Re-assessment of schistosomiasis in nine endemic districts with cluster sampling in Sierra Leone.

Background: Baseline mapping showed that schistosomiasis was highly/moderately endemic in nine districts in Sierra Leone. Mass drug administration (MDA) with praziquantel started in 2009, and after multiple rounds of treatment, an impact assessment was conducted in 2016 followed by a second re-assessment in 2022 using cluster sampling to provide more granular data for refining chiefdom (sub-district) treatment strategies. Methods: On average, 20 rural villages were systematically selected per district by probability proportional to population size across the nine districts. Surveys were conducted in schools, and 24 school children aged between 5 and 14 years were randomly selected, with an equal number of boys and girls. One stool sample and one urine sample were collected per child. Two Kato-Katz slides were examined per stool for Schistosoma mansoni infection. Hemastix strips were used as a proxy for S. haematobium infection with urine filtration used for egg counts on hematuria-positive samples. Results: In total, 4,736 stool samples and 4,618 urine samples were examined across 200 schools in 125 chiefdoms. Overall, the prevalence of S. mansoni was 16.3% (95% CI: 15.3-17.4%), while the overall prevalence of S. haematobium was 2.0% (95% CI: 1.6-2.4%) by hematuria. The prevalence of heavy infections for S. mansoni and S. haematobium was 1.5% (95% CI: 1.1-1.9%) and 0.02% (95% CI: 0.0-0.14%), respectively. Among 125 chiefdoms surveyed, the overall schistosomiasis prevalence was <10% in 65 chiefdoms, 10-49.9% in 47 chiefdoms, and ≥ 50% in 13 chiefdoms. There was a mixed relationship between schistosomiasis in school children and WASH access in schools. Conclusion: Sierra Leone has made significant progress in reducing schistosomiasis prevalence across the country after a decade of MDA intervention. However, high prevalence remains in some hotspot chiefdoms. The next steps are for the national program to investigate and address any potential issues such as low coverage or poor knowledge of schistosomiasis risk behaviors and, where appropriate, consider broadening to community-wide treatment in hotspot chiefdoms or communities.

Re-assessing thermal response of schistosomiasis transmission risk: Evidence for a higher thermal optimum than previously predicted.

The geographical range of schistosomiasis is affected by the ecology of schistosome parasites and their obligate host snails, including their response to temperature. Previous models predicted schistosomiasis' thermal optimum at 21.7°C, which is not compatible with the temperature in sub-Saharan Africa (SSA) regions where schistosomiasis is hyperendemic. We performed an extensive literature search for empirical data on the effect of temperature on physiological and epidemiological parameters regulating the free-living stages of S. mansoni and S. haematobium and their obligate host snails, i.e., Biomphalaria spp. and Bulinus spp., respectively. We derived nonlinear thermal responses fitted on these data to parameterize a mechanistic, process-based model of schistosomiasis. We then re-cast the basic reproduction number and the prevalence of schistosome infection as functions of temperature. We found that the thermal optima for transmission of S. mansoni and S. haematobium range between 23.1-27.3°C and 23.6-27.9°C (95% CI) respectively. We also found that the thermal optimum shifts toward higher temperatures as the human water contact rate increases with temperature. Our findings align with an extensive dataset of schistosomiasis prevalence in SSA. The refined nonlinear thermal-response model developed here suggests a more suitable current climate and a greater risk of increased transmission with future warming for more than half of the schistosomiasis suitable regions with mean annual temperature below the thermal optimum.

Urogenital schistosomiasis among adult male population in an endemic area of southern Tanzania: a descriptive cross-sectional study.

BACKGROUND: Urogenital schistosomiasis (UGS) caused by Schistosoma haematobium is endemic in Southern Tanzania. The disease has significant implications for both socioeconomic and public health. Because infections with S. haematobium usually peak in childhood, the majority of studies have concentrated on school-aged children leaving other groups such as males which might be continuous reservoir of infection transmission. However, despite its chronic consequences in the male population, the disease has received insufficient attention, especially in sub-Saharan Africa. This study was conducted to describe the previous and current schistosomiasis status among adult males living in high-endemic areas of southern Tanzania DESIGN, SETTING AND PARTICIPANTS: A descriptive cross-sectional study was employed to gather data on the prevalence of UGS among adult men residing at schistosomiasis endemic in the Mtama District Council. Quantitative methods of data collection which included questionnaire and laboratory procedures were used. RESULTS: Out of 245 participants, macrohaematuria and microhaematuria were found in 12 (4.9%, 95% CI 2.4% to 7.8%) and 66 (26.9%, 95% CI 21.6% to 32.7%) participants, respectively. S. haematobium ova were recovered from the urine samples of 54 (22.0%, 95% CI 16.7% to 27.3%) participants. The median intensity of infection was 20 eggs per 10 mL of urine ranging from 1 to 201 eggs per 10 mL of urine (IQR) 60.5). Out of 245 participants 33 (13.5% 95% CI 9.0% to 17.6%) had light intensity of infection and 21 (38.9%, 95% CI; 25.0% to 52.5%) had heavy intensity of infection. Overall, the prevalence of heavy intensity of infection was 8.6% (95% CI 4.9% to 12.6%). The prevalence and intensity of UGS varied significantly by age, marital status and village of residence. CONCLUSION: This study sheds light on the prevalence of UGS among adult males in endemic areas of southern Tanzania. The results highlight the urgent need for comprehensive intervention strategies to address the burden of the disease.

Capacities and needs of health care facilities for schistosomiasis diagnosis and management in elimination settings.

BACKGROUND: Schistosomiasis is a debilitating neglected tropical disease endemic in sub-Saharan Africa. The role of health facilities in the prevention, diagnosis, control, and elimination of schistosomiasis is poorly documented. In a setting targeted for schistosomiasis elimination in Zanzibar, we assessed the prevalence of Schistosoma haematobium among patients seeking care in a health facility and investigated schistosomiasis-related knowledge of staff, and health facilities' capacities and needs for schistosomiasis diagnosis and management. METHODS: We conducted a health facility-based mixed-method study on Pemba Island from June to August 2023. Patients aged ≥ 4 years seeking care in four health facilities were screened for S. haematobium infection using urine filtration and reagent strips. Those patients aged ≥ 10 years were additionally interviewed about signs and symptoms. Staff from 23 health facilities responded to a questionnaire assessing knowledge and practices. Ten staff participated in a focus group discussion (FGD) about capacities and needs for schistosomiasis diagnosis and management. RESULTS: The prevalence of S. haematobium infection in patients attending the health facilities, as determined by the presence of eggs in urine, was 1.1% (8/712). Microhaematuria was detected in 13.3% (95/712) of the patients using reagent strips. Among patients responding to the questionnaire, pelvic pain, pain during sex, and painful urination were reported by 38.0% (237/623), 6.3% (39/623), and 3.2% (20/623), respectively. Among the health facility staff, 90.0% (44/49) and 87.8% (43/49) identified blood in urine and pelvic pain, respectively, as symptoms of urogenital schistosomiasis, 81.6% (40/49) and 93.9% (46/49) reported collecting a urine sample and pursuing a reagent strip test, respectively, for diagnosis, and 87.8% (43/49) administered praziquantel for treatment. The most reoccurring themes in the FGD were the need for more staff training about schistosomiasis, requests for diagnostic equipment, and the need to improve community response to schistosomiasis services in health facilities. CONCLUSIONS: The prevalence of S. haematobium infection in patients seeking care in health facilities in Pemba is very low and similar to what has been reported from recent community-based cross-sectional surveys. The health facility staff had good schistosomiasis-related knowledge and practices. However, to integrate schistosomiasis patient management more durably into routine health facility activities, scalable screening pathways need to be identified and capacities need to be improved by regular staff training, and an unbroken supply of accurate point-of-care diagnostics and praziquantel for the treatment of cases.

Immunochromatography Lateral Flow Strip Enhancement Based on Passive Gold Nanoparticles Conjugation to Detect Schistosma haematobium Antigens in Human Serum.

PURPOSE: This study aimed to develop and evaluate a lateral flow card for the detection of active Schistosoma haematobium infection. METHODS: In order to prepare the immunochromatography lateral flow strip (ICLFS), antibodies purified from schistosomiasis were conjugated passively with gold nanoparticles using a potassium carbonate buffer. RESULTS: The novel ICLFS was able to correctly identify 64 out of 67 samples of schistosomiasis, 6 out of 90 samples of other parasites, and 0 out of 27 control samples. Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) were 95.5%, 93.3%, 90%, and 91.4% respectively. Comparatively, the sensitivity, specificity, NPV, and PPV of sandwich enzyme-linked immunosorbent assays (ELISA) conjugated with gold nanoparticles (AuNPs) were 91.1%, 88.8%, 85.9%, and 84.4% respectively. The increased sensitivity and specificity of ICLFS produced superior results to those of sandwich ELISA. CONCLUSION: In conclusion, ICLFS is more beneficial and precise than sandwich ELISA for detection of S. haematobium infection at early stage.

Female genital schistosomiasis burden and risk factors in two endemic areas in Malawi nested in the Morbidity Operational Research for Bilharziasis Implementation Decisions (MORBID) cross-sectional study.

BACKGROUND: Female genital schistosomiasis (FGS), caused by the parasite Schistosoma haematobium (Sh), is prevalent in Sub-Saharan Africa. FGS is associated with sexual dysfunction and reproductive morbidity, and increased prevalence of HIV and cervical precancerous lesions. Lack of approved guidelines for FGS screening and diagnosis hinder accurate disease burden estimation. This study evaluated FGS burden in two Sh-endemic areas in Southern Malawi by visual and molecular diagnostic methods. METHODOLOGY/PRINCIPAL FINDINGS: Women aged 15-65, sexually active, not menstruating, or pregnant, were enrolled from the MORBID study. A midwife completed a questionnaire, obtained cervicovaginal swab and lavage, and assessed FGS-associated genital lesions using hand-held colposcopy. 'Visual-FGS' was defined as specific genital lesions. 'Molecular-FGS' was defined as Sh DNA detected by real-time PCR from swabs. Microscopy detected urinary Sh egg-patent infection. In total, 950 women completed the questionnaire (median age 27, [IQR] 20-38). Visual-and molecular-FGS prevalence were 26·9% (260/967) and 8·2% (78/942), respectively. 6·5% of women with available genital and urinary samples (38/584) had egg-patent Sh infection. There was a positive significant association between molecular- and visual-FGS (AOR = 2·9, 95%CI 1·7-5·0). 'Molecular-FGS' was associated with egg-patent Sh infection (AOR = 7·5, 95% CI 3·27-17·2). Some villages had high 'molecular-FGS' prevalence, despite <10% prevalence of urinary Sh among school-age children. CONCLUSIONS/SIGNIFICANCE: Southern Malawi carries an under-recognized FGS burden. FGS was detectable in villages not eligible for schistosomiasis control strategies, potentially leaving girls and women untreated under current WHO guidelines. Validated field-deployable methods could be considered for new control strategies.

Characterizing genetic variation on the Z chromosome in Schistosoma japonicum reveals host-parasite co-evolution.

BACKGROUND: Schistosomiasis is a neglected tropical disease that afflicts millions of people worldwide; it is caused by Schistosoma, the only dioecious flukes with ZW systems. Schistosoma japonicum is endemic to Asia; the Z chromosome of S. japonicum comprises one-quarter of the entire genome. Detection of positive selection using resequencing data to understand adaptive evolution has been applied to a variety of pathogens, including S. japonicum. However, the contribution of the Z chromosome to evolution and adaptation is often neglected. METHODS: We obtained 1,077,526 high-quality SNPs on the Z chromosome in 72 S. japonicum using re-sequencing data publicly. To examine the faster Z effect, we compared the sequence divergence of S. japonicum with two closely related species, Schistosoma haematobium and S. mansoni. Genetic diversity was compared between the Z chromosome and autosomes in S. japonicum by calculating the nucleotide diversity (π) and Dxy values. Population structure was also assessed based on PCA and structure analysis. Besides, we employed multiple methods including Tajima's D, FST, iHS, XP-EHH, and CMS to detect positive selection signals on the Z chromosome. Further RNAi knockdown experiments were performed to investigate the potential biological functions of the candidate genes. RESULTS: Our study found that the Z chromosome of S. japonicum showed faster evolution and more pronounced genetic divergence than autosomes, although the effect may be smaller than the variation among genes. Compared with autosomes, the Z chromosome in S. japonicum had a more pronounced genetic divergence of sub-populations. Notably, we identified a set of candidate genes associated with host-parasite co-evolution. In particular, LCAT exhibited significant selection signals within the Taiwan population. Further RNA interference experiments suggested that LCAT is necessary for S. japonicum survival and propagation in the definitive host. In addition, we identified several genes related to the specificity of the intermediate host in the C-M population, including Rab6 and VCP, which are involved in adaptive immune evasion to the host. CONCLUSIONS: Our study provides valuable insights into the adaptive evolution of the Z chromosome in S. japonicum and further advances our understanding of the co-evolution of this medically important parasite and its hosts.

Efficacy of praziquantel drug against Schistosoma haematobium and performance of urine reagent strips among pre-and-school aged children during the high transmission season in North-Western Tanzania.

The World Health Organization calls for schistosomiasis endemic countries to regularly monitor the efficacy of Praziquantel (PZQ) drug, the only antischistosomal drug used for four decades in Tanzania. In response to that call, the current study investigated the efficacy of single dose of PZQ against Schistosoma haematobium during the high transmission season and further assessed, the sensitivity and specificity of urine reagent strips before and after treatment. The study recruited a total of 2,498 -children aged (4 -17 years old) who provided a single urine sample that was visually examined for macro-haematuria, then using urine dipstick and urine filtration technique for microhaematuria and the presence of S. haematobium eggs. The baseline prevalence of S. haematobium eggs positive based on urine filtration test was 29.2 % (95 %CI:27.5-31.0) and that of microhaematuria was 43.1 % (95 %CI:41.1-45.0). Of the infected participants, 40.9 % (95 %CI:37.4-44.6) had a heavy intensity of infection and the geometrical mean intensity (GMI) of infection was 33.7 eggs/10mls of urine. A single dose of PZQ reduced the prevalence of infection to 16.2 %, the GMI of infection to 18.8eggs/10mls of urine and that of microhaematuria to 27.9 %. Cure rate and egg reduction rates (ERR) were 83.8 % and 44.3 % respectively. At baseline, the sensitivity and specificity of the urine reagent strips were 59.7 % and 93.8 %, whereas at post-treatment they were 16.7 % and 93.6 %. When PZQ drug is administered during the high transmission season, its efficacy in term of ERR is poor. The urine reagent strips had low sensitivity but high specificity at pre-and-post PZQ treatment.

Experimental Infections Reveal Acquired Zoonotic Capacity of Human Schistosomiasis Trough Hybridization.

We are currently witnessing the endemization of urogenital schistosomiasis in southern Europe. The incriminated parasite is a hybrid between a human parasite and a livestock parasite. Using an experimental evolutionary protocol, we created hybrid lines from pure strains of both parasite species. We showed that the host spectrum of the human parasite is enlarged to the livestock parasite after genomic introgression. We also evidenced that the tropism of the parasites within the host changes and that some hybrid lines are more virulent than the parental strains. These results engage a paradigm shift from human to zoonotic transmission of urogenital schistosomiasis.

Antibody response to malaria vaccine candidates in pregnant women with Plasmodium falciparum and Schistosoma haematobium infections.

Malaria in pregnancy has severe consequences for the mother and foetus. Antibody response to specific malaria vaccine candidates (MVC) has been associated with a decreased risk of clinical malaria and its outcomes. We studied Plasmodium falciparum (Pf) and Schistosoma haematobium (Sh) infections and factors that could influence antibody responses to MVC in pregnant women. A total of 337 pregnant women receiving antenatal care (ANC) and 139 for delivery participated in this study. Pf infection was detected by qPCR and Sh infection using urine filtration method. Antibody levels against CSP, AMA-1, GLURP-R0, VAR2CSA and Pfs48/45 MVC were quantified by ELISA. Multivariable linear regression models identified factors associated with the modulation of antibody responses. The prevalence of Pf and Sh infections was 27% and 4% at ANC and 7% and 4% at delivery. Pf infection, residing in Adidome and multigravidae were positively associated with specific IgG response to CSP, AMA-1, GLURP-R0 and VAR2CSA. ITN use and IPTp were negatively associated with specific IgG response to GLURP-R0 and Pfs48/45. There was no association between Sh infection and antibody response to MVC at ANC or delivery. Pf infections in pregnant women were positively associated with antibody response to CSP, GLURP-R0 and AMA-1. Antibody response to GLURP-R0 and Pfs48/45 was low for IPTp and ITN users. This could indicate a lower exposure to Pf infection and low malaria prevalence observed at delivery.

Extant interspecific hybridization among trematodes within the Schistosoma haematobium species complex in Nigeria.

BACKGROUND: Natural interspecific hybridization between the human parasite (Schistosoma haematobium [Sh]) and bovine parasites (Schistosoma bovis [Sb], Schistosoma curassoni [Sc]) is increasingly reported in Africa. We developed a multi-locus PCR DNA-Seq strategy that amplifies two unlinked nuclear (transITS, BF) and two linked organellar genome markers (CO1, ND5) to genotype S. haematobium eggs collected from infected people in Ile Oluji/Oke Igbo, Ondo State (an agrarian community) and Kachi, Jigawa State (a pastoral community) in Southwestern and Northern Nigeria, respectively. PRINCIPAL FINDINGS: Out of a total of 219 urine samples collected, 57 were positive for schistosomes. All patients from Jigawa state possessed an Sh mitochondrial genome and were infected with a genetic profile consistent with an Sh x Sb hybrid based on sequences obtained at CO1, ND5, transITS and BF nuclear markers. Whereas samples collected from Ondo state were more varied. Mitonuclear discordance was observed in all 17 patients, worms possessed an Sb mitochondrial genome but one of four different genetic profiles at the nuclear markers, either admixed (heterozygous between Sh x Sc or Sh x Sb) at both markers (n = 10), Sh at BF and admixed at transITS (Sh x Sc) (n = 5), admixed (Sh x Sc) at BF and homozygous Sc at transITS (n = 1) or homozygous Sh at BF and homozygous Sc at transITS (n = 1). SIGNIFICANCE: Previous work suggested that zoonotic transmission of S. bovis in pastoral communities, where humans and animals share a common water source, is a driving factor facilitating interspecific hybridization. However, our data showed that all samples were hybrids, with greater diversity identified in Southwestern Nigeria, a non-pastoral site. Further, one patient possessed an S. bovis mitochondrial genome but was homozygous for S. haematobium at BF and homozygous for S. curassoni at transITS supporting at least two separate backcrosses in its origin, suggesting that interspecific hybridization may be an ongoing process.

Endemic status of urogenital schistosomiasis and the efficacy of a single-dose praziquantel treatment in unmapped rural farming communities in Oyo East Local Government Area, Oyo State, Nigeria.

BACKGROUND: Schistosomiasis is endemic in Nigeria, and the treatment is largely concentrated on children enrolled in schools. Consequently, the coverage of non-enrolled school-aged children is often neglected. Ajagba and Awosan are two communities in Nigeria that have never had any control intervention. Hence, this survey was designed to determine the endemicity of urogenital schistosomiasis and to evaluate the efficacy of a single-dose praziquantel in the communities. METHODS: Urine sample (10 mL) of each participant from Ajagba and Awosan communities was filtered through 12µm polycarbonate filter. The filter was placed on a microscope slide, and stained with a drop of 1% Lugol iodine solution. The stained slides were examined under the microscope and the numbers of S. haematobium eggs were counted. Water contact sites were searched for snail hosts and the snails collected were shed for Schistosoma cercariae. Data were analyzed using SPSS version 24.0 and the significance level was set at 95%. RESULTS: The overall prevalence of infection in the Ajagba community was 45.6% with a mean intensity of 61.1 ± 144.5 eggs/10 mL of urine, while the prevalence of infection in the Awosan community was 5.7% with a mean intensity of 1.4 ± 6.8 eggs/10 mL of urine. The school-aged children had a prevalence and mean intensity of infection of 73.1% and 111.6 ± 177.9 eggs/10 mL of urine, respectively. Following treatment, women had a higher egg reduction rate than men (p = 0.0283). Bulinus globosus were found in Ajagba but not in Awosan, with 5.7% shedding Schistosoma spp, cercariae. CONCLUSION: Urogenital schistosomiasis was hyperendemic in the Ajagba community, and hypoendemic in the Awosan community. The presence of Bulinus globosus supported the transmission of the schistosomiasis in the Ajagba community. Communities where schistosomiasis is still actively transmitted in Nigeria should be identified for effective intervention through the MDA programs.

Assessing urogenital schistosomiasis and female genital schistosomiasis (FGS) among adolescents in Anaocha, Anambra State, Nigeria: implications for ongoing control efforts.

BACKGROUND: Urogenital schistosomiasis (UgS) remains a persistent health challenge among adolescents in Anambra State, Nigeria, despite ongoing control efforts. Mass praziquantel treatment programs, initiated in 2013, primarily target primary school-aged children (5-14 years old), leaving adolescents (10-19 years old) enrolled in secondary schools vulnerable to urogenital schistosomiaisis. Additionally, the extent of female genital schistosomiasis (FGS), a neglected gynaecological manifestation of UgS remains unclear. METHODOLOGY: To address these gaps, a cross-sectional study was conducted in Anaocha Local Government Area from February to May 2023. Four hundred and seventy consenting adolescents aged 10-19 years were enrolled. Urinalysis including urine filtration was employed to confirm haematuria and detect urogenital schistosomiasis (UGS) among the participants. For females with heavy infections (≥ 50 eggs/10 ml urine), a gynaecologist performed colposcopy examinations, complemented by acetic acid and Lugol's iodine staining to assess for female genital schistosomiasis (FGS) lesions or other related reproductive health conditions. Socio-demographic data, including information on potential risk factors, were systematically collected using the Kobo ToolBox software, following gender-sensitive data collection guidelines. Data were analysed using SPSS version 25, incorporating descriptive statistics, multinomial logistic regression, odds ratios, and significance testing. RESULTS: Among the 470 adolescents (52.8% females, 47.2% males) examined, an overall UgS prevalence of 14.5% was observed, with an average of 5.25 eggs per 10 ml of urine. Females had a slightly higher prevalence (16.1%), and 7.5% had heavy infections. Although gender differences in infection rates were not statistically significant, males had slightly higher odds of infection (OR: 1.332; 95% CI: 0.791-2.244; p-value: 0.280). Adolescents aged 10-14 had the highest prevalence, with significantly increased odds of infection (OR: 1.720; 95% CI: 1.012-2.923; p-value: 0.045). Colposcopy examinations of females with heavy infections revealed FGS lesions and co-infections with Trichomonas vaginalis. Haematuria, though prevalent (24.6%), was not the sole indicator, as those without it faced significantly higher odds of infection (OR: 2.924; 95% CI: 1.731-4.941; p-value: 0.000). Dysuria and genital itching/burning sensation were other UgS and FGS associated symptoms. Direct water contact was associated with higher infection odds (OR: 2.601; 95% CI: 1.007-6.716; p-value: 0.048). Various risk factors were associated with UgS. CONCLUSION: The study highlights the need for a comprehensive Urogenital Schistosomiasis (UGS) control strategy that includes secondary school adolescents, emphasizes risk factor management, promotes safe water practices, and raises awareness about UGS and Female Genital Schistosomiasis (FGS) among adolescents, thus improving control efforts and mitigating this health challenge in the region.

Predictors for participation in mass-treatment and female genital schistosomiasis re-investigation, and the effect of praziquantel treatment in South African adolescents.

OBJECTIVE: Female Genital Schistosomiasis (FGS) causes intravaginal lesions and symptoms that could be mistaken for sexually transmitted diseases or cancer. In adults, FGS lesions [grainy sandy patches (GSP), homogenous yellow patches (HYP), abnormal blood vessels and rubbery papules] are refractory to treatment. The effect of treatment has never been explored in young women; it is unclear if gynaecological investigation will be possible in this young age group (16-23 years). We explored the predictors for accepting anti-schistosomal treatment and/or gynaecological reinvestigation in young women, and the effects of anti-schistosomal mass-treatment (praziquantel) on the clinical manifestations of FGS at an adolescent age. METHOD: The study was conducted between 2011 and 2013 in randomly selected, rural, high schools in Ilembe, uThungulu and Ugu Districts, KwaZulu-Natal Province, East Coast of South Africa. At baseline, gynaecological investigations were conducted in female learners in grades 8 to 12, aged 16-23 years (n = 2293). Mass-treatment was offered in the low-transmission season between May and August (a few in September, n = 48), in accordance with WHO recommendations. Reinvestigation was offered after a median of 9 months (range 5-14 months). Univariate, multivariable and logistic regression analysis were used to measure the association between variables. RESULTS: Prevalence: Of the 2293 learners who came for baseline gynaecological investigations, 1045 (46%) had FGS lesions and/or schistosomiasis, 209/1045 (20%) had GSP; 208/1045 (20%) HYP; 772/1045 (74%) had abnormal blood vessels; and 404/1045 (39%) were urine positive. Overall participation rate for mass treatment and gynaecological investigation: Only 26% (587/2293) learners participated in the mass treatment and 17% (401/2293) participated in the follow up gynaecological reinvestigations. Loss to follow-up among those with FGS: More than 70% of learners with FGS lesions at baseline were lost to follow-up for gynaecological investigations: 156/209 (75%) GSP; 154/208 (74%) HYP; 539/722 (75%) abnormal blood vessels; 238/404 (59%) urine positive. The grade 12 pupil had left school and did not participate in the reinvestigations (n = 375; 16%). Follow-up findings: Amongst those with lesions who came for both treatment and reinvestigation, 12/19 still had GSP, 8/28 had HYP, and 54/90 had abnormal blood vessels. Only 3/55 remained positive for S. haematobium ova. Factors influencing treatment and follow-up gynaecological investigation: HIV, current water contact, water contact as a toddler and urinary schistosomiasis influenced participation in mass treatment. Grainy sandy patches, abnormal blood vessels, HYP, previous pregnancy, current water contact, water contact as a toddler and father present in the family were strongly associated with coming back for follow-up gynaecological investigation. Challenges in sample size for follow-up analysis of the effect of treatment: The low mass treatment uptake and loss to follow up among those who had baseline FGS reduced the chances of a larger sample size at follow up investigation. However, multivariable analysis showed that treatment had effect on the abnormal blood vessels (adjusted odds ratio = 2.1, 95% CI 1.1-3.9 and p = 0.018). CONCLUSION: Compliance to treatment and gynaecological reinvestigation was very low. There is need to embark on large scale awareness and advocacy in schools and communities before implementing mass-treatment and investigation studies. Despite challenges in sample size and significant loss to follow-up, limiting the ability to fully understand the treatment's effect, multivariable analysis demonstrated a significant treatment effect on abnormal blood vessels.

Diagnostic tests for human Schistosoma mansoni and Schistosoma haematobium infection: a systematic review and meta-analysis.

BACKGROUND: Accurate diagnosis is pivotal for implementing strategies for surveillance, control, and elimination of schistosomiasis. Despite their low sensitivity in low-endemicity areas, microscopy-based urine filtration and the Kato-Katz technique are considered as reference diagnostic tests for Schistosoma haematobium and Schistosoma mansoni infections, respectively. We aimed to collate all available evidence on the accuracy of other proposed diagnostic techniques. METHODS: In this systematic review and meta-analysis, we searched PubMed, Embase, the Cochrane Library, and LILACS for studies published from database inception to Dec 31, 2022, investigating the sensitivity and specificity of diagnostic tests for S haematobium and S mansoni infections against Kato-Katz thick smears or urine microscopy (reference tests) involving adults (aged ≥18 years), school-aged children (aged 7 to 18 years), or preschool-aged children (aged 1 month to 7 years). We extracted raw data on true positives, true negatives, false positives, and false negatives for the diagnostic tests and data on the number of participants, study authors, publication year, journal, study design, participants' age and sex, prevalence of Schistosoma infection, and treatment status. To account for imperfect reference tests, we used a hierarchical Bayesian latent class meta-analysis to model test accuracy. FINDINGS: Overall, we included 121 studies, assessing 28 different diagnostic techniques. Most studies (103 [85%] of 121) were done in Africa, 14 (12%) in South America, one (1%) in Asia, and one (1%) in an unknown country. Compared with the reference test, Kato-Katz thick smears, circulating cathodic antigen urine cassette assay version 1 (CCA1, 36 test comparisons) had excellent sensitivity (95% [95% credible interval 88-99]) and reasonable specificity (74% [63-83]) for S mansoni. ELISA-based tests had a performance comparable to circulating cathodic antigen, but there were few available test comparisons. For S haematobium, proteinuria (42 test comparisons, sensitivity 73% [62-82]; specificity 94% [89-98]) and haematuria (75 test comparisons, sensitivity 85% [80-90]; specificity 96% [92-99]) reagent strips showed high specificity, with haematuria reagent strips having better sensitivity. Despite limited data, nucleic acid amplification tests (NAATs; eg, PCR or loop-mediated isothermal amplification [LAMP]) showed promising results with sensitivity estimates above 90%. We found an unclear risk of bias of about 70% in the use of the reference or index tests and of 50% in patient selection. All analyses showed substantial heterogeneity (I2>80%). INTERPRETATION: Although NAATs and immunological diagnostics show promise, the limited information available precludes drawing definitive conclusions. Additional research on diagnostic accuracy and cost-effectiveness is needed before the replacement of conventional tests can be considered. FUNDING: WHO and Luxembourg Institute of Health.

Genetic characterization of schistosome species from cattle in Côte d'Ivoire.

BACKGROUND: Schistosomiasis is a water-based parasitic disease that affects humans, livestock and wild animals. While considerable resources are dedicated to the surveillance, disease mapping, control and elimination of human schistosomiasis, this is not the case for livestock schistosomiasis. Indeed, there are important data and knowledge gaps concerning the species present, population genetic diversity, infection prevalence, morbidity and economic impact. This study aimed to identify circulating schistosome species in cattle across Côte d'Ivoire and to investigate their population diversity and structuring. METHODS: Overall, 400 adult schistosomes were collected from slaughtered cattle at six sites across Côte d'Ivoire. Additionally, 114 miracidia were collected from live cattle at one site: Ferkessédougou, in the northern part of Côte d'Ivoire. DNA from all specimens was extracted and the cox1 and ITS1/2 regions amplified and analysed to confirm species. The genetic diversity and structuring of the schistosome populations were investigated using 12 microsatellite markers. RESULTS: All adult schistosomes and miracidia presented Schistosoma bovis mitochondrial cox1 profile. Nuclear ITS1/2 data were obtained from 101 adult schistosomes and four miracidia, all of which presented an S. bovis profile. Genetic diversity indices revealed a deficiency of heterozygotes and signals of inbreeding across all sites, while structure analyses displayed little geographic structuring and differentiation. Cattle in Côte d'Ivoire thus appear to be mono-species infected with S. bovis. Hybrids of Schistosoma haematobium × S. bovis have not been identified in this study. Cattle schistosomes appear to be panmictic across the country. CONCLUSIONS: Our results contribute to a deeper understanding of schistosome populations in Ivorian cattle and emphasize a One Health approach of joint human and animal surveillance and prevention and control programmes for schistosomiasis.

Female genital schistosomiasis is a neglected public health problem in Tanzania: Evidence from a scoping review.

Schistosoma haematobium, the parasite that causes urogenital schistosomiasis, is widely prevalent in Tanzania. In addition to well-known effects on the urinary tract, S. haematobium also causes clinically- evident damage to the reproductive tract in approximately half of infected women, which is known as female genital schistosomiasis (FGS). FGS has major gynecologic and social consequences on women's reproductive health, yet little information is available regarding FGS in Tanzania. To cover that gap, we conducted the present scoping review to examine the epidemiology of FGS in Tanzania (both in the mainland and Zanzibar island) and to make recommendations for future work in this area. The available evidence from community-based and hospital-based retrospective studies indicates that FGS is a significant health problem in the country. Very few community-based studies have been reported from mainland Tanzania, and Zanzibar. Our review highlights the scarcity of efforts to address FGS in Tanzania and the need for additional community-based studies. The studies will help us understand the true burden of the disease nationwide, to assess the impact of praziquantel on FGS lesions, and to address social and mental health in relation to FGS. This review emphasizes integration of delivery of FGS related services in primary health care systems through the reproductive health clinics which covers sexually transmitted infections, HIV and cervical cancer screening. These actions are essential if this neglected gynecological disease is to be addressed in Tanzania.

Impact of Schistosoma sp., Infection on Biological, Feeding, Physiological, Histological, and Genotoxicological Aspects of Biomphalaria alexandrina and Bulinus truncatus Snails.

BACKGROUND: Trematode infections of the genus Schistosoma can induce physiological and behavioral changes in intermediate snail hosts. This is because the parasite consumes essential resources necessary for the host's survival, prompting hosts to adapt their behavior to maintain some level of fitness before parasite-induced mortality occurs. METHODS: In this study, the reproductive and biochemical parameters of Biomphalaria alexandrina and Bulinus truncatus were examined during the cercareal shedding stage of infection with Schistosoma mansoni and Schistosoma haematobium, respectively, compared with controls. RESULTS: The study revealed an infection rate of 34.7% for S. mansoni and 30.4% for S. haematobium. In B. alexandrina infected with S. mansoni, a survival rate of 65.2% was recorded, along with a mean prepatent period of 30.3 ± 1.41 days, a mean shedding duration of 14.2 ± 0.16 days, and a mean lifespan of 44.1 ± 0.24 days. Meanwhile, in B. truncatus infected with S. haematobium, a survival rate of 56.4% was observed, with a mean prepatent period of 44.3 ± 1.41 days, a mean shedding duration of 22.6 ± 2.7 days, and a mean lifespan of 66.9 ± 1.6 days. Feeding increased in both infected species of snails, while the net reproductive rate (Ro) of the infected snails decreased. Total antioxidant (TAO) and lipid peroxidation activity increased in the two infected snail species during shedding, while Glutathione-S-transferase levels decreased. Lipid peroxidase activity and nitrogen oxide levels significantly decreased in infected B. alexandrina and increased in infected Bulinus. Steroid hormone levels were elevated in infected Biomphalaria, whereas they were reduced in infected Bulinus. Comet assay parameters showed an increase in the two infected genera after infection compared to control snails, indicating genotoxic damage and histopathological damage was observed. CONCLUSIONS: These findings demonstrate that infection with larva species diverse biochemical, hormonal, genotoxic, and histopathological changes in the tissues responsible for fecundity and reproduction in B. alexandrina and B. truncates comparing with controls.

Transcriptional profiling of Bulinus globosus provides insights into immune gene families in snails supporting the transmission of urogenital schistosomiasis.

Schistosomiasis, urogenital and intestinal, afflicts 251 million people worldwide with approximately two-thirds of the patients suffering from the urogenital form of the disease. Freshwater snails of the genus Bulinus (Gastropoda: Planorbidae) serve as obligate intermediate hosts for Schistosoma haematobium, the etiologic agent of human urogenital schistosomiasis. These snails also act as vectors for the transmission of schistosomiasis in livestock and wildlife. Despite their crucial role in human and veterinary medicine, our basic understanding at the molecular level of the entire Bulinus genus, which comprises 37 recognized species, is very limited. In this study, we employed Illumina-based RNA sequencing (RNAseq) to profile the genome-wide transcriptome of Bulinus globosus, one of the most important intermediate hosts for S. haematobium in Africa. A total of 179,221 transcripts (N50 = 1,235) were assembled and the benchmarking universal single-copy orthologs (BUSCO) was estimated to be 97.7%. The analysis revealed a substantial number of transcripts encoding evolutionarily conserved immune-related proteins, particularly C-type lectin (CLECT) domain-containing proteins (n = 316), Toll/Interleukin 1-receptor (TIR)-containing proteins (n = 75), and fibrinogen related domain-containing molecules (FReD) (n = 165). Notably, none of the FReDs are fibrinogen-related proteins (FREPs) (immunoglobulin superfamily (IgSF) + fibrinogen (FBG)). This RNAseq-based transcriptional profile provides new insights into immune capabilities of Bulinus snails, helps provide a framework to explain the complex patterns of compatibility between snails and schistosomes, and improves our overall understanding of comparative immunology.