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1.
PLoS Negl Trop Dis ; 15(12): e0010062, 2021 12.
Article in English | MEDLINE | ID: mdl-34941866

ABSTRACT

Schistosomes cause schistosomiasis, the world's second most important parasitic disease after malaria in terms of public health and social-economic impacts. A peculiar feature of these dioecious parasites is their ability to produce viable and fertile hybrid offspring. Originally only present in the tropics, schistosomiasis is now also endemic in southern Europe. Based on the analysis of two genetic markers the European schistosomes had previously been identified as hybrids between the livestock- and the human-infective species Schistosoma bovis and Schistosoma haematobium, respectively. Here, using PacBio long-read sequencing technology we performed genome assembly improvement and annotation of S. bovis, one of the parental species for which no satisfactory genome assembly was available. We then describe the whole genome introgression levels of the hybrid schistosomes, their morphometric parameters (eggs and adult worms) and their compatibility with two European snail strains used as vectors (Bulinus truncatus and Planorbarius metidjensis). Schistosome-snail compatibility is a key parameter for the parasites life cycle progression, and thus the capability of the parasite to establish in a given area. Our results show that this Schistosoma hybrid is strongly introgressed genetically, composed of 77% S. haematobium and 23% S. bovis origin. This genomic admixture suggests an ancient hybridization event and subsequent backcrosses with the human-specific species, S. haematobium, before its introduction in Corsica. We also show that egg morphology (commonly used as a species diagnostic) does not allow for accurate hybrid identification while genetic tests do.


Subject(s)
Genome, Helminth , Hybridization, Genetic , Schistosoma haematobium/growth & development , Schistosoma haematobium/genetics , Schistosoma/growth & development , Schistosoma/genetics , Animals , Body Size , Bulinus/parasitology , Chimera/anatomy & histology , Chimera/genetics , Chimera/growth & development , Disease Vectors , Europe , Female , Humans , Male , Schistosoma/anatomy & histology , Schistosoma haematobium/anatomy & histology , Schistosomiasis/parasitology , Snails/parasitology
2.
PLoS Negl Trop Dis ; 15(5): e0009363, 2021 05.
Article in English | MEDLINE | ID: mdl-33945524

ABSTRACT

Species usually develop reproductive isolation mechanisms allowing them to avoid interbreeding. These preventive barriers can act before reproduction, "pre-zygotic barriers", or after reproduction, "post-zygotic barriers". Pre-zygotic barriers prevent unfavourable mating, while post-zygotic barriers determine the viability and selective success of the hybrid offspring. Hybridization in parasites and the underlying reproductive isolation mechanisms maintaining their genetic integrity have been overlooked. Using an integrated approach this work aims to quantify the relative importance of pre-zygotic barriers in Schistosoma haematobium x S. bovis crosses. These two co-endemic species cause schistosomiasis, one of the major debilitating parasitic diseases worldwide, and can hybridize naturally. Using mate choice experiments we first tested if a specific mate recognition system exists between both species. Second, using RNA-sequencing we analysed differential gene expression between homo- and hetero-specific pairing in male and female adult parasites. We show that homo- and hetero-specific pairing occurs randomly between these two species, and few genes in both sexes are affected by hetero-specific pairing. This suggests that i) mate choice is not a reproductive isolating factor, and that ii) no pre-zygotic barrier except spatial isolation "by the final vertebrate host" seems to limit interbreeding between these two species. Interestingly, among the few genes affected by the pairing status of the worms, some can be related to pathways affected during male and female interactions and may also present interesting candidates for species isolation mechanisms and hybridization in schistosome parasites.


Subject(s)
Mosaicism/embryology , Reproduction/physiology , Reproductive Isolation , Schistosoma haematobium/classification , Animals , Cricetinae , Female , Gene Expression Regulation , Genetic Speciation , Male , Schistosoma haematobium/embryology , Schistosoma haematobium/growth & development
3.
J Korean Med Sci ; 35(46): e394, 2020 Nov 30.
Article in English | MEDLINE | ID: mdl-33258330

ABSTRACT

This study compared the anthelminthic effects of three different brands of praziquantel being used in Sudan against Schistosoma haematobium (S. haematobium) infection. We enrolled 1,286 schoolchildren from six primary schools and examined their urine samples for eggs of S. haematobium at the baseline survey and follow-up two weeks after administering the medication. The schoolchildren were divided into three groups based on the three brands of praziquantel (different material production), with two school children for one brand. The overall baseline prevalence of S. haematobium infection was 15.5%. Two weeks after treatment with brands A, B, and C of praziquantel, cure rates were 87.1%, 82.4% and 83.8% respectively, and the egg-reduction rates were 69.0%, 81.0% and 70.6% respectively. There was no statistically significant difference in cure rates and egg-reduction rates between the three brands. We conclude that the three different commercial brands of praziquantel used in Sudan have similar anthelminthic effects on S. haematobium.


Subject(s)
Anthelmintics/therapeutic use , Praziquantel/therapeutic use , Schistosomiasis haematobia/drug therapy , Animals , Anthelmintics/chemistry , Anthelmintics/pharmacology , Child , Female , Humans , Male , Ovum/drug effects , Praziquantel/chemistry , Praziquantel/pharmacology , Schistosoma haematobium/drug effects , Schistosoma haematobium/growth & development , Schistosoma haematobium/isolation & purification , Schools , Sudan , Treatment Outcome
4.
Parasitol Res ; 119(7): 2189-2205, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32468189

ABSTRACT

Schistosomiasis remains a parasitic infection which poses serious public health consequences around the world, particularly on the African continent where cases of introgression/hybridization between human and cattle schistosomiasis are being discovered on a more frequent basis in humans, specifically between Schistosoma haematobium and S. bovis. The aim of this paper is to analyze the occurrence of S. bovis in cattle and its relationship with S. haematobium in an area where cattle and humans share the same site in Benin (West Africa). We used the chronobiology of cercarial emergence as an ecological parameter and both molecular biology (COI mtDNA and ITS rDNA) of the larvae and morphology of the eggs as taxonomic parameters. The results showed a chronobiological polymorphism in the cercarial emergence rhythm. They showed for the first time the presence of S. bovis in Benin, the presence of introgressive hybridization between S. bovis and S. haematobium in domestic cattle, and the presence of atypical chronobiological patterns in schistosomes from cattle, with typical S. haematobium shedding pattern, double-peak patterns, and nocturnal patterns. Our results showed that the chronobiological life-history trait is useful for the detection of new hosts and also may reveal the possible presence of introgressive hybridization in schistosomes. Our results, for the first time, place cattle as reservoir host for S. haematobium and S. bovis x S. haematobium. The consequences of these results on the epidemiology of the disease, the transmission to humans, and the control of the disease are very important.


Subject(s)
Cattle/parasitology , Schistosoma/isolation & purification , Schistosomiasis/veterinary , Animals , Benin/epidemiology , Cercaria/genetics , Cercaria/growth & development , Cercaria/isolation & purification , Circadian Rhythm , DNA, Mitochondrial/genetics , DNA, Ribosomal/genetics , Genetic Introgression , Humans , Schistosoma/genetics , Schistosoma/growth & development , Schistosoma haematobium/genetics , Schistosoma haematobium/growth & development , Schistosoma haematobium/isolation & purification , Schistosomiasis/parasitology
6.
Lancet Glob Health ; 7(8): e1118-e1129, 2019 08.
Article in English | MEDLINE | ID: mdl-31255591

ABSTRACT

BACKGROUND: Elimination of schistosomiasis as a public health problem and interruption of transmission in selected areas are targets set by WHO for 2025. Our aim was to assess biannual mass drug administration (MDA) applied alone or with complementary snail control or behaviour change interventions for the reduction of Schistosoma haematobium prevalence and infection intensity in children from Zanzibar and to compare the effect between the clusters. METHODS: In a 5-year repeated cross-sectional cluster-randomised trial, 90 shehias (small administrative regions; clusters) in Zanzibar eligible owing to available natural open freshwater bodies and public primary schools were randomly allocated (ratio 1:1:1) to receive one of three interventions: biannual MDA with praziquantel alone (arm 1) or in combination with snail control (arm 2), or behaviour change activities (arm 3). Neither participants nor field or laboratory personnel were blinded to the intervention arms. From 2012 to 2017, annually, a single urine sample was collected from approximately 100 children aged 9-12 years in the main public primary school of each shehia. The primary outcome was S haematobium infection prevalence and intensity in 9-12-year-old children after 5 years of follow-up. This study is completed and was registered with the ISRCTN, number 48837681. FINDINGS: The trial was done from Nov 1, 2011, through to Dec 31, 2017 and recruitment took place from Nov 2, 2011, until May 17, 2017. At baseline we enrolled 8278 participants, of whom 2899 (35%) were randomly allocated to arm 1, 2741 (33%) to arm 2, and 2638 (32%) to arm 3. 120 (4·2%) of 2853 in arm 1, 209 (7·8%) of 2688 in arm 2, and 167 (6·4%) of 2613 in arm 3 had S haematobium infections at baseline. Heavy infections (≥50 eggs per 10 mL of urine) were found in 126 (1·6%) of 8073 children at baseline. At the 5-year endline survey, 46 (1·4%) of 3184 in arm 1, 56 (1·7%) of 3217 (odds ratio [OR] 1·2 [95% CI 0·6-2·7] vs arm 1) in arm 2, and 58 (1·9%) of 3080 (1·3 [0·6-2·9]) in arm 3 had S haematobium infections. Heavy infections were detected in 33 (0·3%) of 9462 children. INTERPRETATION: Biannual MDA substantially reduced the S haematobium prevalence and infection intensity but was insufficient to interrupt transmission. Although snail control or behaviour change activities did not significantly boost the effect of MDA in our study, they might enhance interruption of transmission when tailored to focal endemicity and applied for a longer period. It is now necessary to focus on reducing prevalence in remaining hotspot areas and to introduce new methods of surveillance and public health response so that the important gains can be maintained and advanced. FUNDING: University of Georgia Research Foundation Inc and Bill & Melinda Gates Foundation.


Subject(s)
Anthelmintics/administration & dosage , Delivery of Health Care, Integrated , Disease Eradication , Praziquantel/administration & dosage , Schistosoma haematobium/drug effects , Schistosomiasis haematobia/drug therapy , Schistosomiasis haematobia/prevention & control , Animals , Child , Cluster Analysis , Female , Health Promotion , Humans , Male , Schistosoma haematobium/growth & development , Schistosomiasis haematobia/epidemiology , Tanzania/epidemiology
7.
BMC Infect Dis ; 19(1): 219, 2019 Mar 04.
Article in English | MEDLINE | ID: mdl-30832614

ABSTRACT

BACKGROUND: Schistosomiasis is a devastating parasitic disease. The mainstay of schistosomiasis control is by praziquantel treatment. The study aimed to determine benefits of annual chemotherapy of schistosomiasis on development of protective immunity in school children in a selected endemic rural area in Zimbabwe. METHODS: Urine specimens from 212 school children (7-13 years) were collected and examined to determine prevalence, intensity and reinfection of S.haematobium at baseline, 6 weeks and 2 years following annual rounds of praziquantel treatment. Blood samples from the participants were assayed for total and S. haematobium (Sh13)-specific antibodies before and 2 years after annual rounds of treatment. RESULTS: Annual treatment reduced the prevalence of S. haematobium infection (p < 0.05) from 23.1% at baseline to 0.47% after 2 years. Overall cure rate was 97.8%. Intensity of infection declined (p < 0.05) from 15.9 eggs/10 ml urine at baseline to 2 eggs/10 ml urine. After two years, overall rate of reinfection was 0.96%. At baseline, total IgG4 was higher in S. haematobium-infected children (p = 0.042) ,while all other immunoglobulins were within normal ranges. There was an increase in total IgG2 (p = 0.044) levels and a decrease in total IgG4 (p = 0.031) levels 2 years post-treatment; and no significant changes in other total immunoglobulins. Schistosoma-infected children at baseline showed an increase in anti-Sh13 IgG1 (p = 0.005) and a decrease in Sh13 IgG4 levels (p = 0.012) following treatment. CONCLUSION: Annual praziquantel treatment delivered to school children over 2 years significantly reduce prevalence, intensity of infection and reinfection of S. haematobium infection. Treatment was also observed to cause a reduction in schistosome-specific blocking IgG4 and an increase in Schistosoma-specific protecting IgG1.


Subject(s)
Adaptive Immunity , Anthelmintics/therapeutic use , Schistosomiasis haematobia/drug therapy , Adolescent , Animals , Antibodies, Helminth/blood , Child , Female , Hematuria/pathology , Hematuria/urine , Humans , Immunoglobulin G/metabolism , Immunoglobulin Isotypes/blood , Longitudinal Studies , Male , Ovum/cytology , Praziquantel/therapeutic use , Prevalence , Schistosoma haematobium/growth & development , Schistosoma haematobium/immunology , Schistosomiasis haematobia/epidemiology , Schistosomiasis haematobia/immunology , Treatment Outcome , Zimbabwe/epidemiology
8.
Infect Immun ; 87(1)2019 01.
Article in English | MEDLINE | ID: mdl-30323023

ABSTRACT

Schistosome worms infect over 200 million people worldwide. They live in the host's bloodstream and alter host immunity. Epidemiological data suggest that males and females have different responses to schistosome infection, but the effect of sex on systemic response is undetermined. Our objective was to characterize differences in peripheral blood transcriptional profiles in people with or without active Schistosoma haematobium infection and to determine whether this signature differs between males and females. mRNA was isolated using poly(A) selection and sequenced on an Illumina Hi-Seq4000 platform. Transcripts were aligned to the human hg19 reference genome and counted with the HTSeq package. Genes were compared for differential expression using DESeq2. Ingenuity Pathway Analysis (IPA) was used to identify gene networks altered in the presence of S. haematobium We enrolled 33 participants from villages in rural Tanzania where S. haematobium is endemic. After correction for multiple comparisons, we observed 383 differentially expressed genes between those with or without S. haematobium infection when sex was included as a covariate. Heat-mapping of the genes with >1.5-fold differences in gene expression revealed clustering by S. haematobium infection status. The top networks included development, cell death and survival, cell signaling, and immunologic disease pathways. We observed a distinct whole blood transcriptional profile, as well as differences in men and women, with S. haematobium infection. Additional studies are needed to determine the clinical effects of these divergent responses. Attention to sex-based differences should be included in studies of human schistosome infection.


Subject(s)
Blood Cells/immunology , Blood Cells/parasitology , Gene Expression Profiling , Host-Pathogen Interactions , Schistosoma haematobium/immunology , Schistosomiasis haematobia/immunology , Schistosomiasis haematobia/pathology , Adolescent , Adult , Animals , Female , Gene Regulatory Networks , Humans , Male , Middle Aged , Schistosoma haematobium/growth & development , Sequence Analysis, RNA , Sex Factors , Tanzania , Young Adult
9.
Trans R Soc Trop Med Hyg ; 112(7): 361-365, 2018 07 01.
Article in English | MEDLINE | ID: mdl-29992295

ABSTRACT

Background: Barombi Kotto, Cameroon serves as a reference location for assessing intervention strategies against Schistosoma haematobium. Methods: As part of a pilot study, the whole community was treated with praziquantel, inclusive of pre-school-age children (PSAC) and their mothers. One year later, egg-patent infections were reassessed and water contact patterns of 12 pairs of PSAC and their mothers were measured with global positioning system (GPS) data loggers. Results: A substantial reduction in general infection prevalence, from 44.8% to 12.2%, was observed but certain PSAC and mothers continued to have egg-patent infections. Analysis of GPS data demonstrated similar water contact levels between the child and mother groups, although certain individuals were numerical outliers. Conclusions: This study shows the potential of GPS data loggers to clarify the at-risk status of PSAC and mothers.


Subject(s)
Environmental Exposure/analysis , Lakes , Schistosoma haematobium/growth & development , Schistosomiasis haematobia/epidemiology , Urogenital System/parasitology , Water , Adolescent , Adult , Animals , Cameroon/epidemiology , Child , Child, Preschool , Female , Female Urogenital Diseases/drug therapy , Female Urogenital Diseases/epidemiology , Female Urogenital Diseases/parasitology , Geographic Information Systems , Humans , Male , Mass Drug Administration , Pilot Projects , Praziquantel/therapeutic use , Prevalence , Residence Characteristics , Risk Assessment , Schistosomiasis haematobia/drug therapy , Schistosomiasis haematobia/parasitology , Wearable Electronic Devices
10.
Nat Commun ; 9(1): 837, 2018 02 26.
Article in English | MEDLINE | ID: mdl-29483531

ABSTRACT

Schistosomiasis is a snail-borne parasitic disease that ranks among the most important water-based diseases of humans in developing countries. Increased prevalence and spread of human schistosomiasis to non-endemic areas has been consistently linked with water resource management related to agricultural expansion. However, the role of agrochemical pollution in human schistosome transmission remains unexplored, despite strong evidence of agrochemicals increasing snail-borne diseases of wildlife and a projected 2- to 5-fold increase in global agrochemical use by 2050. Using a field mesocosm experiment, we show that environmentally relevant concentrations of fertilizer, a herbicide, and an insecticide, individually and as mixtures, increase densities of schistosome-infected snails by increasing the algae snails eat and decreasing densities of snail predators. Epidemiological models indicate that these agrochemical effects can increase transmission of schistosomes. Identifying agricultural practices or agrochemicals that minimize disease risk will be critical to meeting growing food demands while improving human wellbeing.


Subject(s)
Agrochemicals/pharmacology , Astacoidea/drug effects , Heteroptera/drug effects , Schistosoma haematobium/drug effects , Schistosoma mansoni/drug effects , Schistosomiasis/veterinary , Snails/drug effects , Animals , Astacoidea/physiology , Atrazine/pharmacology , Chlorpyrifos/pharmacology , Cricetinae , Ecosystem , Fertilizers/toxicity , Food Chain , Heteroptera/physiology , Humans , Parasite Egg Count , Periphyton/drug effects , Periphyton/physiology , Phytoplankton/drug effects , Phytoplankton/growth & development , Ponds , Risk , Schistosoma haematobium/growth & development , Schistosoma mansoni/growth & development , Schistosomiasis/parasitology , Schistosomiasis/transmission , Snails/parasitology
11.
Trans R Soc Trop Med Hyg ; 111(7): 316-324, 2017 07 01.
Article in English | MEDLINE | ID: mdl-29165707

ABSTRACT

Background: This cohort study assessed urinary eosinophil cationic protein (ECP) as an indicator for urinary tract morbidity and inflammation indication related to single-dose or dual-dose praziquantel (PZQ) treatment. Methods: Urinary ECP was measured at baseline, 24 h and 9 weeks after treatment (baseline 305, follow-up 204 participants, ages 2-40 years). Results: ECP was significantly associated with the intensity of infection at baseline (p<0.05). Levels at baseline were 8.31 times higher (p<0.01) in participants with bladder morbidity than in those without. There was no correlation with kidney morbidity and no significant effect of a repeated dose of PZQ 40 mg/kg. Baseline ECP and ECP after 9 weeks were associated with microhaematuria (geometric mean ratio at baseline 7.56 [95% confidence limit {CL} 2.34-24.45]; p<0.01) and macrohaematuria (geometric mean ratio at baseline 6.22 [95% CL 2.71-14.24]; p<0.001). Mean levels of ECP dropped significantly during the first follow-up period and far less so in the second follow-up period (mean ECP at baseline: 70.8 ng/mL; ECP at 24 h: 24.5 ng/mL; ECP at 9 weeks: 14.6 ng/mL). Conclusion: The urine ECP decrease happened immediately after treatment, reflecting the rapid action of PZQ on eggs in the bladder tissue. ECP in urine can be used as an indirect marker of the degree of local inflammatory reaction in the bladder and is not significantly affected by a repeated dose of PZQ.


Subject(s)
Anthelmintics/therapeutic use , Eosinophil Cationic Protein/urine , Inflammation/urine , Praziquantel/therapeutic use , Schistosoma haematobium/drug effects , Schistosomiasis haematobia/drug therapy , Urinary Bladder , Adolescent , Adult , Animals , Anthelmintics/administration & dosage , Anthelmintics/pharmacology , Biomarkers/urine , Child , Child, Preschool , Cohort Studies , Female , Hematuria , Humans , Inflammation/etiology , Kidney , Male , Parasite Egg Count , Praziquantel/administration & dosage , Praziquantel/pharmacology , Schistosoma haematobium/growth & development , Schistosoma haematobium/pathogenicity , Schistosomiasis haematobia/parasitology , Schistosomiasis haematobia/pathology , Schistosomiasis haematobia/urine , Urinary Bladder/drug effects , Urinary Bladder/parasitology , Urinary Bladder/pathology , Young Adult
12.
Parasitol Res ; 116(11): 3175-3188, 2017 Nov.
Article in English | MEDLINE | ID: mdl-29026995

ABSTRACT

Schistosomiasis remains a major global health problem. Despite large-scale schistosomiasis control efforts, clear limitations such as possible emergence of drug resistance and reinfection rates highlight the need for an effective schistosomiasis vaccine. Schistosoma mansoni large subunit of calpain (Sm-p80)-based vaccine formulations have shown remarkable efficacy in protecting against S. mansoni challenge infections in mice and baboons. In this study, we evaluated the cross-species protective efficacy of Sm-p80 vaccine against S. japonicum and S. haematobium challenge infections in rodent models. We also elucidated the expression of Sm-p80 and Sm-p80 ortholog proteins in different developmental stages of S. mansoni, S. haematobium, and S. japonicum. Immunization with Sm-p80 vaccine reduced worm burden by 46.75% against S. japonicum challenge infection in mice. DNA prime/protein boost (1 + 1 dose administered on a single day) resulted in 26.95% reduction in worm burden in S. haematobium-hamster infection/challenge model. A balanced Th1 (IFN-γ, TNF-α, IL-2, and IL-12) and Th2 (IL-4, IgG1) type of responses were observed following vaccination in both S. japonicum and S. haematobium challenge trials and these are associated with the prophylactic efficacy of Sm-p80 vaccine. Immunohistochemistry demonstrated that Sm-p80/Sm-p80 ortholog proteins are expressed in different life cycle stages of the three major human species of schistosomes studied. The data presented in this study reinforce the potential of Sm-p80-based vaccine for both hepatic/intestinal and urogenital schistosomiasis occurring in different geographical areas of the world. Differential expression of Sm-p80/Sm-p80 protein orthologs in different life cycle makes this vaccine potentially useful in targeting different levels of infection, disease, and transmission.


Subject(s)
Antigens, Helminth/immunology , Protozoan Vaccines/immunology , Schistosoma haematobium/immunology , Schistosoma japonicum/immunology , Schistosoma mansoni/immunology , Schistosomiasis haematobia/prevention & control , Schistosomiasis japonica/prevention & control , Schistosomiasis mansoni/prevention & control , Animals , Antibodies, Helminth/immunology , Calpain/immunology , Cricetinae , Disease Models, Animal , Female , Humans , Immunoglobulin G/immunology , Interleukin-12/biosynthesis , Interleukin-2/biosynthesis , Interleukin-4/biosynthesis , Male , Mice , Mice, Inbred C57BL , Papio , Schistosoma haematobium/growth & development , Schistosoma japonicum/growth & development , Schistosoma mansoni/growth & development , Schistosomiasis haematobia/immunology , Schistosomiasis haematobia/parasitology , Schistosomiasis japonica/immunology , Schistosomiasis japonica/parasitology , Schistosomiasis mansoni/immunology , Schistosomiasis mansoni/parasitology , Tumor Necrosis Factor-alpha/biosynthesis , Vaccination , Vaccines, DNA/immunology
13.
BMC Res Notes ; 9(1): 493, 2016 Nov 22.
Article in English | MEDLINE | ID: mdl-27876076

ABSTRACT

BACKGROUND: Schistosomiasis is a severe parasitic infestation with debilitating complications and is the third most devastating tropical disease in the world. It is one of the neglected tropical diseases (NTDs) with a high disease-burden. We present two rare cases of bladder outlet obstruction: one which led to a chronic kidney disease and ultimately death and a second which recovered after treatment with praziquantel. CASE PRESENTATIONS: A 72 year old male presented with lower urinary tract symptoms which culminated in an episode of acute urinary retention. The patient had never received preventive chemotherapy with praziquantel. After suprapubic aspiration, the cause of the obstructive uropathy was found to be several mature live worms of Schistosoma haematobium. Despite treatment with praziquantel and haemodialysis; we lost the patient due to sepsis from a urinary tract infection. In the second case, a 15 year old male presented with LUTS for a 1 year duration and was diagnosed to have schistosomiasis after eggs of Schistosoma haematobium were found in his urine. He was treated with praziquantel. CONCLUSION: There are several gaps in the public health policies in place to control this NTD in Cameroon as annual distribution of preventive chemotherapy is inadequate due to inaccessibility of some high-endemic zones and is based on data obtained two decades ago. Population education is insufficient leading to poor health-seeking behaviour. These gaps in public health policies need to be addressed to aid in the overall achievement of the sustainable development goals.


Subject(s)
Anthelmintics/therapeutic use , Praziquantel/therapeutic use , Schistosomiasis haematobia/diagnosis , Urinary Bladder Neck Obstruction/diagnosis , Urinary Tract Infections/diagnosis , Adolescent , Aged , Animals , Cameroon , Delayed Diagnosis , Health Knowledge, Attitudes, Practice , Humans , Male , Public Health/education , Schistosoma haematobium/drug effects , Schistosoma haematobium/growth & development , Schistosoma haematobium/pathogenicity , Schistosomiasis haematobia/complications , Schistosomiasis haematobia/drug therapy , Schistosomiasis haematobia/parasitology , Urinary Bladder/drug effects , Urinary Bladder/parasitology , Urinary Bladder/pathology , Urinary Bladder Neck Obstruction/complications , Urinary Bladder Neck Obstruction/drug therapy , Urinary Bladder Neck Obstruction/parasitology , Urinary Tract Infections/complications , Urinary Tract Infections/drug therapy , Urinary Tract Infections/parasitology
14.
PLoS Negl Trop Dis ; 10(11): e0005138, 2016 11.
Article in English | MEDLINE | ID: mdl-27861520

ABSTRACT

For scientists working on gonochoric organisms, determining sex can be crucial for many biological questions and experimental studies, such as crossbreeding, but it can also be a challenging task, particularly when no sexual dimorphism is visible or cannot be directly observed. In metazoan parasites of the genus Schistosoma responsible for schistosomiasis, sex is genetically determined in the zygote with a female heterogametic ZW/ZZ system. Adult flukes have a pronounced sexual dimorphism, whereas the sexes of the larval stages are morphologically indistinguishable but can be distinguished uniquely by using molecular methods. Therefore, reliable methods are needed to identify the sex of larvae individuals. Here, we present an endpoint PCR-based assay using female-specific sequences identified using a genome-wide comparative analysis between males and females. This work allowed us to identify sex-markers for Schistosoma haematobium and Schistosoma bovis but also the hybrid between both species that has recently emerged in Corsica (France). Five molecular sex-markers were identified and are female-specific in S. haematobium and the hybrid parasite, whereas three of them are also female-specific in S. bovis. These molecular markers will be useful to conduct studies, such as experimental crosses on these disease-causing blood flukes, which are still largely neglected but no longer restricted to tropical areas.


Subject(s)
Schistosoma haematobium/genetics , Schistosoma/genetics , Animals , Female , Genome, Helminth , Helminth Proteins/genetics , Hybridization, Genetic , Larva/genetics , Larva/growth & development , Larva/physiology , Male , Schistosoma/growth & development , Schistosoma/physiology , Schistosoma haematobium/growth & development , Schistosoma haematobium/physiology
15.
Am J Trop Med Hyg ; 95(2): 394-400, 2016 08 03.
Article in English | MEDLINE | ID: mdl-27273645

ABSTRACT

Infections with helminths and Plasmodium spp. overlap in their geographical distribution. It has been postulated that helminth infections may influence malarial transmission by altering Plasmodium falciparum gametocytogenesis. This cross-sectional study assessed the effect of helminth infections on P. falciparum gametocyte carriage and on humoral immune responses to sexual stage antigens in Gabon. Schistosoma haematobium and filarial infections as well as P. falciparum asexual forms and gametocyte carriage were determined. The antibody responses measured were to sexual (Pfs230, Pfs48/45) and asexual P. falciparum antigens (AMA1, MSP1, and GLURP). A total of 287 subjects were included. The prevalence of microscopically detectable P. falciparum asexual parasites was higher in S. haematobium-infected subjects in comparison to their uninfected counterparts (47% versus 26%, P = 0.003), but this was not different when filarial infections were considered. Plasmodium falciparum gametocyte carriage was similar between Schistosoma- or filaria-infected and uninfected subjects. We observed a significant decrease of Pfs48/45 immunoglobulin G titer in S. haematobium-infected subjects (P = 0.037), whereas no difference was seen for Pfs230 antibody titer, nor for antibodies to AMA1, MSP1, or GLURP. Our findings suggest an effect of S. haematobium on antibody responses to some P. falciparum gametocyte antigens that may have consequences for transmission-blocking immunity.


Subject(s)
Antibodies, Protozoan/biosynthesis , Life Cycle Stages/immunology , Malaria, Falciparum/immunology , Plasmodium falciparum/immunology , Schistosoma haematobium/immunology , Schistosomiasis haematobia/immunology , Adolescent , Animals , Antigens, Protozoan/genetics , Antigens, Protozoan/immunology , Child , Coinfection , Cross-Sectional Studies , Female , Gabon/epidemiology , Gene Expression , Humans , Immunity, Humoral , Life Cycle Stages/genetics , Malaria, Falciparum/epidemiology , Malaria, Falciparum/parasitology , Male , Membrane Glycoproteins/genetics , Membrane Glycoproteins/immunology , Membrane Proteins/genetics , Membrane Proteins/immunology , Merozoite Surface Protein 1/genetics , Merozoite Surface Protein 1/immunology , Plasmodium falciparum/genetics , Plasmodium falciparum/growth & development , Protozoan Proteins/genetics , Protozoan Proteins/immunology , Schistosoma haematobium/genetics , Schistosoma haematobium/growth & development , Schistosomiasis haematobia/epidemiology , Schistosomiasis haematobia/parasitology
16.
Article in Chinese | MEDLINE | ID: mdl-25051845

ABSTRACT

Schistosomiasis is a neglected tropical disease that severely threatens human health and affects the socioeconomic development. The causative agent that parasitizes in humans mainly involves Schistosoma japonicum, S. mansoni, S. haematobiurn, S. intercalatum and S. mekongi. As the firstly identified schistosome, S. haematobium infection is found to strongly correlate with bladder cancer. This paper mainly reviews the discovery, morphology and life cycle of S. haematobium.


Subject(s)
Schistosoma haematobium , Animals , Humans , Schistosoma haematobium/growth & development , Schistosoma haematobium/isolation & purification , Schistosoma haematobium/physiology , Schistosomiasis haematobia/parasitology
17.
Biochem Biophys Res Commun ; 446(1): 255-60, 2014 Mar 28.
Article in English | MEDLINE | ID: mdl-24589739

ABSTRACT

Schistosomiasis is second only to malaria in prevalence and severity, and is still a major health problem in many tropical countries worldwide with about 200-300 million cases and with more than 800 million people at risk of infection. Based on these data, the World Health Organization recommends fostering research efforts for understanding at any level the mechanisms of the infection and then decreasing the social and economical impact of schistosomiasis. A key role is played by the parasite apical lipid membrane, which is entirely impervious to the surrounding elements of the immune system. We have previously demonstrated that the interaction between schistosomes and surrounding medium is governed by a parasite surface membrane sphingomyelin-based hydrogen barrier. In the present article, the elastic contribution to the total motion as a function of the exchanged wave-vector Q and the mean square displacement values for Schistosoma mansoni larvae and worms and Schistosomahaematobium worms have been evaluated by quasi elastic neutron scattering (QENS). The results point out that S. mansoni larvae show a smaller mean square displacement in comparison to S. mansoni and S. haematobium worms. These values increased by repeating the measurements after one day. These differences, which are analogous to those observed for the diffusion coefficient we previously evaluated, are interpreted in terms of rigidity of the parasite-medium interaction. S. mansoni larvae are the most rigid systems, while S. haematobium worms are the most flexible. In addition, temperature and hypoxia induce a weakening of the schistosome-medium interaction. These evidences are related to the strength of the hydrogen-bonded interaction between parasites and environment that we previously determined. We have shown that S. mansoni worms are characterized by a weakened interaction in respect to the larvae, while the S. haematobium worms more weakly interact with the surrounding medium than S. mansoni. The present QENS analysis allowed us to characterize the rigidity of larval- and adult S. mansoni and S. haematobium-host interface and to relate it to the parasite resistance to the hostile elements of the surrounding medium and to the immune effectors attack.


Subject(s)
Schistosoma haematobium/physiology , Schistosoma mansoni/physiology , Animals , Cricetinae , Elasticity , Host-Parasite Interactions/physiology , Humans , Larva/physiology , Male , Membrane Lipids/chemistry , Membrane Lipids/physiology , Mesocricetus , Neutron Diffraction , Scattering, Radiation , Schistosoma haematobium/growth & development , Schistosoma haematobium/pathogenicity , Schistosoma mansoni/growth & development , Schistosoma mansoni/pathogenicity , Schistosomiasis haematobia/parasitology , Schistosomiasis mansoni/parasitology , Sphingomyelins/chemistry , Sphingomyelins/physiology
18.
Parasite ; 21: 3, 2014.
Article in English | MEDLINE | ID: mdl-24502943

ABSTRACT

Although schistosomiasis has been a public health issue in Gabon for nearly a century, little is known about its current transmission dynamics. We analyzed the chronobiology of 137 cercarial emission profiles of Schistosoma haematobium from Libreville, the capital of Gabon, located in an open area for schistosomiasis. We found that 88% of the cercariae were shed between 11 a.m. and 3 p.m. and that the average pattern was of circadian type, with the average peak at 1 p.m., and representing 27% of the total number of cercariae of the day. The rhythms of emergence may be associated with environmental pressures on the parasite, especially those related to their definitive hosts.


Subject(s)
Bulinus/parasitology , Cercaria/physiology , Circadian Rhythm , Schistosoma haematobium/growth & development , Animals , Environment , Gabon , Gerbillinae/parasitology , Light , Schistosoma haematobium/radiation effects
19.
Cell Biochem Biophys ; 68(2): 359-67, 2014 Mar.
Article in English | MEDLINE | ID: mdl-23943053

ABSTRACT

Schistosomes develop, mature, copulate, lay eggs, and live for years in the mammalian host bloodstream, importing nutrients across the tegument, but entirely impervious to the surrounding elements of the immune system. We have hypothesized that sphingomyelin (SM) in the parasite apical lipid bilayer is responsible for these sieving properties via formation of a tight hydrogen bond network with the surrounding water. Here we have used quasi-elastic neutron scattering for characterizing the diffusion of larval and adult Schistosoma mansoni and adult Schistosoma haematobium in the surrounding medium, under various environmental conditions. The results documented the presence of a hydrogen bond barrier around larvae and adult schistosomes. The hydrogen bond network readily collapses if worms are subjected to hypoxic conditions, likely via activation of the parasite tegument-associated neutral sphingomyelinase, and consequent excessive SM hydrolysis. The slower dynamics of lung-stage larvae as compared to adult worms has been related to the existence of hydrogen-bonded networks of different strength and then to their differential resistance to immune attacks.


Subject(s)
Host-Parasite Interactions , Schistosoma haematobium/physiology , Schistosoma mansoni/physiology , Sphingomyelins/metabolism , Animals , Cricetinae , Female , Helminth Proteins/metabolism , Hydrogen Bonding , Hydrolysis , Larva/physiology , Lipid Bilayers/metabolism , Male , Schistosoma haematobium/growth & development , Schistosoma mansoni/growth & development , Sphingomyelin Phosphodiesterase/metabolism , Sphingomyelins/chemistry , Water/chemistry
20.
Urol Nurs ; 33(4): 163-70, 2013.
Article in English | MEDLINE | ID: mdl-24079113

ABSTRACT

Schistosomiasis is a parasitic infection caused by flatworms (trematodes). It is second only to malaria in public health significance, with over 200 million people infected worldwide, leading to severe consequences in 20 million persons and 100,000 deaths, annually. There are four species that cause intestinal schistosomiasis: Schistosoma mansoni; Schistosoma japonicum, Schistosoma mekongi, and Schistosoma intercalatum. Schistosoma haematobium causes urinary schistosomias, and is endemic in Africa and the Middle East, with the greatest prevalence in poor rural areas. Fibrotic changes in the urinary tract can lead to hydroureter, hydronephrosis, bacterial urinary infections, and ultimately, kidney disease or eventually bladder cancer. A rare lesion can also arise in patients infected with Schistosomiasis haematobium, resulting in squamous and adenosquamous prostate cancers. Imported diseases, such as schistosomiasis, are entering the United States through immigration via illegal aliens, refugees, and travelers. Schistosomiasis is a neglected tropical disease, and its global health impact is grossly underestimated.


Subject(s)
Hematuria , Schistosoma haematobium/growth & development , Schistosomiasis , Specialties, Nursing , Adult , Animals , Education, Nursing, Continuing , Hematuria/epidemiology , Hematuria/nursing , Hematuria/parasitology , Humans , Male , Risk Factors , Schistosomiasis/epidemiology , Schistosomiasis/nursing , Schistosomiasis/transmission
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