciparum in utero and is correlated to congenital malaria and early development of clinical episodes during infancy. This interaction plausibly results from an ongoing immune tolerance process to antigens in utero, however, a complete explanation of this immune process remains a question for further research, as does the precise role of protective maternal antibodies. Preventive interventions against PAM modify foetal exposure to P. falciparum in utero, and have thus an effect on perinatal malaria outcomes. Effective intermittent preventive treatment in pregnancy (IPTp) diminishes placental malaria (PM) and its subsequent malaria-associated morbidity. However, emerging resistance to sulphadoxine-pyrimethamine (SP) is currently hindering the efficacy of IPTp regimes and the efficacy of alternative strategies, such as intermittent screening and treatment (IST), has not been accurately evaluated in different transmission settings. Due to the increased risk of clinical malaria for offspring of malaria infected mothers, PAM preventive interventions should ideally start during the preconceptual period. Innovative research examining the effect of PAM on the neurocognitive development of the infant, as well as examining the potential influence of HLA-G polymorphisms on malaria symptoms, is urged to contribute to a better understanding of PAM and infant health. PMID:25015559

  18. Pregnancy-associated malaria and malaria in infants: an old problem with present consequences

    PubMed Central

    2014-01-01

    Albeit pregnancy-associated malaria (PAM) poses a potential risk for over 125 million women each year, an accurate review assessing the impact on malaria in infants has yet to be conducted. In addition to an effect on low birth weight (LBW) and prematurity, PAM determines foetal exposure to Plasmodium falciparum in utero and is correlated to congenital malaria and early development of clinical episodes during infancy. This interaction plausibly results from an ongoing immune tolerance process to antigens in utero, however, a complete explanation of this immune process remains a question for further research, as does the precise role of protective maternal antibodies. Preventive interventions against PAM modify foetal exposure to P. falciparum in utero, and have thus an effect on perinatal malaria outcomes. Effective intermittent preventive treatment in pregnancy (IPTp) diminishes placental malaria (PM) and its subsequent malaria-associated morbidity. However, emerging resistance to sulphadoxine-pyrimethamine (SP) is currently hindering the efficacy of IPTp regimes and the efficacy of alternative strategies, such as intermittent screening and treatment (IST), has not been accurately evaluated in different transmission settings. Due to the increased risk of clinical malaria for offspring of malaria infected mothers, PAM preventive interventions should ideally start during the preconceptual period. Innovative research examining the effect of PAM on the neurocognitive development of the infant, as well as examining the potential influence of HLA-G polymorphisms on malaria symptoms, is urged to contribute to a better understanding of PAM and infant health. PMID:25015559

  19. Experimental infection of dogs (Canis familiaris) with sporulated oocysts of Neospora caninum.

    PubMed

    Bandini, Luciana A; Neto, Aldo F A; Pena, Hilda F J; Cavalcante, Guacyara T; Schares, Gereon; Nishi, Sandra M; Gennari, Solange M

    2011-03-10

    Neospora caninum is widely distributed in the world and this parasite is one of the major causes of abortion in cattle. Dogs and coyotes are definitive hosts of N. caninum and several species of domestic and wild animals are intermediate hosts. Dogs can become infected by the ingestion of tissues containing cysts and then excrete oocysts. It is not yet known whether sporulated oocysts are able to induce a patent infection in dogs, i.e. a shedding of N. caninum oocysts in feces. The objective of this study was to experimentally examine the infection of dogs by sporulated oocysts. The oocysts used in the experiment were obtained by feeding dogs with brain of buffaloes (Bubalus bubalis) positive for anti-N. caninum antibodies by indirect fluorescent antibody test (IFAT ≥200). Oocysts shed by these dogs were confirmed to be N. caninum by molecular methods and by bioassay in gerbils, and sporulated N. caninum oocysts were used for the oral infection of four dogs. The dogs were 8 weeks old and negative for antibodies to N. caninum and Toxoplasma gondii. Dogs 1 and 4 received an inoculum of 10,000 sporulated oocysts each; dog 2 an inoculum of 5000 sporulated oocysts and dog 3 received 1000 sporulated oocysts of N. caninum. The total feces excreted by these dogs were collected and examined daily for a period of 30 days. No oocysts were found in their feces. The dogs were monitored monthly for a 6-month period to observe a possible seroconversion and when this occurred the animals were eliminated from the experiment. Dogs 1 and 4 seroconverted 1 month after the infection with titer, in the IFAT, of 1600 and 800, respectively; the other two dogs presented no seroconvertion during the 6-month period. Dogs 1 and 2 were euthanized 180 days after infection and were examined for the detection of N. caninum in tissues (brain, muscle, lymph node, liver, lung, heart and bone marrow) by immunohistochemistry and PCR with negative results in both techniques. Bioassay in gerbils with

  20. Progress towards malaria control targets in relation to national malaria programme funding

    PubMed Central

    2013-01-01

    Background Malaria control has been dramatically scaled up the past decade, mainly thanks to increasing international donor financing since 2003. This study assessed progress up to 2010 towards global malaria impact targets, in relation to Global Fund, other donor and domestic malaria programme financing over 2003 to 2009. Methods Assessments used domestic malaria financing reported by national programmes, and Global Fund/OECD data on donor financing for 90 endemic low- and middle-income countries, WHO estimates of households owning one or more insecticide-treated mosquito net (ITN) for countries in sub-Saharan Africa, and WHO-estimated malaria case incidence and deaths in countries outside sub-Saharan Africa. Results Global Fund and other donor funding is concentrated in a subset of the highest endemic African countries. Outside Africa, donor funding is concentrated in those countries with highest malaria mortality and case incidence rates over the years 2000 to 2003. ITN coverage in 2010 in Africa, and declines in case and death rates per person at risk over 2004 to 2010 outside Africa, were greatest in countries with highest donor funding per person at risk, and smallest in countries with lowest donor malaria funding per person at risk. Outside Africa, all-source malaria programme funding over 2003 to 2009 per case averted ($56-5,749) or per death averted ($58,000-3,900,000) over 2004 to 2010 tended to be lower (more favourable) in countries with higher donor malaria funding per person at risk. Conclusions Increases in malaria programme funding are associated with accelerated progress towards malaria control targets. Associations between programme funding per person at risk and ITN coverage increases and declines in case and death rates suggest opportunities to maximize the impact of donor funding, by strategic re-allocation to countries with highest continued need. PMID:23317000

  1. Geostatistical modelling of household malaria in Malawi

    NASA Astrophysics Data System (ADS)

    Chirombo, J.; Lowe, R.; Kazembe, L.

    2012-04-01

    Malaria is one of the most important diseases in the world today, common in tropical and subtropical areas with sub-Saharan Africa being the region most burdened, including Malawi. This region has the right combination of biotic and abiotic components, including socioeconomic, climatic and environmental factors that sustain transmission of the disease. Differences in these conditions across the country consequently lead to spatial variation in risk of the disease. Analysis of nationwide survey data that takes into account this spatial variation is crucial in a resource constrained country like Malawi for targeted allocation of scare resources in the fight against malaria. Previous efforts to map malaria risk in Malawi have been based on limited data collected from small surveys. The Malaria Indicator Survey conducted in 2010 is the most comprehensive malaria survey carried out in Malawi and provides point referenced data for the study. The data has been shown to be spatially correlated. We use Bayesian logistic regression models with spatial correlation to model the relationship between malaria presence in children and covariates such as socioeconomic status of households and meteorological conditions. This spatial model is then used to assess how malaria varies spatially and a malaria risk map for Malawi is produced. By taking intervention measures into account, the developed model is used to assess whether they have an effect on the spatial distribution of the disease and Bayesian kriging is used to predict areas where malaria risk is more likely to increase. It is hoped that this study can help reveal areas that require more attention from the authorities in the continuing fight against malaria, particularly in children under the age of five.

  2. Recovery of waterborne oocysts of Cryptosporidium from water samples by the membrane-filter dissolution method.

    PubMed

    Graczyk, T K; Cranfield, M R; Fayer, R

    1997-01-01

    The cellulose-acetate membrane (CAM)-filter dissolution method implemented into a Millipore Glass Microanalysis system was used for recovery of Cryptosporidium parvum oocysts seeded into 25 l of drinking water in polyethylene carboy aspirator bottles. CAM-entrapped oocysts were detected by immunofluorescence microscopy. From 65 to 94 oocysts/l (mean 75 oocysts/l), 34.7% overall of the inoculated oocysts, were unrecovered as determined after the water had been drained from the bottle, rinsed with 1 l of eluting fluid (EF), and CAM-filtered. Efficiency rates of oocyst recovery ranged from 24.0% to 64.0% (mean 44.1%), without the use of EF and from 72.1% to 82.3% (mean 78.8%) when EF was used. To ensure a high recovery efficiency of Cryptosporidium oocysts from sampled water by the CAM-filter dissolution method, it is recommended that 1 l of EF per 25 l of water be used. PMID:9039693

  3. Modeling Fate and Transport of Cryptosporidium Parvum Oocysts in Overland and Near- surface Flow

    NASA Astrophysics Data System (ADS)

    Bhattarai, R.; Kalita, P.; Kuhlenschmidt, M. S.

    2008-12-01

    Cryptosporidium parvum is a manure-borne protozoan parasite which is common in the environment. It has been recognized as an important microbial contaminant of water and can cause infection and diarrhea in many mammalian hosts, including humans. The laboratory experiments carried out have demonstrated that recovery of C. parvum oocysts was significantly affected by climatic and surface conditions like slope, rainfall and surface cover. The objective of this study is to develop a model for simulating transport of C. parvum oocysts in overland and near-surface flow. Modeling can help understanding oocysts transport pathways. Accordingly, best management practices (BMP) can be developed. Transport of oocysts in overland flow can be simulated mathematically by including terms for the concentration of the oocysts in the liquid phase (in suspension or free-floating) and the solid phase (adsorbed to the fine solid particles like clay). Oocysts adsorption, advection and decay processes are considered. These processes are solved using numerical technique to predict spatial and temporal changes in oocyst concentrations in solid and liquid phases. The model results are compared with experimental data to validate the model outcome. The model output reproduced observed recovery kinetics for 1.5% slope but not for higher slopes (3.0% and 4.5%).

  4. Murine infection model for maintenance and amplification of Cryptosporidium parvum oocysts.

    PubMed Central

    Petry, F; Robinson, H A; McDonald, V

    1995-01-01

    Propagation of Cryptosporidium parvum is problematic because in vitro development of the parasite is poor and animals are only briefly susceptible as neonates. At present oocysts of the parasite are usually procured by passage in neonatal sheep or cattle. In the present study, large numbers of oocysts of C. parvum could be isolated following infection of dexamethasone-treated adult C57BL/6 mice. The amount of immunosuppressive drug and the regimen of administration were critical for successful maintenance of the parasite, however. Routinely, 10 mice (age, 8 to 12 weeks) were injected four times on alternate days with 1.0 mg of dexamethasone, and the last injection was given on the same day as oral inoculation with 10(6) oocysts. By using a simplified procedure for oocyst purification from mouse feces, approximately 10(9) oocysts were obtained. This model is inexpensive and comparatively safe to handle, and the numbers of animals inoculated can be varied to obtain the required number of oocysts. Thus, this murine infection model would be a suitable alternative to the use of neonatal calves or sheep for efficient oocyst propagation. PMID:7665672

  5. Evaluation of a strategy for Toxoplasma gondii oocyst detection in water.

    PubMed

    Villena, Isabelle; Aubert, Dominique; Gomis, Philippe; Ferté, Hubert; Inglard, Jean-Christophe; Denis-Bisiaux, Hélène; Dondon, Julie-Muriel; Pisano, Eric; Ortis, Naïma; Pinon, Jean-Michel

    2004-07-01

    Several recent outbreaks of toxoplasmosis were related to drinking water. We propose a strategy for Toxoplasma oocyst detection as part of an approach to detecting multiple waterborne parasites, including Giardia and Cryptosporidium spp., by the U.S. Environmental Protection Agency method with the same sample. Water samples are filtered to recover Toxoplasma oocysts and purified on a sucrose density gradient. Detection is based on PCR and mouse inoculation (bioassay) to determine the presence and infectivity of recovered oocysts. In an experimental seeding assay with 100 liters of deionized water, a parasite density of 1 oocyst/liter was successfully detected by PCR in 60% of cases and a density of 10 oocysts/liter was detected in 100% of cases. The sensitivity of the PCR assay varied from less than 10 to more than 1000 oocysts/liter, depending on the sample source. PCR was always more sensitive than mouse inoculation. This detection strategy was then applied to 139 environmental water samples collected over a 20-month period. Fifty-three samples contained PCR inhibitors, which were overcome in 39 cases by bovine serum albumin addition. Among 125 interpretable samples, we detected Toxoplasma DNA in 10 cases (8%). None of the samples were positive by mouse inoculation. This strategy efficiently detects Toxoplasma oocysts in water and may be suitable as a public health sentinel method. PMID:15240280

  6. Evaluation of the immunofluorescence procedure for detection of Giardia cysts and Cryptosporidium oocysts in water.

    PubMed Central

    LeChevallier, M W; Norton, W D; Siegel, J E; Abbaszadegan, M

    1995-01-01

    The accurate determination of the presence of Giardia cysts and Cryptosporidium oocysts in surface waters requires a reliable method for the detection and enumeration of these pathogenic organisms. Published methods have usually reported recovery efficiencies of less than 50% for both cysts and oocysts. Typically, the losses are greater for Cryptosporidium oocysts than they are for Giardia cysts. The purpose of this study was to examine procedures used for sample collection, elution, concentration, and clarification to determine when losses of cysts and oocysts occurred during processing. The results showed that major losses of cysts and oocysts occurred during centrifugation and clarification. Depending on the centrifugation force, oocyst losses of as high as 30% occurred for each centrifugation step. A 1.15-specific-gravity Percoll-sucrose gradient was needed to optimize recovery of oocysts from natural water samples. Minor improvements in the procedure could be accomplished by selecting a filter other than the recommended 1-micron-pore-size (nominal-porosity) polypropylene filter. PMID:7574607

  7. Evaluation of USEPA method 1622 for detection of Cryptosporidium oocysts in stream waters

    USGS Publications Warehouse

    Simmons, O. D., III; Sobsey, M.D.; Schaefer, F. W., III; Francy, D.S.; Nally, R.A.; Heaney, C.D.

    2001-01-01

    To improve surveillance for Cryptosporidium oocysts in water, the US Environmental Protection Agency developed method 1622, which consists of filtration, concentration, immunomagnetic separation, fluorescent antibody and 4, 6-diamidino-2-phenylindole (DAPI) counter-staining, and microscopic evaluation. Two filters were compared for analysis of 11 stream water samples collected throughout the United States. Replicate 10-L stream water samples (unspiked and spiked with 100-250 oocysts) were tested to evaluate matrix effects. Oocyst recoveries from the stream water samples averaged 22% (standard deviation [SD] = ??17%) with a membrane disk and 12% (SD = ??6%) with a capsule filter. Oocyst recoveries from reagent water precision and recovery samples averaged 39% (SD = ??13%) with a membrane disk and 47% (SD = ??19%) with a capsule filter. These results demonstrate that Cryptosporidium oocysts can be recovered from stream waters using method 1622, but recoveries are lower than those from reagent-grade water. This research also evaluated concentrations of indicator bacteria in the stream water samples. Because few samples were oocyst-positive, relationships between detections of oocysts and concentrations of indicator organisms could not be determined.

  8. Identification of Cryptosporidium parvum Oocysts by an Artificial Neural Network Approach

    PubMed Central

    Widmer, Kenneth W.; Oshima, Kevin H.; Pillai, Suresh D.

    2002-01-01

    Microscopic detection of Cryptosporidium parvum oocysts is time-consuming, requires trained analysts, and is frequently subject to significant human errors. Artificial neural networks (ANN) were developed to help identify immunofluorescently labeled C. parvum oocysts. A total of 525 digitized images of immunofluorescently labeled oocysts, fluorescent microspheres, and other miscellaneous nonoocyst images were employed in the training of the ANN. The images were cropped to a 36- by 36-pixel image, and the cropped images were placed into two categories, oocyst and nonoocyst images. The images were converted to grayscale and processed into a histogram of gray color pixel intensity. Commercially available software was used to develop and train the ANN. The networks were optimized by varying the number of training images, number of hidden neurons, and a combination of these two parameters. The network performance was then evaluated using a set of 362 unique testing images which the network had never “seen” before. Under optimized conditions, the correct identification of authentic oocyst images ranged from 81 to 97%, and the correct identification of nonoocyst images ranged from 78 to 82%, depending on the type of fluorescent antibody that was employed. The results indicate that the ANN developed were able to generalize the training images and subsequently discern previously unseen oocyst images efficiently and reproducibly. Thus, ANN can be used to reduce human errors associated with the microscopic detection of Cryptosporidium oocysts. PMID:11872458

  9. Oocyst-Derived Extract of Toxoplasma Gondii Serves as Potent Immunomodulator in a Mouse Model of Birch Pollen Allergy

    PubMed Central

    Wagner, Angelika; Schabussova, Irma; Drinic, Mirjana; Akgün, Johnnie; Loupal, Gerhard; Kundi, Michael; Joachim, Anja; Wiedermann, Ursula

    2016-01-01

    Introduction Previously, we have shown that oral infection with Toxoplasma gondii oocysts prevented type I allergy in mice. Here we investigated whether the application of a T. gondii oocyst lysate antigen (OLA) could also reduce allergy development. BALB/c mice were immunised twice with OLA followed by sensitisation with the major birch pollen (BP) allergen Bet v 1 and an aerosol challenge with BP extract. Methods First, we tested OLA in vitro. Stimulation of splenocytes and bone marrow-derived dendritic cells (BMDC) with OLA led to the production of pro-inflammatory and regulatory cytokines such as IL-6, IFN-γ and IL-10. Moreover, BMDC exposed to OLA upregulated the maturation markers CD40, CD80, CD86, and MHCII. Furthermore, OLA was recognised by TLR2-transfected human embryonic kidney cells. Results Immunisation of mice with OLA induced high levels of Toxoplasma-specific IgG antibodies in sera along with increased production of IFN-γ and IL-10 in Toxoplasma-antigen restimulated splenocytes. OLA reduced allergic airway inflammation as manifested by significant reduction of eosinophils in bronchoalveolar fluids, decreased cellular infiltrates and mucus production in the lungs. Accordingly, Bet v 1-specific IgE was decreased in OLA-pretreated mice. The reduced allergic immune responses were accompanied by increased numbers of CD4+CD25highFoxp3+ regulatory T cells in spleens as well as by increased numbers of granulocytic myeloid-derived suppressor cells in lungs when compared to sensitised controls suggesting that these two cell populations might be involved in the suppression of the allergic immune responses. Conclusion Our data demonstrate that pretreatment with the oocyst extract can exert anti-allergic effects comparable to T. gondii infection. Thus, the immunomodulatory properties of the parasite extract indicate that this extract and in the future defined molecules thereof might serve as immunomodulatory adjuvants in allergy treatment and prophylaxis. PMID

  10. Efficacy of two peroxygen-based disinfectants for inactivation of Cryptosporidium parvum oocysts.

    PubMed

    Quilez, Joaquin; Sanchez-Acedo, Caridad; Avendaño, Catalina; del Cacho, Emilio; Lopez-Bernad, Fernando

    2005-05-01

    Two commercial peroxygen-based disinfectants containing hydrogen peroxide plus either peracetic acid (Ox-Virin) or silver nitrate (Ox-Agua) were tested for their ability to inactivate Cryptosporidium parvum oocysts. Oocysts were obtained from naturally infected goat kids and exposed to concentrations of 2, 5, and 10% Ox-Virin or 1, 3, and 5% Ox-Agua for 30, 60, and 120 min. In vitro excystation, vital dyes (4',6'-diamidino-2-phenylindole and propidium iodide), and infectivity in neonatal BALB/c mice were used to assess the viability and infectivity of control and disinfectant-treated oocysts. Both disinfectants had a deleterious effect on the survival of C. parvum oocysts, since disinfection significantly reduced and in some cases eliminated their viability and infectivity. When in vitro assays were compared with an infectivity assay as indicators of oocyst inactivation, the excystation assay showed 98.6% inactivation after treatment with 10% Ox-Virin for 60 min, while the vital-dye assay showed 95.2% inactivation and the infectivity assay revealed 100% inactivation. Treatment with 3% Ox-Agua for 30 min completely eliminated oocyst infectivity for mice, although we were able to observe only 74.7% inactivation as measured by excystation assays and 24.3% with vital dyes (which proved to be the least reliable method for predicting C. parvum oocyst viability). These findings indicate the potential efficacy of both disinfectants for C. parvum oocysts in agricultural settings where soil, housing, or tools might be contaminated and support the argument that in comparison to the animal infectivity assay, vital-dye and excystation methods overestimate the viability of oocysts following chemical disinfection. PMID:15870337

  11. Efficacy of Two Peroxygen-Based Disinfectants for Inactivation of Cryptosporidium parvum Oocysts

    PubMed Central

    Quilez, Joaquin; Sanchez-Acedo, Caridad; Avendaño, Catalina; del Cacho, Emilio; Lopez-Bernad, Fernando

    2005-01-01

    Two commercial peroxygen-based disinfectants containing hydrogen peroxide plus either peracetic acid (Ox-Virin) or silver nitrate (Ox-Agua) were tested for their ability to inactivate Cryptosporidium parvum oocysts. Oocysts were obtained from naturally infected goat kids and exposed to concentrations of 2, 5, and 10% Ox-Virin or 1, 3, and 5% Ox-Agua for 30, 60, and 120 min. In vitro excystation, vital dyes (4′,6′-diamidino-2-phenylindole and propidium iodide), and infectivity in neonatal BALB/c mice were used to assess the viability and infectivity of control and disinfectant-treated oocysts. Both disinfectants had a deleterious effect on the survival of C. parvum oocysts, since disinfection significantly reduced and in some cases eliminated their viability and infectivity. When in vitro assays were compared with an infectivity assay as indicators of oocyst inactivation, the excystation assay showed 98.6% inactivation after treatment with 10% Ox-Virin for 60 min, while the vital-dye assay showed 95.2% inactivation and the infectivity assay revealed 100% inactivation. Treatment with 3% Ox-Agua for 30 min completely eliminated oocyst infectivity for mice, although we were able to observe only 74.7% inactivation as measured by excystation assays and 24.3% with vital dyes (which proved to be the least reliable method for predicting C. parvum oocyst viability). These findings indicate the potential efficacy of both disinfectants for C. parvum oocysts in agricultural settings where soil, housing, or tools might be contaminated and support the argument that in comparison to the animal infectivity assay, vital-dye and excystation methods overestimate the viability of oocysts following chemical disinfection. PMID:15870337

  12. Inactivation kinetics of Cryptosporidium parvum oocysts in a swine waste lagoon and spray field.

    PubMed

    Jenkins, Michael B; Liotta, Janice L; Bowman, Dwight D

    2013-04-01

    Because of outbreaks of cryptosporidiosis in humans, some Cryptosporidium spp. have become a public health concern. Commercial swine operations can be a source of this protozoan parasite. Although the species distribution of Cryptosporidium is likely dominated by Cryptosporidium suis , a fraction may be comprised of other Cryptosporidium species infectious to humans such as Cryptosporidium parvum . To better understand the survival dynamics of Cryptosporidium spp., oocysts associated with swine operations, 2 experiments were performed to determine die-off rates of C. parvum oocysts in a swine waste lagoon (2009 and 2010) and its spray field (2010 and 2011). Sentinel chambers containing a lagoon effluent suspension of C. parvum oocysts were submerged in the lagoon, and triplicate chambers were removed over time; oocysts were extracted and assayed for viability. For comparative purposes, inactivation rates of Ascaris suum eggs contained in sentinel chambers were also determined. For 2 spray field experiments, air-dried and sieved surface soil was placed in sentinel chambers, hydrated, and inoculated with a lagoon effluent suspension of C. parvum oocysts. Sentinel chambers and control oocysts in PBS contained in microcentrifuge tubes were buried 1.5 cm below the soil surface in 3 blocks. Triplicate chambers and controls were removed over time; oocysts were extracted and assayed for viability. Based on the first order decay equation, days to reach 99% die-off (T(99)) were determined. T(99)-values determined for the 2 lagoon experiments were 13.1 and 20.1 wk, respectively. A T(99)-value for C. parvum in the spray field was significantly longer at 38.0 wk than the control oocysts in PBS at 29.0 wk. The waste lagoon and spray field system of manure management at this large-scale farrowing operation appeared to reduce the load of C. parvum oocysts before they can be hydrologically transported off the operation and reduces their likelihood of contaminating surface waters

  13. Strategies To Discover the Structural Components of Cyst and Oocyst Walls

    PubMed Central

    Bushkin, G. Guy; Chatterjee, Aparajita; Robbins, Phillips W.

    2013-01-01

    Cysts of Giardia lamblia and Entamoeba histolytica and oocysts of Toxoplasma gondii and Cryptosporidium parvum are the infectious and sometimes diagnostic forms of these parasites. To discover the structural components of cyst and oocyst walls, we have developed strategies based upon a few simple assumptions. Briefly, the most abundant wall proteins are identified by monoclonal antibodies or mass spectrometry. Structural components include a sugar polysaccharide (chitin for Entamoeba, β-1,3-linked glucose for Toxoplasma, and β-1,3-linked GalNAc for Giardia) and/or acid-fast lipids (Toxoplasma and Cryptosporidium). Because Entamoeba cysts and Toxoplasma oocysts are difficult to obtain, studies of walls of nonhuman pathogens (E. invadens and Eimeria, respectively) accelerate discovery. Biochemical methods to dissect fungal walls work well for cyst and oocyst walls, although the results are often unexpected. For example, echinocandins, which inhibit glucan synthases and kill fungi, arrest the development of oocyst walls and block their release into the intestinal lumen. Candida walls are coated with mannans, while Entamoeba cysts are coated in a dextran-like glucose polymer. Models for cyst and oocyst walls derive from their structural components and organization within the wall. Cyst walls are composed of chitin fibrils and lectins that bind chitin (Entamoeba) or fibrils of the β-1,3-GalNAc polymer and lectins that bind the polymer (Giardia). Oocyst walls of Toxoplasma have two distinct layers that resemble those of fungi (β-1,3-glucan in the inner layer) or mycobacteria (acid-fast lipids in the outer layer). Oocyst walls of Cryptosporidium have a rigid bilayer of acid-fast lipids and inner layer of oocyst wall proteins. PMID:24096907

  14. Improved stool concentration procedure for detection of Cryptosporidium oocysts in fecal specimens.

    PubMed Central

    Weber, R; Bryan, R T; Juranek, D D

    1992-01-01

    Epidemiologic and laboratory data suggest that coprodiagnostic methods may fail to detect Cryptosporidium oocysts in stool specimens of infected patients. To improve the efficacy of stool concentration procedures, we modified different steps of the Formalin-ethyl acetate (FEA) stool concentration technique and evaluated these modifications by examining stool samples seeded with known numbers of Cryptosporidium oocysts. Because these modifications failed to improve oocyst detection, we developed a new stool concentration technique that includes FEA sedimentation followed by layering and flotation over hypertonic sodium chloride solution to separate parasites from stool debris. Compared with the standard FEA procedure, this technique improved Cryptosporidium oocyst detection. The sensitivities of the two concentration techniques were similar for diarrheal (watery) stool specimens (100% of watery stool specimens seeded with 5,000 oocysts per g of stool were identified as positive by the new technique, compared with 90% of stools processed by the standard FEA technique). However, the most significant improvement in diagnosis occurred with formed stool specimens that were not fatty; 70 to 90% of formed stool specimens seeded with 5,000 oocysts were identified as positive by the new technique, compared with 0% of specimens processed by the standard FEA technique. One hundred percent of formed specimens seeded with 10,000 oocysts were correctly diagnosed by using the new technique, while 0 to 60% of specimens processed by the standard FEA technique were found positive. Similarly, only 50 to 90% of stool specimens seeded with 50,000 oocysts were identified as positive by using the standard FEA technique, compared with a 100% positive rate by the new technique. The new stool concentration procedure provides enhanced detection of Cryptosporidium oocysts in all stool samples. PMID:1452656

  15. Modelling homogeneous regions of social vulnerability to malaria in Rwanda.

    PubMed

    Bizimana, Jean Pierre; Kienberger, Stefan; Hagenlocher, Michael; Twarabamenye, Emmanuel

    2016-01-01

    Despite the decline in malaria incidence due to intense interventions, potentials for malaria transmission persist in Rwanda. To eradicate malaria in Rwanda, strategies need to expand beyond approaches that focus solely on malaria epidemiology and also consider the socioeconomic, demographic and biological/disease-related factors that determine the vulnerability of potentially exposed populations. This paper analyses current levels of social vulnerability to malaria in Rwanda by integrating a set of weighted vulnerability indicators. The paper uses regionalisation techniques as a spatially explicit approach for delineating homogeneous regions of social vulnerability to malaria. This overcomes the limitations of administrative boundaries for modelling the trans-boundary social vulnerability to malaria. The utilised approach revealed high levels of social vulnerability to malaria in the highland areas of Rwanda, as well as in remote areas where populations are more susceptible. Susceptibility may be due to the populations' lacking the capacity to anticipate mosquito bites, or lacking resilience to cope with or recover from malaria infection. By highlighting the most influential indicators of social vulnerability to malaria, the applied approach indicates which vulnerability domains need to be addressed, and where appropriate interventions are most required. Interventions to improve the socioeconomic development in highly vulnerable areas could prove highly effective, and provide sustainable outcomes against malaria in Rwanda. This would ultimately increase the resilience of the population and their capacity to better anticipate, cope with, and recover from possible infection. PMID:27063738

  16. A sticky situation: the unexpected stability of malaria elimination.

    PubMed

    Smith, David L; Cohen, Justin M; Chiyaka, Christinah; Johnston, Geoffrey; Gething, Peter W; Gosling, Roly; Buckee, Caroline O; Laxminarayan, Ramanan; Hay, Simon I; Tatem, Andrew J

    2013-08-01

    Malaria eradication involves eliminating malaria from every country where transmission occurs. Current theory suggests that the post-elimination challenges of remaining malaria-free by stopping transmission from imported malaria will have onerous operational and financial requirements. Although resurgent malaria has occurred in a majority of countries that tried but failed to eliminate malaria, a review of resurgence in countries that successfully eliminated finds only four such failures out of 50 successful programmes. Data documenting malaria importation and onwards transmission in these countries suggests malaria transmission potential has declined by more than 50-fold (i.e. more than 98%) since before elimination. These outcomes suggest that elimination is a surprisingly stable state. Elimination's 'stickiness' must be explained either by eliminating countries starting off qualitatively different from non-eliminating countries or becoming different once elimination was achieved. Countries that successfully eliminated were wealthier and had lower baseline endemicity than those that were unsuccessful, but our analysis shows that those same variables were at best incomplete predictors of the patterns of resurgence. Stability is reinforced by the loss of immunity to disease and by the health system's increasing capacity to control malaria transmission after elimination through routine treatment of cases with antimalarial drugs supplemented by malaria outbreak control. Human travel patterns reinforce these patterns; as malaria recedes, fewer people carry malaria from remote endemic areas to remote areas where transmission potential remains high. Establishment of an international resource with backup capacity to control large outbreaks can make elimination stickier, increase the incentives for countries to eliminate, and ensure steady progress towards global eradication. Although available evidence supports malaria elimination's stickiness at moderate

  17. [Malaria in Moscow in 2000-2004].

    PubMed

    Ivanova, T N; Petrova, G N; Timoshenko, N I

    2005-01-01

    Malaria was eradicated on the territory of Moscow in 1960; its imported cases mainly from the countries of Asia and Africa and sporadic cases secondary to the imported ones were recorded during the following 40 years. Mass migration of the population (businessmen, seasonal workers, etc.) from the endemic CIS countries in the late 1990s, particularly to the Moscow Region, increased cases of tertian malaria, resulting from the transmission of the infection by the mosquitoes Anopheles. A total of 793 cases of malaria, including 27 parasitic carriers, were recorded from 2000 to 2004. The proportion of Muscovites was 24.1% of the total cases of malaria in 2002 and increased up to 50% in 2004. The causative agents of tertian malaria (Plasmodium vivax) were detected in 74.8% of the total number of cases. The ongoing importation of malaria from Tadjikistan and Azerbaijan, the late establishment of final diagnosis, the shortage of antimalarial drugs make the malaria situation worse in Moscow, which requires that antiepidemic measures should be intensified in the coming 3 years. PMID:16445228

  18. Aging of Cryptosporidium parvum oocysts in river water and their susceptibility to disinfection by chlorine and monochloramine.

    PubMed

    Chauret, C; Nolan, K; Chen, P; Springthorpe, S; Sattar, S

    1998-12-01

    Cryptosporidium parvum oocysts were aged in waters from both the St. Lawrence River and the Ottawa River. In situ survival experiments were carried out by incubating the oocysts in either dialysis cassettes or microtubes floated into an overflow tank. A significant portion of the oocysts survived in the test waters for several weeks. Oocyst survival in the St. Lawrence River was better in membrane-filtered (0.2 microm-pore diameter) water than in unfiltered water, suggesting that biological antagonism may play a role in the environmental fate of the parasite. Oocysts aged in river waters under in situ conditions and control oocysts kept refrigerated in synthetic water (100 ppm as CaCO3); pH 7.0) were subjected to the same disinfection protocol. Aged oocysts were at least as resistant as, if not more resistant than, the control oocysts to disinfection. This indicates that the oocysts surviving in the water environment may be just as difficult to inactivate by potable water disinfection as freshly shed oocysts. Therefore, water treatment should not be based on the assumption that environmental oocysts may be more easily inactivated than freshly shed oocysts. First-order kinetics die-off rates varied from one river to another (from 0.013 to 0.039 log(10).day(-1)) and from one experiment to another with water from the same river collected at different times. Calculation of the die-off rates based on either in vitro excystation or in vitro excystation in combination with total counts (overall die-off rates) showed that the assessment of oocyst viability by microscopic methods must account for the total oocyst loss observed during long-term inactivation assays of river waters. PMID:10383227

  19. In Vitro Interactions of Asian Freshwater Clam (Corbicula fluminea) Hemocytes and Cryptosporidium parvum Oocysts

    PubMed Central

    Graczyk, T. K.; Fayer, R.; Cranfield, M. R.; Conn, D. B.

    1997-01-01

    Corbicula fluminea hemocytes phagocytosed infectious oocysts of Cryptosporidium parvum in vitro. After 15, 30, 60, 90, and 120 min of incubation, averages of 35.8, 58.0, 69.7, 77.7, and 81.6% of the oocysts were phagocytosed by 24.3, 70.0, 78.5, 87.3, and 93.0% of the hemocytes, respectively. A single clam can retain by phagocytosis an average of 1.84 x 10(sup6) oocysts per ml of hemolymph. C. fluminea bivalves can serve as biological indicators of contamination of wastewaters and agricultural drainages with Cryptosporidium. PMID:16535656

  20. Malaria in India: The Center for the Study of Complex Malaria in India

    PubMed Central

    Das, Aparup; Anvikar, Anupkumar R.; Cator, Lauren J.; Dhiman, Ramesh C.; Eapen, Alex; Mishra, Neelima; Nagpal, Bhupinder N.; Nanda, Nutan; Raghavendra, Kamaraju; Read, Andrew F.; Sharma, Surya K.; Singh, Om P.; Singh, Vineeta; Sinnis, Photini; Srivastava, Harish C.; Sullivan, Steven A.; Sutton, Patrick L.; Thomas, Matthew B.; Carlton, Jane M.; Valecha, Neena

    2012-01-01

    Malaria is a major public health problem in India and one which contributes significantly to the overall malaria burden in Southeast Asia. The National Vector Borne Disease Control Program of India reported ~1.6 million cases and ~1100 malaria deaths in 2009. Some experts argue that this is a serious underestimation and that the actual number of malaria cases per year is likely between 9 and 50 times greater, with an approximate 13-fold underestimation of malaria-related mortality. The difficulty in making these estimations is further exacerbated by (i) highly variable malaria eco-epidemiological profiles, (ii) the transmission and overlap of multiple Plasmodium species and Anopheles vectors, (iii) increasing antimalarial drug resistance and insecticide resistance, and (iv) the impact of climate change on each of these variables. Simply stated, the burden of malaria in India is complex. Here we describe plans for a Center for the Study of Complex Malaria in India (CSCMi), one of ten International Centers of Excellence in Malaria Research (ICEMRs) located in malarious regions of the world recently funded by the National Institute of Allergy and Infectious Diseases, National Institutes of Health. The CSCMi is a close partnership between Indian and United States scientists, and aims to address major gaps in our understanding of the complexity of malaria in India, including changing patterns of epidemiology, vector biology and control, drug resistance, and parasite genomics. We hope that such a multidisciplinary approach that integrates clinical and field studies with laboratory, molecular, and genomic methods will provide a powerful combination for malaria control and prevention in India. PMID:22142788

  1. [Pulmonary complications of malaria: An update].

    PubMed

    Cabezón Estévanez, Itxasne; Górgolas Hernández-Mora, Miguel

    2016-04-15

    Malaria is the most important parasitic disease worldwide, being a public health challenge in more than 90 countries. The incidence of pulmonary manifestations has increased in recent years. Acute respiratory distress syndrome is the most severe form within the pulmonary complications of malaria, with high mortality despite proper management. This syndrome manifests with sudden dyspnoea, cough and refractory hypoxaemia. Patients should be admitted to intensive care units and treated with parenteral antimalarial drug treatment and ventilatory and haemodynamic support without delay. Therefore, dyspnoea in patients with malaria should alert clinicians, as the development of respiratory distress is a poor prognostic factor. PMID:26897507

  2. Spatial targeting of interventions against malaria.

    PubMed Central

    Carter, R.; Mendis, K. N.; Roberts, D.

    2000-01-01

    Malaria transmission is strongly associated with location. This association has two main features. First, the disease is focused around specific mosquito breeding sites and can normally be transmitted only within certain distances from them: in Africa these are typically between a few hundred metres and a kilometre and rarely exceed 2-3 kilometres. Second, there is a marked clustering of persons with malaria parasites and clinical symptoms at particular sites, usually households. In localities of low endemicity the level of malaria risk or case incidence may vary widely between households because the specific characteristics of houses and their locations affect contact between humans and vectors. Where endemicity is high, differences in human/vector contact rates between different households may have less effect on malaria case incidences. This is because superinfection and exposure-acquired immunity blur the proportional relationship between inoculation rates and case incidences. Accurate information on the distribution of malaria on the ground permits interventions to be targeted towards the foci of transmission and the locations and households of high malaria risk within them. Such targeting greatly increases the effectiveness of control measures. On the other hand, the inadvertent exclusion of these locations causes potentially effective control measures to fail. The computerized mapping and management of location data in geographical information systems should greatly assist the targeting of interventions against malaria at the focal and household levels, leading to improved effectiveness and cost-effectiveness of control. PMID:11196487

  3. Absence of a role for natural killer cells in the control of acute infection by Toxoplasma gondii oocysts.

    PubMed Central

    Hughes, H P; Kasper, L H; Little, J; Dubey, J P

    1988-01-01

    The active phase of primary and challenge oral infections of Toxoplasma gondii was investigated with respect to natural killer (NK) activity against YAC-1 tumour cell targets in vitro and serum interferon (IFN) titres. Primary (non-lethal) oral infection of BALB/c mice with Me49 oocysts resulted in a rapid increase of serum IFN titres, followed by augmented NK activity. NK levels became depressed, rising again by 15 days after infection to normal levels, again preceded by elevated IFN titres. In challenge infections NK was not augmented and IFN titres rose only if a high dose of oocysts was given. IFN activity was pH2-labile in all cases and considered to be due to IFN-gamma. Cold target inhibition studies indicated that T. gondii did not bind to NK cells. A bioassay for the effects of NK cells on T. gondii tachyzoites was developed and there was no evidence of killing in vitro by cells with NK function; T. gondii survived better when cultured with NK cells than when cultured alone. Studies using C57BL/6bg/bg,bg/+ and +/+ mice showed that there was no difference in mean time to death after administration of a lethal ME49 oocyst infection by mouth. Cytotoxicity against YAC-1 in both spleen and mesenteric lymph node (MLN) cell populations was highly augmented in bg/+ and +/+, but not in bg/bg mice. Genetic deficiency of NK activity had no effect on survival of mice after infection. Therefore NK has at best a minimal role to play in protection during the acute phase of Toxoplasma infection. PMID:3139341

  4. Is asymptomatic malaria really asymptomatic? Hematological, vascular and inflammatory effects of asymptomatic malaria parasitemia.

    PubMed

    de Mast, Quirijn; Brouwers, Judith; Syafruddin, Din; Bousema, Teun; Baidjoe, Amrish Y; de Groot, Philip G; van der Ven, Andre J; Fijnheer, Rob

    2015-11-01

    Asymptomatic malaria infections are highly prevalent in malaria endemic regions and most of these infections remain undiagnosed and untreated. Whereas conventional malaria symptoms are by definition absent, little is known on the more subtle health consequences of these infections. The aim of our study was to analyze the hematologic, vascular and inflammatory effects of patent and subpatent asymptomatic malaria parasitemia in children and adults on the Indonesian island Sumba. Both children and adults with parasitemia had increased high-sensitive C-reactive protein levels compared to aparasitemic individuals. In addition, children, but not adults with parasitemia also had lower platelet counts and Hb levels and higher levels of von Willebrand factor and platelet factor-4, markers of endothelial and platelet activation, respectively. These findings suggest that asymptomatic malaria infections have subtle health consequences, especially in children, and should be regarded as potentially harmful. PMID:26304688

  5. Removal effect of the water purifier for home use against Cryptosporidium parvum oocysts.

    PubMed

    Matsui, Toshihiro; Kajima, Junko; Fujino, Takashi

    2004-08-01

    The removal effects of the faucet mounted type water purifier for home use were examined against Cryptosporidium parvum oocysts. The water purifier is composed of a layer of granular activated carbon and the hollow fiber membrane filter. The cartridges were unused, 25%, 50% and 75% flow down by Arizona-dust of U. S. A. Two respective cartridges were used of the examination. The faucet and the water purifier were connected by anti-pressure tube, and 3.0 x 10(7) oocysts of Cryptosporidium parvum were injected into anti-pressure tube while water was running. Twenty liter of collected purified water was examined under the fluorescent microscope. Any oocysts in the purified water collected from all cartridges were not found. Therefore, we considered this purifier as an effective one in removing Cryptosporidium oocysts from drinking water. PMID:15353844

  6. Detection of Infectious Cryptosporidium parvum Oocysts in Mussels (Mytilus galloprovincialis) and Cockles (Cerastoderma edule)

    PubMed Central

    Gomez-Bautista, M.; Ortega-Mora, L. M.; Tabares, E.; Lopez-Rodas, V.; Costas, E.

    2000-01-01

    Infective Cryptosporidium parvum oocysts were detected in mussels (Mytilus galloprovincialis) and cockles (Cerastoderma edule) from a shellfish-producing region (Gallaecia, northwest Spain, bounded by the Atlantic Ocean) that accounts for the majority of European shellfish production. Shellfish were collected from bay sites with different degrees of organic pollution. Shellfish harboring C. parvum oocysts were recovered only from areas located near the mouths of rivers with a high density of grazing ruminants on their banks. An approximation of the parasite load of shellfish collected in positive sites indicated that each shellfish transported more than 103 oocysts. Recovered oocysts were infectious for neonatal mice, and PCR-restriction fragment length polymorphism analysis demonstrated a profile similar to that described for genotype C or 2 of the parasite. These results demonstrate that mussels and cockles could act as a reservoir of C. parvum infection for humans. Moreover, estuarine shellfish could be used as an indicator of river water contamination. PMID:10788352

  7. EVALUATING IN VITRO INFECTIVITY FOR MEASURING UV DISINFECTION OF CRYPTOSPORIDIUM PARVUM OOCYSTS IN FINISHED WATER

    EPA Science Inventory

    UV technology to inactivate Cryptosporidium parvum oocysts has become well established in the US. The challenge now is to effectively demonstrate UV reactor performance and disinfection capacity with various finished water matrices and under different operational conditions. In s...

  8. Shedding of Toxoplasma gondii oocysts by Felidae in zoos in the Czech Republic.

    PubMed

    Lukesová, D; Literák, I

    1998-01-15

    In 1995 and 1996, the shedding of Toxoplasma gondii oocysts was monitored in the faeces of Felidae in six zoos in the Czech Republic. In all, 2287 samples of faeces from 19 species of Felidae were examined. In Ostrava Zoo, four episodes of shedding of Toxoplasma-like oocysts were identified, using a flotation examination, in a pair of wild cats (Felis silvestris), six episodes in a wild cat held separately, and three episodes in a pair of Amur leopard cats (F. euptilurus). After the passage of sporulated oocysts through laboratory mice, T. gondii was confirmed in the pair of wild cats (three episodes), in the wild cat held separately (three episodes) and in the pair of Amur leopard cats (one episode). In Jihlava Zoo, one episode of shedding of T. gondii oocyst was identified in Geoffroy's cat (Oncifelis geoffroyi) using flotation and isolation examination. The possible sources of toxoplasmosis of the Felidae in zoos are discussed. PMID:9493305

  9. ENHANCED CONCENTRATION AND ISOLATION OF CYCLOSPORA CAYETANENSIS OOCYSTS FROM HUMAN FECAL SAMPLES

    EPA Science Inventory

    Cyclospora cayetanensis is the causative agent of cyclosporiasis, an emerging infections disease. A new method for the purification of Cycloposra cayetanensis oocysts from fecal matter has been developed, using a modified detachment solution and a Renocal-sucrose gradient sedimen...

  10. EVALUATION OF CRYPTOSPORIDIUM OOCYSTS AND GIARDIA CYSTS IN A WATERSHED RESERVOIR

    EPA Science Inventory

    This investigation evaluated the occurrence of Cryptosporidium oocysts and Giardia cysts at 17 sampling locations in Lake Texoma reservoir using method 1623 with standard Envirocheck" capsule filters. The watershed serves rural agricultural communities active in cattle ranching,...

  11. EVALUATION OF CRYPTOSPORIDIUM OOCYSTS AND GIARDIA CYSTS IN A WATERSHED RESERVOIR

    EPA Science Inventory

    This investigation evaluated the occurrence of Cryptosporidium oocysts and Giardia cysts at 17 sampling locations in Lake Texoma reservoir using method 1623 with standard Envirocheck™ capsule filters. The watershed serves rural agricultural communities active in cattle ranching, ...

  12. CRYPTOSPORIDIUM OOCYST RECOVERY IN WATER BY EPA METHOD 1623: EVALUATION OF A MODIFIED IMS DISSOCIATION

    EPA Science Inventory

    EPA Methods 1622 and 1623 are the benchmarks for detection of Cryptosporidium spp. oocysts in water. These methods consist of filtration, elution, purification by immunomagnetic separation (IMS), and microscopic analysis after staining with a fluorescein isothiocyanate conjugate...

  13. Malaria in Zhejiang Province, China, from 2005 to 2014.

    PubMed

    Chen, Hualiang; Yao, Linong; Zhang, Lingling; Zhang, Xuan; Lu, Qiaoyi; Yu, Kegen; Ruan, Wei

    2015-08-01

    To summarize the changing epidemiological characteristics of malaria in Zhejiang Province, China, we collected data on malaria from the Chinese Notifiable Disease Reporting System (NDRS) and analyzed them. A total of 2,738 malaria cases were identified in Zhejiang Province from 2005 to 2014, of which 2,018 were male and 720 were female. Notably, only 7% of malaria cases were indigenous and the other cases were all imported. The number of malaria cases increased from 2005 to 2007, peaked in 2007, and then decreased from 2007 to 2011. There were no indigenous cases from 2012 to 2014. Of all cases, 68% of cases contracted Plasmodium vivax, 27% of cases contracted P. falciparum, and two cases contracted P. malariae. About 88% of malaria cases during 2005-2011 occurred yearly between May and October, but the number of malaria cases in different months during 2012-2014 was similar. The median age was 33 years, and 1,892 cases occurred in persons aged 20-50 years. The proportion of businessmen increased and the proportion of migrant laborers decreased in recent years. The median time from illness onset to confirmation of malaria cases was 5 days and it decreased from 2005 to 2014. Some epidemiological characteristics of malaria have changed, and businessmen are the emphases to surveillance in every month. PMID:26078321

  14. Malaria in Zhejiang Province, China, from 2005 to 2014

    PubMed Central

    Chen, Hualiang; Yao, Linong; Zhang, Lingling; Zhang, Xuan; Lu, Qiaoyi; Yu, Kegen; Ruan, Wei

    2015-01-01

    To summarize the changing epidemiological characteristics of malaria in Zhejiang Province, China, we collected data on malaria from the Chinese Notifiable Disease Reporting System (NDRS) and analyzed them. A total of 2,738 malaria cases were identified in Zhejiang Province from 2005 to 2014, of which 2,018 were male and 720 were female. Notably, only 7% of malaria cases were indigenous and the other cases were all imported. The number of malaria cases increased from 2005 to 2007, peaked in 2007, and then decreased from 2007 to 2011. There were no indigenous cases from 2012 to 2014. Of all cases, 68% of cases contracted Plasmodium vivax, 27% of cases contracted P. falciparum, and two cases contracted P. malariae. About 88% of malaria cases during 2005–2011 occurred yearly between May and October, but the number of malaria cases in different months during 2012–2014 was similar. The median age was 33 years, and 1,892 cases occurred in persons aged 20–50 years. The proportion of businessmen increased and the proportion of migrant laborers decreased in recent years. The median time from illness onset to confirmation of malaria cases was 5 days and it decreased from 2005 to 2014. Some epidemiological characteristics of malaria have changed, and businessmen are the emphases to surveillance in every month. PMID:26078321

  15. Total and infectious Cryptosporidium oocyst and total Giardia cyst concentrations from distinct agricultural and urban contamination sources in Eastern Canada.

    PubMed

    Lalancette, Cindy; Généreux, Mylène; Mailly, Jacinthe; Servais, Pierre; Côté, Caroline; Michaud, Aubert; Di Giovanni, George D; Prévost, Michèle

    2012-03-01

    Cryptosporidium and Giardia (oo)cyst concentrations are frequently used for assessing drinking water safety. The widely used USEPA Method 1623 provides total counts of (oo)cysts, but may not be accurate for human health risk characterization, since it does not provide infectivity information. The total counts and infectious fraction of Cryptosporidium oocysts and the total counts of Giardia cysts were assessed in major fecal pollution sources. Fresh calf and cow feces, their manure, and the discharge point were sampled in a small rural sub-watershed (n = 20, 21, 10, 10). Median concentrations for total (oo)cysts were higher in calves (333 oocysts g(-1); 111 cysts g(-1)) than in cows (52 oocysts g(-1); 7 cysts g(-1)). Infectious oocysts were found in 17 (7%) of the samples and none were found in manure or at the discharge point. Urban sources were sampled in the influent and effluent (n = 19, 18) of two wastewater treatment plants. Peak concentrations were 533 oocysts L(-1) and 9,010 cysts L(-1) for influents and 89 oocysts L(-1) and 472 cysts L(-1) for effluents. Infectious oocyst fractions varied from below the detection limit to 7-22% in the effluent and influent respectively. These infectious fractions are significantly lower than those currently used for quantitative microbial risk assessment estimates. PMID:22361710

  16. Malaria epidemiological trends in Italy.

    PubMed

    Sabatinelli, G; Majori, G; D'Ancona, F; Romi, R

    1994-08-01

    Based on the official reports received from local health laboratories, an epidemiological analysis of malaria cases reported in Italy from 1989 to 1992 is presented. A total of 1,941 cases were reported, 1,287 among Italians and 654 among foreigners. The incidence of cases was on average 500 per year with a maximum in 1990. A slight, but constant decrease of incidence of malaria cases was recorded in this period among Italian citizens (-21.5%), while the incidence among foreigners increased (+80%). Plasmodium falciparum accounted for 74.2% of total infections, followed by P. vivax (19%). The highest number of cases was imported from Africa (86.5%), followed by Asia, South America, and Oceania. 11 cases were contracted in Europe (transfusion, airport and cryptic malaria). 26 people died from malaria during the four years, with a fatality rate of 2.3% among Italians. Other epidemiological features concerning incidence in the different categories of travellers, countries of infection, clinical and therapeutic aspects of cases, are also discussed. PMID:7843343

  17. Factors associated with the occurrence and level of Isospora suis oocyst excretion in nursing piglets of Greek farrow-to-finish herds

    PubMed Central

    2012-01-01

    Background Piglet isosporosis is one of the most common parasitic diseases in modern pig production. To prevent clinical disease, prophylactic treatment of piglets with toltrazuril (BAYCOX® 5%, Bayer HealthCare, Animal Health, Monheim, Germany) is widely practiced in the past 20 years. There are only very few reports documenting the likely effect of managerial practices, such as hygiene measures, all-in-all-out management of farrowing facilities and piglet manipulations, and/or farm-specific environment - i.e. design and materials of the farrowing pen and room - in the risk of disease occurrence and transmission. Therefore, in this cross-sectional study, we identified litter- and herd-level factors associated with the odds and the level of Isospora suis oocyst excretion in nursing piglets of Greek farrow-to-finish pig herds. Faecal samples were collected from 314 liters of 55 randomly selected herds. Oocyst counts were determined by a modified McMaster technique and possible risk-factor data were collected through a questionnaire. In the analysis, we employed a two-part model that simultaneously assessed the odds and the level of oocyst excretion. Results Factors associated with lower odds of oocyst excretion were: use of toltrazuril treatment, all-in all-out management of the farrowing rooms, no cross-fostering or fostering during the first 24 hours after farrowing, plastic flooring in the farrowing pens, farrowing rooms with more than fourteen farrowing pens and employment of more than two caretakers in the farrowing section. Factors associated with lower oocyst excretion level were: use of toltrazuril treatment and caretakers averting from entering into farrowing pens. Conclusion Apart from prophylactic treatment with toltrazuril, the risk and the level of I. suis oocyst excretion from piglets in their second week of life, was associated with managerial and environmental factors. Changes in these factors, which may enhance prevention of piglet isosporosis

  18. Integrated Approach to Malaria Control

    PubMed Central

    Shiff, Clive

    2002-01-01

    Malaria draws global attention in a cyclic manner, with interest and associated financing waxing and waning according to political and humanitarian concerns. Currently we are on an upswing, which should be carefully developed. Malaria parasites have been eliminated from Europe and North America through the use of residual insecticides and manipulation of environmental and ecological characteristics; however, in many tropical and some temperate areas the incidence of disease is increasing dramatically. Much of this increase results from a breakdown of effective control methods developed and implemented in the 1960s, but it has also occurred because of a lack of trained scientists and control specialists who live and work in the areas of endemic infection. Add to this the widespread resistance to the most effective antimalarial drug, chloroquine, developing resistance to other first-line drugs such as sulfadoxine-pyrimethamine, and resistance of certain vector species of mosquito to some of the previously effective insecticides and we have a crisis situation. Vaccine research has proceeded for over 30 years, but as yet there is no effective product, although research continues in many promising areas. A global strategy for malaria control has been accepted, but there are critics who suggest that the single strategy cannot confront the wide range of conditions in which malaria exists and that reliance on chemotherapy without proper control of drug usage and diagnosis will select for drug resistant parasites, thus exacerbating the problem. An integrated approach to control using vector control strategies based on the biology of the mosquito, the epidemiology of the parasite, and human behavior patterns is needed to prevent continued upsurge in malaria in the endemic areas. PMID:11932233

  19. Malaria in selected non-Amazonian countries of Latin America

    PubMed Central

    Arevalo-Herrera, Myriam; Quiñones, Martha Lucia; Guerra, Carlos; Céspedes, Nora; Giron, Sandra; Ahumada, Martha; Piñeros, Juan Gabriel; Padilla, Norma; Terrientes, Zilka; Rosas, Ángel; Padilla, Julio Cesar; Escalante, Ananias A.; Beier, John C.; Herrera, Socrates

    2011-01-01

    Approximately 170 million inhabitants of the American continent live at risk of malaria transmission. Although the continent’s contribution to the global malaria burden is small, at least 1 to 1.2 million malaria cases are reported annually. Sixty per cent of the malaria cases occur in Brazil and the other 40% are distributed in 20 other countries of Central and South America. Plasmodium vivax is the predominant species (74.2 %) followed by P. falciparum (25.7 %) and P. malariae (0.1%), and no less than 10 Anopheles species have been identified as primary or secondary malaria vectors. Rapid deforestation and agricultural practices are directly related to increases in Anopheles species diversity and abundance, as well as in the number of malaria cases. Additionally, climate changes profoundly affect malaria transmission and are responsible for malaria epidemics in some regions of South America. Parasite drug resistance is increasing, but due to bio-geographic barriers there is extraordinary genetic differentiation of parasites with limited dispersion. Although the clinical spectrum ranges from uncomplicated to severe malaria cases, due to the generally low to middle transmission intensity, features such as severe anemia, cerebral malaria and other complications appear to be less frequent than in other endemic regions and asymptomatic infections are a common feature. Although the National Malaria Control Programs (NMCP) of different countries differ in their control activities these are all directed to reduce morbidity and mortality by using strategies like health promotion, vector control and impregnate bed nets among others. Recently, international initiatives such as the Malaria Control Program in Andean-country Border Regions (PAMAFRO) (implemented by the Andean Organism for Health (ORAS) and sponsored by The Global Fund to Fight AIDS, Tuberculosis and Malaria (GFATM)) and The Amazon Network for the Surveillance of Antimalarial Drug Resistance (RAVREDA

  20. Rationale for the Coadministration of Albendazole and Ivermectin to Humans for Malaria Parasite Transmission Control

    PubMed Central

    Kobylinski, Kevin C.; Alout, Haoues; Foy, Brian D.; Clements, Archie; Adisakwattana, Poom; Swierczewski, Brett E.; Richardson, Jason H.

    2014-01-01

    Recently there have been calls for the eradication of malaria and the elimination of soil-transmitted helminths (STHs). Malaria and STHs overlap in distribution, and STH infections are associated with increased risk for malaria. Indeed, there is evidence that suggests that STH infection may facilitate malaria transmission. Malaria and STH coinfection may exacerbate anemia, especially in pregnant women, leading to worsened child development and more adverse pregnancy outcomes than these diseases would cause on their own. Ivermectin mass drug administration (MDA) to humans for malaria parasite transmission suppression is being investigated as a potential malaria elimination tool. Adding albendazole to ivermectin MDAs would maximize effects against STHs. A proactive, integrated control platform that targets malaria and STHs would be extremely cost-effective and simultaneously reduce human suffering caused by multiple diseases. This paper outlines the benefits of adding albendazole to ivermectin MDAs for malaria parasite transmission suppression. PMID:25070998

  1. Rationale for the coadministration of albendazole and ivermectin to humans for malaria parasite transmission control.

    PubMed

    Kobylinski, Kevin C; Alout, Haoues; Foy, Brian D; Clements, Archie; Adisakwattana, Poom; Swierczewski, Brett E; Richardson, Jason H

    2014-10-01

    Recently there have been calls for the eradication of malaria and the elimination of soil-transmitted helminths (STHs). Malaria and STHs overlap in distribution, and STH infections are associated with increased risk for malaria. Indeed, there is evidence that suggests that STH infection may facilitate malaria transmission. Malaria and STH coinfection may exacerbate anemia, especially in pregnant women, leading to worsened child development and more adverse pregnancy outcomes than these diseases would cause on their own. Ivermectin mass drug administration (MDA) to humans for malaria parasite transmission suppression is being investigated as a potential malaria elimination tool. Adding albendazole to ivermectin MDAs would maximize effects against STHs. A proactive, integrated control platform that targets malaria and STHs would be extremely cost-effective and simultaneously reduce human suffering caused by multiple diseases. This paper outlines the benefits of adding albendazole to ivermectin MDAs for malaria parasite transmission suppression. PMID:25070998

  2. Prevalence of Cryptosporidium oocysts and Giardia cysts in raw and treated sewage sludges.

    PubMed

    Amorós, Inmaculada; Moreno, Yolanda; Reyes, Mariela; Moreno-Mesonero, Laura; Alonso, Jose L

    2016-11-01

    Treated sludge from wastewater treatment plants (WWTPs) is commonly used in agriculture as fertilizers and to amend soils. The most significant health hazard for sewage sludge relates to the wide range of pathogenic microorganisms such as protozoa parasites.The objective of this study was to collect quantitative data on Cryptosporidium oocysts and Giardia cysts in the treated sludge in wastewater treatment facilities in Spain. Sludge from five WWTPs with different stabilization processes has been analysed for the presence of Cryptosporidium and Giardia in the raw sludge and after the sludge treatment. A composting plant (CP) has also been assessed. After a sedimentation step, sludge samples were processed and (oo)cysts were isolated by immunomagnetic separation (IMS) and detected by immunofluorescence assay (IFA). Results obtained in this study showed that Cryptosporidium oocysts and Giardia cysts were present in 26 of the 30 samples (86.6%) of raw sludge samples. In treated sludge samples, (oo)cysts have been observed in all WWTP's analysed (25 samples) with different stabilization treatment (83.3%). Only in samples from the CP no (oo)cysts were detected. This study provides evidence that (oo)cysts are present in sewage sludge-end products from wastewater treatment processes with the negative consequences for public health. PMID:27080207

  3. Viability of sporulated oocysts of Neospora caninum after exposure to different physical and chemical treatments.

    PubMed

    Alves Neto, Aldo F; Bandini, Luciana A; Nishi, Sandra M; Soares, Rodrigo M; Driemeier, David; Antoniassi, Nadia A B; Schares, Gereon; Gennari, Solange M

    2011-02-01

    The aim of the present study was to evaluate the viability of Neospora caninum sporulated oocysts after various chemical and physical treatments. Bioassays in gerbils and molecular techniques (PCR-RFLP) were used for identification of the oocysts shed by experimentally infected dogs. Sporulated oocysts were purified and divided into 11 treatment groups as follows: absolute ethanol for 1 hr; 20 C for 6 hr; 4 C for 6 hr; 60 C for 1 min; 100 C for 1 min; 10% formaldehyde for 1 hr; 10% ammonia for 1 hr; 2% iodine for 1 hr; 10% sodium hypochlorite for 1 hr; 70% ethanol for 1 hr; and one group was left untreated and kept as a positive control. All chemical treatments were performed at room temperature (37 C). A total of 33 gerbils, or 3 gerbils per treatment, were used for bioassays. After treatment, the oocysts were divided into aliquots of 1,000 oocysts and orally administered to gerbils. After 63 days, the gerbils were anesthetized and killed with 0.2 ml of T61; blood and tissue samples were collected for serological (IFAT and western blotting), molecular (real-time PCR), histopathology, and immunohistochemical tests. Treatments were considered effective only if all 5 detection techniques tested negative. High temperatures at 100 C for 1 min and 10% sodium hypochlorite for 1 hr were the only treatments that met this condition, effectively inactivating all oocysts. PMID:21348620

  4. Malaria and anemia.

    PubMed

    Ekvall, Håkan

    2003-03-01

    Anemia due to infection is a major health problem in endemic areas for young children and pregnant women. The anemia is caused by excess removal of nonparasitized erythrocytes in addition to immune destruction of parasitized red cells, and impaired compensation for this loss by bone marrow dysfunction. The pathogenesis is complex, and a predominant mechanism has not been identified. Certain parasite and host characteristics may modify the anemia. Concomitant infections and nutritional deficiencies also contribute to anemia and may interact with the malarial infection. Few preventive strategies exist, and the management of severe malarial anemia with blood transfusion carries a risk of HIV transmission. The current increase in malaria-specific childhood mortality in sub-Saharan Africa attributed to drug-resistant infection is likely partly related to an increase in severe anemia. This review summarizes recent findings on the pathogenesis and epidemiology of malarial anemia. PMID:12579035

  5. Malaria in pregnancy

    PubMed Central

    Soma-Pillay, P; Macdonald, A P

    2012-01-01

    Malaria is a complex parasitic disease affecting about 32 million pregnancies each year in sub-Saharan Africa. Pregnant women are especially susceptible to malarial infection and have the risk of developing severe disease and birth complications. The target of Millennium Development Goal 6 is to end malaria deaths by 2015. Maternal and perinatal morbidity and mortality due to malaria may be reduced by implementing preventive measures, early diagnosis of suspected cases, effective antimalarial therapy and treatment of complications.

  6. Association of PECAM1/CD31 polymorphisms with cerebral malaria

    PubMed Central

    Ohashi, Jun; Naka, Izumi; Hananantachai, Hathairad; Patarapotikul, Jintana

    2016-01-01

    Platelet/endothelial cell adhesion molecule-1 (PECAM1/CD31), a receptor recognized by P. falciparum-infected red blood cells (iRBCs), on the vascular endothelium has been implicated in mediating cytoadherence in patients with P. falciparum malaria. To examine associations of PECAM1 polymorphisms with cerebral malaria, 11 tag single nucleotide polymorphisms (SNPs) of PECAM1 were analysed for 312 Thai patients with P. falciparum malaria (109 with cerebral malaria and 203 with mild malaria). The rs1122800-C allele was significantly associated with protection from cerebral malaria (P = 0.017), and the rs9912957-A significantly increased the risk for cerebral malaria (P = 0.0065) in malaria patients. Fine-scale mapping using genotyped and imputed SNPs and linkage disequilibrium (LD) analysis revealed that rs1122800 and rs9912957 were located in two distinct LD blocks and were independently associated with cerebral malaria. The rs1122800-C allele was significantly associated with lower expression level of PECAM1 in EBV-transformed lymphoblastoid cell lines (P = 0.045). The present results suggest that PECAM1-mediated cytoadherence of iRBCs to brain endothelium plays a crucial role in the pathogenesis of cerebral malaria. PMID:27335627

  7. Malaria Modeling and Surveillance for the Greater Mekong Subregion

    NASA Technical Reports Server (NTRS)

    Kiang, Richard; Adimi, Farida; Soika, Valerii; Nigro, Joseph

    2005-01-01

    At 4,200 km, the Mekong River is the tenth longest river in the world. It directly and indirectly influences the lives of hundreds of millions of inhabitants in its basin. The riparian countries - Thailand, Myanmar, Cambodia, Laos, Vietnam, and a small part of China - form the Greater Mekong Subregion (GMS). This geographical region has the misfortune of being the world's epicenter of falciparum malaria, which is the most severe form of malaria caused by Plasmodium falciparum. Depending on the country, approximately 50 to 90% of all malaria cases are due to this species. In the Malaria Modeling and Surveillance Project, we have been developing techniques to enhance public health's decision capability for malaria risk assessments and controls. The main objectives are: 1) Identifying the potential breeding sites for major vector species; 2) Implementing a malaria transmission model to identify the key factors that sustain or intensify malaria transmission; and 3) Implementing a risk algorithm to predict the occurrence of malaria and its transmission intensity. The potential benefits are: 1) Increased warning time for public health organizations to respond to malaria outbreaks; 2) Optimized utilization of pesticide and chemoprophylaxis; 3) Reduced likelihood of pesticide and drug resistance; and 4) Reduced damage to environment. Environmental parameters important to malaria transmission include temperature, relative humidity, precipitation, and vegetation conditions. These parameters are extracted from NASA Earth science data sets. Hindcastings based on these environmental parameters have shown good agreement to epidemiological records.

  8. Contribution of cattle farms towards river contamination with Giardia cysts and Cryptosporidium oocysts in Sungai Langat Basin.

    PubMed

    Farizawati, S; Lim, Y A L; Ahmad, R A; Fatimah, C T N I; Siti-Nor, Y

    2005-12-01

    A study to determine the contribution of Giardia cysts and Cryptosporidium oocysts from cattle farms was carried out at the Langat Basin. This study investigated the contribution of cattle farms, located near Sungai Langat and Sungai Semenyih, towards river contamination with these cysts and oocysts. The findings showed that out of 24 samples of water taken from Sungai Semenyih, 4.2% was positive for Giardia cysts with a concentration of 1.3 cysts/L and 20.8% were positive with Cryptosporidium oocysts with a range of 0.7 - 2.7 oocysts/L. At Sungai Langat, from the 43 samples taken, 23.3% were positive for Giardia cysts with a range of 1.5 - 9 cysts/L whereas 11.6% were positive with Cryptosporidium oocysts with a range of 2.5 - 240 oocysts/L. Isolation of cysts and oocysts in bovine faecal materials revealed that 14.6% of faecal samples were positive for Giardia cysts which had a range of 75 - 1.3x104 cysts/g and 25% were positive for Cryptosporidium oocysts with a range of 50 - 3.9x105 oocysts/g. From the cattle wastewater, 98% were positive with oocysts and 6.7% with cysts. The concentrations were between 20 - 3.1x103 oocysts/mL for Cryptosporidium and 4 - 75 cysts/mL for Giardia. Given that the prevalence of Cryptosporidium and Giardia are high amongst the cattle and the positive findings of the (oo)cysts in the river samples, it could be deduced that there is a very high possibility of the cattle farms contaminating the river with Giardia cysts and Cryptosporidium oocysts. Viability study of Cryptosporidium oocysts in the surrounding soil and pond within the cattle farm showed that the viability of Cryptosporidium oocysts decreased with time. It was estimated that it will take 52 days for all the oocysts from both environment to be non-viable. With a viability rate of approximately 2 months in a cattle farm setup, river water contaminated with Cryptosporidium oocysts has a high chance of acting as an agent of transmission. As cattle farms are also inhabited by

  9. Malaria ecotypes and stratification.

    PubMed

    Schapira, Allan; Boutsika, Konstantina

    2012-01-01

    To deal with the variability of malaria, control programmes need to stratify their malaria problem into a number of smaller units. Such stratification may be based on the epidemiology of malaria or on its determinants such as ecology. An ecotype classification was developed by the World Health Organization (WHO) around 1990, and it is time to assess its usefulness for current malaria control as well as for malaria modelling on the basis of published research. Journal and grey literature was searched for articles on malaria or Anopheles combined with ecology or stratification. It was found that all malaria in the world today could be assigned to one or more of the following ecotypes: savanna, plains and valleys; forest and forest fringe; foothill; mountain fringe and northern and southern fringes; desert fringe; coastal and urban. However, some areas are in transitional or mixed zones; furthermore, the implications of any ecotype depend on the biogeographical region, sometimes subregion, and finally, the knowledge on physiography needs to be supplemented by local information on natural, anthropic and health system processes including malaria control. Ecotyping can therefore not be seen as a shortcut to determine control interventions, but rather as a framework to supplement available epidemiological and entomological data so as to assess malaria situations at the local level, think through the particular risks and opportunities and reinforce intersectoral action. With these caveats, it does however emerge that several ecotypic distinctions are well defined and have relatively constant implications for control within certain biogeographic regions. Forest environments in the Indo-malay and the Neotropics are, with a few exceptions, associated with much higher malaria risk than in adjacent areas; the vectors are difficult to control, and the anthropic factors also often converge to impose constraints. Urban malaria in Africa is associated with lower risk than savanna

  10. Honeymoon malaria and "herbal" therapy: A case report.

    PubMed

    Schmid, M L; Green, S T; Read, R C

    1999-12-01

    A marked rise in the number of cases of malaria in the UK contracted in east Africa has been reported in 1998. This may be explained by the "Lariam"-media hype, poor understanding, poverty of health education, or increase in travel to more exotic destinations. European centers have experienced changes in the pattern of imported malaria and constant up-dates are essential. However even the best informed may still acquire malaria. PMID:10575177

  11. [Update in the diagnosis and treatment of malaria].

    PubMed

    García López Hortelano, M; Fumadó Pérez, V; González Tomé, M I

    2013-02-01

    An increase in the cases of malaria in our country has been observed due to immigration, and adopted children. Malaria management requires an integrate approach, including prompt diagnoses and treatment to avoid the associated morbidity and mortality. In the last years, new recommendations have been introduced due to the appearance of new resistant areas. In this article we aim to provide a summary of the key recommendations following the main malaria guidelines (WHO and CDC). PMID:22963952

  12. Malaria in UK travellers: assessment, prevention and treatment.

    PubMed

    Chiodini, Jane

    Malaria is the most serious tropical disease. Increasing numbers of people are travelling to tropical destinations where they are at risk of malaria. Nurses need to be aware of the disease risk, prevention of mosquito bites and appropriate chemoprophylaxis to protect the health of travellers. This article describes the malaria lifecycle, bite prevention, chemoprophylaxis, diagnosis and prevention strategies for people travelling to malarious areas. Additional resources are supplied for nurses who want further information. PMID:16708668

  13. The Multilateral Initiative on Malaria: looking back and looking ahead

    PubMed Central

    Miller, Louis H.

    2012-01-01

    The Multilateral Initiative on Malaria (MIM) started in 1997 with the aim of giving African scientists an equal voice with Northern scientists in making decisions about malaria research in Africa. Is there a need for MIM today with the large increase in funding for malaria research from governments and foundations? I conclude that MIM is still needed today to support African scientists’ investigator-initiated research and training. PMID:20097134

  14. Spatial and temporal distribution of falciparum malaria in China

    PubMed Central

    Lin, Hualiang; Lu, Liang; Tian, Linwei; Zhou, Shuisen; Wu, Haixia; Bi, Yan; Ho, Suzanne C; Liu, Qiyong

    2009-01-01

    of adult men cases. Imported falciparum malaria in the non-endemic area of China, affected mainly by the malaria transmission in Yunnan, has increased both spatially and temporally. Specific intervention measures targeted at the mobile population groups are warranted. PMID:19523209

  15. An easy 'one tube' method to estimate viability of Cryptosporidium oocysts using real-time qPCR.

    PubMed

    Paziewska-Harris, A; Schoone, G; Schallig, H D F H

    2016-07-01

    Viability estimation of the highly resistant oocysts of Cryptosporidium remains a key issue for the monitoring and control of this pathogen. We present here a simple 'one tube' quantitative PCR (qPCR) protocol for viability estimation using a DNA extraction protocol which preferentially solubilizes excysted sporozoites rather than oocysts. Parasite DNA released from excysted sporozoites was quantified by real-time qPCR using a ribosomal DNA marker. The qPCR signal was directly proportional to the number of oocysts excysted, and a power-law relationship was noted between oocyst age and the proportion excysting. Unexcysted oocysts released negligible amounts of DNA making the method suitable for estimating viability of as few as 10 oocysts. PMID:27095569

  16. Effect of storage media, temperature, and time on preservation of Cryptosporidium parvum oocysts for PCR analysis.

    PubMed

    Lalonde, L F; Gajadhar, A A

    2009-03-23

    The effect of storage media, temperature, and time on suitability of oocysts for use in subsequent molecular studies was examined. Cryptosporidium parvum oocysts were stored for 3, 6, 9, or 12 months in sterile dH(2)O, 70 or 95% ethanol, (room temperature [RT], 4, -20, and -70 degrees C), 10% formalin (RT and 4 degrees C), PBS, TE buffer, antibiotic-antimycotic (A-A) solution (4, -20 and -70 degrees C), 2% sulphuric acid, 2.5% potassium dichromate (4 degrees C), and gDNA from 10(4) oocysts was extracted in triplicate and subjected to PCR. To determine the effect of storage media on PCR sensitivity, gDNA from 10(4), 10(2), and 10(0) oocysts stored for 15 months in the media listed above at RT or 4 degrees C was also extracted in triplicate and subjected to PCR. At RT, ethanol was suitable for up to 15 months, while gDNA from oocysts stored in dH(2)O amplified inconsistently after 3 months. At 4 degrees C, all tested media except dH(2)O and formalin were suitable for storage of 10(4) oocysts up to 15 months, but only 70% ethanol, A-A solution, 2% sulphuric acid and 2.5% potassium dichromate supported amplification of gDNA from fewer than 100 oocysts. At -20 degrees C, 95% ethanol, PBS, or TE were suitable for up to 9 months, while 70% ethanol and A-A solution were effective up to 12 months, and gDNA from oocysts stored in dH(2)O was inconsistently amplified after 6 months. Storage at -70 degrees C for up to 12 months was effective regardless of media type. Oocysts stored in formalin at RT or 4 degrees C could not be amplified by PCR despite washing prior to gDNA extraction. To maintain gDNA quality suitable for PCR, it is recommended that coccidian oocysts be stored at -70 degrees C in dH(2)O, ethanol, PBS, TE or A-A solution, at 4 degrees C in A-A or ethanol, or at RT in ethanol where refrigerated storage is unavailable. PMID:19128883

  17. Occurrence of Cryptosporidium oocysts and Giardia cysts in effluent from sewage treatment plant from eastern Poland.

    PubMed

    Sroka, Jacek; Stojecki, Krzysztof; Zdybel, Jolanta; Karamon, Jacek; Cencek, Tomasz; Dutkiewicz, Jacek

    2013-01-01

    Cryptosporidium spp. and Giardia lamblia (synonyms: Giardia duodenalis, Giardia intestinalis) are emerging protozoa causing disease in humans and animals worldwide. These parasites can pose a serious threat to immunocompromised people, for whom the symptoms are more severe and may include abdominal pain, watery diarrhoea, nausea, headaches, malaise, and fever. One of the sources of these parasites can be treated wastewater from wastewater treatment plants (WTPs). Samples of treated wastewater (effluent), each of 10 L volume, were collected from 13 municipal WTPs located in eastern Poland. Cryptosporidium oocysts and Giardia cysts were separated by the immunomagnetic method. The presence and/or concentration of protozoan (oo)cysts in effluent samples were determined by direct immunofluorescent microscopy, nested PCR and Real Time PCR. Viability of (oo)cysts was determined by double-staining with the use of Live/Dead BacLight kit (Invitrogen). Cryptosporidium spp. oocysts were detected in 8 WTPs (61.5%) and Giardia spp. cysts in 11 WTPs (84.6%) by microscopic analysis. Both pathogens were detected in samples from 7 WTPs. Median concentrations of Cryptosporidium and Giardia (oo)cysts in 13 examined samples were 2.2/L and 6.6/L, respectively, while mean concentrations were 28.5/L and 113.6/L, respectively. In positive samples, Cryptosporidium oocysts concentrations ranged from 0.4 - 154.1 oocysts per litre, and Giardia cysts concentrations ranged from 0.7 - 660 cysts per litre. By nested PCR, Giardia DNA was detected in 4 samples of the 13 examined, (30.8%) while Cryptosporidium DNA was never detected. In Real Time PCR, positive results for Giardia were obtained in 5 samples (38.5%) and in none of the samples for Cryptosporidium, with the exception of one equivocal result. Viable (oo)cysts of Cryptosporidium and Giardia were detected in 3 out of 4 samples examined, in the ranges of 12.5 - 60% and 50 - 100% of total (oo)cysts, respectively. In view of our preliminary

  18. Changes in the burden of malaria following scale up of malaria control interventions in Mutasa District, Zimbabwe

    PubMed Central

    2013-01-01

    Background To better understand trends in the burden of malaria and their temporal relationship to control activities, a survey was conducted to assess reported cases of malaria and malaria control activities in Mutasa District, Zimbabwe. Methods Data on reported malaria cases were abstracted from available records at all three district hospitals, three rural hospitals and 25 rural health clinics in Mutasa District from 2003 to 2011. Results Malaria control interventions were scaled up through the support of the Roll Back Malaria Partnership, the Global Fund to Fight AIDS, Tuberculosis and Malaria, and The President’s Malaria Initiative. The recommended first-line treatment regimen changed from chloroquine or a combination of chloroquine plus sulphadoxine/pyrimethamine to artemisinin-based combination therapy, the latter adopted by 70%, 95% and 100% of health clinics by 2008, 2009 and 2010, respectively. Diagnostic capacity improved, with rapid diagnostic tests (RDTs) available in all health clinics by 2008. Vector control consisted of indoor residual spraying and distribution of long-lasting insecticidal nets. The number of reported malaria cases initially increased from levels in 2003 to a peak in 2008 but then declined 39% from 2008 to 2010. The proportion of suspected cases of malaria in older children and adults remained high, ranging from 75% to 80%. From 2008 to 2010, the number of RDT positive cases of malaria decreased 35% but the decrease was greater for children younger than five years of age (60%) compared to older children and adults (26%). Conclusions The burden of malaria in Mutasa District decreased following the scale up of malaria control interventions. However, the persistent high number of cases in older children and adults highlights the need for strategies to identify locally effective control measures that target all age groups. PMID:23815862

  19. Deforestation and malaria in Mâncio Lima County, Brazil.

    PubMed

    Olson, Sarah H; Gangnon, Ronald; Silveira, Guilherme Abbad; Patz, Jonathan A

    2010-07-01

    Malaria is the most prevalent vector-borne disease in the Amazon. We used malaria reports for health districts collected in 2006 by the Programa Nacional de Controle da Malaria to determine whether deforestation is associated with malaria incidence in the county (municipio) of Mancio Lima, Acre State, Brazil. Cumulative percent deforestation was calculated for the spatial catchment area of each health district by using 60 x 60-meter, resolution-classified imagery. Statistical associations were identified with univariate and multivariate general additive negative binomial models adjusted for spatial effects. Our cross-sectional study shows malaria incidence across health districts in 2006 is positively associated with greater changes in percentage of cumulative deforestation within respective health districts. After adjusting for access to care, health district size, and spatial trends, we show that a 4.2%, or 1 SD, change in deforestation from August 1997 through August 2001 is associated with a 48% increase of malaria incidence. PMID:20587182

  20. Elevation and vegetation determine Cryptosporidium oocyst shedding by yellow-bellied marmots (Marmota flaviventris) in the Sierra Nevada Mountains.

    PubMed

    Montecino-Latorre, Diego; Li, Xunde; Xiao, Chengling; Atwill, Edward R

    2015-08-01

    Wildlife are increasingly recognized as important biological reservoirs of zoonotic species of Cryptosporidium that might contaminate water and cause human exposure to this protozoal parasite. The habitat range of the yellow-bellied marmot (Marmota flaviventris) overlaps extensively with the watershed boundaries of municipal water supplies for California communities along the foothills of the Sierra Nevada. We conducted a cross-sectional epidemiological study to estimate the fecal shedding of Cryptosporidium oocysts by yellow-bellied marmots and to quantify the environmental loading rate and determine risk factors for Cryptosporidium fecal shedding in this montane wildlife species. The observed proportion of Cryptosporidium positive fecal samples was 14.7% (33/224, positive number relative to total number samples) and the environmental loading rate was estimated to be 10,693 oocysts animal(-1) day(-1). Fecal shedding was associated with the elevation and vegetation status of their habitat. Based on a portion of the 18s rRNA gene sequence of 2 isolates, the Cryptosporidium found in Marmota flaviventris were 99.88%-100% match to multiple isolates of C. parvum in the GenBank. PMID:25834788

  1. Elevation and vegetation determine Cryptosporidium oocyst shedding by yellow-bellied marmots (Marmota flaviventris) in the Sierra Nevada Mountains

    PubMed Central

    Montecino-Latorre, Diego; Li, Xunde; Xiao, Chengling; Atwill, Edward R.

    2015-01-01

    Wildlife are increasingly recognized as important biological reservoirs of zoonotic species of Cryptosporidium that might contaminate water and cause human exposure to this protozoal parasite. The habitat range of the yellow-bellied marmot (Marmota flaviventris) overlaps extensively with the watershed boundaries of municipal water supplies for California communities along the foothills of the Sierra Nevada. We conducted a cross-sectional epidemiological study to estimate the fecal shedding of Cryptosporidium oocysts by yellow-bellied marmots and to quantify the environmental loading rate and determine risk factors for Cryptosporidium fecal shedding in this montane wildlife species. The observed proportion of Cryptosporidium positive fecal samples was 14.7% (33/224, positive number relative to total number samples) and the environmental loading rate was estimated to be 10,693 oocysts animal-1 day-1. Fecal shedding was associated with the elevation and vegetation status of their habitat. Based on a portion of the 18s rRNA gene sequence of 2 isolates, the Cryptosporidium found in Marmota flaviventris were 99.88%–100% match to multiple isolates of C. parvum in the GenBank. PMID:25834788

  2. Correlation between Diarrhea Severity and Oocyst Count via Quantitative PCR or Fluorescence Microscopy in Experimental Cryptosporidiosis in Calves

    PubMed Central

    Operario, Darwin J.; Bristol, Lauren S.; Liotta, Janice; Nydam, Daryl V.; Houpt, Eric R.

    2015-01-01

    Cryptosporidium is an important diarrhea-associated pathogen, however the correlation between parasite burden and diarrhea severity remains unclear. We studied this relationship in 10 experimentally infected calves using immunofluorescence microscopy and real-time polymerase chain reaction (qPCR) (N = 124 fecal samples). The qPCR data were corrected for extraction/amplification efficiency and gene copy number to generate parasite counts. The qPCR and microscopic oocyst quantities exhibited significant correlation (R2 = 0.33, P < 0.05), however qPCR had increased sensitivity. Upon comparison with diarrhea severity scores (from 0 to 3), a PCR-based count of ≥ 2.6 × 105 parasites or an immunofluorescence microscopy count of ≥ 4.5 × 104 oocysts were discriminatory predictors of moderate-to-severe diarrhea (versus no-to-mild diarrhea), with accuracies and predictive values of 72–82%. In summary, a quantitative approach for Cryptosporidium can refine predictive power for diarrhea and appears useful for distinguishing clinical cryptosporidiosis versus subclinical infection. PMID:25371182

  3. Remotely Sensed Environmental Conditions and Malaria Mortality in Three Malaria Endemic Regions in Western Kenya

    PubMed Central

    Ahlm, Clas; Rocklöv, Joacim

    2016-01-01

    Background Malaria is an important cause of morbidity and mortality in malaria endemic countries. The malaria mosquito vectors depend on environmental conditions, such as temperature and rainfall, for reproduction and survival. To investigate the potential for weather driven early warning systems to prevent disease occurrence, the disease relationship to weather conditions need to be carefully investigated. Where meteorological observations are scarce, satellite derived products provide new opportunities to study the disease patterns depending on remotely sensed variables. In this study, we explored the lagged association of Normalized Difference Vegetation Index (NVDI), day Land Surface Temperature (LST) and precipitation on malaria mortality in three areas in Western Kenya. Methodology and Findings The lagged effect of each environmental variable on weekly malaria mortality was modeled using a Distributed Lag Non Linear Modeling approach. For each variable we constructed a natural spline basis with 3 degrees of freedom for both the lag dimension and the variable. Lag periods up to 12 weeks were considered. The effect of day LST varied between the areas with longer lags. In all the three areas, malaria mortality was associated with precipitation. The risk increased with increasing weekly total precipitation above 20 mm and peaking at 80 mm. The NDVI threshold for increased mortality risk was between 0.3 and 0.4 at shorter lags. Conclusion This study identified lag patterns and association of remote- sensing environmental factors and malaria mortality in three malaria endemic regions in Western Kenya. Our results show that rainfall has the most consistent predictive pattern to malaria transmission in the endemic study area. Results highlight a potential for development of locally based early warning forecasts that could potentially reduce the disease burden by enabling timely control actions. PMID:27115874

  4. Knowledge of Malaria and Its Association with Malaria-Related Behaviors—Results from the Malaria Indicator Survey, Ethiopia, 2007

    PubMed Central

    Hwang, Jimee; Graves, Patricia M.; Jima, Daddi; Reithinger, Richard; Kachur, S. Patrick

    2010-01-01

    Background In 2005, the Ministry of Health in Ethiopia launched a major effort to distribute over 20 million long-lasting insecticidal nets, provide universal access to artemisinin-based combination therapy (ACTs), and train 30,000 village-based health extension workers. Methods and Findings A cross-sectional, nationally representative Malaria Indicator Survey was conducted during the malaria transmission season in 2007. Multivariate logistic regression analyses were performed to assess the effect of women's malaria knowledge on household ITN ownership and women's ITN use. In addition, we investigated the effect of mothers' malaria knowledge on their children under 5 years of age's (U5) ITN use and their access to fever treatment on behalf of their child U5. Malaria knowledge was based on a composite index about the causes, symptoms, danger signs and prevention of malaria. Approximately 67% of women (n = 5,949) and mothers of children U5 (n = 3,447) reported some knowledge of malaria. Women's knowledge of malaria was significantly associated with household ITN ownership (adjusted Odds Ratio [aOR] = 2.1; 95% confidence interval [CI] 1.6–2.7) and with increased ITN use for themselves (aOR = 1.8; 95% CI 1.3–2.5). Knowledge of malaria amongst mothers of children U5 was associated with ITN use for their children U5 (aOR = 1.6; 95% CI 1.1–2.4), but not significantly associated with their children U5 seeking care for a fever. School attendance was a significant factor in women's ITN use (aOR = 2.0; 95% CI 1.1–3.9), their children U5′s ITN use (aOR = 4.4; 95% CI 1.6–12.1), and their children U5 having sought treatment for a fever (aOR = 6.5; 95% CI 1.9–22.9). Conclusions Along with mass free distribution of ITNs and universal access to ACTs, delivery of targeted malaria educational information to women could improve ITN ownership and use. Efforts to control malaria could be influenced by progress towards broader goals of

  5. Comparison of transport and attachment behaviors of Cryptosporidium parvum oocysts and oocyst-sized microspheres being advected through three minerologically different granular porous media.

    PubMed

    Mohanram, Arvind; Ray, Chittaranjan; Harvey, Ronald W; Metge, David W; Ryan, Joseph N; Chorover, Jon; Eberl, D D

    2010-10-01

    In order to gain more information about the fate of Cryptosporidium parvum oocysts in tropical volcanic soils, the transport and attachment behaviors of oocysts and oocyst-sized polystyrene microspheres were studied in the presence of two soils. These soils were chosen because of their differing chemical and physical properties, i.e., an organic-rich (43-46% by mass) volcanic ash-derived soil from the island of Hawaii, and a red, iron (22-29% by mass), aluminum (29-45% by mass), and clay-rich (68-76% by mass) volcanic soil from the island of Oahu. A third agricultural soil, an organic- (13% by mass) and quartz-rich (40% by mass) soil from Illinois, was included for reference. In 10-cm long flow-through columns, oocysts and microspheres advecting through the red volcanic soil were almost completely (98% and 99%) immobilized. The modest breakthrough resulted from preferential flow-path structure inadvertently created by soil-particle aggregation during the re-wetting process. Although a high (99%) removal of oocysts and microsphere within the volcanic ash soil occurred initially, further examination revealed that transport was merely retarded because of highly reversible interactions with grain surfaces. Judging from the slope of the substantive and protracted tail of the breakthrough curve for the 1.8-μm microspheres, almost all (>99%) predictably would be recovered within ∼4000 pore volumes. This suggests that once contaminated, the volcanic ash soil could serve as a reservoir for subsequent contamination of groundwater, at least for pathogens of similar size or smaller. Because of the highly reversible nature of organic colloid immobilization in this soil type, C. parvum could contaminate surface water should overland flow during heavy precipitation events pick up near-surface grains to which they are attached. Surprisingly, oocyst and microsphere attachment to the reference soil from Illinois appeared to be at least as sensitive to changes in pH as was

  6. Comparison of transport and attachment behaviors of Cryptosporidium parvum oocysts and oocyst-sized microspheres being advected through three minerologically different granular porous media

    USGS Publications Warehouse

    Mohanram, A.; Ray, C.; Harvey, R.W.; Metge, D.W.; Ryan, J.N.; Chorover, J.; Eberl, D.D.

    2010-01-01

    In order to gain more information about the fate of Cryptosporidium parvum oocysts in tropical volcanic soils, the transport and attachment behaviors of oocysts and oocyst-sized polystyrene microspheres were studied in the presence of two soils. These soils were chosen because of their differing chemical and physical properties, i.e., an organic-rich (43-46% by mass) volcanic ash-derived soil from the island of Hawaii, and a red, iron (22-29% by mass), aluminum (29-45% by mass), and clay-rich (68-76% by mass) volcanic soil from the island of Oahu. A third agricultural soil, an organic- (13% by mass) and quartz-rich (40% by mass) soil from Illinois, was included for reference. In 10-cm long flow-through columns, oocysts and microspheres advecting through the red volcanic soil were almost completely (98% and 99%) immobilized. The modest breakthrough resulted from preferential flow-path structure inadvertently created by soil-particle aggregation during the re-wetting process. Although a high (99%) removal of oocysts and microsphere within the volcanic ash soil occurred initially, further examination revealed that transport was merely retarded because of highly reversible interactions with grain surfaces. Judging from the slope of the substantive and protracted tail of the breakthrough curve for the 1.8-??m microspheres, almost all (>99%) predictably would be recovered within ~4000 pore volumes. This suggests that once contaminated, the volcanic ash soil could serve as a reservoir for subsequent contamination of groundwater, at least for pathogens of similar size or smaller. Because of the highly reversible nature of organic colloid immobilization in this soil type, C. parvum could contaminate surface water should overland flow during heavy precipitation events pick up near-surface grains to which they are attached. Surprisingly, oocyst and microsphere attachment to the reference soil from Illinois appeared to be at least as sensitive to changes in pH as was observed

  7. Leaching of Cryptosporidium parvum Oocysts, Escherichia coli, and a Salmonella enterica Serovar Typhimurium Bacteriophage through Intact Soil Cores following Surface Application and Injection of Slurry▿

    PubMed Central

    Forslund, Anita; Markussen, Bo; Toenner-Klank, Lise; Bech, Tina B.; Jacobsen, Ole Stig; Dalsgaard, Anders

    2011-01-01

    Increasing amounts of livestock manure are being applied to agricultural soil, but it is unknown to what extent this may be associated with contamination of aquatic recipients and groundwater if microorganisms are transported through the soil under natural weather conditions. The objective of this study was therefore to evaluate how injection and surface application of pig slurry on intact sandy clay loam soil cores influenced the leaching of Salmonella enterica serovar Typhimurium bacteriophage 28B, Escherichia coli, and Cryptosporidium parvum oocysts. All three microbial tracers were detected in the leachate on day 1, and the highest relative concentration was detected on the fourth day (0.1 pore volume). Although the concentration of the phage 28B declined over time, the phage was still found in leachate at day 148. C. parvum oocysts and chloride had an additional rise in the relative concentration at a 0.5 pore volume, corresponding to the exchange of the total pore volume. The leaching of E. coli was delayed compared with that of the added microbial tracers, indicating a stronger attachment to slurry particles, but E. coli could be detected up to 3 months. Significantly enhanced leaching of phage 28B and oocysts by the injection method was seen, whereas leaching of the indigenous E. coli was not affected by the application method. Preferential flow was the primary transport vehicle, and the diameter of the fractures in the intact soil cores facilitated transport of all sizes of microbial tracers under natural weather conditions. PMID:21948848

  8. Uncomplicated malaria in children: The place of rapid diagnostic test

    PubMed Central

    Elechi, Hassan Abdullahi; Rabasa, Adamu Ibrahim; Bashir, Muhammad Faruk; Gofama, Mustapha Modu; Ibrahim, Halima Abubakar; Askira, Umoru Muhammed

    2015-01-01

    Background: Malaria has remained a major cause of morbidity and mortality among the under-five children in Nigeria. Prompt and accurate diagnosis of malaria is necessary in controlling this high burden and preventing unnecessary use of anti-malarial drugs. Malaria rapid diagnostic test (MRDT) offers the hope of achieving this goal. However, the performance of these kits among the most vulnerable age group to malaria is inadequate. Materials and Methods: In this cross-sectional study, 433 out-patients, aged <5 years with fever or history of fever were enrolled. Each candidate was tested for malaria parasitaemia using ACON; malaria pf. Thick and thin films were also prepared from the same finger prick blood for each candidate. Result: Malaria rapid diagnostic test had sensitivity of 8.3%, specificity of 100%, positive predictive value (PPV) of 100% and negative predictive value (NPV) of 74%. The sensitivity of MRDT increased with increasing age. This effect of age on sensitivity was statistically significant (P = 0.007). Similarly parasite density had significant effect on the sensitivity of MRDT (P = <0.001). Conclusion: Histidine-rich protein-2 based MRDT is not a reliable mean of diagnosing malaria in the under-five age children with acute uncomplicated malaria. PMID:25838621

  9. Malaria in South Asia: prevalence and control.

    PubMed

    Kumar, Ashwani; Chery, Laura; Biswas, Chinmoy; Dubhashi, Nagesh; Dutta, Prafulla; Dua, Virendra Kumar; Kacchap, Mridula; Kakati, Sanjeeb; Khandeparkar, Anar; Kour, Dalip; Mahajan, Satish N; Maji, Ardhendu; Majumder, Partha; Mohanta, Jagadish; Mohapatra, Pradyumna K; Narayanasamy, Krishnamoorthy; Roy, Krishnangshu; Shastri, Jayanthi; Valecha, Neena; Vikash, Rana; Wani, Reena; White, John; Rathod, Pradipsinh K

    2012-03-01

    The "Malaria Evolution in South Asia" (MESA) program project is an International Center of Excellence for Malaria Research (ICEMR) sponsored by the US National Institutes of Health. This US-India collaborative program will study the origin of genetic diversity of malaria parasites and their selection on the Indian subcontinent. This knowledge should contribute to a better understanding of unexpected disease outbreaks and unpredictable disease presentations from Plasmodium falciparum and Plasmodium vivax infections. In this first of two reviews, we highlight malaria prevalence in India. In particular, we draw attention to variations in distribution of different human-parasites and different vectors, variation in drug resistance traits, and multiple forms of clinical presentations. Uneven malaria severity in India is often attributed to large discrepancies in health care accessibility as well as human migrations within the country and across neighboring borders. Poor access to health care goes hand in hand with poor reporting from some of the same areas, combining to possibly distort disease prevalence and death from malaria in some parts of India. Corrections are underway in the form of increased resources for disease control, greater engagement of village-level health workers for early diagnosis and treatment, and possibly new public-private partnerships activities accompanying traditional national malaria control programs in the most severely affected areas. A second accompanying review raises the possibility that, beyond uneven health care, evolutionary pressures may alter malaria parasites in ways that contribute to severe disease in India, particularly in the NE corridor of India bordering Myanmar Narayanasamy et al., 2012. PMID:22248528

  10. Malaria in South Asia: Prevalence and control

    PubMed Central

    Kumar, Ashwani; Chery, Laura; Biswas, Chinmoy; Dubhashi, Nagesh; Dutta, Prafulla; Dua, Virendra Kumar; Kacchap, Mridula; Kakati, Sanjeeb; Khandeparkar, Anar; Kour, Dalip; Mahajanj, Satish N.; Maji, Ardhendu; Majumder, Partha; Mohanta, Jagadish; Mohapatra, Pradyumna K.; Narayanasamy, Krishnamoorthy; Roy, Krishnangshu; Shastri, Jayanthi; Valecha, Neena; Vikash, Rana; Wani, Reena; White, John; Rathod, Pradipsinh K

    2013-01-01

    The “Malaria Evolution in South Asia” (MESA) program project is an International Center of Excellence for Malaria Research (ICEMR) sponsored by the US National Institutes of Health. This US–India collaborative program will study the origin of genetic diversity of malaria parasites and their selection on the Indian subcontinent. This knowledge should contribute to a better understanding of unexpected disease outbreaks and unpredictable disease presentations from Plasmodium falciparum and Plasmodium vivax infections. In this first of two reviews, we highlight malaria prevalence in India. In particular, we draw attention to variations in distribution of different human-parasites and different vectors, variation in drug resistance traits, and multiple forms of clinical presentations. Uneven malaria severity in India is often attributed to large discrepancies in health care accessibility as well as human migrations within the country and across neighboring borders. Poor access to health care goes hand in hand with poor reporting from some of the same areas, combining to possibly distort disease prevalence and death from malaria in some parts of India. Corrections are underway in the form of increased resources for disease control, greater engagement of village-level health workers for early diagnosis and treatment, and possibly new public–private partnerships activities accompanying traditional national malaria control programs in the most severely affected areas. A second accompanying review raises the possibility that, beyond uneven health care, evolutionary pressures may alter malaria parasites in ways that contribute to severe disease in India, particularly in the NE corridor of India bordering Myanmar Narayanasamy et al., 2012. PMID:22248528

  11. Global malaria connectivity through air travel

    PubMed Central

    2013-01-01

    travel is playing an important role in the global epidemiology of malaria, with the endemic world becoming increasingly connected to both malaria-free areas and other endemic regions. The research presented here provides an initial effort to quantify and analyse the connectivity that exists across the malaria-endemic world through air travel, and provide a basic assessment of the risks it results in for movement of infections. PMID:23914776

  12. Malaria in the Era of Food Fortification With Folic Acid.

    PubMed

    Nzila, Alexis; Okombo, John; Hyde, John

    2016-06-01

    Food fortified with folic acid has been available for consumption in North America for over a decade. This strategy has led to an increase in folate levels in the general population and, more importantly, a significant decrease in the incidence of neural tube defects. However, this increase in folate intake has been associated with a greater risk of cancer disease. Many African countries are now embracing this concept; however, because folate promotes malaria parasite division, as it does in cancer cells, there is a possibility of malaria exacerbation if folate intake is increased. A precedent for such a concern is the now compelling evidence showing that an increase in iron intake can lead to a higher malaria risk; as a result, mass administration of iron in malaria-endemic areas is not recommended. In this article, we review work on the effect of folate on malaria parasites. Although this topic has received little research attention, the available data suggest that the increase in folate concentration could be associated with an increase in malaria infection. Thus, the introduction of food fortification with folic acid in malaria-endemic areas should be attended by precautionary programs to monitor the risk of malaria. PMID:26944505

  13. [Malaria in Iraq].

    PubMed

    Shamo, F J

    2001-01-01

    Malaria control campaign started in Iraq in 1957. This made the country largely free of the disease. Since 1991, following the recent war, Iraq has been affected by serious epidemic of P. vivax malaria that started in 3 autonomous governorates and soon involved other parts of the country. There were 49,840 malaria cases in the country in 1995. The national malaria programme personnel did their best to contain and control the epidemic. Active and passive case detection and treatment were introduced. Free of charge drugs are provided at all levels in the endemic area. Vector control includes environmental management, distribution of Gambusia fish, larviciding, indoor residual spraying with pyrithroids. A total of 4134 malaria cases were recorded in the country in 1999. PMID:11548316

  14. Malaria control: achievements, problems and strategies.

    PubMed

    Nájera, J A

    2001-06-01

    Even if history has not always been the Magistra vitae, Cicero expected it to be, it should provide, as Baas said, a mirror in which to observe and compare the past and present in order to draw therefrom well-grounded conclusions for the future. Based on this belief, this paper aims to provide an overview of the foundations and development of malaria control policies during the XX century. It presents an analysis of the conflicting tendencies which shaped the development of these policies and which appear to have oscillated between calls for frontal attack in an all-out campaign and calls for sustainable gains, even if slow. It discusses the various approaches to the control of malaria, their achievements and their limitations, not only to serve as a background to understand better the foundations of current policies, but also to prevent that simplistic generalisations may again lead to exaggerated expectations and disillusion. The first part of the paper is devoted to the development of malaria control during the first half of the century, characterised by the ups and downs in the reliance on mosquito control as the control measure applicable everywhere. The proliferation of "man-made-malaria", which accompanied the push for economic development in most of the endemic countries, spurred the need for control interventions and, while great successes were obtained in many specific projects, the general campaigns proposed by the enthusiasts of vector control faced increasing difficulties in their practical implementation in the field. Important events, which may be considered representative of this period are, on the campaign approach, the success of Gorgas in the Panama Canal, but also the failure of the Mian Mir project in India; while on the developmental approach, the Italian and Dutch schools of malariology, the Tennessee Valley and the development of malaria sanitation, included the so called species sanitation. The projection of these developments to a global

  15. Assessment of Pregnancy Status, Malaria Knowledge and Malaria Fever Morbidity among Women of Reproductive Ages in Nigeria

    PubMed Central

    OYEKALE, Abayomi Samuel

    2014-01-01

    Abstract Background Malaria is one the major health problem in Nigeria. During pregnancy, it poses serious threat to the survival of both unborn foetus and the mothers. This study determined the effect of adequate malaria knowledge and pregnancy status of women on use of mosquito nets and reported malaria fever morbidity. Methods The data were collected during the Malaria Indicator Survey (MIS) from 4632 women. Data analyses were carried out with descriptive statistics and Seemingly Unrelated Bivariate Probit regression. Results Results show that 13.19% of the women were pregnant, of which about one-third slept under mosquito nets. Also, 25.26% reported malaria associated fever in the previous two weeks to the time of interview, while 78.28% correctly answered that mosquitoes are responsible for malaria. Knowledge on malaria prevention was low with 55.70% and 14.93% indicating sleeping under mosquito nets and ITN, respectively. Probability of sleeping under mosquito nets significantly increased with knowing that sleeping under mosquito nets and ITN could prevent malaria while it decreased with having fever, age, urban residence and knowing that use of mosquito spray and coil can prevent malaria. The probability of having fever increased significantly with household size, being pregnant and age at first birth but decreased with age, knowing that sleeping under ITN, cutting grasses and closing door/windows would prevent malaria. Conclusions Use of mosquito nets among the women was low. Also, efforts to enhance their knowledge on malaria prevention and ensuring adequate access to mosquito nets especially for pregnant women would curtail the impact of malaria. PMID:26175973

  16. Asparagine requirement in Plasmodium berghei as a target to prevent malaria transmission and liver infections.

    PubMed

    Nagaraj, Viswanathan A; Mukhi, Dhanunjay; Sathishkumar, Vinayagam; Subramani, Pradeep A; Ghosh, Susanta K; Pandey, Rajeev R; Shetty, Manjunatha C; Padmanaban, Govindarajan

    2015-01-01

    The proteins of Plasmodium, the malaria parasite, are strikingly rich in asparagine. Plasmodium depends primarily on host haemoglobin degradation for amino acids and has a rudimentary pathway for amino acid biosynthesis, but retains a gene encoding asparagine synthetase (AS). Here we show that deletion of AS in Plasmodium berghei (Pb) delays the asexual- and liver-stage development with substantial reduction in the formation of ookinetes, oocysts and sporozoites in mosquitoes. In the absence of asparagine synthesis, extracellular asparagine supports suboptimal survival of PbAS knockout (KO) parasites. Depletion of blood asparagine levels by treating PbASKO-infected mice with asparaginase completely prevents the development of liver stages, exflagellation of male gametocytes and the subsequent formation of sexual stages. In vivo supplementation of asparagine in mice restores the exflagellation of PbASKO parasites. Thus, the parasite life cycle has an absolute requirement for asparagine, which we propose could be targeted to prevent malaria transmission and liver infections. PMID:26531182

  17. Asparagine requirement in Plasmodium berghei as a target to prevent malaria transmission and liver infections

    PubMed Central

    Nagaraj, Viswanathan A.; Mukhi, Dhanunjay; Sathishkumar, Vinayagam; Subramani, Pradeep A.; Ghosh, Susanta K.; Pandey, Rajeev R.; Shetty, Manjunatha C.; Padmanaban, Govindarajan

    2015-01-01

    The proteins of Plasmodium, the malaria parasite, are strikingly rich in asparagine. Plasmodium depends primarily on host haemoglobin degradation for amino acids and has a rudimentary pathway for amino acid biosynthesis, but retains a gene encoding asparagine synthetase (AS). Here we show that deletion of AS in Plasmodium berghei (Pb) delays the asexual- and liver-stage development with substantial reduction in the formation of ookinetes, oocysts and sporozoites in mosquitoes. In the absence of asparagine synthesis, extracellular asparagine supports suboptimal survival of PbAS knockout (KO) parasites. Depletion of blood asparagine levels by treating PbASKO-infected mice with asparaginase completely prevents the development of liver stages, exflagellation of male gametocytes and the subsequent formation of sexual stages. In vivo supplementation of asparagine in mice restores the exflagellation of PbASKO parasites. Thus, the parasite life cycle has an absolute requirement for asparagine, which we propose could be targeted to prevent malaria transmission and liver infections. PMID:26531182

  18. Plasmodium vivax Malaria among Military Personnel, French Guiana, 1998–2008

    PubMed Central

    Texier, Gaëtan; Ollivier, Lénaïck; Galoisy-Guibal, Laurent; Michel, Rémy; Meynard, Jean-Baptiste; Decam, Christophe; Verret, Catherine; Pommier de Santi, Vincent; Spiegel, André; Boutin, Jean-Paul; Migliani, René; Deparis, Xavier

    2011-01-01

    We obtained health surveillance epidemiologic data on malaria among French military personnel deployed to French Guiana during 1998–2008. Incidence of Plasmodium vivax malaria increased and that of P. falciparum remained stable. This new epidemiologic situation has led to modification of malaria treatment for deployed military personnel. PMID:21762587

  19. Occurrence of Cryptosporidium oocysts in fecal samples submitted for routine microbiological examination.

    PubMed Central

    Ratnam, S; Paddock, J; McDonald, E; Whitty, D; Jong, M; Cooper, R

    1985-01-01

    During a 7-month period, 2,252 fecal samples submitted for routine microbiological examination from 1,621 patients were screened for Cryptosporidium oocysts by the auramine staining method with Kinyoun acid-fast stain as the confirmatory stain. Cryptosporidium oocysts were detected in fecal samples from 19 (1.2%) patients, 18 of whom had gastroenteritis. Diarrheic stools from 14 of these 18 patients were negative for the usual enteropathogens but contained the oocysts in moderate to large numbers. Although Cryptosporidium oocysts were found in patients of all ages, they occurred slightly more frequently in infants and children than in the rest. Cryptosporidium species was one of the common enteropathogens identified in fecal samples submitted for routine parasitological examination during the period of the survey and was second only to Giardia species in terms of frequency. Considering cryptosporidiosis in the differential diagnosis of gastroenteritis in immunocompetent persons and including a search for Cryptosporidium oocysts in routine parasitological examinations of fecal samples appear warranted. PMID:4044798

  20. Sources and species of cryptosporidium oocysts in the Wachusett Reservoir watershed.

    PubMed

    Jellison, Kristen L; Hemond, Harold F; Schauer, David B

    2002-02-01

    Understanding the behavior of Cryptosporidium oocysts in the environment is critical to developing improved watershed management practices for protection of the public from waterborne cryptosporidiosis. Analytical methods of improved specificity and sensitivity are essential to this task. We developed a nested PCR-restriction fragment length polymorphism assay that allows detection of a single oocyst in environmental samples and differentiates the human pathogen Cryptosporidium parvum from other Cryptosporidium species. We tested our method on surface water and animal fecal samples from the Wachusett Reservoir watershed in central Massachusetts. We also directly compared results from our method with those from the immunofluorescence microscopy assay recommended in the Information Collection Rule. Our results suggest that immunofluorescence microscopy may not be a reliable indicator of public health risk for waterborne cryptosporidiosis. Molecular and environmental data identify both wildlife and dairy farms as sources of oocysts in the watershed, implicate times of cold water temperatures as high-risk periods for oocyst contamination of surface waters, and suggest that not all oocysts in the environment pose a threat to public health. PMID:11823192

  1. Proteomic Analysis of Fractionated Toxoplasma Oocysts Reveals Clues to Their Environmental Resistance

    PubMed Central

    Bogyo, Matthew; Conrad, Patricia A.; Boothroyd, John C.

    2012-01-01

    Toxoplasma gondii is an obligate intracellular parasite that is unique in its ability to infect a broad range of birds and mammals, including humans, leading to an extremely high worldwide prevalence and distribution. This work focuses on the environmentally resistant oocyst, which is the product of sexual replication in felids and an important source of human infection. Due to the difficulty in producing and working with oocysts, relatively little is known about how this stage is able to resist extreme environmental stresses and how they initiate a new infection, once ingested. To fill this gap, the proteome of the wall and sporocyst/sporozoite fractions of mature, sporulated oocysts were characterized using one-dimensional gel electrophoresis followed by LC-MS/MS on trypsin-digested peptides. A combined total of 1021 non-redundant T. gondii proteins were identified in the sporocyst/sporozoite fraction and 226 were identified in the oocyst wall fraction. Significantly, 172 of the identified proteins have not previously been identified in Toxoplasma proteomic studies. Among these are several of interest for their likely role in conferring environmental resistance including a family of small, tyrosine-rich proteins present in the oocyst wall fractions and late embryogenesis abundant domain-containing (LEA) proteins in the cytosolic fractions. The latter are known from other systems to be key to enabling survival against desiccation. PMID:22279555

  2. Establishment of a germ carrier assay to assess disinfectant efficacy against oocysts of coccidian parasites.

    PubMed

    Dresely, Ira; Daugschies, Arwid; Lendner, Matthias

    2015-01-01

    Parasites are a common threat to human and animal health. One option to combat parasites that produce infective environmental stages is to inactivate them by chemical disinfection. Standardised laboratory assays that enable proper evaluation of products suspected to be efficient are highly desirable to allow prudent selection and use of such potentially hazardous agents. Here, we present a newly developed in vitro germ carrier assay to evaluate inactivation of oocysts of the model organism Cryptosporidium parvum by chemical disinfectants. Stainless steel discs were used as carrier to mimic surface contamination by C. parvum oocysts. The germ carriers were incubated with approved chemical disinfectant for the specified time (2 h) and rinsed thereafter to remove the disinfectant and recover the exposed oocysts. Recovered oocysts were transferred to HCT-8 monolayers, and 48 h later, genomic DNA was extracted and quantified by real-time PCR targeting the hsp70 gene to estimate parasite reproduction. A panel of commercially available and approved disinfectants were examined and data compared with those of suspension assays and historical data obtained from efficacy assays based on infection of chicken with oocysts of Eimeria tenella. Altogether, data achieved by these divergent assays allowed similar conclusions although the sensitivity of the in vitro assay was higher. Consequently, a threshold of 99.5% inactivation is proposed to evaluate disinfectants in vitro using C. parvum as model organism as compared to the E. tenella animal infection assay (95%). PMID:25339515

  3. Development of Eimeria nieschulzi (Coccidia, Apicomplexa) Gamonts and Oocysts in Primary Fetal Rat Cells.

    PubMed

    Chen, Hong; Wiedmer, Stefanie; Hanig, Sacha; Entzeroth, Rolf; Kurth, Michael

    2013-01-01

    The in vitro production of gametocytes and oocysts of the apicomplexan parasite genus Eimeria is still a challenge in coccidiosis research. Until today, an in vitro development of gametocytes or oocysts had only been shown in some Eimeria species. For several mammalian Eimeria species, partial developments could be achieved in different cell types, but a development up to gametocytes or oocysts is still lacking. This study compares several permanent cell lines with primary fetal cells of the black rat (Rattus norvegicus) concerning the qualitative in vitro development of the rat parasite Eimeria nieschulzi. With the help of transgenic parasites, the developmental progress was documented. The selected Eimeria nieschulzi strain constitutively expresses the yellow fluorescent protein and a macrogamont specific upregulated red tandem dimer tomato. In the majority of all investigated host cells the development stopped at the second merozoite stage. In a mixed culture of cells derived from inner fetal organs the development of schizont generations I-IV, macrogamonts, and oocysts were observed in crypt-like organoid structures. Microgamonts and microgametes could not be observed and oocysts did not sporulate under air supply. By immunohistology, we could confirm that wild-type E. nieschulzi stages can be found in the crypts of the small intestine. The results of this study may be helpful for characterization of native host cells and for development of an in vitro cultivation system for Eimeria species. PMID:23862053

  4. Mini-FLOTAC for counting Toxoplasma gondii oocysts from cat feces--comparison with cell counting plates.

    PubMed

    Djokic, Vitomir; Blaga, Radu; Rinaldi, Laura; Le Roux, Delphine; Ducry, Tamara; Maurelli, Maria Paola; Perret, Catherine; Djurkovic Djakovic, Olgica; Cringoli, Giuseppe; Boireau, Pascal

    2014-12-01

    Oocysts of Toxoplasma gondii represent one of the most common environmental contaminants causing the zoonotic infection toxoplasmosis. The aim of the present study was to compare the Mini-FLOTAC device with traditional cell counting plates (Kova Slide) for the detection of T. gondii oocysts from feline feces. Two types of experiments were performed: (i) purified oocysts were counted in different dilutions and (ii) specific pathogen free T. gondii-negative cat feces was inoculated with numbers of purified oocysts and counting was performed directly from feces. Our analysis showed a thousand times higher sensitivity of Mini-FLOTAC (5 × 10(2) oocysts) compared to Kova Slide (5 × 10(5) oocysts). Also, when compared by McNemar's test, counting of the purified oocysts showed a higher sensitivity of Mini-FLOTAC compared to Kova Slide, for a dilution of 10(3) oocysts/ml (chi(2) = 6.1; P < 0.05). A better sensitivity was also found with Mini-FLOTAC in dilutions of 10(5) and 10(4) oocysts/ml, when counted from feces (chi(2) = 4.2 and 8.1, respectively, P < 0.05). Our results show that Mini-FLOTAC is more sensitive than traditional methods of T. gondii oocysts detection and quantification is more accurate. Furthermore, Mini-FLOTAC simplicity and cost effectiveness allow it to be used with light microscopes in any laboratory or field conditions. We therefore recommend its use for regular screening. Further studies are needed to validate Mini-FLOTAC for the detection of oocysts in soil and water samples in field conditions. PMID:25448359

  5. A historical perspective on malaria control in Brazil

    PubMed Central

    Griffing, Sean Michael; Tauil, Pedro Luiz; Udhayakumar, Venkatachalam; Silva-Flannery, Luciana

    2015-01-01

    Malaria has always been an important public health problem in Brazil. The early history of Brazilian malaria and its control was powered by colonisation by Europeans and the forced relocation of Africans as slaves. Internal migration brought malaria to many regions in Brazil where, given suitableAnopheles mosquito vectors, it thrived. Almost from the start, officials recognised the problem malaria presented to economic development, but early control efforts were hampered by still developing public health control and ignorance of the underlying biology and ecology of malaria. Multiple regional and national malaria control efforts have been attempted with varying success. At present, the Amazon Basin accounts for 99% of Brazil’s reported malaria cases with regional increases in incidence often associated with large scale public works or migration. Here, we provide an exhaustive summary of primary literature in English, Spanish and Portuguese regarding Brazilian malaria control. Our goal was not to interpret the history of Brazilian malaria control from a particular political or theoretical perspective, but rather to provide a straightforward, chronological narrative of the events that have transpired in Brazil over the past 200 years and identify common themes. PMID:26517649

  6. Malaria situation in India with special reference to tribal areas

    PubMed Central

    Sharma, Ravendra K.; Thakor, H.G.; Saha, K.B.; Sonal, G.S.; Dhariwal, A.C.; Singh, Neeru

    2015-01-01

    Background & objectives: In India, malaria is a major public health problem in States having predominantly tribal population. The objective of this analysis was to find out the incidence of malaria in various States/districts having varied proportions of tribal population using National Vector Borne Disease Control Programme (NVBDCP) data. Methods: States and districts were classified into three categories based on proportions of Scheduled Tribes (ST) population as <10, 10-29.9 and 30 per cent + ST population. Five year average (2008-2012) of all important malaria indicators collected by NVBDCP was taken to normalize the effect of annual fluctuations in malaria incidence. Results: State level analysis revealed that ten States/UTs with 30 per cent or more tribal population comprising only three per cent of total population, contributed 14 per cent of total malaria, 21 per cent Plasmodium falciparum and 29 per cent of deaths due to malaria. Similarly, district level analysis showed that districts with 30 per cent or more tribal population comprising about eight per cent country's population contributed to 46 per cent of total malaria cases, 70 per cent P. falciparum and 47 per cent malarial deaths in the country. Interpretation & conclusions: Our analysis showed that the neglect of the ethnic communities in tribal areas would be detrimental to the overall reduction of morbidity and mortality due to malaria. The fight against the increasing burden of malaria in tribal belt requires adoption of multiple approaches and socio-economic development of the tribal communities. PMID:26139770

  7. A historical perspective on malaria control in Brazil.

    PubMed

    Griffing, Sean Michael; Tauil, Pedro Luiz; Udhayakumar, Venkatachalam; Silva-Flannery, Luciana

    2015-09-01

    Malaria has always been an important public health problem in Brazil. The early history of Brazilian malaria and its control was powered by colonisation by Europeans and the forced relocation of Africans as slaves. Internal migration brought malaria to many regions in Brazil where, given suitable Anopheles mosquito vectors, it thrived. Almost from the start, officials recognised the problem malaria presented to economic development, but early control efforts were hampered by still developing public health control and ignorance of the underlying biology and ecology of malaria. Multiple regional and national malaria control efforts have been attempted with varying success. At present, the Amazon Basin accounts for 99% of Brazil's reported malaria cases with regional increases in incidence often associated with large scale public works or migration. Here, we provide an exhaustive summary of primary literature in English, Spanish and Portuguese regarding Brazilian malaria control. Our goal was not to interpret the history of Brazilian malaria control from a particular political or theoretical perspective, but rather to provide a straightforward, chronological narrative of the events that have transpired in Brazil over the past 200 years and identify common themes. PMID:26517649

  8. Prospects for Malaria Elimination in Mesoamerica and Hispaniola

    PubMed Central

    Herrera, Sócrates; Ochoa-Orozco, Sergio Andrés; González, Iveth J.; Peinado, Lucrecia; Quiñones, Martha L.; Arévalo-Herrera, Myriam

    2015-01-01

    Malaria remains endemic in 21 countries of the American continent with an estimated 427,000 cases per year. Approximately 10% of these occur in the Mesoamerican and Caribbean regions. During the last decade, malaria transmission in Mesoamerica showed a decrease of ~85%; whereas, in the Caribbean region, Hispaniola (comprising the Dominican Republic [DR] and Haiti) presented an overall rise in malaria transmission, primarily due to a steady increase in Haiti, while DR experienced a significant transmission decrease in this period. The significant malaria reduction observed recently in the region prompted the launch of an initiative for Malaria Elimination in Mesoamerica and Hispaniola (EMMIE) with the active involvement of the National Malaria Control Programs (NMCPs) of nine countries, the Regional Coordination Mechanism (RCM) for Mesoamerica, and the Council of Health Ministries of Central America and Dominican Republic (COMISCA). The EMMIE initiative is supported by the Global Fund for Aids, Tuberculosis and Malaria (GFATM) with active participation of multiple partners including Ministries of Health, bilateral and multilateral agencies, as well as research centers. EMMIE’s main goal is to achieve elimination of malaria transmission in the region by 2020. Here we discuss the prospects, challenges, and research needs associated with this initiative that, if successful, could represent a paradigm for other malaria-affected regions. PMID:25973753

  9. Transmission-blocking activity induced by malaria vaccine candidates Pfs25/Pvs25 is a direct and predictable function of antibody titer

    PubMed Central

    Miura, Kazutoyo; Keister, David B; Muratova, Olga V; Sattabongkot, Jetsumon; Long, Carole A; Saul, Allan

    2007-01-01

    Background Mosquito stage malaria vaccines are designed to induce an immune response in the human host that will block the parasite's growth in the mosquito and consequently block transmission of the parasite. A mosquito membrane-feeding assay (MFA) is used to test transmission-blocking activity (TBA), but in this technique cannot accommodate many samples. A clear understanding of the relationship between antibody levels and TBA may allow ELISA determinations to be used to predict TBA and assist in planning vaccine development. Methods Rabbit anti-Pfs25 sera and monkey anti-Pvs25 sera were generated and the antibody titers were determined by a standardized ELISA. The biological activity of the same sera was tested by MFA using Plasmodium gametocytes (cultured Plasmodium falciparum or Plasmodium vivax from malaria patients) and Anopheles mosquitoes. Results Anti-Pfs25 and anti-Pvs25 sera showed that ELISA antibody units correlate with the percent reduction in the oocyst density per mosquito (Spearman Rank correlations: 0.934 and 0.616, respectively), and fit a hyperbolic curve when percent reduction in oocyst density is plotted against antibody units of the tested sample. Antibody levels also correlated with the number of mosquitoes that failed to become infected, and this proportion can be calculated from the reduction in oocyst numbers and the distribution of oocysts per infected mosquito in control group. Conclusion ELISA data may be used as a surrogate for the MFA to evaluate transmission-blocking vaccine efficacy. This will facilitate the evaluation of transmission-blocking vaccines and implementation of this malaria control strategy. PMID:17686163

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

    PubMed Central

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

    2014-01-01

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

  11. Direct and indirect QMRA of infectious Cryptosporidium oocysts in reclaimed water.

    PubMed

    Agulló-Barceló, M; Casas-Mangas, R; Lucena, F

    2012-12-01

    Water scarcity leads to an increased use of reclaimed water, which in turn calls for an improvement in water reclamation procedures to ensure adequate quality of the final effluent. The presence of infectious Cryptosporidium oocysts (IOO) in reclaimed water is a health hazard for users of this resource. Here, we gathered information on Cryptosporidium (concentrations, infectivity and genotype) in order to perform quantitative microbial risk assessment (QMRA). Moreover, data concerning the spores of sulphite-reducing clostridia (SRC) were used to undertake QMRA at a screening level. Our results show that the probability of infection (PI) by Cryptosporidium depends on the tertiary treatment type. The mean PI using the exponential dose-response model was 3.69 × 10(-6) in tertiary effluents (TE) treated with UV light, whereas it was 3 log(10) units higher, 1.89 × 10(-3), in TE not treated with this disinfection method. With the β-Poisson model, the mean PI was 1.56 × 10(-4) in UV-treated TE and 2 log(10) units higher, 4.37 × 10(-2), in TE not treated with UV. The use of SRC to perform QMRA of Cryptosporidium showed higher PI than when using directly IOO data. This observation suggests the former technique is a conservative method of QMRA. PMID:23165711

  12. Quantitative classification of cryptosporidium oocysts and giardia cysts in water using UV/vis spectroscopy

    NASA Astrophysics Data System (ADS)

    Bacon, Christina P.; Rose, J. B.; Patten, K.; Garcia-Rubio, Luis H.

    1995-05-01

    Cryptosporidium and Giardia are enteric protozoa which cause waterborne diseases. To date, the detection of these organisms in water has relied upon microscopic immunofluorescent assay technology which uses antibodies directed against the cyst and oocyst forms of the protozoa. In this paper, the uv/vis extinction spectra of aqueous dispersions of Cryptosporidium and Giardia have been studied to investigate the potential use of light scattering-spectral deconvolution techniques as a rapid method for the identification and quantification of protozoa in water. Examination of purified samples of Cryptosporidium and Giardia suggests that spectral features apparent in the short wavelength region of the uv/vis spectra contain information that may be species specific for each protozoa. The spectral characteristics, as well as the particle size analysis, determined from the same spectra, allow for the quantitative classification, identification, and possibly, the assessment of the viability of the protozoa. To further increase the sensitivity of this technique, specific antibodies direction against these organisms, labelled with FITC and rhodamine are being used. It is demonstrated that uv/vis spectroscopy provides an alternative method for the characterization of Giardia and Cryptosporidium. The simplicity and reproducibility of uv/vis spectroscopy measurements makes this technique ideally suited for the development of on-line instrumentation for the rapid detection of microorganisms in water supplies.

  13. IDENTIFICATION OF SPECIES AND SOURCES OF CRYPTOSPORIDIUM OOCYSTS IN STORM WATERS BY A SMALL SUBUNIT RRNA-BASED DIAGNOSTIC AND GENOTYPING TOOL

    EPA Science Inventory

    The identification of Cryptosporidium oocysts in environmental samples is largely made by the use of immunofluorescent assay (IFA). because IFA detects oocysts from all Cryptosporidium parasites, the species distribution and source of Cryptosporidium parasites in environmental sa...

  14. Neurological manifestations of malaria.

    PubMed

    Román, G C; Senanayake, N

    1992-03-01

    The involvement of the nervous system in malaria is reviewed in this paper. Cerebral malaria, the acute encephalopathy which complicates exclusively the infection by Plasmodium falciparum commonly affects children and adolescents in hyperendemic areas. Plugging of cerebral capillaries and venules by clumped, parasitized red cells causing sludging in the capillary circulation is one hypothesis to explain its pathogenesis. The other is a humoral hypothesis which proposes nonspecific, immune-mediated, inflammatory responses with release of vasoactive substances capable of producing endothelial damage and alterations of permeability. Cerebral malaria has a mortality rate up to 50%, and also a considerable longterm morbidity, particularly in children. Hypoglycemia, largely in patients treated with quinine, may complicate the cerebral symptomatology. Other central nervous manifestations of malaria include intracranial hemorrhage, cerebral arterial occlusion, and transient extrapyramidal and neuropsychiatric manifestations. A self-limiting, isolated cerebellar ataxia, presumably caused by immunological mechanisms, in patients recovering from falciparum malaria has been recognized in Sri Lanka. Malaria is a common cause of febrile seizures in the tropics, and it also contributes to the development of epilepsy in later life. Several reports of spinal cord and peripheral nerve involvement are also available. A transient muscle paralysis resembling periodic paralysis during febrile episodes of malaria has been described in some patients. The pathogenesis of these neurological manifestations remains unexplored, but offers excellent perspectives for research at a clinical as well as experimental level. PMID:1307475

  15. Malaria in Children

    PubMed Central

    Schumacher, Richard-Fabian; Spinelli, Elena

    2012-01-01

    This review is focused on childhood specific aspects of malaria, especially in resource-poor settings. We summarise the actual knowledge in the field of epidemiology, clinical presentation, diagnosis, management and prevention. These aspects are important as malaria is responsible for almost a quarter of all child death in sub-Saharan Africa. Malaria control is thus one key intervention to reduce childhood mortality, especially as malaria is also an important risk factor for other severe infections, namely bacteraemia. In children symptoms are more varied and often mimic other common childhood illness, particularly gastroenteritis, meningitis/encephalitis, or pneumonia. Fever is the key symptom, but the characteristic regular tertian and quartan patterns are rarely observed. There are no pathognomonic features for severe malaria in this age group. The well known clinical (fever, impaired consciousness, seizures, vomiting, respiratory distress) and laboratory (severe anaemia, thrombocytopenia, hypoglycaemia, metabolic acidosis, and hyperlactataemia) features of severe falciparum malaria in children, are equally typical for severe sepsis. Appropriate therapy (considering species, resistance patterns and individual patient factors) – possibly a drug combination of an artemisinin derivative with a long-acting antimalarial drug - reduces treatment duration to only three days and should be urgently started. While waiting for the results of ongoing vaccine trials, all effort should be made to better implement other malaria-control measures like the use of treated bed-nets, repellents and new chemoprophylaxis regimens. PMID:23205261

  16. Mitochondrial ATP synthase is dispensable in blood-stage Plasmodium berghei rodent malaria but essential in the mosquito phase

    PubMed Central

    Sturm, Angelika; Mollard, Vanessa; Cozijnsen, Anton; Goodman, Christopher D.; McFadden, Geoffrey I.

    2015-01-01

    Mitochondrial ATP synthase is driven by chemiosmotic oxidation of pyruvate derived from glycolysis. Blood-stage malaria parasites eschew chemiosmosis, instead relying almost solely on glycolysis for their ATP generation, which begs the question of whether mitochondrial ATP synthase is necessary during the blood stage of the parasite life cycle. We knocked out the mitochondrial ATP synthase β subunit gene in the rodent malaria parasite, Plasmodium berghei, ablating the protein that converts ADP to ATP. Disruption of the β subunit gene of the ATP synthase only marginally reduced asexual blood-stage parasite growth but completely blocked mouse-to-mouse transmission via Anopheles stephensi mosquitoes. Parasites lacking the β subunit gene of the ATP synthase generated viable gametes that fuse and form ookinetes but cannot progress beyond this stage. Ookinetes lacking the β subunit gene of the ATP synthase had normal motility but were not viable in the mosquito midgut and never made oocysts or sporozoites, thereby abrogating transmission to naive mice via mosquito bite. We crossed the self-infertile ATP synthase β subunit knockout parasites with a male-deficient, self-infertile strain of P. berghei, which restored fertility and production of oocysts and sporozoites, which demonstrates that mitochondrial ATP synthase is essential for ongoing viability through the female, mitochondrion-carrying line of sexual reproduction in P. berghei malaria. Perturbation of ATP synthase completely blocks transmission to the mosquito vector and could potentially be targeted for disease control. PMID:25831536

  17. Predicting malaria vector distribution under climate change scenarios in China: Challenges for malaria elimination

    PubMed Central

    Ren, Zhoupeng; Wang, Duoquan; Ma, Aimin; Hwang, Jimee; Bennett, Adam; Sturrock, Hugh J. W.; Fan, Junfu; Zhang, Wenjie; Yang, Dian; Feng, Xinyu; Xia, Zhigui; Zhou, Xiao-Nong; Wang, Jinfeng

    2016-01-01

    Projecting the distribution of malaria vectors under climate change is essential for planning integrated vector control activities for sustaining elimination and preventing reintroduction of malaria. In China, however, little knowledge exists on the possible effects of climate change on malaria vectors. Here we assess the potential impact of climate change on four dominant malaria vectors (An. dirus, An. minimus, An. lesteri and An. sinensis) using species distribution models for two future decades: the 2030 s and the 2050 s. Simulation-based estimates suggest that the environmentally suitable area (ESA) for An. dirus and An. minimus would increase by an average of 49% and 16%, respectively, under all three scenarios for the 2030 s, but decrease by 11% and 16%, respectively in the 2050 s. By contrast, an increase of 36% and 11%, respectively, in ESA of An. lesteri and An. sinensis, was estimated under medium stabilizing (RCP4.5) and very heavy (RCP8.5) emission scenarios. in the 2050 s. In total, we predict a substantial net increase in the population exposed to the four dominant malaria vectors in the decades of the 2030 s and 2050 s, considering land use changes and urbanization simultaneously. Strategies to achieve and sustain malaria elimination in China will need to account for these potential changes in vector distributions and receptivity. PMID:26868185

  18. Predicting malaria vector distribution under climate change scenarios in China: Challenges for malaria elimination.

    PubMed

    Ren, Zhoupeng; Wang, Duoquan; Ma, Aimin; Hwang, Jimee; Bennett, Adam; Sturrock, Hugh J W; Fan, Junfu; Zhang, Wenjie; Yang, Dian; Feng, Xinyu; Xia, Zhigui; Zhou, Xiao-Nong; Wang, Jinfeng

    2016-01-01

    Projecting the distribution of malaria vectors under climate change is essential for planning integrated vector control activities for sustaining elimination and preventing reintroduction of malaria. In China, however, little knowledge exists on the possible effects of climate change on malaria vectors. Here we assess the potential impact of climate change on four dominant malaria vectors (An. dirus, An. minimus, An. lesteri and An. sinensis) using species distribution models for two future decades: the 2030 s and the 2050 s. Simulation-based estimates suggest that the environmentally suitable area (ESA) for An. dirus and An. minimus would increase by an average of 49% and 16%, respectively, under all three scenarios for the 2030 s, but decrease by 11% and 16%, respectively in the 2050 s. By contrast, an increase of 36% and 11%, respectively, in ESA of An. lesteri and An. sinensis, was estimated under medium stabilizing (RCP4.5) and very heavy (RCP8.5) emission scenarios. in the 2050 s. In total, we predict a substantial net increase in the population exposed to the four dominant malaria vectors in the decades of the 2030 s and 2050 s, considering land use changes and urbanization simultaneously. Strategies to achieve and sustain malaria elimination in China will need to account for these potential changes in vector distributions and receptivity. PMID:26868185

  19. Predicting malaria vector distribution under climate change scenarios in China: Challenges for malaria elimination

    NASA Astrophysics Data System (ADS)

    Ren, Zhoupeng; Wang, Duoquan; Ma, Aimin; Hwang, Jimee; Bennett, Adam; Sturrock, Hugh J. W.; Fan, Junfu; Zhang, Wenjie; Yang, Dian; Feng, Xinyu; Xia, Zhigui; Zhou, Xiao-Nong; Wang, Jinfeng

    2016-02-01

    Projecting the distribution of malaria vectors under climate change is essential for planning integrated vector control activities for sustaining elimination and preventing reintroduction of malaria. In China, however, little knowledge exists on the possible effects of climate change on malaria vectors. Here we assess the potential impact of climate change on four dominant malaria vectors (An. dirus, An. minimus, An. lesteri and An. sinensis) using species distribution models for two future decades: the 2030 s and the 2050 s. Simulation-based estimates suggest that the environmentally suitable area (ESA) for An. dirus and An. minimus would increase by an average of 49% and 16%, respectively, under all three scenarios for the 2030 s, but decrease by 11% and 16%, respectively in the 2050 s. By contrast, an increase of 36% and 11%, respectively, in ESA of An. lesteri and An. sinensis, was estimated under medium stabilizing (RCP4.5) and very heavy (RCP8.5) emission scenarios. in the 2050 s. In total, we predict a substantial net increase in the population exposed to the four dominant malaria vectors in the decades of the 2030 s and 2050 s, considering land use changes and urbanization simultaneously. Strategies to achieve and sustain malaria elimination in China will need to account for these potential changes in vector distributions and receptivity.

  20. Iron, anemia and hepcidin in malaria

    PubMed Central

    Spottiswoode, Natasha; Duffy, Patrick E.; Drakesmith, Hal

    2014-01-01

    Malaria and iron have a complex but important relationship. Plasmodium proliferation requires iron, both during the clinically silent liver stage of growth and in the disease-associated phase of erythrocyte infection. Precisely how the protozoan acquires its iron from its mammalian host remains unclear, but iron chelators can inhibit pathogen growth in vitro and in animal models. In humans, iron deficiency appears to protect against severe malaria, while iron supplementation increases risks of infection and disease. Malaria itself causes profound disturbances in physiological iron distribution and utilization, through mechanisms that include hemolysis, release of heme, dyserythropoiesis, anemia, deposition of iron in macrophages, and inhibition of dietary iron absorption. These effects have significant consequences. Malarial anemia is a major global health problem, especially in children, that remains incompletely understood and is not straightforward to treat. Furthermore, the changes in iron metabolism during a malaria infection may modulate susceptibility to co-infections. The release of heme and accumulation of iron in granulocytes may explain increased vulnerability to non-typhoidal Salmonella during malaria. The redistribution of iron away from hepatocytes and into macrophages may confer host resistance to superinfection, whereby blood-stage parasitemia prevents the development of a second liver-stage Plasmodium infection in the same organism. Key to understanding the pathophysiology of iron metabolism in malaria is the activity of the iron regulatory hormone hepcidin. Hepcidin is upregulated during blood-stage parasitemia and likely mediates much of the iron redistribution that accompanies disease. Understanding the regulation and role of hepcidin may offer new opportunities to combat malaria and formulate better approaches to treat anemia in the developing world. PMID:24910614

  1. Malaria and Vascular Endothelium

    PubMed Central

    de Alencar, Aristóteles Comte; de Lacerda, Marcus Vinícius Guimarães; Okoshi, Katashi; Okoshi, Marina Politi

    2014-01-01

    Involvement of the cardiovascular system in patients with infectious and parasitic diseases can result from both intrinsic mechanisms of the disease and drug intervention. Malaria is an example, considering that the endothelial injury by Plasmodium-infected erythrocytes can cause circulatory disorders. This is a literature review aimed at discussing the relationship between malaria and endothelial impairment, especially its effects on the cardiovascular system. We discuss the implications of endothelial aggression and the interdisciplinarity that should guide the malaria patient care, whose acute infection can contribute to precipitate or aggravate a preexisting heart disease. PMID:25014058

  2. Malaria and vascular endothelium.

    PubMed

    Alencar Filho, Aristóteles Comte de; Lacerda, Marcus Vinícius Guimarães de; Okoshi, Katashi; Okoshi, Marina Politi

    2014-08-01

    Involvement of the cardiovascular system in patients with infectious and parasitic diseases can result from both intrinsic mechanisms of the disease and drug intervention. Malaria is an example, considering that the endothelial injury by Plasmodium-infected erythrocytes can cause circulatory disorders. This is a literature review aimed at discussing the relationship between malaria and endothelial impairment, especially its effects on the cardiovascular system. We discuss the implications of endothelial aggression and the interdisciplinarity that should guide the malaria patient care, whose acute infection can contribute to precipitate or aggravate a preexisting heart disease. PMID:25014058

  3. Characterization of Plasmodium developmental transcriptomes in Anopheles gambiae midgut reveals novel regulators of malaria transmission

    PubMed Central

    Akinosoglou, Karolina A; Bushell, Ellen S C; Ukegbu, Chiamaka Valerie; Schlegelmilch, Timm; Cho, Jee-Sun; Redmond, Seth; Sala, Katarzyna; Christophides, George K; Vlachou, Dina

    2015-01-01

    The passage through the mosquito is a major bottleneck for malaria parasite populations and a target of interventions aiming to block disease transmission. Here, we used DNA microarrays to profile the developmental transcriptomes of the rodent malaria parasite Plasmodium berghei in vivo, in the midgut of Anopheles gambiae mosquitoes, from parasite stages in the midgut blood bolus to sporulating oocysts on the basal gut wall. Data analysis identified several distinct transcriptional programmes encompassing genes putatively involved in developmental processes or in interactions with the mosquito. At least two of these programmes are associated with the ookinete development that is linked to mosquito midgut invasion and establishment of infection. Targeted disruption by homologous recombination of two of these genes resulted in mutant parasites exhibiting notable infection phenotypes. GAMER encodes a short polypeptide with granular localization in the gametocyte cytoplasm and shows a highly penetrant loss-of-function phenotype manifested as greatly reduced ookinete numbers, linked to impaired male gamete release. HADO encodes a putative magnesium phosphatase with distinctive cortical localization along the concave ookinete periphery. Disruption of HADO compromises ookinete development leading to significant reduction of oocyst numbers. Our data provide important insights into the molecular framework underpinning Plasmodium development in the mosquito and identifies two genes with important functions at initial stages of parasite development in the mosquito midgut. PMID:25225164

  4. A simple and efficient method for isolation of a single Eimeria oocyst from poultry litter using a micromanipulator

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The chicken, which is the host for seven species of Eimeria, typically is infected simultaneously by multiple Eimeria species and the oocysts of coccidia are excreted in the feces. A prerequisite for investigation of individual Eimeria species is to isolate a single oocyst from fecal samples. A nov...

  5. Threshold of detection of Cryptosporidium oocysts in human stool specimens: evidence for low sensitivity of current diagnostic methods.

    PubMed Central

    Weber, R; Bryan, R T; Bishop, H S; Wahlquist, S P; Sullivan, J J; Juranek, D D

    1991-01-01

    To determine the minimum number of Cryptosporidium oocysts that can be detected in stool specimens by diagnostic procedures, stool samples seeded with known numbers of Cryptosporidium parvum oocysts were processed by the modified Formalin-ethyl acetate (FEA) stool concentration method. FEA concentrates were subsequently examined by both the modified cold Kinyoun acid-fast (AF) staining and fluorescein-tagged monoclonal antibody (immunofluorescence [IF]) techniques. Oocysts were more easily detected in watery diarrheal stool specimens than they were in formed stool specimens. For watery stool specimens, a 100% detection rate was accomplished at a concentration of 10,000 oocysts per g of stool by both the AF staining and IF techniques. In formed stool specimens, 100% of specimens seeded with 50,000 oocysts per gram of stool were detected by the IF technique, whereas 500,000 oocysts per g of stool were needed for a 100% detection rate by AF staining. Counting of all oocysts on IF slides indicated a mean oocyst loss ranging from 51.2 to 99.6%, depending on the stool consistency as determined by the FEA concentration procedure. Our findings suggest that the most commonly used coprodiagnostic techniques may fail to detect cryptosporidiosis in many immunocompromised and immunocompetent individuals. PMID:1715881

  6. A family of cysteine-rich proteins is involved in the formation of the oocyst wall of Toxoplasma gondii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Among apicomplexan parasites, the coccidia and Cryptosporidium spp. are important pathogens of livestock and humans and the environmentally resistant stage (oocyst) is essential for their transmission. Little is known of the chemical and molecular composition of the oocyst wall. Currently, the only ...

  7. Effect of malaria on HIV/AIDS transmission and progression

    PubMed Central

    2013-01-01

    Malaria and HIV are among the two most important global health problems of developing countries. They cause more than 4 million deaths a year. These two infections interact bidirectionally and synergistically with each other. HIV infection increases the risk of an increase in the severity of malaria infection and burdens of malaria, which in turn facilitates the rate of malaria transmission. Malaria infection is also associated with strong CD4+ cell activation and up-regulation of proinflammatory cytokines and it provides an ideal microenvironment for the spread of the virus among the CD4+ cells and for rapid HIV-1 replication. Additionally, malaria increases blood viral burden by different mechanisms. Therefore, high concentrations of HIV-1 RNA in the blood are predictive of disease progression, and correlate with the risk of blood-borne, vertical, and sexual transmission of the virus. Therefore, this article aims to review information about HIV malaria interactions, the effect of malaria on HIV transmission and progression and the implications related to prevention and treatment of coinfection. PMID:23327493

  8. A global assessment of closed forests, deforestation and malaria risk

    PubMed Central

    GUERRA, C. A.; SNOW, R. W.; HAY, S. I.

    2011-01-01

    Global environmental change is expected to affect profoundly the transmission of the parasites that cause human malaria. Amongst the anthropogenic drivers of change, deforestation is arguably the most conspicuous, and its rate is projected to increase in the coming decades. The canonical epidemiological understanding is that deforestation increases malaria risk in Africa and the Americas and diminishes it in South–east Asia. Partial support for this position is provided here, through a systematic review of the published literature on deforestation, malaria and the relevant vector bionomics. By using recently updated boundaries for the spatial limits of malaria and remotely-sensed estimates of tree cover, it has been possible to determine the population at risk of malaria in closed forest, at least for those malaria-endemic countries that lie within the main blocks of tropical forest. Closed forests within areas of malaria risk cover approximately 1.5 million km2 in the Amazon region, 1.4 million km2 in Central Africa, 1.2 million km2 in the Western Pacific, and 0.7 million km2 in South–east Asia. The corresponding human populations at risk of malaria within these forests total 11.7 million, 18.7 million, 35.1 million and 70.1 million, respectively. By coupling these numbers with the country-specific rates of deforestation, it has been possible to rank malaria-endemic countries according to their potential for change in the population at risk of malaria, as the result of deforestation. The on-going research aimed at evaluating these relationships more quantitatively, through the Malaria Atlas Project (MAP), is highlighted. PMID:16630376

  9. Efficacy of treatment of elevated coccidial oocyst counts in goats using amprolium versus ponazuril.

    PubMed

    Gibbons, Philippa; Love, David; Craig, Thomas; Budke, Christine

    2016-03-15

    Coccidiosis is an important disease of young goats leading to weight loss, diarrhea, and death. In the USA, both ionophores and decoquinate are labeled for prevention of coccidia in goats. However, there are no drugs approved for treatment of clinical cases of coccidiosis in this species. Amprolium is labeled for treatment of coccidiosis in calves while ponazuril, a metabolite of toltrazuril, is labeled for treatment of equine protozoal myeloencephalitis. In this study, 150 young goats housed on concrete lots had fecal samples collected and McMaster fecal oocyst per gram counts performed at 0, 7, 14, and 21 days post-processing. Goats were randomly assigned to receive either amprolium (50mg/kg once a day for 5 days by mouth) or ponazuril (10mg/kg by mouth once) if they had fecal oocyst counts >5,000 per gram. Fecal samples were obtained and oocyst counts performed at days 7, 14, 21, and 28 after the cessation of treatment. Goats were weighed on days 0 and 21 post-processing. Seven goats were enrolled into the amprolium group and 8 into the ponazuril group. Both treatments resulted in decreased oocyst counts post-treatment compared to before treatment. There was no significant difference between fecal coccidian oocyst counts between goats in each group. There was no significant difference in body weight between goats in each group. This study showed that both amprolium and ponazuril were effective in decreasing fecal coccidia oocyst counts in this group of goats. Use of both drugs is currently extra-label in the USA. PMID:26872920

  10. Effect of tillage and rainfall on transport of manure-applied Cryptosporidium parvum oocysts through soil.

    PubMed

    Ramirez, Norma E; Wang, Ping; Lejeune, Jeff; Shipitalo, Martin J; Ward, Lucy A; Sreevatsan, Srinand; Dick, Warren A

    2009-01-01

    Most waterborne outbreaks of cryptosporidiosis have been attributed to agricultural sources due to the high prevalence of Cryptosporidium oocysts in animal wastes and manure spreading on farmlands. No-till, an effective conservation practice, often results in soil having higher water infiltration and percolation rates than conventional tillage. We treated six undisturbed no-till and six tilled soil blocks (30 by 30 by 30 cm) with 1 L liquid dairy manure containing 10(5) C. parvum oocysts per milliliter to test the effect of tillage and rainfall on oocyst transport. The blocks were subjected to rainfall treatments consisting of 5 mm or 30 mm in 30 min. Leachate was collected from the base of the blocks in 35-mL increments using a 64-cell grid lysimeter. Even before any rain was applied, approximately 300 mL of water from the liquid manure (30% of that applied) was transported through the no-till soil, but none through the tilled blocks. After rain was applied, a greater number and percentage of first leachate samples from the no-till soil blocks compared to the tilled blocks tested positive for Cryptosporidium oocysts. In contrast to leachate, greater numbers of oocysts were recovered from the tilled soil, itself, than from the no-till soil. Although tillage was the most important factor affecting oocyst transport, rainfall timing and intensity were also important. To minimize transport of Cryptosporidium in no-till fields, manure should be applied at least 48 h before heavy rainfall is anticipated or methods of disrupting the direct linkage of surface soil to drains, via macropores, need to be used. PMID:19875795

  11. Epidemiology of malaria in Malaysia.

    PubMed

    Rahman, K M

    1982-01-01

    Malaria is a major public health problem in Malaysia, particularly in peninsular Malaysia and the state of Sabah. An eradication program started in the states of Sabah and Sarawak in 1961 initially was remarkably successful. A similar but staged program was started in peninsular Malaysia in 1967 and was also quite successful. However, a marked upsurge in incidence in Sabah in 1975-1978 showed that malaria is still a major hazard. The disease leads to great economic losses in terms of the productivity of the labor force and the learning capacity of schoolchildren. The topography, the climate, and the migrations of the people due to increased economic activity are similar in peninsular Malaysia, Sabah, and Sarawak. However, the epidemiologic picture differs strikingly from area to area in terms of species of vectors, distribution of parasitic species, and resistance of Plasmodium falciparum to chloroquine. Likewise, the problems faced by the eradication or control programs in the three regions are dissimilar. Because solutions to only some of these problems are possible, the eradication of malaria in Malaysia is not likely in the near future. However, the situation offers an excellent opportunity for further studies of antimalaria measures. PMID:6755616

  12. Recognition and characterization of stage-specific oocyst/sporozoite antigens of Toxoplasma gondii by human antisera.

    PubMed Central

    Kasper, L H; Ware, P L

    1985-01-01

    Human infection with Toxoplasma gondii is presumed due to the ingestion of either tissue cysts containing bradyzoites or oocyst/sporozoites that are excreted in the feces of infected cats. The incidence of human infection in the general population by either of these routes is unknown. We have previously described unique stage-specific oocyst/sporozoite antigens identified by murine hybridoma monoclonal antibodies. We obtained acute and convalescent antitoxoplasma antisera from patients in an epidemiologically well-documented outbreak of oocyst-transmitted infection associated with the ingestion of contaminated water. An enzyme-linked immunosorbent assay comparing equal numbers of tachyzoites (invasive stage) and oocyst/sporozoite (excreted stage) indicated that these antisera recognized antigens from both life forms. Absorption of pooled antisera with purified oocyst/sporozoites reduced both the antioocyst immunoglobulin G (IgG) and immunoglobulin M (IgM) titer but had only minimal effect on the antitachyzoite titer. Absorption of the antisera with tachyzoites reduced the IgG and IgM antioocyst and antitachyzoite titer. A sodium dodecyl sulfate-polyacrylamide gel analysis of radioiodinated oocyst/sporozoites shows that the principal stage-specific surface proteins of the oocyst/sporozoite have approximate Mr of 67,000 and 25,000. Periodic acid and silver stain of purified oocyst/sporozoite identified bands of similar molecular weight not present in the tachyzoite preparation. Western blot analysis of purified parasites assayed with human antioocyst antisera identified specific oocyst/sporozoite antigens not present on the tachyzoites. At least two major stage-specific oocyst/sporozoite antigens of approximate Mr of 67,000 and 190,000 were identified by the infected patients' antisera and not by the normal controls. Reaction to these oocyst/sporozoite antigens was seen primarily in the IgM fraction of the acute phase and the IgG fraction of convalescent phase

  13. Placental Malaria in Colombia: Histopathologic Findings in Plasmodium vivax and P. falciparum Infections

    PubMed Central

    Carmona-Fonseca, Jaime; Arango, Eliana; Maestre, Amanda

    2013-01-01

    Studies on gestational malaria and placental malaria have been scarce in malaria-endemic areas of the Western Hemisphere. To describe the histopathology of placental malaria in Colombia, a longitudinal descriptive study was conducted. In this study, 179 placentas were studied by histologic analysis (112 with gestational malaria and 67 negative for malaria). Placental malaria was confirmed in 22.35%, 50.0% had previous infections, and 47.5% had acute infections. Typical malaria-associated changes were observed in 37%. The most common changes were villitis, intervillitis, deciduitis, increased fibrin deposition, increased syncytial knots, mononuclear (monocytes/macrophages and lymphocytes), polymorphonuclear cell infiltration, and trophozoites in fetal erythrocytes. No association was found between type of placental changes observed and histopathologic classification of placental malaria. The findings are consistent with those reported for placental malaria in other regions. Plasmodium vivax was the main parasite responsible for placental and gestational malaria, but its role in the pathogenesis of placental malaria was not conclusive. PMID:23546807

  14. Associations Between Maternal Helminth and Malaria Infections in Pregnancy and Clinical Malaria in the Offspring: A Birth Cohort in Entebbe, Uganda

    PubMed Central

    Ndibazza, Juliet; Webb, Emily L.; Lule, Swaib; Mpairwe, Harriet; Akello, Miriam; Oduru, Gloria; Kizza, Moses; Akurut, Helen; Muhangi, Lawrence; Magnussen, Pascal; Vennervald, Birgitte; Elliott, Alison

    2013-01-01

    Background. Helminth and malaria coinfections are common in the tropics. We investigated the hypothesis that prenatal exposure to these parasites might influence susceptibility to malaria in childhood. Methods. In a birth cohort of 2345 mother–child pairs in Uganda, maternal helminth and malaria infection status was determined during pregnancy, and childhood malaria episodes were recorded from birth to age 5 years. We examined associations between maternal infections and malaria in the offspring. Results. Common maternal infections were hookworm (45%), Mansonella perstans (21%), Schistosoma mansoni (18%), and Plasmodium falciparum (11%). At age 5 years, 69% of the children were still under follow-up. The incidence of malaria was 34 episodes per 100 child-years, and the mean prevalence of asymptomatic malaria at annual visits was 5.4%. Maternal hookworm and M. perstans infections were associated with an increased rate of childhood clinical malaria (adjusted hazard ratio [aHR], 1.24, 95% confidence interval [CI], 1.10–1.41; aHR, 1.20, 95% CI, 1.05–1.38, respectively). S. mansoni infection had no consistent association with childhood malaria. Conclusions. This is the first report of an association between helminth infections in pregnancy and malaria in the offspring and indicates that helminth infections in pregnancy may increase the burden of childhood malaria morbidity. PMID:23904293

  15. Real-time, sensitive electrical detection of Cryptosporidium parvum oocysts based on chemical vapor deposition-grown graphene

    NASA Astrophysics Data System (ADS)

    It Wong, Jen; Wang, Lu; Shi, Yumeng; Palacios, Tomás; Kong, Jing; Dong, Xiaochen; Ying Yang, Hui

    2014-02-01

    Cryptosporidium parvum is a common intestinal parasitic protozoan that causes gastroenteritis in man and animals. It poses high risks to drinking water supply because of its ubiquitous distribution in water and their oocysts are resistant to harsh environment conditions. In this work, we demonstrated the use of large-size chemical vapor deposition (CVD) grown graphene films configured as field-effect device for rapid electrical detection of Cryptosporidium parvum oocysts (Cp. oocysts). The presence of Cp. oocysts causes the change in the transport characteristics of the antibody-functionalized graphene device, which can be measured in terms of the dependence of the drain current on the sweep of the gate voltage or the real-time drain current data under a constant gate voltage. The high sensor sensitivity of 25 oocysts per milliliter solution and good specificity were evaluated, indicating it a promising candidate for detecting waterborne pathogens in water quality control.

  16. Immunopathology of malaria*

    PubMed Central

    Voller, Alister

    1974-01-01

    Antibodies with different spectra of reactivity are produced during malarial infections and marked changes in IgG and IgM levels occur. In addition malaria elicits serological changes that are usually associated with connective tissue disease. The excessive anaemia associated with malaria may, in part, be an autoimmune phenomenon. Transient nephritis accompanies many plasmodial infections but chronic malarial nephrotic syndrome is specifically associated with quartan malaria. Malarial infection leads to splenomegaly, the most extreme form of which is idiopathic tropical splenomegaly, which probably represents an aberrant immune response to the infection. Malaria can affect the humoral immune response to unrelated antigens and infectious agents. This may be relevant to the etiology of Burkitt's lymphoma. During pregnancy there is some loss of acquired immunity to P. falciparum and the placenta appears to be an immunologically privileged site for the multiplication of this parasite. PMID:4216408

  17. Malaria diseases and parasites.

    PubMed

    Ascenzi, A

    1999-09-01

    The milestones in the discovery of malaria parasites and their relationships with malaria diseases are presented and discussed with particular reference to the contribution of the Italian scientists. Laveran's discovery (1880) of the malaria parasite produced some schepticism among the Roman scientists who were under the influence of Tommasi-Crudeli, the discoverer of the supposed Bacillus malariae. However, Marchiafava and Celli confirmed soon Laveran's observations and, between 1883 and 1885, improved the description of the parasite adding important details. They described, then, the aestivo-autumnal tertian fever as a distinct disease from the 'primaverile' or benign tertian. This work influenced Golgi who went on to analyse the features that distinguish the benign tertian parasite from that of the quartan. The fact that in North Italy the aestivo-autumnal tertian fever was hardly ever found, whereas it was common in the Roman Campagna and the Pontin marshes, explains why it was Celli and Marchiafava and later Bignami and Bastianelli, and Marchiafava and Bignami--but not Golgi--who were committed to work on this pernicious form of malaria. By the early 1890s the Italian scientists came to define the three malaria parasites, presently known as Plasmodium vivax, P. malariae, and P. falciparum, and to associate them with precise anatomo-pathological and clinical features. By the middle 1890s the Italian school was prepared to contribute also to the discovery of the mosquito cycle in human malaria, clearly hypothesized by Bignami in 1896 and experimentally proved in 1898 by Bignami, Bastianelli and Grassi. PMID:10697831

  18. Epidemic malaria and warmer temperatures in recent decades in an East African highland.

    PubMed

    Alonso, David; Bouma, Menno J; Pascual, Mercedes

    2011-06-01

    Climate change impacts on malaria are typically assessed with scenarios for the long-term future. Here we focus instead on the recent past (1970-2003) to address whether warmer temperatures have already increased the incidence of malaria in a highland region of East Africa. Our analyses rely on a new coupled mosquito-human model of malaria, which we use to compare projected disease levels with and without the observed temperature trend. Predicted malaria cases exhibit a highly nonlinear response to warming, with a significant increase from the 1970s to the 1990s, although typical epidemic sizes are below those observed. These findings suggest that climate change has already played an important role in the exacerbation of malaria in this region. As the observed changes in malaria are even larger than those predicted by our model, other factors previously suggested to explain all of the increase in malaria may be enhancing the impact of climate change. PMID:21068045

  19. [An outbreak of Plasmodium vivax malaria in Kyrghyzstan].

    PubMed

    Usenbaev, N T; Ezhov, M N; Zvantsov, A B; Annarbaev, A; Zhoroev, A A; Almerekov, K Sh

    2006-01-01

    Malaria was not notified in the republic in 1960 to 1982, with exception of 1963 where one case of imported malaria was identified. Twenty-four cases of locally transmitted malaria were detected, 11 of them being registered in the Batken district, Osh Region, contiguous with Tadjikistan and Uzbekistan. In 1981 to 2000, a total of 101 cases of malaria were notified, in 2001 there was an increase in cases of malaria to 136, while in 2002, a total of 2744 cases of malaria were registered mainly in the Fergana valley. Malaria was imported from Tadjikistan, Azerbaijan, Uzbekistan, and Afghanistan. The infectious agent of malaria was P. vivax in 98% of cases and P. falciparum in 2%. The high malarial potential areas are the Osh, Zhalalabat, and Batken Regions and town of Osh. In 2002, the investigators identified patients with malaria, made its chloroquine eliminating treatment, seasonal chemoprevention of some 5000 dwellers of the Leilek District of the Batken Region contiguous with Tadjikistan, and larvicidal treatments of water reservoirs and rice checks with dimilin. Almost 1,988,000 m2 of premises were treated with Solfac. Mosquito fishes were placed into more water reservoirs in 2003. In 2003 there was a tendency for a decrease in the incidence of malaria, as compared with 2002, which may be ascribed to the small size of vectors, which is due to the cold spring and cool June and July. In 2003, there were treatments of premises, mosquito fish enrichment of water reservoirs, interseasonal chemoprophylaxis of patients who experienced malaria in 2002; impregnated bed curtains were available to protect the dwellers of foci from mosquito bites. PMID:16562744

  20. Human movement data for malaria control and elimination strategic planning.

    PubMed

    Pindolia, Deepa K; Garcia, Andres J; Wesolowski, Amy; Smith, David L; Buckee, Caroline O; Noor, Abdisalan M; Snow, Robert W; Tatem, Andrew J

    2012-01-01

    Recent increases in funding for malaria control have led to the reduction in transmission in many malaria endemic countries, prompting the national control programmes of 36 malaria endemic countries to set elimination targets. Accounting for human population movement (HPM) in planning for control, elimination and post-elimination surveillance is important, as evidenced by previous elimination attempts that were undermined by the reintroduction of malaria through HPM. Strategic control and elimination planning, therefore, requires quantitative information on HPM patterns and the translation of these into parasite dispersion. HPM patterns and the risk of malaria vary substantially across spatial and temporal scales, demographic and socioeconomic sub-groups, and motivation for travel, so multiple data sets are likely required for quantification of movement. While existing studies based on mobile phone call record data combined with malaria transmission maps have begun to address within-country HPM patterns, other aspects remain poorly quantified despite their importance in accurately gauging malaria movement patterns and building control and detection strategies, such as cross-border HPM, demographic and socioeconomic stratification of HPM patterns, forms of transport, personal malaria protection and other factors that modify malaria risk. A wealth of data exist to aid filling these gaps, which, when combined with spatial data on transport infrastructure, traffic and malaria transmission, can answer relevant questions to guide strategic planning. This review aims to (i) discuss relevant types of HPM across spatial and temporal scales, (ii) document where datasets exist to quantify HPM, (iii) highlight where data gaps remain and (iv) briefly put forward methods for integrating these datasets in a Geographic Information System (GIS) framework for analysing and modelling human population and Plasmodium falciparum malaria infection movements. PMID:22703541

  1. Human movement data for malaria control and elimination strategic planning

    PubMed Central

    2012-01-01

    Recent increases in funding for malaria control have led to the reduction in transmission in many malaria endemic countries, prompting the national control programmes of 36 malaria endemic countries to set elimination targets. Accounting for human population movement (HPM) in planning for control, elimination and post-elimination surveillance is important, as evidenced by previous elimination attempts that were undermined by the reintroduction of malaria through HPM. Strategic control and elimination planning, therefore, requires quantitative information on HPM patterns and the translation of these into parasite dispersion. HPM patterns and the risk of malaria vary substantially across spatial and temporal scales, demographic and socioeconomic sub-groups, and motivation for travel, so multiple data sets are likely required for quantification of movement. While existing studies based on mobile phone call record data combined with malaria transmission maps have begun to address within-country HPM patterns, other aspects remain poorly quantified despite their importance in accurately gauging malaria movement patterns and building control and detection strategies, such as cross-border HPM, demographic and socioeconomic stratification of HPM patterns, forms of transport, personal malaria protection and other factors that modify malaria risk. A wealth of data exist to aid filling these gaps, which, when combined with spatial data on transport infrastructure, traffic and malaria transmission, can answer relevant questions to guide strategic planning. This review aims to (i) discuss relevant types of HPM across spatial and temporal scales, (ii) document where datasets exist to quantify HPM, (iii) highlight where data gaps remain and (iv) briefly put forward methods for integrating these datasets in a Geographic Information System (GIS) framework for analysing and modelling human population and Plasmodium falciparum malaria infection movements. PMID:22703541

  2. Barriers to Malaria Control among Marginalized Tribal Communities: A Qualitative Study

    PubMed Central

    Sundararajan, Radhika; Kalkonde, Yogeshwar; Gokhale, Charuta; Greenough, P. Gregg; Bang, Abhay

    2013-01-01

    healers partners in malaria control; promoting within-village rapid diagnosis and treatment; increasing ITN distribution and promoting their use as potential strategies to decrease infection rates in these communities. These insights may be used to shape malaria control programs among marginalized populations. PMID:24376507

  3. [The malaria situation in the WHO European region].

    PubMed

    Sabatinelli, G

    2000-01-01

    The number of indigenous malaria cases in European region peaked in 1997, when 77,985 cases were officially reported. These were caused almost exclusively by P. vivax, P. falciparum being restricted to a rather limited number of cases in Tajikistan only. Another important problem in the European Region is the importation of malaria associated with a high fatality rate from tropical endemic countries. There were 841 cases of malaria in Armenia, 567 of which were locally transmitted, 30 out of 81 districts recorded malaria cases. 89% of the indigenous cases were registered in Masis district, in the Ararat valley. In 1998, total number of cases increased to 1156. Of the 542 indigenous cases registered, 376 were in Masis district. 9911 cases were officially reported in 1997 in Azerbaijan and 5175 cases in 1998. Approximately half of malaria cases were reported from seven districts: Nakhichivan (10.4%), Imishli (14.6%), Fizuli (8.1%), Sabirabad (6.8%), Saatly (6%), Bejlagan (5.6%) and Bilasuvar (4.8%). Local transmission is also reported from the periurban areas of Baku, where many displaced people are living in temporary shelters. In 1997, a total of 30,054 malaria cases were officially registered in Tajikistan, of which 85.3% occurred in the Khatlon region, 10.5% in Dushanbe region, 3.5% in Gorno-Badakhshan region and 0.7% in Leninabad region. Following implementation of malaria control activities with WHO assistance, the number of malaria cases officially registered in 1998 dropped to 19,361 (187 were cases of falciparum malaria). A dramatic change occurred in malaria situation in Turkmenistan in 1998, when 115 indigenous cases were registered. The majority of malaria cases (104) were registered in the Kushka district, in south-east of Turkmenistan, among military service personnel. In recent years, the Government of Turkey has renewed its efforts to fight malaria, incorporating them into GAP with support from UNDP and WHO. In 1998, 36,451 cases were reported, 87

  4. Tetracyclines in malaria.

    PubMed

    Gaillard, Tiphaine; Madamet, Marylin; Pradines, Bruno

    2015-01-01

    Malaria, a parasite vector-borne disease, is one of the greatest health threats in tropical regions, despite the availability of malaria chemoprophylaxis. The emergence and rapid extension of Plasmodium falciparum resistance to various anti-malarial drugs has gradually limited the number of potential malaria therapeutics available to clinicians. In this context, doxycycline, a synthetically derived tetracycline, constitutes an interesting alternative for malaria treatment and prophylaxis. Doxycycline is a slow-acting blood schizontocidal agent that is highly effective at preventing malaria. In areas with chloroquine and multidrug-resistant P. falciparum parasites, doxycycline has already been successfully used in combination with quinine to treat malaria, and it has been proven to be effective and well-tolerated. Although not recommended for pregnant women and children younger than 8 years of age, severe adverse effects are rarely reported. In addition, resistance to doxycycline is rarely described. Prophylactic and clinical failures of doxycycline have been associated with both inadequate doses and poor patient compliance. The effects of tetracyclines on parasites are not completely understood. A better comprehension of the mechanisms underlying drug resistance would facilitate the identification of molecular markers of resistance to predict and survey the emergence of resistance. PMID:26555664

  5. Time trend of malaria in relation to climate variability in Papua New Guinea

    PubMed Central

    Kolam, Joel; Inape, Kasis

    2016-01-01

    Objectives This study was conducted to describe the regional malaria incidence in relation to the geographic and climatic conditions and describe the effect of altitude on the expansion of malaria over the last decade in Papua New Guinea. Methods Malaria incidence was estimated in five provinces from 1996 to 2008 using national health surveillance data. Time trend of malaria incidence was compared with rainfall and minimum/maximum temperature. In the Eastern Highland Province, time trend of malaria incidence over the study period was stratified by altitude. Spatio-temporal pattern of malaria was analyzed. Results Nationwide, malaria incidence was stationary. Regionally, the incidence increased markedly in the highland region (292.0/100000/yr, p =0.021), and remained stationary in the other regions. Seasonality of the malaria incidence was related with rainfall. Decreasing incidence of malaria was associated with decreasing rainfall in the southern coastal region, whereas it was not evident in the northern coastal region. In the Eastern Highland Province, malaria incidence increased in areas below 1700 m, with the rate of increase being steeper at higher altitudes. Conclusions Increasing trend of malaria incidence was prominent in the highland region of Papua New Guinea, while long-term trend was dependent upon baseline level of rainfall in coastal regions. PMID:26987606

  6. Prospects for malaria elimination in non-Amazonian regions of Latin America.

    PubMed

    Herrera, Sócrates; Quiñones, Martha Lucia; Quintero, Juan Pablo; Corredor, Vladimir; Fuller, Douglas O; Mateus, Julio Cesar; Calzada, Jose E; Gutierrez, Juan B; Llanos, Alejandro; Soto, Edison; Menendez, Clara; Wu, Yimin; Alonso, Pedro; Carrasquilla, Gabriel; Galinski, Mary; Beier, John C; Arévalo-Herrera, Myriam

    2012-03-01

    Latin America contributes 1-1.2 million clinical malaria cases to the global malaria burden of about 300 million per year. In 21 malaria endemic countries, the population at risk in this region represents less than 10% of the total population exposed worldwide. Factors such as rapid deforestation, inadequate agricultural practices, climate change, political instability, and both increasing parasite drug resistance and vector resistance to insecticides contribute to malaria transmission. Recently, several malaria endemic countries have experienced a significant reduction in numbers of malaria cases. This is most likely due to actions taken by National Malaria Control Programs (NMCP) with the support from international funding agencies. We describe here the research strategies and activities to be undertaken by the Centro Latino Americano de Investigación en Malaria (CLAIM), a new research center established for the non-Amazonian region of Latin America by the National Institute of Allergy and Infectious Diseases (NIAID). Throughout a network of countries in the region, initially including Colombia, Guatemala, Panama, and Peru, CLAIM will address major gaps in our understanding of changing malaria epidemiology, vector biology and control, and clinical malaria mainly due to Plasmodium vivax. In close partnership with NMCPs, CLAIM seeks to conduct research on how and why malaria is decreasing in many countries of the region as a basis for developing and implementing new strategies that will accelerate malaria elimination. PMID:21781953

  7. Prospects for malaria elimination in non-Amazonian regions of Latin America

    PubMed Central

    Herrera, Sócrates; Quiñones, Martha Lucia; Quintero, Juan Pablo; Corredor, Vladimir; Fuller, Douglas O.; Mateus, Julio Cesar; Calzada, Jose E.; Gutierrez, Juan B.; Llanos, Alejandro; Soto, Edison; Menendez, Clara; Wu, Yimin; Alonso, Pedro; Carrasquilla, Gabriel; Galinski, Mary; Beier, John C.; Arevalo-Herrera, Myriam

    2011-01-01

    Latin America contributes 1 to 1.2 million clinical malaria cases to the global malaria burden of about 300 million per year. In 21 malaria endemic countries, the population at risk in this region represents less than 10% of the total population exposed worldwide. Factors such as rapid deforestation, inadequate agricultural practices, climate change, political instability, and both increasing parasite drug resistance and vector resistance to insecticides contribute to malaria transmission. Recently, several malaria endemic countries have experienced a significant reduction in numbers of malaria cases. This is most likely due to actions taken by National Malaria Control Programs (NMCP) with the support from international funding agencies. We describe here the research strategies and activities to be undertaken by the Centro Latino Americano de Investigación en Malaria (CLAIM), a new research center established for the non-Amazonian region of Latin America by the National Institute of Allergy and Infectious Diseases (NIAID). Throughout a network of countries in the region, initially including Colombia, Guatemala, Panama, and Peru, CLAIM will address major gaps in our understanding of changing malaria epidemiology, vector biology and control, and clinical malaria mainly due to Plasmodium vivax. In close partnership with NMCPs, CLAIM seeks to conduct research on how and why malaria is decreasing in many countries of the region as a basis for developing and implementing new strategies that will accelerate malaria elimination. PMID:21781953

  8. Thermal behaviour of Anopheles stephensi in response to infection with malaria and fungal entomopathogens

    PubMed Central

    Blanford, Simon; Read, Andrew F; Thomas, Matthew B

    2009-01-01

    Background Temperature is a critical determinant of the development of malaria parasites in mosquitoes, and hence the geographic distribution of malaria risk, but little is known about the thermal preferences of Anopheles. A number of other insects modify their thermal behaviour in response to infection. These alterations can be beneficial for the insect or for the infectious agent. Given current interest in developing fungal biopesticides for control of mosquitoes, Anopheles stephensi were examined to test whether mosquitoes showed thermally-mediated behaviour in response to infection with fungal entomopathogens and the rodent malaria, Plasmodium yoelii. Methods Over two experiments, groups of An. stephensi were infected with one of three entomopathogenic fungi, and/or P. yoelii. Infected and uninfected mosquitoes were released on to a thermal gradient (14 – 38°C) for "snapshot" assessments of thermal preference during the first five days post-infection. Mosquito survival was monitored for eight days and, where appropriate, oocyst prevalence and intensity was assessed. Results and conclusion Both infected and uninfected An. stephensi showed a non-random distribution on the gradient, indicating some capacity to behaviourally thermoregulate. However, chosen resting temperatures were not altered by any of the infections. There is thus no evidence that thermally-mediated behaviours play a role in determining malaria prevalence or that they will influence the performance of fungal biopesticides against adult Anopheles. PMID:19379519

  9. Plasmodium vivax malaria incidence over time and its association with temperature and rainfall in four counties of Yunnan Province, China

    PubMed Central

    2013-01-01

    Background Transmission of Plasmodium vivax malaria is dependent on vector availability, biting rates and parasite development. In turn, each of these is influenced by climatic conditions. Correlations have previously been detected between seasonal rainfall, temperature and malaria incidence patterns in various settings. An understanding of seasonal patterns of malaria, and their weather drivers, can provide vital information for control and elimination activities. This research aimed to describe temporal patterns in malaria, rainfall and temperature, and to examine the relationships between these variables within four counties of Yunnan Province, China. Methods Plasmodium vivax malaria surveillance data (1991–2006), and average monthly temperature and rainfall were acquired. Seasonal trend decomposition was used to examine secular trends and seasonal patterns in malaria. Distributed lag non-linear models were used to estimate the weather drivers of malaria seasonality, including the lag periods between weather conditions and malaria incidence. Results There was a declining trend in malaria incidence in all four counties. Increasing temperature resulted in increased malaria risk in all four areas and increasing rainfall resulted in increased malaria risk in one area and decreased malaria risk in one area. The lag times for these associations varied between areas. Conclusions The differences detected between the four counties highlight the need for local understanding of seasonal patterns of malaria and its climatic drivers. PMID:24350670

  10. UK malaria treatment guidelines.

    PubMed

    Lalloo, David G; Shingadia, Delane; Pasvol, Geoffrey; Chiodini, Peter L; Whitty, Christopher J; Beeching, Nicholas J; Hill, David R; Warrell, David A; Bannister, Barbara A

    2007-02-01

    Malaria is the tropical disease most commonly imported into the UK, with 1500-2000 cases reported each year, and 10-20 deaths. Approximately three-quarters of reported malaria cases in the UK are caused by Plasmodium falciparum, which is capable of invading a high proportion of red blood cells and rapidly leading to severe or life-threatening multi-organ disease. Most non-falciparum malaria cases are caused by Plasmodium vivax; a few cases are caused by the other two species of Plasmodium: Plasmodium ovale or Plasmodium malariae. Mixed infections with more than 1 species of parasite can occur; they commonly involve P. falciparum with the attendant risks of severe malaria. Management of malaria depends on awareness of the diagnosis and on performing the correct diagnostic tests: the diagnosis cannot be excluded until 3 blood specimens have been examined by an experienced microscopist. There are no typical clinical features of malaria, even fever is not invariably present. The optimum diagnostic procedure is examination of thick and thin blood films by an expert to detect and speciate the malarial parasites; P. falciparum malaria can be diagnosed almost as accurately using rapid diagnostic tests (RDTs) which detect plasmodial antigens or enzymes, although RDTs for other Plasmodium species are not as reliable. The treatment of choice for non-falciparum malaria is a 3-day course of oral chloroquine, to which only a limited proportion of P. vivax strains have gained resistance. Dormant parasites (hypnozoites) persist in the liver after treatment of P. vivax or P. ovale infection: the only currently effective drug for eradication of hypnozoites is primaquine. This must be avoided or given with caution under expert supervision in patients with glucose-6-phosphate dehydrogenase deficiency (G6PD), in whom it may cause severe haemolysis. Uncomplicated P. falciparum malaria can be treated orally with quinine, atovaquone plus proguanil (Malarone) or co-artemether (Riamet

  11. Comparison of immunofluorescence assay and immunomagnetic electrochemiluminescence in detection of Cryptosporidium parvum oocysts in karst water samples.

    PubMed

    Kuczynska, Ewa; Boyer, Douglas G; Shelton, Daniel R

    2003-04-01

    Immunofluorescence assay (IFA) and immunomagnetic electrochemiluminescence (IM-ECL) were used for comparison of the percent recovery of Cryptosporidium parvum in environmental water samples obtained from a spring draining a karst basin. The monoclonal antibodies to C. parvum, isotype IgG3 were used for optimization of the IM-ECL protocol. The combination of biotinylated and TAG-labeled anti-C. parvum antibodies with the streptavidin beads gave a linear regression slope for log ECL vs. log fresh oocysts of 0.79 (from 5 to 5,000 oocysts), which indicates a constant ECL signal per oocyst. Standard curves gave a dynamic range of 5 to 5,000 oocysts/ml (fresh) and 10 to 100,000 cells/ml (4-month-old oocysts) with the maximum limit of linear detection higher than 100,000. The linear slope of 4-month-old oocysts decreased to 0.62, which indicates that ECL signal is a function of oocyst age. The experiment associated with bead storage time shows that even after 4 months of storage of the biotinylated antibodies, the complex retains the ability for binding the oocysts and generating the ECL signal. Based on the IFA results in the experiment evaluating different protocols for oocysts recovery from karst water samples, the most efficient protocol involved dispersion, followed by flotation and immunomagnetic separation (IMS) (24% recovery). The ECL results obtained in that experiment were very similar to the results obtained in the IFA method, which indicates that the IM-ECL method is accurate. Results of the IFA in the study of the prevalence of C. parvum in the groundwater showed that oocysts were present in 78% of 1 L water samples with average number of oocysts of 6.4+/-5.5 and ranged from 0 (13 samples) to 23.3 (2 samples). The ECL signal generated from these water samples ranged from 3,771 to 622 (average 1,620+/-465). However, the background value estimated in groundwater samples with low number of oocysts detected by IFA was highly variable and elevated (from 3,702 to

  12. Impact of Pregnancy-Associated Malaria on Infant Malaria Infection in Southern Benin

    PubMed Central

    Borgella, Sophie; Fievet, Nadine; Huynh, Bich-Tram; Ibitokou, Samad; Hounguevou, Gbetognon; Affedjou, Jacqueline; Sagbo, Jean-Claude; Houngbegnon, Parfait; Guezo-Mévo, Blaise; Massougbodji, Achille; Luty, Adrian J. F.

    2013-01-01

    Background Infants of mothers with placental Plasmodium falciparum infections at delivery are themselves more susceptible to malaria attacks or to infection in early life. Methodology/ Principal Findings To assess the impact of either the timing or the number of pregnancy-associated malaria (PAM) infections on the incidence of parasitemia or malaria attacks in infancy, we followed 218 mothers through pregnancy (monthly visits) up to delivery and their infants from birth to 12 months of age (fortnightly visits), collecting detailed clinical and parasitological data. After adjustment on location, mother’s age, birth season, bed net use, and placental malaria, infants born to a mother with PAM during the third trimester of pregnancy had a significantly increased risk of infection (OR [95% CI]: 4.2 [1.6; 10.5], p = 0.003) or of malaria attack (4.6 [1.7; 12.5], p = 0.003). PAM during the first and second trimesters had no such impact. Similarly significant results were found for the effect of the overall number of PAM episodes on the time to first parasitemia and first malaria attack (HR [95% CI]: 2.95 [1.58; 5.50], p = 0.001 and 3.19 [1.59; 6.38], p = 0.001) respectively. Conclusions/ Significance This study highlights the importance of protecting newborns by preventing repeated episodes of PAM in their mothers. PMID:24236190

  13. Tackling imported malaria: an elimination endgame.

    PubMed

    Sturrock, Hugh J W; Roberts, Kathryn W; Wegbreit, Jennifer; Ohrt, Colin; Gosling, Roly D

    2015-07-01

    As countries move toward malaria elimination, imported infections become increasingly significant as they often represent the majority of cases, can sustain transmission, cause resurgences, and lead to mortality. Here we review and critique current methods to prevent malaria importation in countries pursuing elimination and explore methods applied in other transmission settings and to other diseases that could be transferred to support malaria elimination. To improve intervention targeting we need a better understanding of the characteristics of populations importing infections and their patterns of migration, improved methods to reliably classify infections as imported or acquired locally, and ensure early and accurate diagnosis. The potential for onward transmission in the most receptive and vulnerable locations can be predicted through high-resolution risk mapping that can help malaria elimination or prevention of reintroduction programs target resources. Cross border and regional initiatives can be highly effective when based on an understanding of human and parasite movement. Ultimately, determining the optimal combinations of approaches to address malaria importation will require an evaluation of their impact, cost effectiveness, and operational feasibility. PMID:26013369

  14. Tackling Imported Malaria: An Elimination Endgame

    PubMed Central

    Sturrock, Hugh J. W.; Roberts, Kathryn W.; Wegbreit, Jennifer; Ohrt, Colin; Gosling, Roly D.

    2015-01-01

    As countries move toward malaria elimination, imported infections become increasingly significant as they often represent the majority of cases, can sustain transmission, cause resurgences, and lead to mortality. Here we review and critique current methods to prevent malaria importation in countries pursuing elimination and explore methods applied in other transmission settings and to other diseases that could be transferred to support malaria elimination. To improve intervention targeting we need a better understanding of the characteristics of populations importing infections and their patterns of migration, improved methods to reliably classify infections as imported or acquired locally, and ensure early and accurate diagnosis. The potential for onward transmission in the most receptive and vulnerable locations can be predicted through high-resolution risk mapping that can help malaria elimination or prevention of reintroduction programs target resources. Cross border and regional initiatives can be highly effective when based on an understanding of human and parasite movement. Ultimately, determining the optimal combinations of approaches to address malaria importation will require an evaluation of their impact, cost effectiveness, and operational feasibility. PMID:26013369

  15. Malaria vaccines: identifying Plasmodium falciparum liver-stage targets

    PubMed Central

    Longley, Rhea J.; Hill, Adrian V. S.; Spencer, Alexandra J.

    2015-01-01

    The development of a highly efficacious and durable vaccine for malaria remains a top priority for global health researchers. Despite the huge rise in recognition of malaria as a global health problem and the concurrent rise in funding over the past 10–15 years, malaria continues to remain a widespread burden. The evidence of increasing resistance to anti-malarial drugs and insecticides is a growing concern. Hence, an efficacious and durable preventative vaccine for malaria is urgently needed. Vaccines are one of the most cost-effective tools and have successfully been used in the prevention and control of many diseases, however, the development of a vaccine for the Plasmodium parasite has proved difficult. Given the early success of whole sporozoite mosquito-bite delivered vaccination strategies, we know that a vaccine for malaria is an achievable goal, with sub-unit vaccines holding great promise as they are simple and cheap to both manufacture and deploy. However a major difficulty in development of sub-unit vaccines lies within choosing the appropriate antigenic target from the 5000 or so genes expressed by the parasite. Given the liver-stage of malaria represents a bottle-neck in the parasite’s life cycle, there is widespread agreement that a multi-component sub-unit malaria vaccine should preferably contain a liver-stage target. In this article we review progress in identifying and screening Plasmodium falciparum liver-stage targets for use in a malaria vaccine. PMID:26441899

  16. Treating severe malaria in pregnancy: a review of the evidence.

    PubMed

    Kovacs, Stephanie D; Rijken, Marcus J; Stergachis, Andy

    2015-02-01

    Severe malaria in pregnancy is a large contributor to maternal morbidity and mortality. Intravenous quinine has traditionally been the treatment drug of choice for severe malaria in pregnancy. However, recent randomized clinical trials (RCTs) indicate that intravenous artesunate is more efficacious for treating severe malaria, resulting in changes to the World Health Organization (WHO) treatment guidelines. Artemisinins, including artesunate, are embryo-lethal in animal studies and there is limited experience with their use in the first trimester. This review summarizes the current literature supporting 2010 WHO treatment guidelines for severe malaria in pregnancy and the efficacy, pharmacokinetics, and adverse event data for currently used antimalarials available for severe malaria in pregnancy. We identified ten studies on the treatment of severe malaria in pregnancy that reported clinical outcomes. In two studies comparing intravenous quinine with intravenous artesunate, intravenous artesunate was more efficacious and safe for use in pregnant women. No studies detected an increased risk of miscarriage, stillbirth, or congenital anomalies associated with first trimester exposure to artesunate. Although the WHO recommends using either quinine or artesunate for the treatment of severe malaria in first trimester pregnancies, our findings suggest that artesunate should be the preferred treatment option for severe malaria in all trimesters. PMID:25556421

  17. Does malaria epidemiology project Cameroon as 'Africa in miniature'?

    PubMed

    Mbenda, Huguette Gaelle Ngassa; Awasthi, Gauri; Singh, Poonam K; Gouado, Inocent; Das, Aparup

    2014-09-01

    Cameroon, a west-central African country with a ~ 20 million population, is commonly regarded as 'Africa in miniature' due to the extensive biological and cultural diversities of whole Africa being present in a single-country setting. This country is inhabited by ancestral human lineages in unique eco-climatic conditions and diverse topography. Over 90 percent Cameroonians are at risk of malaria infection, and ~ 41 percent have at least one episode of malaria each year. Historically, the rate of malaria infection in Cameroon has fluctuated over the years; the number of cases was about 2 million in 2010 and 2011. The Cameroonian malaria control programme faces an uphill task due to high prevalence of multidrug-resistant parasites and insecticide-resistant malaria vectors. Above all, continued human migration from the rural to urban areas as well as population exchange with adjoining countries, high rate of ecological instabilities caused by deforestation, poor housing, lack of proper sanitation and drainage system might have resulted in the recent increase in incidences of malaria and other vector-borne diseases in Cameroon. The available data on eco-environmental variability and intricate malaria epidemiology in Cameroon reflect the situation in the whole of Africa, and warrant the need for in-depth study by using modern surveillance tools for meaningful basic understanding of the malaria triangle (host-parasite-vector-environment). PMID:25116627

  18. DDT, global strategies, and a malaria control crisis in South America.

    PubMed Central

    Roberts, D. R.; Laughlin, L. L.; Hsheih, P.; Legters, L. J.

    1997-01-01

    Malaria is reemerging in endemic-disease countries of South America. We examined the rate of real growth in annual parasite indexes (API) by adjusting APIs for all years to the annual blood examination rate of 1965 for each country. The standardized APIs calculated for Brazil, Peru, Guyana, and for 18 other malaria-endemic countries of the Americas presented a consistent pattern of low rates up through the late 1970s, followed by geometric growth in malaria incidence in subsequent years. True growth in malaria incidence corresponds temporally with changes in global strategies for malaria control. Underlying the concordance of these events is a causal link between decreased spraying of homes with DDT and increased malaria; two regression models defining this link showed statistically significant negative relationships between APIs and house-spray rates. Separate analyses of data from 1993 to 1995 showed that countries that have recently discontinued their spray programs are reporting large increases in malaria incidence. Ecuador, which has increased use of DDT since 1993, is the only country reporting a large reduction (61%) in malaria rates since 1993. DDT use for malaria control and application of the Global Malaria Control Strategy to the Americas should be subjects of urgent national and international debate. We discuss the recent actions to ban DDT, the health costs of such a ban, perspectives on DDT use in agriculture versus malaria control, and costs versus benefits of DDT and alternative insecticides. PMID:9284373

  19. Oral iron supplements for children in malaria-endemic areas

    PubMed Central

    Neuberger, Ami; Okebe, Joseph; Yahav, Dafna; Paul, Mical

    2016-01-01

    Background Iron-deficiency anaemia is common during childhood. Iron administration has been claimed to increase the risk of malaria. Objectives To evaluate the effects and safety of iron supplementation, with or without folic acid, in children living in areas with hyperendemic or holoendemic malaria transmission. Search methods We searched the Cochrane Infectious Diseases Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL), published in the Cochrane Library, MEDLINE (up to August 2015) and LILACS (up to February 2015). We also checked the metaRegister of Controlled Trials (mRCT) and World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) up to February 2015. We contacted the primary investigators of all included trials, ongoing trials, and those awaiting assessment to ask for unpublished data and further trials. We scanned references of included trials, pertinent reviews, and previous meta-analyses for additional references. Selection criteria We included individually randomized controlled trials (RCTs) and cluster RCTs conducted in hyperendemic and holoendemic malaria regions or that reported on any malaria-related outcomes that included children younger than 18 years of age. We included trials that compared orally administered iron, iron with folic acid, and iron with antimalarial treatment versus placebo or no treatment. We included trials of iron supplementation or fortification interventions if they provided at least 80% of the Recommended Dietary Allowance (RDA) for prevention of anaemia by age. Antihelminthics could be administered to either group, and micronutrients had to be administered equally to both groups. Data collection and analysis The primary outcomes were clinical malaria, severe malaria, and death from any cause. We assessed the risk of bias in included trials with domain-based evaluation and assessed the quality of the evidence using the Grading of Recommendations Assessment

  20. Costs of Eliminating Malaria and the Impact of the Global Fund in 34 Countries

    PubMed Central

    Zelman, Brittany; Kiszewski, Anthony; Cotter, Chris; Liu, Jenny

    2014-01-01

    Background International financing for malaria increased more than 18-fold between 2000 and 2011; the largest source came from The Global Fund to Fight AIDS, Tuberculosis and Malaria (Global Fund). Countries have made substantial progress, but achieving elimination requires sustained finances to interrupt transmission and prevent reintroduction. Since 2011, global financing for malaria has declined, fueling concerns that further progress will be impeded, especially for current malaria-eliminating countries that may face resurgent malaria if programs are disrupted. Objectives This study aims to 1) assess past total and Global Fund funding to the 34 current malaria-eliminating countries, and 2) estimate their future funding needs to achieve malaria elimination and prevent reintroduction through 2030. Methods Historical funding is assessed against trends in country-level malaria annual parasite incidences (APIs) and income per capita. Following Kizewski et al. (2007), program costs to eliminate malaria and prevent reintroduction through 2030 are estimated using a deterministic model. The cost parameters are tailored to a package of interventions aimed at malaria elimination and prevention of reintroduction. Results The majority of Global Fund-supported countries experiencing increases in total funding from 2005 to 2010 coincided with reductions in malaria APIs and also overall GNI per capita average annual growth. The total amount of projected funding needed for the current malaria-eliminating countries to achieve elimination and prevent reintroduction through 2030 is approximately US$8.5 billion, or about $1.84 per person at risk per year (PPY) (ranging from $2.51 PPY in 2014 to $1.43 PPY in 2030). Conclusions Although external donor funding, particularly from the Global Fund, has been key for many malaria-eliminating countries, sustained and sufficient financing is critical for furthering global malaria elimination. Projected cost estimates for elimination provide

  1. Gel-Bead Delivery of Eimeria Oocysts Protects Chickens Against Coccidiosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vaccines composed of either virulent or attenuated Eimeria spp. oocysts have been developed as an alternative to medication of feed with ionophore drugs or synthetic chemicals. The purpose of this study was to evaluate the use of gel beads containing a mixture of E. acervulina, E. maxima, and E. te...

  2. Detection of Toxoplasma gondii oocysts in water sample concentrates by real-time PCR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    PCR techniques in combination with conventional parasite concentration procedures have potential for sensitive and specific detection of Toxoplasma gondii oocysts in water. Three real-time PCR assays based on the B1 gene and a 529-bp repetitive element were compared for detection of T. gondii tachyz...

  3. TOXOPLASMA GONDII : UPTAKE AND SURVIVAL OF OOCYSTS IN FREE-LIVING AMOEBAE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Waterborne transmission of the oocyst stage of Toxoplasma gondii can cause outbreaks of clinical toxoplasmosis in humans and infection of marine mammals. In water-related environments and soil, free-living amoebae are considered potential carriers of various pathogens, but knowledge on interactions ...

  4. Prevalence and risk factors associated with Cryptosporidium oocysts shedding in pigs in Central Vietnam.

    PubMed

    Nguyen, Sam Thi; Honma, Hajime; Geurden, Thomas; Ikarash, Makoto; Fukuda, Yasuhiro; Huynh, Vu Vy; Nguyen, Duc Tan; Nakai, Yutaka

    2012-10-01

    We investigated the prevalence and risk factors associated with Cryptosporidium oocysts shedding in pigs in Central Vietnam. A total of 740 single fecal samples collected from diarrheic and non-diarrheic pigs on 89 farms were screened by the modified Ziehl-Neelsen staining method. Prevalence at the animal and the farm levels were 18.1% (134/740) and 71.9% (64/89), respectively. Risk factors for the infection were identified using univariate and multivariate logistic regression analysis. The results revealed that age, sanitary condition and topography were significantly associated with oocyst shedding (P<0.05). Pre-weaned piglets were at the highest risk for infection, followed by post-weaners, sows and finishing pigs. Good sanitary conditions showed positive effects in decreasing oocysts shedding. Topographically, Cryptosporidium was more common in mountainous zone than that in coastal delta zone. There was an association between the occurrence of diarrhea and the level of Cryptosporidium oocyst excretion within infected pigs. This is the first epidemiological investigation of prevalence and risk factors of Cryptosporidium in pigs in Vietnam. PMID:22342125

  5. Application of gel-bead technology for delivering Eimeria oocysts to day-old broilers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current methods of preventing outbreaks of avian coccidiosis involve medication of feed with ionophore drugs or synthetic chemicals or by vaccination of chicks with low doses of Eimeria oocysts in ovo or by spray vaccination just after hatch. Our data indicates that the uniformity and efficiency of...

  6. APPLICATION OF RAMAN SPECTROSCOPY TO ANALYSE THE CRYPTOSPORIDIUM PARVUM OOCYST WALL AND SUTURE CONSTITUENTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The protozoan parasite Cryptosporidium parvum, associated with diarrheal disease in humans, livestock, companion animals, and wildlife, infects drinking water. Fecal contamination is the ultimate source of the oocyst, found in surface waters throughout the United States. The parasite has so far sho...

  7. Non-invasive methods for identifyig oocysts of Sarcocystis spp. from definitive hosts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Because the excreted sporocysts of various species of Sarcocystis may not be discriminated morphologically, we sought to validate a diagnostic technique based on variation in the 18S rDNA sequence. Oocysts of Sarcocystis hominis, Sarcocystis fusiformis and Sarcocystis cruzi were collected from the f...

  8. Cryptosporidium Propidium Monoazide-PCR, a Molecular Biology-Based Technique for Genotyping Viable Cryptosporidium Oocysts

    EPA Science Inventory

    Cryptosporidium is an important waterborne protozoan parasite that can cause severe diarrhea and death in the immunocompromised. Current methods to monitor for Cryptosporidium oocysts in water are microscopy-based USEPA Methods 1622 and 1623. These methods assess total levels o...

  9. Human pathogenic Cryptosporidium species bioanalytical detection method with single oocyst detection capability.

    PubMed

    Connelly, John T; Nugen, Sam R; Borejsza-Wysocki, Wlodek; Durst, Richard A; Montagna, Richard A; Baeumner, Antje J

    2008-05-01

    A bioanalytical detection method for specific detection of viable human pathogenic Cryptosporidium species, C. parvum, C. hominis, and C. meleagridis is described. Oocysts were isolated from water samples via immunomagnetic separation, and mRNA was extracted with oligo-dT magnetic beads, amplified using nucleic acid sequence-based amplification (NASBA), and then detected in a nucleic acid hybridization lateral flow assay. The amplified target sequence employed was hsp70 mRNA, production of which is stimulated via a brief heat shock. The described method was capable of detecting one oocyst in 10 μL using flow-cytometer-counted samples. Only viable oocysts were detected, as confirmed using 4',6-diamidino-2-phenylindole and propidium iodide (DAPI/PI) staining. The detection system was challenged by detecting oocysts in the presence of large numbers of common waterborne microorganisms and packed pellet material filtered from environmental water samples. When the method was compared with EPA Method 1622 for C. parvum detection, highly comparable results were obtained. Since the described detection system yields unambiguous results within 4.5 h, it is an ideal method for monitoring the safety of drinking water. PMID:18311563

  10. Giardia cysts and Cryptosporidium oocysts in membrane-filtered municipal wastewater used for irrigation.

    PubMed

    Lonigro, A; Pollice, A; Spinelli, R; Berrilli, F; Di Cave, D; D'Orazi, C; Cavallo, P; Brandonisio, O

    2006-12-01

    A wastewater tertiary treatment system based on membrane ultrafiltration and fed with secondary-treated municipal wastewater was evaluated for its Giardia cyst and Cryptosporidium oocyst removal efficiency. Giardia duodenalis (assemblages A and B) and Cryptosporidium parvum were identified in feed water but were found in filtered water only during occasional failure of the filtration system. PMID:17056696

  11. The effects of nitric oxide donors on the sporulation of Eimeria tenella oocysts.

    PubMed

    Li, J G; Liu, Z P; Tao, J P

    2008-07-01

    Nitric oxide (NO) is involved in many physiological processes including regulation of blood pressure, immune response, and neural communication. The effects of NO donors on the sporogony of Eimeria tenella oocysts and the blocking effects of NO scavenger, hemoglobin (Hb), against NO donors were investigated in this study. The results showed that the sporulation of oocysts could be completely inhibited by acidic sodium nitrite (NaNO2), S-nitroso-glutathione (GSNO) or S-nitroso-N-acetyl-dl-penicillamine (SNAP) in profound dose-dependent and time-dependent manners, and the inhibiting process was irreversible and not affected by feces of chickens. However, not all NO donors in this study, such as sodium nitroprusside (SNP), demonstrated above-mentioned effect. The NO scavenger Hb could significantly prevent the detrimental effects of NO donors on the sporogony of oocysts in a dose-dependent manner. At present, the inhibiting mechanism of NO donors on the sporulation of oocysts was still unclear. PMID:18472220

  12. Gamma irradiation of Cryptosporidium parvum oocysts affects intracelluar levels of the viral symbiont CPV

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous studies have shown a dose-dependent effect of gamma irradiation on Cryptosporidium parvum development in neonatal mice and newborn calves. In mice, C. parvum oocysts exposed to 200 Gy showed nearly complete inability to develop as measured by C. parvum-specific quantitative PCR of ileal ti...

  13. BLIND TRIALS EVALUATING IN VITRO INFECTIVITY OF CRYPTOSPORIDIUM PARVUM OOCYSTS USING CELL CULTURE IMMUNOFLUORESCENCE

    EPA Science Inventory

    An optimized cell culture-immunofluorescence (IFA) procedure, using the HCT-8 cell line, was evaluated in 'blind' trials to determine the sensitivity and reproducibility for measuring infectivity of flow cytometry prepared inocula of C. parvum oocysts. In separate trials, suspens...

  14. Assessment of Methods for Detection of Infectious Cryptosporidium Oocysts and Giardia Cysts in Reclaimed Effluents

    PubMed Central

    Quintero-Betancourt, W.; Gennaccaro, A. L.; Scott, T. M.; Rose, J. B.

    2003-01-01

    This study evaluates the occurrence of Cryptosporidium oocysts and Giardia cysts in reclaimed effluents if method 1623 with the Envirochek capsule filters (standard and high-volume [HV] filters) and a modified version of the Information Collection Rule method (ICR) with the polypropylene yarn-wound cartridge filter are used. The recovery efficiency of the analytical methods was evaluated with samples of reagent, tap, and reclaimed water by using flow cytometer-sorted spike suspensions. (Oo)cyst recovery efficiency determined filter performance and method reproducibility in the water matrix tested. Method 1623 with the Envirochek HV capsule filter generated significantly higher recovery rates than did the standard Envirochek filter and the modified ICR method. Notwithstanding, large variations in recovery rates (>80%) occurred with samples of reclaimed water, and none of the water quality parameters analyzed in the reclaimed effluents could explain such variability. The highest concentrations of indigenous oocysts were detected by method 1623 with the HV filter, which provided a sufficient number of oocysts for further confirmation of infectious potential. Confirmation of species and potential infectivity for all positive protozoan samples was made by using a nested PCR restriction fragment polymorphism assay and the focus detection method most-probable-number assay, respectively. The methodology and results described in the present investigation provide useful information for the establishment of pathogen numeric standards for reclaimed effluents used for unrestricted irrigation. PMID:12957926

  15. Evaluating the transport of bacillus spores as a potential surrogate for Cryptosporidium parvum Oocysts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USEPA has recommended the use of aerobic spores as an indicator for Cryptosporidium oocysts when determining groundwater under the direct influence of surface water. Surface properties, interaction energies, transport, retention, and release behavior of B. subtilis spores were measured over a r...

  16. MOLECULAR DETECTION OF CRYPTOSPORIDIUM OOCYSTS IN WATER: THE CHALLENGE AND PROMISE

    EPA Science Inventory

    Because of the presence of host-adapted Cryptosporidium species and genotypes, molecular tools can help assess the source and hazardous potential of Cryptosporidium oocysts in water. The development and use of molecular tools in the analysis of environmental samples have gone tho...

  17. SEROLOGICAL EVALUATION OF CRYPTOSPORIDIUM OOCYSTS FINDINGS IN THE WATER SUPPLY OF SYDNEY, AUSTRALIA

    EPA Science Inventory

    From July to September, 1998, high levels of Cryptospordium oocysts and Giardia cysts were detected in Sydney, Australia drinking water. To evaluate whether Sydney residents had an elevated risk of infection, serological responses to two Cryptospordium antigen groups (15/17 - an...

  18. Coupled Factors Influencing the Transport and Retention of Cryptosporidium Parvum Oocysts in Saturated Porous Media

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The coupled role of solution ionic strength (IS), system hydrodynamics and pore structure on the transport and retention of viable Cryptosporidium parvum oocyst was investigated via batch, packed-bed column, and micromodel systems. The experiments were conducted over a wide range of IS (0.1-100 mM)...

  19. Infectivity of Cryptosporidium parvum oocysts after storage of experimentally contaminated apples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irrigation water has been associated with contamination of fresh fruits and vegetables with pathogenic microorganisms infectious for humans. The objective of the present study was to experimentally determine if apples contaminated with waterborne oocysts of Cryptosporidium might represent a food saf...

  20. COMPARISON OF TWO METHODS FOR DETECTION OF GIARDIA CYSTS AND CRYTOSPORIDIUM OOCYSTS IN WATER

    EPA Science Inventory

    The steps of two immunofluorescent-antibody-based detection methods were evaluated for their efficiencies in detecting Giardia cysts and Cryptosporidium oocysts. The two methods evaluated were the American Society for Testing and Materials proposed test method for Giardia cysts a...

  1. A sticky situation: the unexpected stability of malaria elimination

    PubMed Central

    Smith, David L.; Cohen, Justin M.; Chiyaka, Christinah; Johnston, Geoffrey; Gething, Peter W.; Gosling, Roly; Buckee, Caroline O.; Laxminarayan, Ramanan; Hay, Simon I.; Tatem, Andrew J.

    2013-01-01

    Malaria eradication involves eliminating malaria from every country where transmission occurs. Current theory suggests that the post-elimination challenges of remaining malaria-free by stopping transmission from imported malaria will have onerous operational and financial requirements. Although resurgent malaria has occurred in a majority of countries that tried but failed to eliminate malaria, a review of resurgence in countries that successfully eliminated finds only four such failures out of 50 successful programmes. Data documenting malaria importation and onwards transmission in these countries suggests malaria transmission potential has declined by more than 50-fold (i.e. more than 98%) since before elimination. These outcomes suggest that elimination is a surprisingly stable state. Elimination's ‘stickiness’ must be explained either by eliminating countries starting off qualitatively different from non-eliminating countries or becoming different once elimination was achieved. Countries that successfully eliminated were wealthier and had lower baseline endemicity than those that were unsuccessful, but our analysis shows that those same variables were at best incomplete predictors of the patterns of resurgence. Stability is reinforced by the loss of immunity to disease and by the health system's increasing capacity to control malaria transmission after elimination through routine treatment of cases with antimalarial drugs supplemented by malaria outbreak control. Human travel patterns reinforce these patterns; as malaria recedes, fewer people carry malaria from remote endemic areas to remote areas where transmission potential remains high. Establishment of an international resource with backup capacity to control large outbreaks can make elimination stickier, increase the incentives for countries to eliminate, and ensure steady progress towards global eradication. Although available evidence supports malaria elimination's stickiness at moderate

  2. Aquatic biomonitoring of Giardia cysts and Cryptosporidium oocysts in peninsular Malaysia.

    PubMed

    Lee, Soo Ching; Ngui, Romano; Tan, Tiong Kai; Roslan, Muhammad Aidil; Ithoi, Init; Lim, Yvonne A L

    2014-01-01

    An aquatic biomonitoring of Giardia cysts and Cryptosporidium oocysts in river water corresponding to five villages situated in three states in peninsular Malaysia was determined. There were 51.3% (20/39) and 23.1% (9/39) samples positive for Giardia and Cryptosporidium (oo)cysts, respectively. Overall mean concentration between villages for Giardia cysts ranged from 0.10 to 25.80 cysts/l whilst Cryptosporidium oocysts ranged from 0.10 to 0.90 oocysts/l. Detailed results of the river samples from five villages indicated that Kuala Pangsun 100% (9/9), Kemensah 77.8% (7/9), Pos Piah 33.3% (3/9) and Paya Lebar 33.3% (1/3) were contaminated with Giardia cysts whilst Cryptosporidium (oo)cysts were only detected in Kemensah (100 %; 9/9) and Kuala Pangsun (66.6%; 6/9). However, the water samples from Bentong were all negative for these waterborne parasites. Samples were collected from lower point, midpoint and upper point. Midpoint refers to the section of the river where the studied communities are highly populated. Meanwhile, the position of the lower point is at least 2 km southward of the midpoint and upper point is at least 2 km northward of the midpoint. The highest mean concentration for (oo)cysts was found at the lower points [3.15 ± 6.09 (oo)cysts/l], followed by midpoints [0.66 ± 1.10 (oo)cysts/l] and upper points [0.66 ± 0.92 (oo)cysts/l]. The mean concentration of Giardia cysts was highest at Kuala Pangsun (i.e. 5.97 ± 7.0 cysts/l), followed by Kemensah (0.83 ± 0.81 cysts/l), Pos Piah (0.20 ± 0.35 cysts/l) and Paya Lebar (0.10 ± 0.19 cysts/l). On the other hand, the mean concentration of Cryptosporidium oocysts was higher at Kemensah (0.31 ± 0.19 cysts/l) compared to Kuala Pangsun (0.03 ± 0.03cysts/l). All the physical and chemical parameters did not show significant correlation with both protozoa. In future, viability status and molecular characterisation of Giardia and Cryptosporidium should be applied to identify

  3. Tools and Strategies for Malaria Control and Elimination: What Do We Need to Achieve a Grand Convergence in Malaria?

    PubMed Central

    Hemingway, Janet; Shretta, Rima; Wells, Timothy N. C.; Bell, David; Djimdé, Abdoulaye A.; Achee, Nicole; Qi, Gao

    2016-01-01

    Progress made in malaria control during the past decade has prompted increasing global dialogue on malaria elimination and eradication. The product development pipeline for malaria has never been stronger, with promising new tools to detect, treat, and prevent malaria, including innovative diagnostics, medicines, vaccines, vector control products, and improved mechanisms for surveillance and response. There are at least 25 projects in the global malaria vaccine pipeline, as well as 47 medicines and 13 vector control products. In addition, there are several next-generation diagnostic tools and reference methods currently in development, with many expected to be introduced in the next decade. The development and adoption of these tools, bolstered by strategies that ensure rapid uptake in target populations, intensified mechanisms for information management, surveillance, and response, and continued financial and political commitment are all essential to achieving global eradication. PMID:26934361

  4. Tools and Strategies for Malaria Control and Elimination: What Do We Need to Achieve a Grand Convergence in Malaria?

    PubMed

    Hemingway, Janet; Shretta, Rima; Wells, Timothy N C; Bell, David; Djimdé, Abdoulaye A; Achee, Nicole; Qi, Gao

    2016-03-01

    Progress made in malaria control during the past decade has prompted increasing global dialogue on malaria elimination and eradication. The product development pipeline for malaria has never been stronger, with promising new tools to detect, treat, and prevent malaria, including innovative diagnostics, medicines, vaccines, vector control products, and improved mechanisms for surveillance and response. There are at least 25 projects in the global malaria vaccine pipeline, as well as 47 medicines and 13 vector control products. In addition, there are several next-generation diagnostic tools and reference methods currently in development, with many expected to be introduced in the next decade. The development and adoption of these tools, bolstered by strategies that ensure rapid uptake in target populations, intensified mechanisms for information management, surveillance, and response, and continued financial and political commitment are all essential to achieving global eradication. PMID:26934361

  5. The Effect of the Anionic Surfactant Aerosol-80 on the Transport of Cryptosporidium parvum Oocysts through Soil

    NASA Astrophysics Data System (ADS)

    Jacobson, A. R.; Powelson, D.; Darnault, C.

    2012-12-01

    Transport of the pathogenic protozoan Cryptosporidium parvum through soils threatens ground and surface waters. C. parvum may be introduced into soils in the manure of infected calves. The presence of other chemicals in the soil applied as or with amendments, may affect the transport of the C. parvum oocysts. Surfactants, which are used in many herbicide formulations, decrease water tension and may disrupt the air-water interface where oocysts are thought to accumulate. We investigate the effect of the anionic surfactant Aerosol-80, at two concentrations, on the transport of C. parvum oocysts by unsaturated flow through "undisturbed" soil columns from Illinois and Utah. Following each experiment oocysts in the leachate and distributed throughout the soil profile are quantified by real time PCR. We find that the presence of the surfactant accelerates the transport of the oocysts through preferential flow paths. On the other hand, when connected macropores are not present in the soils, the presence of the surfactant retards the transport of the oocysts through the soil matrix by straining oocyst-surfactant-Ca flocs. Surfactant efficacy is affected by soil type.

  6. Influence of ionic strength and soil characteristics on the behavior of Cryptosporidium oocysts in saturated porous media.

    PubMed

    Balthazard-Accou, Ketty; Fifi, Urbain; Agnamey, Patrice; Casimir, Justin André; Brasseur, Philippe; Emmanuel, Evens

    2014-05-01

    The physico-chemical behavior of Cryptosporidium oocysts was investigated during their transfer through an alluvial formation from Les Cayes (Haiti) via batch tests. Five approximately 3 kg soil samples were collected and combined prior to batch tests from the alluvial formations. The experiments were carried out at soil pH by equilibrating different ranges of pure oocysts concentrations and soil samples with 3mM CaCl2 and 1mM NaBr as electrolyte. We used the Debye-Hückel equation describing ion activity in a solution for a given ionic strength. The equilibrium adsorption mechanism is used to enumerate the oocysts in the soil. The results suggest that the oocysts behavior in porous media depends on soil characteristics such as soil pH, the nature of the mineral and organic constituents of the soil and the ionic strength and activities in solution. These results show that a total transfer in batch containing NaBr solutions against a partial one in batch containing CaCl2 solutions depends on the oocysts media concentration. To confirm the oocysts number retained in soil, confocal microscopy was successfully used and the images demonstrate that the majority of oocysts were retained at the range of concentrations tested. The findings from this study demonstrated that the retention of C. Parvum in soils may be influenced by chemical conditions and soils characteristics, which are important for groundwater risk assessment. PMID:24359923

  7. Malaria in the United Kingdom

    PubMed Central

    Bruce-Chwatt, L. J.; Southgate, B. A.; Draper, C. C.

    1974-01-01

    Over the past decade the United Kingdom had the second highest number of cases of imported malaria among European countries. There has been a substantial rise in recorded cases of malaria during the past three years though some of it may be due to improved notification. Fatal cases of malaria in visitors to Africa have averaged 6.5% of reported infections due to Plasmodium falciparum. Attacks of vivax malaria may occur several months after travellers return from a malarious country. PMID:4604717

  8. Unrecognized Ingestion of Toxoplasma gondii Oocysts Leads to Congenital Toxoplasmosis and Causes Epidemics in North America

    PubMed Central

    Boyer, Kenneth; Hill, Dolores; Mui, Ernest; Wroblewski, Kristen; Karrison, Theodore; Dubey, J. P.; Sautter, Mari; Noble, A. Gwendolyn; Withers, Shawn; Swisher, Charles; Heydemann, Peter; Hosten, Tiffany; Babiarz, Jane; Lee, Daniel

    2011-01-01

    (See the Editorial Commentary by Linn, on pages 1090–1.) Background. Congenital toxoplasmosis presents as severe, life-altering disease in North America. If mothers of infants with congenital toxoplasmosis could be identified by risks, it would provide strong support for educating pregnant women about risks, to eliminate this disease. Conversely, if not all risks are identifiable, undetectable risks are suggested. A new test detecting antibodies to sporozoites demonstrated that oocysts were the predominant source of Toxoplasma gondii infection in 4 North American epidemics and in mothers of children in the National Collaborative Chicago-based Congenital Toxoplasmosis Study (NCCCTS). This novel test offered the opportunity to determine whether risk factors or demographic characteristics could identify mothers infected with oocysts. Methods. Acutely infected mothers and their congenitally infected infants were evaluated, including in-person interviews concerning risks and evaluation of perinatal maternal serum samples. Results. Fifty-nine (78%) of 76 mothers of congenitally infected infants in NCCCTS had primary infection with oocysts. Only 49% of these mothers identified significant risk factors for sporozoite acquisition. Socioeconomic status, hometown size, maternal clinical presentations, and ethnicity were not reliable predictors. Conclusions. Undetected contamination of food and water by oocysts frequently causes human infections in North America. Risks are often unrecognized by those infected. Demographic characteristics did not identify oocyst infections. Thus, although education programs describing hygienic measures may be beneficial, they will not suffice to prevent the suffering and economic consequences associated with congenital toxoplasmosis. Only a vaccine or implementation of systematic serologic testing of pregnant women and newborns, followed by treatment, will prevent most congenital toxoplasmosis in North America. PMID:22021924

  9. Evidence for mucin-like glycoproteins that tether sporozoites of Cryptosporidium parvum to the inner surface of the oocyst wall.

    PubMed

    Chatterjee, Anirban; Banerjee, Sulagna; Steffen, Martin; O'Connor, Roberta M; Ward, Honorine D; Robbins, Phillips W; Samuelson, John

    2010-01-01

    Cryptosporidium parvum oocysts, which are spread by the fecal-oral route, have a single, multilayered wall that surrounds four sporozoites, the invasive form. The C. parvum oocyst wall is labeled by the Maclura pomifera agglutinin (MPA), which binds GalNAc, and the C. parvum wall contains at least two unique proteins (Cryptosporidium oocyst wall protein 1 [COWP1] and COWP8) identified by monoclonal antibodies. C. parvum sporozoites have on their surface multiple mucin-like glycoproteins with Ser- and Thr-rich repeats (e.g., gp40 and gp900). Here we used ruthenium red staining and electron microscopy to demonstrate fibrils, which appear to attach or tether sporozoites to the inner surface of the C. parvum oocyst wall. When disconnected from the sporozoites, some of these fibrillar tethers appear to collapse into globules on the inner surface of oocyst walls. The most abundant proteins of purified oocyst walls, which are missing the tethers and outer veil, were COWP1, COWP6, and COWP8, while COWP2, COWP3, and COWP4 were present in trace amounts. In contrast, MPA affinity-purified glycoproteins from C. parvum oocysts, which are composed of walls and sporozoites, included previously identified mucin-like glycoproteins, a GalNAc-binding lectin, a Ser protease inhibitor, and several novel glycoproteins (C. parvum MPA affinity-purified glycoprotein 1 [CpMPA1] to CpMPA4). By immunoelectron microscopy (immuno-EM), we localized mucin-like glycoproteins (gp40 and gp900) to the ruthenium red-stained fibrils on the inner surface wall of oocysts, while antibodies to the O-linked GalNAc on glycoproteins were localized to the globules. These results suggest that mucin-like glycoproteins, which are associated with the sporozoite surface, may contribute to fibrils and/or globules that tether sporozoites to the inner surface of oocyst walls. PMID:19949049

  10. Vulnerability to changes in malaria transmission due to climate change in West Africa

    NASA Astrophysics Data System (ADS)

    Yamana, T. K.; Eltahir, E. A.

    2012-12-01

    Malaria transmission in West Africa is strongly tied to climate; temperature affects the development rate of the malaria parasite, as well as the survival of the mosquitoes that transmit the disease, and rainfall is tied to mosquito abundance, as the vector lays its eggs in rain-fed water pools. As a result, the environmental suitability for malaria transmission in this region is expected to change as temperatures rise and rainfall patterns are altered. The vulnerability to changes in transmission varies throughout West Africa. Areas where malaria prevalence is already very high will be less sensitive to changes in transmission. Increases in environmental suitability for malaria transmission in the most arid regions may still be insufficient to allow sustained transmission. However, areas were malaria transmission currently occurs at low levels are expected to be the most sensitive to changes in environmental suitability for transmission. Here, we use data on current environment and malaria transmission rates to highlight areas in West Africa that we expect to be most vulnerable to an increase in malaria under certain climate conditions. We then analyze climate predictions from global climate models in vulnerable areas, and make predictions for the expected change in environmental suitability for malaria transmission using the Hydrology, Entomology and Malaria Transmission Simulator (HYDREMATS), a mechanistic model developed to simulate village-scale response of malaria transmission to environmental variables in West Africa.

  11. [The malaria situation in the Russian Federation (1997-1999)].

    PubMed

    Baranova, A M; Sergiev, V P

    2000-01-01

    Profound socio-economic changes within the CIS countries in the 1990s brought a lot of negative changes in malaria prevention in targeted countries. The previously stable connection and cooperation in prophylactic activities have been interrupted. Supply of antimalarials, insecticides and equipment had been stopped. Many qualified cadres in the sanitary-epidemiological services in the countries were lost. Because of difficult economic situation they had to change their occupation and place of job. After prolonged period of a stable benign epidemiological situation within Russia the number of imported cases started to grow up. The sharp increase of imported malaria cases from Azerbaijan and Tajikistan had been noticed since 1994 (Tab. 1). For the first time in the history of malaria registration the number of cases imported from the CIS countries has been exceeded the number of malaria cases imported from all other countries in the world in 1995. Later in the end of the 1990s the imported malaria cases has been registered in Russia from some other CIS countries apart from Azerbaijan and Tajikistan. There were malaria cases imported from Armenia (13 cases), Moldavia (2), Turkmenistan (2), and Uzbekistan (2) in 1998. The number of imported malaria cases in Russia in 1999 (Jan-July) is 437. There is no information about introduced or indigenous malaria cases registered until now] within Russia. There were 13 introduced malaria cases as the result of numerous imported ones. 13 introduced cases have been registered in 10 oblasts (administrative regions of Russia). This number has been increased to 53 (!) in 1998 in 20 oblasts. There was one local outbreak of P. vivax malaria in Izberbash settlement (Dagestan). Number of indigenous malaria cases were 5 (1996), 18 (1997), 1 (1998). The contra-epidemic measures in Izberbash have included active cases detection and treatment indoor insecticide spaying and one tour of mass primaguine treatment during interseasonal period of

  12. Cost of malaria control in China: Henan's consolidation programme from community and government perspectives.

    PubMed Central

    Jackson, Sukhan; Sleigh, Adrian C.; Liu, Xi-Li

    2002-01-01

    OBJECTIVE: To assist with strategic planning for the eradication of malaria in Henan Province, China, which reached the consolidation phase of malaria control in 1992, when only 318 malaria cases were reported. METHODS: We conducted a prospective two-year study of the costs for Henan's malaria control programme. We used a cost model that could also be applied to other malaria programmes in mainland China, and analysed the cost of the three components of Henan's malaria programme: suspected malaria case management, vector surveillance, and population blood surveys. Primary cost data were collected from the government, and data on suspected malaria patients were collected in two malaria counties (population 2 093 100). We enlisted the help of 260 village doctors in six townships or former communes (population 247 762), and studied all 12 325 reported cases of suspected malaria in their catchment areas in 1994 and 1995. FINDINGS: The average annual government investment in malaria control was estimated to be US$ 111 516 (case-management 59%; active blood surveys 25%; vector surveillance 12%; and contingencies and special projects 4%). The average cost (direct and indirect) for patients seeking treatment for suspected malaria was US$ 3.48, equivalent to 10 days' income for rural residents. Each suspected malaria case cost the government an average of US$ 0.78. CONCLUSION: Further cuts in government funding will increase future costs when epidemic malaria returns; investment in malaria control should therefore continue at least at current levels of US$ 0.03 per person at risk. PMID:12219157

  13. Timing of Malaria Infection during Pregnancy Has Characteristic Maternal, Infant and Placental Outcomes

    PubMed Central

    Kalilani-Phiri, Linda; Thesing, Phillip C.; Nyirenda, Osward M.; Mawindo, Patricia; Madanitsa, Mwayi; Membe, Gladys; Wylie, Blair; Masonbrink, Abbey; Makwakwa, Kingsley; Kamiza, Steve; Muehlenbachs, Atis; Taylor, Terrie E.; Laufer, Miriam K.

    2013-01-01

    We conducted a clinical study of pregnant women in Blantyre, Malawi to determine the effect of the timing of malaria infection during pregnancy on maternal, infant and placental outcomes. Women were enrolled in their first or second trimester of their first or second pregnancy and followed every four weeks until delivery. Three doses of sulfadoxine-pyrimethamine were given for intermittent preventive treatment for malaria, and all episodes of parasitemia were treated according to the national guidelines. Placentas were collected at delivery and examined for malaria parasites and pigment by histology. Pregnant women had 0.6 episodes of malaria per person year of follow up. Almost all episodes of malaria were detected at enrollment and malaria infection during the follow up period was rare. Malaria and anemia at the first antenatal visit were independently associated with an increased risk of placental malaria detected at delivery. When all episodes of malaria were treated with effective antimalarial medication, only peripheral malaria infection at the time of delivery was associated with adverse maternal and infant outcomes. One quarter of the analyzed placentas had evidence of malaria infection. Placental histology was 78% sensitive and 89% specific for peripheral malaria infection during pregnancy. This study suggests that in this setting of high antifolate drug resistance, three doses of sulfadoxine-pyrimethamine maintain some efficacy in suppressing microscopically detectable parasitemia, although placental infection remains frequent. Even in this urban setting, a large proportion of women have malaria infection at the time of their first antenatal care visit. Interventions to control malaria early and aggressive case detection are required to limit the detrimental effects of pregnancy-associated malaria. PMID:24058614

  14. Roll back malaria update.

    PubMed

    1999-10-01

    This article presents the activities under WHO's Roll Back Malaria (RBM) program in Asia, particularly in Nepal, Indonesia, India, Bangladesh, Sri Lanka and the Philippines. In India, the RBM program will start in 5 districts with a major malaria problem. A national committee has been formed by researchers, which will be able to provide operational and strategic support and research expertise in relation to malaria. In Bangladesh, the RBM program was initiated in the sparsely populated hill tract areas of Banderban and Chittagong where access to health care is very poor. At the district level, effective partnerships with private practitioners, politicians, community leaders, school teachers, the press and district Ministry of Health officials are operating to plan for rolling back malaria. In Myanmar, Cambodia, Lao People's Democratic Republic, Yunnan province of China, Vietnam, and Thailand, the focus of the RBM program was to move health care closer to the malaria-infected communities. WHO¿s Global Health Leadership Fellowship Programme, supported by the UN Foundation and Rockefeller Foundation, enables potential leaders to experience the work of UN agencies and contribute to the work of the organization for 2 years. Three out of four persons appointed to the RBM program received prestigious awards: Dr. Paola Marchesini of Brazil; Dr. Tieman Diarra of Mali; and Dr. Bob Taylor of the UK. PMID:12295474

  15. Potential impact of global climate change on malaria risk

    SciTech Connect

    Martens, W.J.M.; Rotmans, J. |; Niessen, L.W.; Jetten, T.H.; McMichael, A.J.

    1995-05-01

    The biological activity and geographic distribution of the malarial parasite and its vector are sensitive to climatic influences, especially temperature and precipitation. We have incorporated General Circulation Model-based scenarios of anthropogenic global climate change in an integrated linked-system model for predicting changes in malaria epidemic potential in the next century. The concept of the disability-adjusted life years is included to arrive at a single measure of the effect of anthropogenic climate change on the health impact of malaria. Assessment of the potential impact of global climate change on the incidence of malaria suggests a widespread increase of risk due to expansion of the areas suitable for malaria transmission. This predicted increase is most pronounced at the borders of endemic malaria areas and at higher altitudes within malarial areas. The incidence of infection is sensitive to climate changes in areas of Southeast Asia, South America, and parts of Africa where the disease is less endemic; in these regions the numbers of years of healthy life lost may increase significantly. However, the simulated changes in malaria risk must be interpreted on the basis of local environmental conditions, the effects of socioeconomic developments, and malaria control programs or capabilities. 33 refs., 5 figs., 1 tab.

  16. Quantifying the impact of decay in bed-net efficacy on malaria transmission.

    PubMed

    Ngonghala, Calistus N; Del Valle, Sara Y; Zhao, Ruijun; Mohammed-Awel, Jemal

    2014-12-21

    Insecticide-treated nets (ITNs) are at the forefront of malaria control programs and even though the percentage of households in sub-Saharan Africa that owned nets increased from 3% in 2000 to 53% in 2012, many children continue to die from malaria. The potential impact of ITNs on reducing malaria transmission is limited due to inconsistent or improper use, as well as physical decay in effectiveness. Most mathematical models for malaria transmission have assumed a fixed effectiveness rate for bed-nets, which can overestimate the impact of nets on malaria control. We develop a model for malaria spread that captures the decrease in ITN effectiveness due to physical and chemical decay, as well as human behavior as a function of time. We perform uncertainty and sensitivity analyses to identify and rank parameters that play a critical role in malaria transmission. These analyses show that the basic reproduction number R0, and the infectious human population are most sensitive to bed-net coverage and the biting rate of mosquitoes. Our results show the existence of a backward bifurcation for the case in which ITN efficacy is constant over time, which occurs for some range of parameters and is characterized by high malaria mortality in humans. This result implies that bringing R0 to less than one is not enough for malaria elimination but rather additional efforts will be necessary to control the disease. For the case in which ITN efficacy decays over time, we determine coverage levels required to control malaria for different ITN efficacies and demonstrate that ITNs with longer useful lifespans perform better in malaria control. We conclude that malaria control programs should focus on increasing bed-net coverage, which can be achieved by enhancing malaria education and increasing bed-net distribution in malaria endemic regions. PMID:25158163

  17. Malaria paediatric hospitalization between 1999 and 2008 across Kenya

    PubMed Central

    2009-01-01

    Background Intervention coverage and funding for the control of malaria in Africa has increased in recent years, however, there are few descriptions of changing disease burden and the few reports available are from isolated, single site observations or are of reports at country-level. Here we present a nationwide assessment of changes over 10 years in paediatric malaria hospitalization across Kenya. Methods Paediatric admission data on malaria and non-malaria diagnoses were assembled for the period 1999 to 2008 from in-patient registers at 17 district hospitals in Kenya and represented the diverse malaria ecology of the country. These data were then analysed using autoregressive moving average time series models with malaria and all-cause admissions as the main outcomes adjusted for rainfall, changes in service use and populations-at-risk within each hospital's catchment to establish whether there has been a statistically significant decline in paediatric malaria hospitalization during the observation period. Results Among the 17 hospital sites, adjusted paediatric malaria admissions had significantly declined at 10 hospitals over 10 years since 1999; had significantly increased at four hospitals, and remained unchanged in three hospitals. The overall estimated average reduction in malaria admission rates was 0.0063 cases per 1,000 children aged 0 to 14 years per month representing an average percentage reduction of 49% across the 10 hospitals registering a significant decline by the end of 2008. Paediatric admissions for all-causes had declined significantly with a reduction in admission rates of greater than 0.0050 cases per 1,000 children aged 0 to 14 years per month at 6 of 17 hospitals. Where malaria admissions had increased three of the four sites were located in Western Kenya close to Lake Victoria. Conversely there was an indication that areas with the largest declines in malaria admission rates were areas located along the Kenyan coast and some sites in

  18. Estimating malaria burden in Nigeria: a geostatistical modelling approach.

    PubMed

    Onyiri, Nnadozie

    2015-01-01

    This study has produced a map of malaria prevalence in Nigeria based on available data from the Mapping Malaria Risk in Africa (MARA) database, including all malaria prevalence surveys in Nigeria that could be geolocated, as well as data collected during fieldwork in Nigeria between March and June 2007. Logistic regression was fitted to malaria prevalence to identify significant demographic (age) and environmental covariates in STATA. The following environmental covariates were included in the spatial model: the normalized difference vegetation index, the enhanced vegetation index, the leaf area index, the land surface temperature for day and night, land use/landcover (LULC), distance to water bodies, and rainfall. The spatial model created suggests that the two main environmental covariates correlating with malaria presence were land surface temperature for day and rainfall. It was also found that malaria prevalence increased with distance to water bodies up to 4 km. The malaria risk map estimated from the spatial model shows that malaria prevalence in Nigeria varies from 20% in certain areas to 70% in others. The highest prevalence rates were found in the Niger Delta states of Rivers and Bayelsa, the areas surrounding the confluence of the rivers Niger and Benue, and also isolated parts of the north-eastern and north-western parts of the country. Isolated patches of low malaria prevalence were found to be scattered around the country with northern Nigeria having more such areas than the rest of the country. Nigeria's belt of middle regions generally has malaria prevalence of 40% and above. PMID:26618305

  19. Potential Biomarkers and Their Applications for Rapid and Reliable Detection of Malaria

    PubMed Central

    Jain, Priyamvada; Chakma, Babina; Patra, Sanjukta; Goswami, Pranab

    2014-01-01

    Malaria has been responsible for the highest mortality in most malaria endemic countries. Even after decades of malaria control campaigns, it still persists as a disease of high mortality due to improper diagnosis and rapidly evolving drug resistant malarial parasites. For efficient and economical malaria management, WHO recommends that all malaria suspected patients should receive proper diagnosis before administering drugs. It is thus imperative to develop fast, economical, and accurate techniques for diagnosis of malaria. In this regard an in-depth knowledge on malaria biomarkers is important to identify an appropriate biorecognition element and utilize it prudently to develop a reliable detection technique for diagnosis of the disease. Among the various biomarkers, plasmodial lactate dehydrogenase and histidine-rich protein II (HRP II) have received increasing attention for developing rapid and reliable detection techniques for malaria. The widely used rapid detection tests (RDTs) for malaria succumb to many drawbacks which promotes exploration of more efficient economical detection techniques. This paper provides an overview on the current status of malaria biomarkers, along with their potential utilization for developing different malaria diagnostic techniques and advanced biosensors. PMID:24804253

  20. Association of temperature and historical dynamics of malaria in the Republic of Korea, including reemergence in 1993

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plasmodium vivax malaria reemerged in the Republic of Korea (ROK) in 1993 after it had been declared malaria free in 1979. Malaria rapidly increased and peaked in 2000 with 4,142 cases. Lower but variable numbers of cases were reported through 2011. We examined the association of regional climate tr...

  1. The potential effects of climate change on malaria in tropical Africa using regionalised climate projections

    NASA Astrophysics Data System (ADS)

    Ermert, V.; Fink, A. H.; Paeth, H.; Morse, A. P.

    2012-04-01

    The projected climate change will probably alter the range and transmission potential of malaria in Africa. The potential impacts of climate change on the malaria distribution is assessed for tropical Africa. Bias-corrected regional climate projections with a horizontal resolution of 0.5° are used from the Regional Model (REMO), which include land use and land cover changes. The malaria models employed are the 2010 version of the Liverpool Malaria Model (LMM2010), the Garki model, the Plasmodium falciparum infection model from Smith et al. (2005) (S2005), and the Malaria Seasonality Model (MSM) from the Mapping Malaria Risk in Africa project. The results of the models are compared with data from the Malaria Atlas Project (MAP) and novel validation procedures for the LMM2010 and MSM lend more credence to their results. For climate scenarios A1B and B1 and for 2001-2050, REMO projects an overall drying and warming trend in the African malaria belt, that is largely imposed by the man-made degradation of vegetation. As a result, the malaria projections show a decreased malaria spread in West Africa. The northern Sahel is no more suitable for malaria in the projections. More unstable malaria transmission and shorter malaria seasons are expected for various areas farther south. An increase in the malaria epidemic risk is found for more densely populated areas in the southern part of the Sahel. In East Africa, higher temperatures and nearly unchanged precipitation patterns lead to longer transmission seasons and an increase in the area of highland malaria. For altitudes up to 2000 m the malaria transmission stabilises and the epidemic risk is reduced but for higher altitudes the risk of malaria epidemics is increased. The results of the more complex and simple malaria models are similar to each other. However, a different response to the warming of highlands is found for the LMM2010 and MSM. This shows the requirement of a multi model uncertainty analysis for the

  2. Ecology and conservation biology of avian malaria.

    PubMed

    Lapointe, Dennis A; Atkinson, Carter T; Samuel, Michael D

    2012-02-01

    Avian malaria is a worldwide mosquito-borne disease caused by Plasmodium parasites. These parasites occur in many avian species but primarily affect passerine birds that have not evolved with the parasite. Host pathogenicity, fitness, and population impacts are poorly understood. In contrast to continental species, introduced avian malaria poses a substantial threat to naive birds on Hawaii, the Galapagos, and other archipelagoes. In Hawaii, transmission is maintained by susceptible native birds, competence and abundance of mosquitoes, and a disease reservoir of chronically infected native birds. Although vector habitat and avian communities determine the geographic distribution of disease, climate drives transmission patterns ranging from continuous high infection in warm lowland forests, seasonal infection in midelevation forests, and disease-free refugia in cool high-elevation forests. Global warming is expected to increase the occurrence, distribution, and intensity of avian malaria across this elevational gradient and threaten high-elevation refugia, which is the key to survival of many susceptible Hawaiian birds. Increased temperatures may have already increased global avian malaria prevalence and contributed to an emergence of disease in New Zealand. PMID:22320256

  3. Ecology and conservation biology of avian malaria

    USGS Publications Warehouse

    LaPointe, Dennis A.; Atkinson, Carter T.; Samuel, Michael D.

    2012-01-01

    Avian malaria is a worldwide mosquito-borne disease caused by Plasmodium parasites. These parasites occur in many avian species but primarily affect passerine birds that have not evolved with the parasite. Host pathogenicity, fitness, and population impacts are poorly understood. In contrast to continental species, introduced avian malaria poses a substantial threat to naive birds on Hawaii, the Galapagos, and other archipelagoes. In Hawaii, transmission is maintained by susceptible native birds, competence and abundance of mosquitoes, and a disease reservoir of chronically infected native birds. Although vector habitat and avian communities determine the geographic distribution of disease, climate drives transmission patterns ranging from continuous high infection in warm lowland forests, seasonal infection in midelevation forests, and disease-free refugia in cool high-elevation forests. Global warming is expected to increase the occurrence, distribution, and intensity of avian malaria across this elevational gradient and threaten high-elevation refugia, which is the key to survival of many susceptible Hawaiian birds. Increased temperatures may have already increased global avian malaria prevalence and contributed to an emergence of disease in New Zealand.

  4. Research toward Malaria Vaccines

    NASA Astrophysics Data System (ADS)

    Miller, Louis H.; Howard, Russell J.; Carter, Richard; Good, Michael F.; Nussenzweig, Victor; Nussenzweig, Ruth S.

    1986-12-01

    Malaria exacts a toll of disease to people in the Tropics that seems incomprehensible to those only familiar with medicine and human health in the developed world. The methods of molecular biology, immunology, and cell biology are now being used to develop an antimalarial vaccine. The Plasmodium parasites that cause malaria have many stages in their life cycle. Each stage is antigenically distinct and potentially could be interrupted by different vaccines. However, achieving complete protection by vaccination may require a better understanding of the complexities of B- and T-cell priming in natural infections and the development of an appropriate adjuvant for use in humans.

  5. Impact of climate change on global malaria distribution.

    PubMed

    Caminade, Cyril; Kovats, Sari; Rocklov, Joacim; Tompkins, Adrian M; Morse, Andrew P; Colón-González, Felipe J; Stenlund, Hans; Martens, Pim; Lloyd, Simon J

    2014-03-01

    Malaria is an important disease that has a global distribution and significant health burden. The spatial limits of its distribution and seasonal activity are sensitive to climate factors, as well as the local capacity to control the disease. Malaria is also one of the few health outcomes that has been modeled by more than one research group and can therefore facilitate the first model intercomparison for health impacts under a future with climate change. We used bias-corrected temperature and rainfall simulations from the Coupled Model Intercomparison Project Phase 5 climate models to compare the metrics of five statistical and dynamical malaria impact models for three future time periods (2030s, 2050s, and 2080s). We evaluated three malaria outcome metrics at global and regional levels: climate suitability, additional population at risk and additional person-months at risk across the model outputs. The malaria projections were based on five different global climate models, each run under four emission scenarios (Representative Concentration Pathways, RCPs) and a single population projection. We also investigated the modeling uncertainty associated with future projections of populations at risk for malaria owing to climate change. Our findings show an overall global net increase in climate suitability and a net increase in the population at risk, but with large uncertainties. The model outputs indicate a net increase in the annual person-months at risk when comparing from RCP2.6 to RCP8.5 from the 2050s to the 2080s. The malaria outcome metrics were highly sensitive to the choice of malaria impact model, especially over the epidemic fringes of the malaria distribution. PMID:24596427

  6. Impact of climate change on global malaria distribution

    PubMed Central

    Caminade, Cyril; Kovats, Sari; Rocklov, Joacim; Tompkins, Adrian M.; Morse, Andrew P.; Colón-González, Felipe J.; Stenlund, Hans; Martens, Pim; Lloyd, Simon J.

    2014-01-01

    Malaria is an important disease that has a global distribution and significant health burden. The spatial limits of its distribution and seasonal activity are sensitive to climate factors, as well as the local capacity to control the disease. Malaria is also one of the few health outcomes that has been modeled by more than one research group and can therefore facilitate the first model intercomparison for health impacts under a future with climate change. We used bias-corrected temperature and rainfall simulations from the Coupled Model Intercomparison Project Phase 5 climate models to compare the metrics of five statistical and dynamical malaria impact models for three future time periods (2030s, 2050s, and 2080s). We evaluated three malaria outcome metrics at global and regional levels: climate suitability, additional population at risk and additional person-months at risk across the model outputs. The malaria projections were based on five different global climate models, each run under four emission scenarios (Representative Concentration Pathways, RCPs) and a single population projection. We also investigated the modeling uncertainty associated with future projections of populations at risk for malaria owing to climate change. Our findings show an overall global net increase in climate suitability and a net increase in the population at risk, but with large uncertainties. The model outputs indicate a net increase in the annual person-months at risk when comparing from RCP2.6 to RCP8.5 from the 2050s to the 2080s. The malaria outcome metrics were highly sensitive to the choice of malaria impact model, especially over the epidemic fringes of the malaria distribution. PMID:24596427

  7. Malaria and tuberculosis: our concerns.

    PubMed

    Shiva, M

    1997-01-01

    In 1978 the concept of primary health care was adopted by 116 countries at Alma Ata, yet the negative impact of structural readjustment programs in Africa and South America could be felt due to the cuts in expenditures on health, education, and social matters. The result is a resurgence of communicable diseases such as malaria and tuberculosis. Another factor in this resurgence is extreme poverty. In 1994 over 1000 people died in Rajasthan, India, of a malaria epidemic, and during the same time in Delhi over 300 deaths were attributed to hemorrhagic dengue fever. Malariogenic and tuberculous conditions continue to flourish owing to distorted development patterns and commercialization of medical care as public health and community health services are being replaced by profit-oriented curative care, 80% of which is in private hands. This has resulted in spiraling medical care costs and rural indebtedness. Socioeconomic deprivation in developing countries threatens TB control. Factors contributing to the spread of TB were established in 1899 and are still valid in India and other developing countries: TB contamination of air, inadequate food, overcrowded dwelling, and low state of physical health. Even in developed countries TB is on the rise: there were 172 cases in 1991 in England vs. 305 cases in 1993, half of them among immigrants. The increase occurred in the poorest 30% of the population. The World Bank is providing loans for a revised TB and malaria strategy, and the Disability Adjusted Life Year has been used to identify the greatest burden of diseases. On the other hand, the Indian National Health Policy has not been revised since 1983. Priority must be given to those living in extreme poverty to curb the resurgence of once controlled diseases. PMID:12348003

  8. Avian malaria in New Zealand.

    PubMed

    Schoener, E R; Banda, M; Howe, L; Castro, I C; Alley, M R

    2014-07-01

    Avian malaria parasites of the genus Plasmodium have the ability to cause morbidity and mortality in naïve hosts, and their impact on the native biodiversity is potentially serious. Over the last decade, avian malaria has aroused increasing interest as an emerging disease in New Zealand with some endemic avian species, such as the endangered mohua (Mohua ochrocephala), thought to be particularly susceptible. To date, avian malaria parasites have been found in 35 different bird species in New Zealand and have been diagnosed as causing death in threatened species such as dotterel (Charadrius obscurus), South Island saddleback (Philesturnus carunculatus carunculatus), mohua, hihi (Notiomystis cincta) and two species of kiwi (Apteryx spp.). Introduced blackbirds (Turdus merula) have been found to be carriers of at least three strains of Plasmodium spp. and because they are very commonly infected, they are likely sources of infection for many of New Zealand's endemic birds. The spread and abundance of introduced and endemic mosquitoes as the result of climate change is also likely to be an important factor in the high prevalence of infection in some regions and at certain times of the year. Although still limited, there is a growing understanding of the ecology and epidemiology of Plasmodium spp. in New Zealand. Molecular biology has played an important part in this process and has markedly improved our understanding of the taxonomy of the genus Plasmodium. This review presents our current state of knowledge, discusses the possible infection and disease outcomes, the implications for host behaviour and reproduction, methods of diagnosis of infection, and the possible vectors for transmission of the disease in New Zealand. PMID:24313228

  9. Profoundly Reduced CD1c+ Myeloid Dendritic Cell HLA-DR and CD86 Expression and Increased Tumor Necrosis Factor Production in Experimental Human Blood-Stage Malaria Infection.

    PubMed

    Loughland, Jessica R; Minigo, Gabriela; Burel, Julie; Tipping, Peta E; Piera, Kim A; Amante, Fiona H; Engwerda, Christian R; Good, Michael F; Doolan, Denise L; Anstey, Nicholas M; McCarthy, James S; Woodberry, Tonia

    2016-05-01

    Dendritic cells (DCs) are sentinels of the immune system that uniquely prime naive cells and initiate adaptive immune responses. CD1c (BDCA-1) myeloid DCs (CD1c(+) mDCs) highly express HLA-DR, have a broad Toll-like receptor (TLR) repertoire, and secrete immune modulatory cytokines. To better understand immune responses to malaria, CD1c(+) mDC maturation and cytokine production were examined in healthy volunteers before and after experimental intravenous Plasmodium falciparum infection with 150- or 1,800-parasite-infected red blood cells (pRBCs). After either dose, CD1c(+) mDCs significantly reduced HLA-DR expression in prepatent infections. Circulating CD1c(+) mDCs did not upregulate HLA-DR after pRBC or TLR ligand stimulation and exhibited reduced CD86 expression. At peak parasitemia, CD1c(+) mDCs produced significantly more tumor necrosis factor (TNF), whereas interleukin-12 (IL-12) production was unchanged. Interestingly, only the 1,800-pRBC dose caused a reduction in the circulating CD1c(+) mDC count with evidence of apoptosis. The 1,800-pRBC dose produced no change in T cell IFN-γ or IL-2 production at peak parasitemia or at 3 weeks posttreatment. Overall, CD1c(+) mDCs are compromised by P. falciparum exposure, with impaired HLA-DR and CD86 expression, and have an increased capacity for TNF but not IL-12 production. A first prepatent P. falciparum infection is sufficient to modulate CD1c(+) mDC responsiveness, likely contributing to hampered effector T cell cytokine responses and assisting parasite immune evasion. PMID:26902728

  10. A Slot Blot Immunoassay for Quantitative Detection of Plasmodium falciparum Circumsporozoite Protein in Mosquito Midgut Oocyst

    PubMed Central

    Kumar, Sanjai; Zheng, Hong; Deng, Bingbing; Mahajan, Babita; Grabias, Bryan; Kozakai, Yukiko; Morin, Merribeth J.; Locke, Emily; Birkett, Ashley; Miura, Kazutoyo; Long, Carole

    2014-01-01

    There is still a need for sensitive and reproducible immunoassays for quantitative detection of malarial antigens in preclinical and clinical phases of vaccine development and in epidemiology and surveillance studies, particularly in the vector host. Here we report the results of sensitivity and reproducibility studies for a research-grade, quantitative enhanced chemiluminescent-based slot blot assay (ECL-SB) for detection of both recombinant Plasmodium falciparum circumsporozoite protein (rPfCSP) and native PfCSP from Oocysts (Pf Oocyst) developing in the midguts of Anopheles stephensi mosquitoes. The ECL-SB detects as little as 1.25 pg of rPfCSP (linear range of quantitation 2.5–20 pg; R2 = 0.9505). We also find the earliest detectable expression of native PfCSP in Pf Oocyst by ECL-SB occurs on day 7 post feeding with infected blood meal. The ECL-SB was able to detect approximately as few as 0.5 day 8 Pf Oocysts (linear quantitation range 1–4, R2 = 0.9795) and determined that one Pf Oocyst expressed approximately 2.0 pg (0.5–3 pg) of native PfCSP, suggesting a similar range of detection for recombinant and native forms of Pf CSP. The ECL-SB is highly reproducible; the Coefficient of Variation (CV) for inter-assay variability for rPf CSP and native PfCSP were 1.74% and 1.32%, respectively. The CVs for intra-assay variability performed on three days for rPf CSP were 2.41%, 0.82% and 2% and for native Pf CSP 1.52%, 0.57%, and 1.86%, respectively. In addition, the ECL-SB was comparable to microscopy in determining the P. falciparum prevalence in mosquito populations that distinctly contained either high and low midgut Pf Oocyst burden. In whole mosquito samples, estimations of positivity for P. falciparum in the high and low burden groups were 83.3% and 23.3% by ECL-SB and 85.7% and 27.6% by microscopy. Based on its performance characteristics, ECL-SB could be valuable in vaccine development and to measure the parasite prevalence in mosquitoes and

  11. EVALUATION OF CRYPTOSPORIDIUM OOCYST RECOVERY IN WATER BY EPA METHOD 1623 WITH A MODIFIED IMS DISSOCIATION PROCEDURE.

    EPA Science Inventory

    EPA Methods 1622 and 1623 are the benchmarks for detection of Cryptosporidium spp. oocysts in water. 5-7 These methods consist of filtration, elution, purification by immunomagnetic separation (IMS), and microscopic analysis after staining with a fluorescein isothiocyanate conju...

  12. [Current malaria situation in the Republic of Uzbekistan].

    PubMed

    Razakov, Sh A; Shakhgunova, G Sh

    2001-01-01

    Malaria was once one of the most common diseases in Uzbekistan. There were massive epidemics with high mortality rates, wherein 140,000 to 700,000 cases of malaria were recorded. Following large-scale malaria control measures, the disease was eradicated in Uzbekistan in 1961 and the epidemiological situation is still favorable. The natural and climatic conditions that prevail in the Republic of Uzbekistan mean that the country is very susceptible to malaria. There are large water areas varying in type and origin, which provide a habitat for a number of epidemiologically dangerous species of malaria-transmitting mosquitoes in a single area. These are Anopheles maculipennis, An. pulcherrimus and An. superpictus. The prevailing temperatures promote rapid growth of vector mosquitoes and parasites and the malaria transmission season is over 5 months long. Seven malaria-transmitting mosquito species have been recently recorded in the Republic. DDT resistance has been so far noted in Anopheles maculipennis, An. hyrcanus and An. bifurcatus. An. superpictus is sensitive to all insecticides used in clinical practice (organophosphorus and organochlorine compounds, HOS, carbamates, pyrethroids). The most dangerous areas for transmitting malaria by importation are the flood plains of the country's main rivers, such as Syrdarya, Amudarya, Chirchik, Surkhana, etc., and rice-growing areas (an area of about 150,000 ha was under rice cultivation in 1999). The Republic is still very subjected to large-scale importations of malaria particularly in the towns and areas along the border with Tajikistan. There has been recently an increase in the incidence of infections imported into the Republic: 27 cases in 1995, 51 in 1996, 52 in 1997, 74 in 1998, and 78 in 1999. Eight regions of Uzbekistan border Tajikistan, their population is over 5.6 million people. In addition, close family ties between the populations of the frontier towns and regions further increase the risk for malaria to be

  13. Mapping Malaria Risk in Low Transmission Settings: Challenges and Opportunities.

    PubMed

    Sturrock, Hugh J W; Bennett, Adam F; Midekisa, Alemayehu; Gosling, Roly D; Gething, Peter W; Greenhouse, Bryan

    2016-08-01

    As malaria transmission declines, it becomes increasingly focal and prone to outbreaks. Understanding and predicting patterns of transmission risk becomes an important component of an effective elimination campaign, allowing limited resources for control and elimination to be targeted cost-effectively. Malaria risk mapping in low transmission settings is associated with some unique challenges. This article reviews the main challenges and opportunities related to risk mapping in low transmission areas including recent advancements in risk mapping low transmission malaria, relevant metrics, and statistical approaches and risk mapping in post-elimination settings. PMID:27238200

  14. Cluster of Imported Vivax Malaria in Travelers Returning From Peru.

    PubMed

    Weitzel, Thomas; Labarca, Jaime; Cortes, Claudia P; Rosas, Reinaldo; Balcells, M Elvira; Perret, Cecilia

    2015-01-01

    We report a cluster of imported vivax malaria in three of five Chilean travelers returning from Peru in March 2015. The cluster highlights the high risk of malaria in the Loreto region in northern Peru, which includes popular destinations for international nature and adventure tourism. According to local surveillance data, Plasmodium vivax is predominating, but Plasmodium falciparum is also present, and the incidence of both species has increased during recent years. Travelers visiting this region should be counseled about the prevention of malaria and the options for chemoprophylaxis. PMID:26354673

  15. Malaria, favism and glucose-6-phosphate dehydrogenase deficiency.

    PubMed

    Huheey, J E; Martin, D L

    1975-10-15

    Although glucose-6-phosphate dehydrogenase deficient individuals may suffer (sometimes fatally) from favism, a high incidence of this trait occurs in many Mediterranean populations. This apparent paradox is explained on the basis of a synergistic interaction between favism and G-6-PD deficiency that provides increased protection against malaria compared to that of the G-6-PD deficiency alone. This relationship is analogous to that between various hemoglobins and malaria in that there is selection for a more severe trait if it provides more protection against malaria. PMID:1107056

  16. Environmental Persistence and Infectivity of Oocysts of Two Species of Gregarines, Blabericola migrator and Blabericola cubensis (Apicomplexa: Eugregarinida: Blabericolidae), Parasitizing Blaberid Cockroaches (Dictyoptera: Blaberidae).

    PubMed

    Clopton, Richard E; Steele, Shelby M; Clopton, Debra T

    2016-04-01

    For apicomplexan parasites using an oral-fecal transmission route with significant environmental exposure, the environmental persistence and infectivity of the oocyst has a direct impact on local infection dynamics, including the ability to withstand extended periods without readily available hosts. Herein we quantify the environmental persistence and infectivity of the oocysts of 2 septate gregarine species at controlled temperature and humidity and demonstrate that they can persist over multiple generational time spans. Species of Blabericola generally complete their endogenous life cycles from oocyst to oocyst within 10 days. The median residual environmental oocyst lifetime for Blabericola oocysts in this study is 21-28 days, but a significant number of oocysts of Blabericola migrator persisted and remained infective in the environment for up to 39 days while those of Blabericola cubensis persisted and remained infective for up to 92 days. Although long-lived relative to their own generational time, the oocysts of Blabericola species infecting cockroaches are short-lived relative to gregarines infecting tenebrionid beetles. For these gregarines, oocysts can persist in the environment and remain infective for up to 787 days. Mechanistically, environmental persistence and infectivity are probably energy-limited phenomena related to the amount of stored amylopectin and the basal metabolic rate of quiescent oocysts. PMID:26771541

  17. Integrated cryptosporidium assay to determine oocyst density, infectivity, and genotype for risk assessment of source and reuse water.

    PubMed

    King, Brendon; Fanok, Stella; Phillips, Renae; Swaffer, Brooke; Monis, Paul

    2015-05-15

    Cryptosporidium continues to be problematic for the water industry, with risk assessments often indicating that treatment barriers may fail under extreme conditions. However, risk analyses have historically used oocyst densities and not considered either oocyst infectivity or species/genotype, which can result in an overestimation of risk if the oocysts are not human infective. We describe an integrated assay for determining oocyst density, infectivity, and genotype from a single-sample concentrate, an important advance that overcomes the need for processing multiple-grab samples or splitting sample concentrates for separate analyses. The assay incorporates an oocyst recovery control and is compatible with standard primary concentration techniques. Oocysts were purified from primary concentrates using immunomagnetic separation prior to processing by an infectivity assay. Plate-based cell culture was used to detect infectious foci, with a monolayer washing protocol developed to allow recovery and enumeration of oocysts. A simple DNA extraction protocol was developed to allow typing of any wells containing infectious Cryptosporidium. Water samples from a variety of source water and wastewater matrices, including a semirural catchment, wastewater, an aquifer recharge site, and storm water, were analyzed using the assay. Results demonstrate that the assay can reliably determine oocyst densities, infectivity, and genotype from single-grab samples for a variety of water matrices and emphasize the varying nature of Cryptosporidium risk extant throughout source waters and wastewaters. This assay should therefore enable a more comprehensive understanding of Cryptosporidium risk for different water sources, assisting in the selection of appropriate risk mitigation measures. PMID:25769833

  18. Integrated Cryptosporidium Assay To Determine Oocyst Density, Infectivity, and Genotype for Risk Assessment of Source and Reuse Water

    PubMed Central

    King, Brendon; Fanok, Stella; Phillips, Renae; Swaffer, Brooke

    2015-01-01

    Cryptosporidium continues to be problematic for the water industry, with risk assessments often indicating that treatment barriers may fail under extreme conditions. However, risk analyses have historically used oocyst densities and not considered either oocyst infectivity or species/genotype, which can result in an overestimation of risk if the oocysts are not human infective. We describe an integrated assay for determining oocyst density, infectivity, and genotype from a single-sample concentrate, an important advance that overcomes the need for processing multiple-grab samples or splitting sample concentrates for separate analyses. The assay incorporates an oocyst recovery control and is compatible with standard primary concentration techniques. Oocysts were purified from primary concentrates using immunomagnetic separation prior to processing by an infectivity assay. Plate-based cell culture was used to detect infectious foci, with a monolayer washing protocol developed to allow recovery and enumeration of oocysts. A simple DNA extraction protocol was developed to allow typing of any wells containing infectious Cryptosporidium. Water samples from a variety of source water and wastewater matrices, including a semirural catchment, wastewater, an aquifer recharge site, and storm water, were analyzed using the assay. Results demonstrate that the assay can reliably determine oocyst densities, infectivity, and genotype from single-grab samples for a variety of water matrices and emphasize the varying nature of Cryptosporidium risk extant throughout source waters and wastewaters. This assay should therefore enable a more comprehensive understanding of Cryptosporidium risk for different water sources, assisting in the selection of appropriate risk mitigation measures. PMID:25769833

  19. Malaria: prevention in travellers

    PubMed Central

    2007-01-01

    Introduction Malaria transmission occurs most frequently in environments with humidity over 60% and ambient temperature of 25-30 °C. Risks increase with longer visits and depend on activity. Infection can follow a single mosquito bite. Incubation is usually 10-14 days but can be up to 18 months depending on the strain of parasite. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of non-drug preventive interventions in adult travellers? What are the effects of drug prophylaxis in adult travellers? What are the effects of antimalaria vaccines in travellers? What are the effects of antimalaria interventions in child travellers, pregnant travellers, and in airline pilots? We searched: Medline, Embase, The Cochrane Library and other important databases up to February 2006 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 69 systematic reviews, RCTs, or observational studies that met our inclusion criteria. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: acoustic buzzers, aerosol insecticides, amodiaquine, air conditioning and electric fans, atovaquone-proguanil, biological control measures, chloroquine (alone or with proguanil), diethyltoluamide (DEET), doxycycline, full-length and light-coloured clothing, insecticide-treated clothing/nets, mefloquine, mosquito coils and vaporising mats, primaquine, pyrimethamine-dapsone, pyrimethamine-sulfadoxine, smoke, topical (skin-applied) insect repellents, and vaccines. PMID:19450348

  20. Epidemiology of malaria in pregnancy in central India.

    PubMed Central

    Singh, N.; Shukla, M. M.; Sharma, V. P.

    1999-01-01

    Analysis of three years of data from a malaria clinic operated by the Indian Council of Medical Research (ICMR) in the Government Medical College Hospital in Jabalpur, central India, showed a high malaria prevalence among pregnant women, which was statistically highly significant (P < 0.0001) compared with the situation among nonpregnant women. Cerebral malaria was a common complication of severe Plasmodium falciparum infection, with a high mortality during pregnancy, requiring immediate attention. The study also showed that malaria infection was more frequent in primigravidae, falling progressively with increasing parity. Mean parasite densities were significantly higher in pregnant women compared with nonpregnant women for both P. falciparum (P < 0.001; df = 137) and P. vivax (P < 0.05; df = 72) infection. Pregnant women with falciparum or vivax malaria were significantly more anaemic than noninfected pregnant women or infected nonpregnant women. The average weight of 155 neonates from infected mothers was 350 g less than that of 175 neonates from noninfected mothers. This difference in birth weight was statistically significant for both P. falciparum (P < 0.0001; df = 278) and P. vivax (P < 0.0001; df = 223) infection. Congenital malaria was not recorded. We conclude that pregnant women from this geographical area require systematic intervention owing to their high susceptibility to malaria during pregnancy and the puerperium. PMID:10444880

  1. Malaria in gold-mining areas in Colombia.

    PubMed

    Castellanos, Angélica; Chaparro-Narváez, Pablo; Morales-Plaza, Cristhian David; Alzate, Alberto; Padilla, Julio; Arévalo, Myriam; Herrera, Sócrates

    2016-01-01

    Gold-mining may play an important role in the maintenance of malaria worldwide. Gold-mining, mostly illegal, has significantly expanded in Colombia during the last decade in areas with limited health care and disease prevention. We report a descriptive study that was carried out to determine the malaria prevalence in gold-mining areas of Colombia, using data from the public health surveillance system (National Health Institute) during the period 2010-2013. Gold-mining was more prevalent in the departments of Antioquia, Córdoba, Bolívar, Chocó, Nariño, Cauca, and Valle, which contributed 89.3% (270,753 cases) of the national malaria incidence from 2010-2013 and 31.6% of malaria cases were from mining areas. Mining regions, such as El Bagre, Zaragoza, and Segovia, in Antioquia, Puerto Libertador and Montelíbano, in Córdoba, and Buenaventura, in Valle del Cauca, were the most endemic areas. The annual parasite index (API) correlated with gold production (R2 0.82, p < 0.0001); for every 100 kg of gold produced, the API increased by 0.54 cases per 1,000 inhabitants. Lack of malaria control activities, together with high migration and proliferation of mosquito breeding sites, contribute to malaria in gold-mining regions. Specific control activities must be introduced to control this significant source of malaria in Colombia. PMID:26814645

  2. Malaria in gold-mining areas in Colombia

    PubMed Central

    Castellanos, Angélica; Chaparro-Narváez, Pablo; Morales-Plaza, Cristhian David; Alzate, Alberto; Padilla, Julio; Arévalo, Myriam; Herrera, Sócrates

    2016-01-01

    Gold-mining may play an important role in the maintenance of malaria worldwide. Gold-mining, mostly illegal, has significantly expanded in Colombia during the last decade in areas with limited health care and disease prevention. We report a descriptive study that was carried out to determine the malaria prevalence in gold-mining areas of Colombia, using data from the public health surveillance system (National Health Institute) during the period 2010-2013. Gold-mining was more prevalent in the departments of Antioquia, Córdoba, Bolívar, Chocó, Nariño, Cauca, and Valle, which contributed 89.3% (270,753 cases) of the national malaria incidence from 2010-2013 and 31.6% of malaria cases were from mining areas. Mining regions, such as El Bagre, Zaragoza, and Segovia, in Antioquia, Puerto Libertador and Montelíbano, in Córdoba, and Buenaventura, in Valle del Cauca, were the most endemic areas. The annual parasite index (API) correlated with gold production (R2 0.82, p < 0.0001); for every 100 kg of gold produced, the API increased by 0.54 cases per 1,000 inhabitants. Lack of malaria control activities, together with high migration and proliferation of mosquito breeding sites, contribute to malaria in gold-mining regions. Specific control activities must be introduced to control this significant source of malaria in Colombia. PMID:26814645

  3. Malaria in Tunisian Military Personnel after Returning from External Operation

    PubMed Central

    Ajili, Faïda; Battikh, Riadh; Laabidi, Janet; Abid, Rim; Bousetta, Najeh; Jemli, Bouthaina; Ben abdelhafidh, Nadia; Bassem, Louzir; Gargouri, Saadia; Othmani, Salah

    2013-01-01

    Introduction. Malaria had been eliminated in Tunisia since 1979, but there are currently 40 to 50 imported cases annually. Soldiers are no exception as the incidence of imported malaria is increasing in Tunisian military personnel after returning from malaria-endemic area, often in Sub-Saharan Africa. Methods. We retrospectively analyzed the clinical and biological presentations, treatment, and outcomes of 37 Tunisian military personnel hospitalized at the Department of Internal Medicine, the Military Hospital of Tunis, between January 1993 and January 2011, for imported malaria. The clinical and laboratory features were obtained from the medical records and a questionnaire was filled by the patients about the compliance of malaria prophylaxis. Results. Thirty-seven male patients, with a mean age of 41 years, were treated for malaria infection. Twenty-two were due to Plasmodium falciparum. The outcome was favourable for all patients, despite two severe access. The long-term use of chemoprophylaxis has been adopted by only 21 (51%) of expatriate military for daily stresses. Moreover, poor adherence was found in 32 patients. Conclusion. The risk of acquiring malaria infection in Tunisian military personnel can largely be prevented by the regular use of chemoprophylactic drugs combined with protective measures against mosquito bites. PMID:23766922

  4. Malaria Theranostics using Hemozoin-Generated Vapor Nanobubbles

    PubMed Central

    Hleb, Ekaterina Y. Lukianova-; Lapotko, Dmitri O.

    2014-01-01

    Malaria remains a widespread and deadly infectious human disease, with increasing diagnostic and therapeutic challenges due to the drug resistance and aggressiveness of malaria infection. Early detection and innovative approaches for parasite destruction are needed. The high optical absorbance and nano-size of hemozoin crystals have been exploited to detect and mechanically destroy the malaria parasite in a single theranostic procedure. Transient vapor nanobubbles are generated around hemozoin crystals in malaria parasites in infected erythrocytes in response to a single short laser pulse. Optical scattering signals of the nanobubble report the presence of the malaria parasite. The mechanical impact of the same nanobubble physically destroys the parasite in nanoseconds in a drug-free manner. Laser-induced nanobubble treatment of human blood in vitro results in destruction of up to 95% of parasites after a single procedure, and delivers an 8-fold better parasiticidal efficacy compared to standard chloroquine drug treatment. The mechanism of destruction is highly selective for malaria infected red cells and does not harm neighboring, uninfected erythrocytes. Thus, laser pulse-induced vapor nanobubble generation around hemozoin supports both rapid and highly specific detection and destruction of malaria parasites in one theranostic procedure. PMID:24883125

  5. Malaria theranostics using hemozoin-generated vapor nanobubbles.

    PubMed

    Lukianova-Hleb, Ekaterina Y; Lapotko, Dmitri O

    2014-01-01

    Malaria remains a widespread and deadly infectious human disease, with increasing diagnostic and therapeutic challenges due to the drug resistance and aggressiveness of malaria infection. Early detection and innovative approaches for parasite destruction are needed. The high optical absorbance and nano-size of hemozoin crystals have been exploited to detect and mechanically destroy the malaria parasite in a single theranostic procedure. Transient vapor nanobubbles are generated around hemozoin crystals in malaria parasites in infected erythrocytes in response to a single short laser pulse. Optical scattering signals of the nanobubble report the presence of the malaria parasite. The mechanical impact of the same nanobubble physically destroys the parasite in nanoseconds in a drug-free manner. Laser-induced nanobubble treatment of human blood in vitro results in destruction of up to 95% of parasites after a single procedure, and delivers an 8-fold better parasiticidal efficacy compared to standard chloroquine drug treatment. The mechanism of destruction is highly selective for malaria infected red cells and does not harm neighboring, uninfected erythrocytes. Thus, laser pulse-induced vapor nanobubble generation around hemozoin supports both rapid and highly specific detection and destruction of malaria parasites in one theranostic procedure. PMID:24883125

  6. Malaria Ecology, Disease Burden and Global Climate Change

    NASA Astrophysics Data System (ADS)

    Mccord, G. C.

    2014-12-01

    Malaria has afflicted human society for over 2 million years, and remains one of the great killer diseases today. The disease is the fourth leading cause of death for children under five in low income countries (after neonatal disorders, diarrhea, and pneumonia) and is responsible for at least one in every five child deaths in sub-Saharan Africa. It kills up to 3 million people a year, though in recent years scale up of anti-malaria efforts in Africa may have brought deaths to below 1 million. Malaria is highly conditioned by ecology, because of which climate change is likely to change the local dynamics of the disease through changes in ambient temperature and precipitation. To assess the potential implications of climate change for the malaria burden, this paper employs a Malaria Ecology Index from the epidemiology literature, relates it to malaria incidence and mortality using global country-level data , and then draws implications for 2100 by extrapolating the index using several general circulation model (GCM) predictions of temperature and precipitation. The results highlight the climate change driven increase in the basic reproduction number of the disease and the resulting complications for further gains in elimination. For illustrative purposes, I report the change in malaria incidence and mortality if climate change were to happen immediately under current technology and public health efforts.

  7. Coadaptation and malaria control.

    PubMed

    Tosta, Carlos Eduardo

    2007-06-01

    Malaria emerges from a disequilibrium of the system 'human-plasmodium-mosquito' (HPM). If the equilibrium is maintained, malaria does not ensue and the result is asymptomatic plasmodium infection. The relationships among the components of the system involve coadaptive linkages that lead to equilibrium. A vast body of evidence supports this assumption, including the strategies involved in the relationships between plasmodium and human and mosquito immune systems, and the emergence of resistance of plasmodia to antimalarial drugs and of mosquitoes to insecticides. Coadaptive strategies for malaria control are based on the following principles: (1) the system HPM is composed of three highly complex and dynamic components, whose interplay involves coadaptive linkages that tend to maintain the equilibrium of the system; (2) human and mosquito immune systems play a central role in the coadaptive interplay with plasmodium, and hence, in the maintenance of the system's equilibrium; the under- or overfunction of human immune system may result in malaria and influence its severity; (3) coadaptation depends on genetic and epigenetic phenomena occurring at the interfaces of the components of the system, and may involve exchange of infectrons (genes or gene fragments) between the partners; (4) plasmodia and mosquitoes have been submitted to selective pressures, leading to adaptation, for an extremely long while and are, therefore, endowed with the capacity to circumvent both natural (immunity) and artificial (drugs, insecticides, vaccines) measures aiming at destroying them; (5) since malaria represents disequilibrium of the system HPM, its control should aim at maintaining or restoring this equilibrium; (6) the disequilibrium of integrated systems involves the disequilibrium of their components, therefore the maintenance or restoration of the system's equilibrium depend on the adoption of integrated and coordinated measures acting on all components, that means, panadaptive

  8. Detection of Toxoplasma gondii oocysts in water: proposition of a strategy and evaluation in Champagne-Ardenne Region, France.

    PubMed

    Aubert, D; Villena, I

    2009-03-01

    Water is a vehicle for disseminating human and veterinary toxoplasmosis due to oocyst contamination. Several outbreaks of toxoplasmosis throughout the world have been related to contaminated drinking water. We have developed a method for the detection of Toxoplasma gondii oocysts in water and we propose a strategy for the detection of multiple waterborne parasites, including Cryptosporidium spp. and Giardia. Water samples were filtered to recover Toxoplasma oocysts and, after the detection of Cryptosporidium oocysts and Giardia cysts by immunofluorescence, as recommended by French norm procedure NF T 90-455, the samples were purified on a sucrose density gradient. Detection of Toxoplasma was based on PCR amplification and mouse inoculation to determine the presence and infectivity of recovered oocysts. After experimental seeding assays, we determined that the PCR assay was more sensitive than the bioassay. This strategy was then applied to 482 environmental water samples collected since 2001. We detected Toxoplasma DNA in 37 environmental samples (7.7%), including public drinking water; however, none of them were positive by bioassay. This strategy efficiently detects Toxoplasma oocysts in water and may be suitable as a public health sentinel method. Alternative methods can be used in conjunction with this one to determine the infectivity of parasites that were detected by molecular methods. PMID:19430655

  9. Analysis of cured meat products for cryptosporidium oocysts following possible contamination during an extensive waterborne outbreak of Cryptosporidiosis.

    PubMed

    Robertson, Lucy J; Huang, Qirong

    2012-05-01

    An outbreak of waterborne cryptosporidiosis in a town in northern Sweden during winter 2010 resulted in the potential exposure of cured meat products to Cryptosporidium oocysts during their manufacture. The purpose of this work was to develop a method for analyzing cured meat products for contamination with Cryptosporidium oocysts and use this method to analyze potentially contaminated product samples. A simple method of elution, concentration, separation, and detection was used, based on work with other food matrices but adapted for the relatively high fat content of cured meat surfaces. Using spiking experiments, the recovery efficiency of this method was found to be over 60%. In the analysis of the potentially contaminated products, only one putative Cryptosporidium oocyst was detected, and this was sufficiently deformed so that it could not be confirmed as an oocyst; if it was an oocyst, it was considered to have been probably deformed and inactivated prior to analysis. Based on the results of the analyses, together with data on the probable extent of contamination of the products and on our knowledge of factors, such as water activity, which affect oocyst survival, the products were safely released to the market. PMID:22564952

  10. [Development of a technique for recovering Giardia cysts and Cryptosporidium oocysts from fresh vegetables].

    PubMed

    Di Benedetto, M A; Di Piazza, F; Oliveri, R; Cerame, G; Valenti, R; Firenze, A

    2006-01-01

    Techniques described for recovering Giardia and Cryptosporidium (oo)cysts from fruit and vegetables are generally inadequate and present variable recovery efficience and elevated costs. The aim of our study was to evaluate the recovery efficiency of a simple and economic technique to apply either to berry vegetables, like tomatoes and peppers, or to large leave vegetables, like lettuce and chicory. The method include contamination and further elution of the vegetables. Then sedimentation of (oo)cysts by centrifugation of the eluate of vegetables and their visualization by means of direct immunofluorescence. The higher recovery values for both protozoa were obtained in large leave vegetables with mean data above 70% for Giardia and 76% for Cryptosporidium, whereas the values observed in the berry vegetables were above 43% for Giardia and above 37% for Cryptosporidium on average. PMID:16649507

  11. In vitro evaluation of the disinfection efficacy on Eimeria tenella unsporulated oocysts isolated from broilers.

    PubMed

    Guimarães, José S; Bogado, Alexey L Gomel; da Cunha, Thiago Cezar B; Garcia, João Luis

    2007-01-01

    The objective of this study was to evaluate in vitro the action of eight chemical principles by disinfection efficacy (DE) of Eimeria tenella oocysts. Disinfection efficacy was evaluated by either destruction or sporulation inhibition of the oocysts. Eight treatments were performed: T1 (Glutaraldehyde 42.5 g + Benzalkonium Chloride 7.5 g); T2 (Benzalkonium chloride + quaternary ammonium salt); T3 (formol 37% + Sodium Dodecylbenzene Sulfonate 12%); T4 (sodium hypochlorite 2%); T5 (Orthodichlorobenzene 60% + Xylene 30%); T6 (Polyoctyl polyamino ethyl glycine + Polyoxyethylene alkylphenol ether + Sodium Chloride); T7 (Chloramine T) and finally T8 (free iodine 2.25% + Phosphoric acid 15 g). The control test was carried out with distilled water (T9). The best DE were observed, respectively, in T3 (79.49%), T5 (75.60%) and T4 (65.56%) treatments. PMID:17706006

  12. Declining incidence of imported malaria in the Netherlands, 2000-2007

    PubMed Central

    2010-01-01

    Background To describe the epidemiology and trends of imported malaria in the Netherlands from 2000 through 2007. Methods Based on national surveillance data regarding all reported infections of imported malaria, diagnosed 2000 through 2007, incidence and trends of imported malaria in the Netherlands were estimated. Travellers statistics were used to estimate incidence, and data on malaria chemoprophylaxis prescriptions were used to estimate the number of unprotected travellers. Results Importation of malaria to the Netherlands is declining even as more travellers visit malaria-endemic countries. On average, 82% were acquired in sub-Saharan Africa, and 75% were caused by Plasmodium falciparum. The overall incidence in imported falciparum malaria fell from 21.5 to 6.6/10,000 of unprotected travellers. The percentage of unprotected travellers rose from 47% to 52% of all travellers. The incidence of imported falciparum infections is greatest from Middle and West Africa, and decreased from 121.3 to 36.5/10,000 travellers. The import of malaria from this region by immigrants visiting friends and relatives (VFR) decreased from 138 infections in 2000, to 69 infections in 2007. Conclusion The annual number of imported malaria shows a continuing declining trend, even with an increasing number of travellers visiting malaria endemic countries. VFR import less malaria than previously, and contribute largely to the declining incidence seen. The decline is not readily explained by increased use of chemoprophylaxis and may reflect a reduced risk of infection due to decreasing local malaria transmission as observed in some malaria endemic areas. Nevertheless, the increasing number of unprotected travellers remains worrisome. PMID:21029424

  13. Malaria and HIV among pediatric inpatients in two Tanzanian referral hospitals: A prospective study.

    PubMed

    Smart, Luke R; Orgenes, Neema; Mazigo, Humphrey D; Minde, Mercy; Hokororo, Adolfine; Shakir, Muhammad; Verweij, Jaco J; Downs, Jennifer A; Peck, Robert N

    2016-07-01

    Malaria remains common in sub-Saharan Africa, but it is frequently over-diagnosed and over-treated in hospitalized children. HIV is prevalent in many malaria endemic areas and may delay parasite clearance and increase mortality among children with malaria. This prospective cohort study enrolled children with suspected malaria between 3 months and 12 years of age hospitalized at two referral hospitals in Tanzania. Both a thick blood smear (BS) and a malaria rapid diagnostic test (mRDT) were performed. If discordant results were obtained, PCR was performed for Plasmodium falciparum. Malaria was confirmed if two out of three tests were positive. Malaria parasite densities were determined for two consecutive days after diagnosis and treatment of malaria. All participants were tested for HIV. Among 1492 hospitalized children, 400 (26.8%) were enrolled with suspected malaria infection. There were 196/400 (49.0%) males, and the median age was 18 [9-36] months. BS was positive in 95/400 (23.8%), and mRDT was positive in 70/400 (17.5%), with moderate agreement (Kappa=0.598). Concordant results excluded malaria in 291/400 (72.8%) and confirmed malaria in 56/400 (14.0%). PCR performed on 53 discordant results confirmed malaria in 1/39 of the BS-positive/mRDT-negative cases, and 6/14 of the BS-negative/mRDT-positive cases. The prevalence of confirmed malaria was 63/400 (15.8%). In multivariable logistic regression, malaria was associated with HIV (OR 3.45 [1.65-7.20], p=0.001). Current breastfeeding (OR 0.25 [0.11-0.56], p=0.001) and higher hemoglobin (OR 0.70 [0.60-0.81], p<0.001 per 1g/dL) were associated with decreased odds of malaria. Malaria parasite clearance was delayed in HIV-infected participants (p<0.001). Malaria is over-diagnosed even at referral centers in high transmission areas. Hospitalized HIV-infected children are more likely to have malaria and exhibit delayed clearance of parasites. Hospitals should consider using mRDTs as a first step for malaria testing

  14. Early malaria resurgence in pre-elimination areas in Kokap Subdistrict, Kulon Progo, Indonesia

    PubMed Central

    2014-01-01

    Background Indonesia is among those countries committed to malaria eradication, with a continuously decreasing incidence of malaria. However, at district level the situation is different. This study presents a case of malaria resurgence Kokap Subdistrict of the Kulon Progo District in Yogyakarta Province, Java after five years of low endemicity. This study also aims to describe the community perceptions and health services delivery situation that contribute to this case. Methods All malaria cases (2007–2011) in Kulon Progo District were stratified to annual parasite incidence (API). Two-hundred and twenty-six cases during an outbreak (May 2011 to April 2012) were geocoded by household addresses using a geographic information system (GIS) technique and clusters were identified by SaTScan software analysis (Arc GIS 10.1). Purposive random sampling was conducted on respondents living inside the clusters to identify community perceptions and behaviour related to malaria. Interviews were conducted with malaria health officers to understand the challenges of malaria surveillance and control. Results After experiencing three consecutive years with API less than 1 per thousand, malaria in Kokap subdistrict increased almost ten times higher than API in the district level and five times higher than national API. Malaria cases were found in all five villages in 2012. One primary and two secondary malaria clusters in Hargotirto and Kalirejo villages were identified during the 2011–2012 outbreak. Most of the respondents were positively aware with malaria signs and activities of health workers to prevent malaria, although some social economic activities could not be hindered. Return transmigrants or migrant workers entering to their villages, reduced numbers of village malaria workers and a surge in malaria cases in the neighbouring district contributed to the resurgence. Conclusion Community perception, awareness and participation could constitute a solid foundation for

  15. [Studies on current trend of imported malaria in Japan--pediatric cases in recent 20 years].

    PubMed

    Mizuno, Y; Ohtomo, H; Kimura, M; Takeuchi, T

    2000-09-01

    Imported malaria has been increasing according to the recent globalization of Japan. There are about 120 clinical cases of malaria which include a few pediatric cases (approximately 1%) every year. Generally, pediatric cases often have an atypical onset and course compared to adult cases, and also develop serious and fatal effects in a short time. In this study, we examined imported malaria cases in subjects under 15 years old from 1980 to 1999 conducted by Research group on clinical evaluation against orphan drugs in the treatment of imported tropical diseases and parasitic diseases. During the 20 years we found 44 clinical cases in children. Of these 70% were foreign cases. Among the species of parasites, there were 21 cases of Vivax malaria and 17 cases of Falciparum malaria and a few cases of Malariae and Ovale malaria were also found, which is rare even in adults. Concerning the drugs chosen in Japan for chemotherapy to treat malaria, chloroquine and primaquine seemed to be employed most frequently before 1990, however mefloquine or artesunate seemed to be more common after 1990. Also, most pediatric cases were former residents or refugees from tropical countries, however some cases were in Japanese children who had recently visited those areas with their families. There have been no fatalities in pediatric cases of malaria, however tropical diseases, including malaria, must be rule out, when examining pyretic children, considering the number of travelers going abroad has been increasing. PMID:11068361

  16. Use of Integrated Malaria Management Reduces Malaria in Kenya

    PubMed Central

    Okech, Bernard A.; Mwobobia, Isaac K.; Kamau, Anthony; Muiruri, Samuel; Mutiso, Noah; Nyambura, Joyce; Mwatele, Cassian; Amano, Teruaki; Mwandawiro, Charles S.

    2008-01-01

    Background During an entomological survey in preparation for malaria control interventions in Mwea division, the number of malaria cases at the Kimbimbi sub-district hospital was in a steady decline. The underlying factors for this reduction were unknown and needed to be identified before any malaria intervention tools were deployed in the area. We therefore set out to investigate the potential factors that could have contributed to the decline of malaria cases in the hospital by analyzing the malaria control knowledge, attitudes and practices (KAP) that the residents in Mwea applied in an integrated fashion, also known as integrated malaria management (IMM). Methods Integrated Malaria Management was assessed among community members of Mwea division, central Kenya using KAP survey. The KAP study evaluated community members' malaria disease management practices at the home and hospitals, personal protection measures used at the household level and malaria transmission prevention methods relating to vector control. Concurrently, we also passively examined the prevalence of malaria parasite infection via outpatient admission records at the major referral hospital in the area. In addition we studied the mosquito vector population dynamics, the malaria sporozoite infection status and entomological inoculation rates (EIR) over an 8 month period in 6 villages to determine the risk of malaria transmission in the entire division. Results A total of 389 households in Mwea division were interviewed in the KAP study while 90 houses were surveyed in the entomological study. Ninety eight percent of the households knew about malaria disease while approximately 70% of households knew its symptoms and methods to manage it. Ninety seven percent of the interviewed households went to a health center for malaria diagnosis and treatment. Similarly a higher proportion (81%) used anti-malarial medicines bought from local pharmacies. Almost 90% of households reported owning and using an

  17. Detection and quantification of Cryptosporidium oocysts in environmental surfaces of an Equine Perinatology Unit.

    PubMed

    Piva, Silvia; Caffara, Monica; Pasquali, Frédérique; Castagnetti, Carolina; Iacono, Eleonora; Massella, Elisa; Zanoni, Renato Giulio; Galuppi, Roberta

    2016-09-01

    The presence of Cryptosporidium in institutions such as veterinary teaching hospitals, where students and staff are in frequent contact with animals, could represent a serious public health risk. In this study the detection and quantification of the Cryptosporidium oocysts present on the environmental surfaces of an Equine Perinatology Unit (EPU) were investigated. During 3 foaling seasons 175 samples obtained by swabbing an area of the floor and walls of boxes and utility rooms of EPU with sterile gauze, in 3 different moments. Samples were collected at the end of foaling season (July), after washing procedures (September) and after washing and disinfecting procedures, at the beginning of a new foaling season (December). All the samples were subjected to nested-PCR, followed by genotyping and sub-typing methods and to qPCR, allowing the oocyst quantification. Cryptosporidium spp. was detected in 14 samples, of which 11 were from walls and three were from floors. The highest number of oocysts was found in a sample collected from the floor of one utility room used for setting up therapies and treatments. In most cases, oocyst numbers, estimated by qPCR, were reduced or eliminated after washing and disinfecting procedures. The genotyping and sub-typing methods allowed identification of 2 subtypes of C. parvum (IIaA15G2R1 and IIdA23G1) and 1 of Cryptosporidium horse genotype (VIaA15G4) that were described in foals hospitalized at the EPU in the same years. The results of the present study show that qPCR can be used to evaluate Cryptosporidium contamination of environmental surfaces of a veterinary teaching hospital and the efficacy of the disinfection procedures. PMID:27544254

  18. Plasmodium berghei ANKA causes intestinal malaria associated with dysbiosis.

    PubMed

    Taniguchi, Tomoyo; Miyauchi, Eiji; Nakamura, Shota; Hirai, Makoto; Suzue, Kazutomo; Imai, Takashi; Nomura, Takahiro; Handa, Tadashi; Okada, Hiroko; Shimokawa, Chikako; Onishi, Risa; Olia, Alex; Hirata, Jun; Tomita, Haruyoshi; Ohno, Hiroshi; Horii, Toshihiro; Hisaeda, Hajime

    2015-01-01

    Gastrointestinal symptoms, such as abdominal pain and diarrhea, are frequently observed in patients with Plasmodium falciparum malaria. However, the correlation between malaria intestinal pathology and intestinal microbiota has not been investigated. In the present study, infection of C57BL/6 mice with P. berghei ANKA (PbA) caused intestinal pathological changes, such as detachment of epithelia in the small intestines and increased intestinal permeability, which correlated with development with experimental cerebral malaria (ECM). Notably, an apparent dysbiosis occurred, characterized by a reduction of Firmicutes and an increase in Proteobacteria. Furthermore, some genera of microbiota correlated with parasite growth and/or ECM development. By contrast, BALB/c mice are resistant to ECM and exhibit milder intestinal pathology and dysbiosis. These results indicate that the severity of cerebral and intestinal pathology coincides with the degree of alteration in microbiota. This is the first report demonstrating that malaria affects intestinal microbiota and causes dysbiosis. PMID:26503461

  19. Plasmodium berghei ANKA causes intestinal malaria associated with dysbiosis

    PubMed Central

    Taniguchi, Tomoyo; Miyauchi, Eiji; Nakamura, Shota; Hirai, Makoto; Suzue, Kazutomo; Imai, Takashi; Nomura, Takahiro; Handa, Tadashi; Okada, Hiroko; Shimokawa, Chikako; Onishi, Risa; Olia, Alex; Hirata, Jun; Tomita, Haruyoshi; Ohno, Hiroshi; Horii, Toshihiro; Hisaeda, Hajime

    2015-01-01

    Gastrointestinal symptoms, such as abdominal pain and diarrhea, are frequently observed in patients with Plasmodium falciparum malaria. However, the correlation between malaria intestinal pathology and intestinal microbiota has not been investigated. In the present study, infection of C57BL/6 mice with P. berghei ANKA (PbA) caused intestinal pathological changes, such as detachment of epithelia in the small intestines and increased intestinal permeability, which correlated with development with experimental cerebral malaria (ECM). Notably, an apparent dysbiosis occurred, characterized by a reduction of Firmicutes and an increase in Proteobacteria. Furthermore, some genera of microbiota correlated with parasite growth and/or ECM development. By contrast, BALB/c mice are resistant to ECM and exhibit milder intestinal pathology and dysbiosis. These results indicate that the severity of cerebral and intestinal pathology coincides with the degree of alteration in microbiota. This is the first report demonstrating that malaria affects intestinal microbiota and causes dysbiosis. PMID:26503461

  20. HIV and malaria interactions: where do we stand?

    PubMed

    González, Raquel; Ataíde, Ricardo; Naniche, Denise; Menéndez, Clara; Mayor, Alfredo

    2012-02-01

    Reversing the spread of HIV infection and the incidence of malaria constitute two of the Millenium Development Goals. However, despite recent achievements, both diseases still entail global heath problems. Furthermore, their overlapping geographical distribution raises concerns and challenges for potential immunological, clinical and therapeutic interactions. It has been reported that HIV infection increases malaria susceptibility and reduces the efficacy of antimalarial drugs. On the other hand, the effect of malaria on HIV-infected individuals has also been explored, with the parasitic infection increasing the risk of HIV disease progression and mother-to-child transmission of HIV. The spread of malaria and parasite resistance to antimalarials could also be accelerated by HIV-associated immunosuppresion. Current knowledge of the epidemiological, clinical, immunological and therapeutic interactions of the two diseases is reviewed in this article. We focus on the latest available data, pointing out key future research areas and challenges of the field. PMID:22339190

  1. Tutorials for Africa - Malaria: MedlinePlus

    MedlinePlus

    Tutorials for Africa: Malaria In Uganda, the burden of malaria outranks that of all other diseases. This tutorial includes information about how malaria spreads, the importance of treatment and techniques for ...

  2. Application of loop analysis for evaluation of malaria control interventions

    PubMed Central

    2014-01-01

    Background Despite continuous efforts and recent rapid expansion in the financing and implementation of malaria control interventions, malaria still remains one of the most devastating global health issues. Even in countries that have been successful in reducing the incidence of malaria, malaria control is becoming more challenging because of the changing epidemiology of malaria and waning community participation in control interventions. In order to improve the effectiveness of interventions and to promote community understanding of the necessity of continued control efforts, there is an urgent need to develop new methodologies that examine the mechanisms by which community-based malaria interventions could reduce local malaria incidence. Methods This study demonstrated how the impact of community-based malaria control interventions on malaria incidence can be examined in complex systems by qualitative analysis combined with an extensive review of literature. First, sign digraphs were developed through loop analysis to analyse seven interventions: source reduction, insecticide/larvicide use, biological control, treatment with anti-malarials, insecticide-treated mosquito net/long-lasting insecticidal net, non-chemical personal protection measures, and educational intervention. Then, for each intervention, the sign digraphs and literature review were combined to analyse a variety of pathways through which the intervention can influence local malaria incidence as well as interactions between variables involved in the system. Through loop analysis it is possible to see whether increases in one variable qualitatively increases or decreases other variables or leaves them unchanged and the net effect of multiple, interacting variables. Results Qualitative analysis, specifically loop analysis, can be a useful tool to examine the impact of community-based malaria control interventions. Without relying on numerical data, the analysis was able to describe pathways through

  3. Forecasting paediatric malaria admissions on the Kenya Coast using rainfall

    PubMed Central

    Karuri, Stella Wanjugu; Snow, Robert W.

    2016-01-01

    Background Malaria is a vector-borne disease which, despite recent scaled-up efforts to achieve control in Africa, continues to pose a major threat to child survival. The disease is caused by the protozoan parasite Plasmodium and requires mosquitoes and humans for transmission. Rainfall is a major factor in seasonal and secular patterns of malaria transmission along the East African coast. Objective The goal of the study was to develop a model to reliably forecast incidences of paediatric malaria admissions to Kilifi District Hospital (KDH). Design In this article, we apply several statistical models to look at the temporal association between monthly paediatric malaria hospital admissions, rainfall, and Indian Ocean sea surface temperatures. Trend and seasonally adjusted, marginal and multivariate, time-series models for hospital admissions were applied to a unique data set to examine the role of climate, seasonality, and long-term anomalies in predicting malaria hospital admission rates and whether these might become more or less predictable with increasing vector control. Results The proportion of paediatric admissions to KDH that have malaria as a cause of admission can be forecast by a model which depends on the proportion of malaria admissions in the previous 2 months. This model is improved by incorporating either the previous month's Indian Ocean Dipole information or the previous 2 months’ rainfall. Conclusions Surveillance data can help build time-series prediction models which can be used to anticipate seasonal variations in clinical burdens of malaria in stable transmission areas and aid the timing of malaria vector control. PMID:26842613

  4. Investigation of Nematopsis spp. oocysts in 7 species of bivalves from Chonburi province, Gulf of Thailand.

    PubMed

    Tuntiwaranuruk, C; Chalermwat, K; Upatham, E S; Kruatrachue, M; Azevedo, C

    2004-01-28

    This is the first detailed report of Nematopsis spp. in Thai bivalves. A monthly survey was conducted on 7 species of commercial bivalves from Chonburi province, on the eastern seaboard of Thailand, from November 2000 to November 2001 to investigate the prevalence of the apicomplexan parasite Nematopsis Schneider, 1892. Nematopsis spp. sporozoites were found in the cultivated bivalves Arcuatula arcuatula, Anadara granosa and Perna viridis as well as the locally harvested Paphia undulata. They were not found in Donax faba, Meretrix meretrix or Saccostrea cucullata. Using light microscopy, we were able to identiby 4 oocyst morphotypes of the gregarine Nematopsis spp. Prevalence of Nematopsis spp. during the 13 mo sampling period was highest in A. arcuatula (91.8%; n = 110) and lowest in A. granosa (59.2%; n = 130). The morphology of the oocysts differed between hosts, with an average (x +/- SD) length/width of 16.28 +/- 0.64/12.01 +/- 0.35 microm (n = 50) for A. arcuatula, 16.90 +/- 0.71/12.69 +/- 0.33 microm (n = 50) for A. granosa, 17.61 +/- 0.69/12.72 +/- 0.36 microm (n = 50) for P. viridis, and 11.21 +/- 0.62/8.55 +/- 0.52 microm (n = 50) for P. undulata. Identification of oocysts of these apicomplexan gregarines to species was not attempted. The prevalence of infection in relation to habitat and time of sampling is discussed. PMID:15038451

  5. Comparison of oocyst shedding and the serum immune response to Cryptosporidium parvum in cattle and pigs.

    PubMed

    Quílez, J; Ares-Mazás, E; Sánchez-Acedo, C; del Cacho, E; Clavel, A; Causapé, A C

    1996-01-01

    A comparison was made between oocyst shedding and the presence of specific serum IgG antibodies to Cryptosporidium parvum in 108 bovines and 90 pigs. Oocysts were detected by a commercial immunofluorescence assay in feces from 26.8% of bovines and 34.4% of pigs, whereas positive titers as determined by an indirect fluorescent antibody method were found in sera from 12.9% and 48.9% of the respective animals. Infection was significantly most frequent in suckling calves (82.7%) and weaned piglets (87.5%). By contrast, the numbers of seropositives were highest in weaned calves (17.1%) and fattening pigs (76.6%). The results of coprological and serological analysis corresponded in 65.7% of bovines and 56.7% of pigs. When used to diagnose the shedding of cryptosporidial oocysts, the detection of specific IgG antibodies had a sensitivity ranging from 10.3% (cattle) to 58.1% (pigs) and a specificity of 86.1% (cattle) and 55.9% (pigs). PMID:8832734

  6. Simplified methods for obtaining purified oocysts from mice and for growing Cryptosporidium parvum in vitro.

    PubMed

    Meloni, B P; Thompson, R C

    1996-10-01

    Seven- to 8-day-old Arc/Swiss mice were infected with 100,000-120,000 Cryptosporidium parvum oocysts. At 8 days postinfection (PI) the jejunum, ileum, cecum, colon, and rectum were removed. Using a simple extraction procedure and purification by Ficoll gradient centrifugation, we rountinely obtained between 3-6 million and up to 15 million purified oocysts per mouse. For in vitro cultivation, purified oocysts were pretreated in a low pH (2.5-3) 0.5% trypsin solution for 20 min, resuspended in supplemented RPMI-1640 containing glucose 0.1 g (5.55 mM), sodium bicarbonate 0.3 g, bovine bile 0.02 g, folic acid 25 micrograms, 4-aminobenzoic acid 100 micrograms, calcium pantothenate 50 micrograms, ascorbic acid 875 micrograms, penicillin G 10,000 U and streptomycin 0.01 g per 100 ml, and 1% fetal bovine serum (pH 7.4 before filtration), and used to inoculate confluent monolayers of the human adenocarcinoma cell line HCT-8. Incubation was in a candle jar at 37 C. We tested numerous supplements to RPMI-1640, different pHs, and atmospheric conditions and found the parameters described above produced the greatest parasite numbers in vitro. We obtained significantly superior growth of C. parvum grown in HCT-8 cells using the conditions described above than in culture conditions described previously. PMID:8885885

  7. Malaria control in Nepal 1963–2012: challenges on the path towards elimination

    PubMed Central

    2014-01-01

    Background Malaria is still a priority public health problem of Nepal where about 84% of the population are at risk. The aim of this paper is to highlight the past and present malaria situation in this country and its challenges for long-term malaria elimination strategies. Methods Malariometric indicator data of Nepal recorded through routine surveillance of health facilities for the years between 1963 and 2012 were compiled. Trends and differences in malaria indicator data were analysed. Results The trend of confirmed malaria cases in Nepal between 1963 and 2012 shows fluctuation, with a peak in 1985 when the number exceeded 42,321, representing the highest malaria case-load ever recorded in Nepal. This was followed by a steep declining trend of malaria with some major outbreaks. Nepal has made significant progress in controlling malaria transmission over the past decade: total confirmed malaria cases declined by 84% (12,750 in 2002 vs 2,092 in 2012), and there was only one reported death in 2012. Based on the evaluation of the National Malaria Control Programme in 2010, Nepal recently adopted a long-term malaria elimination strategy for the years 2011–2026 with the ambitious vision of a malaria-free Nepal by 2026. However, there has been an increasing trend of Plasmodium falciparum and imported malaria proportions in the last decade. Furthermore, the analysis of malariometric indicators of 31 malaria-risk districts between 2004 and 2012 shows a statistically significant reduction in the incidence of confirmed malaria and of Plasmodium vivax, but not in the incidence of P. falciparum and clinically suspected malaria. Conclusions Based on the achievements the country has made over the last decade, Nepal is preparing to move towards malaria elimination by 2026. However, considerable challenges lie ahead. These include especially, the need to improve access to diagnostic facilities to confirm clinically suspected cases and their treatment, the development of

  8. Estimates of child deaths prevented from malaria prevention scale-up in Africa 2001-2010

    PubMed Central

    2012-01-01

    Background Funding from external agencies for malaria control in Africa has increased dramatically over the past decade resulting in substantial increases in population coverage by effective malaria prevention interventions. This unprecedented effort to scale-up malaria interventions is likely improving child survival and will likely contribute to meeting Millennium Development Goal (MDG) 4 to reduce the < 5 mortality rate by two thirds between 1990 and 2015. Methods The Lives Saved Tool (LiST) model was used to quantify the likely impact that malaria prevention intervention scale-up has had on malaria mortality over the past decade (2001-2010) across 43 malaria endemic countries in sub-Saharan African. The likely impact of ITNs and malaria prevention interventions in pregnancy (intermittent preventive treatment [IPTp] and ITNs used during pregnancy) over this period was assessed. Results The LiST model conservatively estimates that malaria prevention intervention scale-up over the past decade has prevented 842,800 (uncertainty: 562,800-1,364,645) child deaths due to malaria across 43 malaria-endemic countries in Africa, compared to a baseline of the year 2000. Over the entire decade, this represents an 8.2% decrease in the number of malaria-caused child deaths that would have occurred over this period had malaria prevention coverage remained unchanged since 2000. The biggest impact occurred in 2010 with a 24.4% decrease in malaria-caused child deaths compared to what would have happened had malaria prevention interventions not been scaled-up beyond 2000 coverage levels. ITNs accounted for 99% of the lives saved. Conclusions The results suggest that funding for malaria prevention in Africa over the past decade has had a substantial impact on decreasing child deaths due to malaria. Rapidly achieving and then maintaining universal coverage of these interventions should be an urgent priority for malaria control programmes in the future. Successful scale-up in many

  9. Rapid diagnostic tests for malaria

    PubMed Central

    Daily, Jennifer; Hotte, Nora; Dolkart, Caitlin; Cunningham, Jane; Yadav, Prashant

    2015-01-01

    Abstract Maintaining quality, competitiveness and innovation in global health technology is a constant challenge for manufacturers, while affordability, access and equity are challenges for governments and international agencies. In this paper we discuss these issues with reference to rapid diagnostic tests for malaria. Strategies to control and eliminate malaria depend on early and accurate diagnosis. Rapid diagnostic tests for malaria require little training and equipment and can be performed by non-specialists in remote settings. Use of these tests has expanded significantly over the last few years, following recommendations to test all suspected malaria cases before treatment and the implementation of an evaluation programme to assess the performance of the malaria rapid diagnostic tests. Despite these gains, challenges exist that, if not addressed, could jeopardize the progress made to date. We discuss recent developments in rapid diagnostic tests for malaria, highlight some of the challenges and provide suggestions to address them. PMID:26668438

  10. Bioaccumulation and elimination of Cryptosporidium parvum oocysts in experimentally exposed Eastern oysters (Crassostrea virginica) held in static tank aquaria.

    PubMed

    Willis, Jessica E; McClure, J T; McClure, Carol; Spears, Jonathan; Davidson, Jeff; Greenwood, Spencer J

    2014-03-01

    A variety of human enteropathogens, including viruses, bacteria, and parasites, have been shown to bioaccumulate in suspension-feeding bivalve shellfish. Cryptosporidium parvum is a zoonotic protozoan parasite that has been detected in many shellfish species within both fecally contaminated and clean oyster growing areas across the globe. For this study, C. parvum oocysts (1000 and 10,000) were spiked into 10 L of water in static tank systems housing Crassostrea virginica. Oysters were either held in the contaminated aquaria for 7 days of exposure or were exposed for 24h and subsequently placed in a clean static tank system for the remainder of the trial. Individual oysters, fecal material, and tank water were analyzed for oocysts up to 7 days post-exposure via direct immunofluorescence. Oysters held under chronic exposure conditions gradually accumulated oocysts (1.5 or 34.4 oocysts/oyster/day for low or high dose exposure groups, respectively) between days 1 and 7, with an exponential uptake in oocysts observed within the first 24h post-exposure (mean uptake of 29.6 or 241.9 oocysts/oyster, respectively). Oysters that were transferred to clean water after 24h were capable of slowly depurating oocysts, following a linear trend. During chronic exposure trials 48-49% of the total spiked inoculum was recovered from oyster tissue, whereas 4.8-5.9% and 38-40% was recovered from tank water and from fecal material at day 7, respectively. In acute exposure trials, 30-31% of the total tank inoculum was found in oysters, suggesting that chronically exposed oysters were likely re-filtering some oocysts. Examinations of oyster fecal material from acute exposures revealed that 72-82% of oocysts recovered were already excreted at the time of oyster transfer (day 1), with only 18-28% being excreted during the static depuration phase. These data support that although most C. parvum oocysts are removed by C. virginica oysters within 24h, elimination after this point occurs slowly

  11. Diversity Cascades and Malaria Vectors

    PubMed Central

    CARLSON, JOHN C.; DYER, LEE A.; OMLIN, FRANCOIS X.; BEIER, JOHN C.

    2009-01-01

    The interactions between predator diversity and primary consumer abundance can include direct effects and indirect, cascading effects. Understanding these effects on immature Anopheles mosquitoes is important in sub-Saharan Africa, where most cases of malaria occur. Aquatic predators and immature mosquitoes were collected from shallow pools of varying age previously excavated by brickmakers in the western highlands of Kenya. Path analysis showed an indirect negative effect of habitat age on An. gambiae (Giles, 1902) mediated by effects on predator diversity. Disturbance resets habitats to an earlier successional stage, diminishing predator diversity and increasing An. gambiae populations. The increase in vector abundance as a result of reduced predator diversity highlights the public health value in conserving native insect diversity. PMID:19496413

  12. Effects of seeding procedures and water quality on recovery of Cryptosporidium oocysts from stream water by using U.S. Environmental Protection Agency method 1623

    USGS Publications Warehouse

    Francy, D.S.; Simmons, O. D., III; Ware, M.W.; Granger, E.J.; Sobsey, M.D.; Schaefer, F. W., III

    2004-01-01

    U.S. Environmental Protection Agency method 1623 is widely used to monitor source waters and drinking water supplies for Cryptosporidium oocysts. Matrix spikes, used to determine the effect of the environmental matrix on the method's recovery efficiency for the target organism, require the collection and analysis of two environmental samples, one for analysis of endemic oocysts and the other for analysis of recovery efficiency. A new product, ColorSeed, enables the analyst to determine recovery efficiency by using modified seeded oocysts that can be differentiated from endemic organisms in a single sample. Twenty-nine stream water samples and one untreated effluent sample from a cattle feedlot were collected in triplicate to compare modified seeding procedures to conventional seeding procedures that use viable, unmodified oocysts. Significant negative correlations were found between the average oocyst recovery and turbidity or suspended sediment; this was especially apparent in samples with turbidities greater than 100 nephelometric turbidity units and suspended sediment concentrations greater than 100 mg/liter. Cryptosporidium oocysts were found in 16.7% of the unseeded environmental samples, and concentrations, adjusted for recoveries, ranged from 4 to 80 oocysts per 10 liters. Determining recovery efficiency also provided data to calculate detection limits; these ranged from <2 to <215 oocysts per 10 liters. Recoveries of oocysts ranged from 2.0 to 61% for viable oocysts and from 3.0 to 59% for modified oocysts. The recoveries between the two seeding procedures were highly correlated (r = 0.802) and were not significantly different. Recoveries by using modified oocysts, therefore, were comparable to recoveries by using conventional seeding procedures.

  13. Role for the Plasmodium sporozoite-specific transmembrane protein S6 in parasite motility and efficient malaria transmission.

    PubMed

    Steinbuechel, Marion; Matuschewski, Kai

    2009-02-01

    Malaria transmission occurs by intradermal deposition of Plasmodium sporozoites during the infectious bite of a female Anopheles mosquito. After formation in midgut-associated oocysts sporozoites actively enter mosquito salivary glands and subsequently invade host hepatocytes where they transform into clinically silent liver stages. To date, two sporozoite-specific transmembrane proteins have been identified that perform vital functions in natural malaria transmission. The sporozoite invasin TRAP drives sporozoite motility and target cell entry whereas the adhesin MAEBL mediates sporozoite recognition of and attachment to salivary glands. Here, we demonstrate that the sporozoite-specific transmembrane protein S6 is required for efficient malaria transmission to the vertebrate host. Targeted deletion of S6 results in severe impairment of sporozoite gliding motility and invasion of mosquito salivary glands. During sporozoite maturation S6 expression is tightly regulated by transcriptional and translational control. We propose that S6 functions together with TRAP/MIC2 family invasins to direct fast, efficient and specific cell entry and, ultimately, life cycle progression of the malaria sporozoite. PMID:19016774

  14. Cytokine Profiling in Immigrants with Clinical Malaria after Extended Periods of Interrupted Exposure to Plasmodium falciparum

    PubMed Central

    Moncunill, Gemma; Mayor, Alfredo; Bardají, Azucena; Puyol, Laura; Nhabomba, Augusto; Barrios, Diana; Aguilar, Ruth; Pinazo, María-Jesús; Almirall, Mercè; Soler, Cristina; Muñoz, José; Gascón, Joaquim; Dobaño, Carlota

    2013-01-01

    Immunity to malaria is believed to wane with time in the absence of exposure to Plasmodium falciparum infection, but immunoepidemiological data on longevity of immunity remain controversial. We quantified serum cytokines and chemokines by suspension array technology as potential biomarkers for durability of immunity in immigrants with clinical malaria after years without parasite exposure. These were compared to serum/plasma profiles in naïve adults (travelers) and semi-immune adults under continuous exposure, with malaria, along with immigrant and traveler patients without malaria. Immigrants had higher levels of IL-2, IL-5 and IL-8 compared to semi-immune adults with malaria (P≤0.0200). Time since immigration correlated with increased IL-2 (rho=0.2738P=0.0495) and IFN-γ (rho=0.3044P=0.0282). However, immigrants did not show as high IFN-γ concentrations as travelers during a first malaria episode (P<0.0001). Immigrants and travelers with malaria had higher levels of IFN-γ, IL-6, and IL-10 (P<0.0100) than patients with other diseases, and IL-8 and IL-1β were elevated in immigrants with malaria (P<0.0500). Therefore, malaria patients had a characteristic strong pro-inflammatory/Th1 signature. Upon loss of exposure, control of pro-inflammatory responses and tolerance to P. falciparum appeared to be reduced. Understanding the mechanisms to maintain non-pathogenic effector responses is important to develop new malaria control strategies. PMID:23967342

  15. Protective role of brain water channel AQP4 in murine cerebral malaria

    PubMed Central

    Promeneur, Dominique; Lunde, Lisa Kristina; Amiry-Moghaddam, Mahmood; Agre, Peter

    2013-01-01

    Tragically common among children in sub-Saharan Africa, cerebral malaria is characterized by rapid progression to coma and death. In this study, we used a model of cerebral malaria appearing in C57BL/6 WT mice after infection with the rodent malaria parasite Plasmodium berghei ANKA. Expression and cellular localization of the brain water channel aquaporin-4 (AQP4) was investigated during the neurological syndrome. Semiquantitative real-time PCR comparing uninfected and infected mice showed a reduction of brain AQP4 transcript in cerebral malaria, and immunoblots revealed reduction of brain AQP4 protein. Reduction of brain AQP4 protein was confirmed in cerebral malaria by quantitative immunogold EM; however, polarized distribution of AQP4 at the perivascular and subpial astrocyte membranes was not altered. To further examine the role of AQP4 in cerebral malaria, WT mice and littermates genetically deficient in AQP4 were infected with P. berghei. Upon development of cerebral malaria, WT and AQP4-null mice exhibited similar increases in width of perivascular astroglial end-feet in brain. Nevertheless, the AQP4-null mice exhibited more severe signs of cerebral malaria with greater brain edema, although disruption of the blood–brain barrier was similar in both groups. In longitudinal studies, cerebral malaria appeared nearly 1 d earlier in the AQP4-null mice, and reduced survival was noted when chloroquine rescue was attempted. We conclude that the water channel AQP4 confers partial protection against cerebral malaria. PMID:23277579

  16. Affinity Proteomics Reveals Elevated Muscle Proteins in Plasma of Children with Cerebral Malaria

    PubMed Central

    Pramana, Setia; Conte, Ianina; Brown, Biobele J.; Orimadegun, Adebola E.; Ajetunmobi, Wasiu A.; Afolabi, Nathaniel K.; Akinkunmi, Francis; Omokhodion, Samuel; Akinbami, Felix O.; Shokunbi, Wuraola A.; Kampf, Caroline; Pawitan, Yudi; Uhlén, Mathias; Sodeinde, Olugbemiro; Schwenk, Jochen M.; Wahlgren, Mats; Fernandez-Reyes, Delmiro; Nilsson, Peter

    2014-01-01

    Systemic inflammation and sequestration of parasitized erythrocytes are central processes in the pathophysiology of severe Plasmodium falciparum childhood malaria. However, it is still not understood why some children are more at risks to develop malaria complications than others. To identify human proteins in plasma related to childhood malaria syndromes, multiplex antibody suspension bead arrays were employed. Out of the 1,015 proteins analyzed in plasma from more than 700 children, 41 differed between malaria infected children and community controls, whereas 13 discriminated uncomplicated malaria from severe malaria syndromes. Markers of oxidative stress were found related to severe malaria anemia while markers of endothelial activation, platelet adhesion and muscular damage were identified in relation to children with cerebral malaria. These findings suggest the presence of generalized vascular inflammation, vascular wall modulations, activation of endothelium and unbalanced glucose metabolism in severe malaria. The increased levels of specific muscle proteins in plasma implicate potential muscle damage and microvasculature lesions during the course of cerebral malaria. PMID:24743550

  17. Affinity proteomics reveals elevated muscle proteins in plasma of children with cerebral malaria.

    PubMed

    Bachmann, Julie; Burté, Florence; Pramana, Setia; Conte, Ianina; Brown, Biobele J; Orimadegun, Adebola E; Ajetunmobi, Wasiu A; Afolabi, Nathaniel K; Akinkunmi, Francis; Omokhodion, Samuel; Akinbami, Felix O; Shokunbi, Wuraola A; Kampf, Caroline; Pawitan, Yudi; Uhlén, Mathias; Sodeinde, Olugbemiro; Schwenk, Jochen M; Wahlgren, Mats; Fernandez-Reyes, Delmiro; Nilsson, Peter

    2014-04-01

    Systemic inflammation and sequestration of parasitized erythrocytes are central processes in the pathophysiology of severe Plasmodium falciparum childhood malaria. However, it is still not understood why some children are more at risks to develop malaria complications than others. To identify human proteins in plasma related to childhood malaria syndromes, multiplex antibody suspension bead arrays were employed. Out of the 1,015 proteins analyzed in plasma from more than 700 children, 41 differed between malaria infected children and community controls, whereas 13 discriminated uncomplicated malaria from severe malaria syndromes. Markers of oxidative stress were found related to severe malaria anemia while markers of endothelial activation, platelet adhesion and muscular damage were identified in relation to children with cerebral malaria. These findings suggest the presence of generalized vascular inflammation, vascular wall modulations, activation of endothelium and unbalanced glucose metabolism in severe malaria. The increased levels of specific muscle proteins in plasma implicate potential muscle damage and microvasculature lesions during the course of cerebral malaria. PMID:24743550

  18. [Malaria situation in the People's Republic of China in 1999].

    PubMed

    2000-01-01

    Although the middle and lower reaches of Changjiang River were consecutively stricken by severe flood in 1998 and 1999, the transmission of malaria was not frequent and prevalence of the disease was basically stable with no reports of outbreaks in the above areas, which was attributed to the intensification of malaria surveillance, prompt implementation of integrated measures including mosquito control and chemoprophylaxis, as well as the zoophilous trend of Anopheles sinensis, the vector in the stricken areas. According to the case reporting system established on the basis of professional institutions of 22 provinces, autonomous regions and municipalities (P/A/M), the number of malaria cases in the country totalled 29,039 in 1999, with lethal cases of 67. Based on pilot-site surveillance and investigation of som