-
PLoS Neglected Tropical Diseases Mar 2024Female Genital Schistosomiasis (FGS) causes intravaginal lesions and symptoms that could be mistaken for sexually transmitted diseases or cancer. In adults, FGS lesions...
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.
Topics: Adult; Pregnancy; Animals; Female; Adolescent; Humans; Praziquantel; South Africa; Schistosoma haematobium; Schistosomiasis haematobia; Genitalia, Female; Genital Diseases, Female; Water
PubMed: 38536861
DOI: 10.1371/journal.pntd.0011798 -
PLOS Global Public Health 2024Male genital schistosomiasis (MGS) is a significantly neglected condition, and its consequences often receive inadequate attention. The disease is suggested to cause...
Male genital schistosomiasis (MGS) is a significantly neglected condition, and its consequences often receive inadequate attention. The disease is suggested to cause schistosomiasis-induced sexual and reproductive health problems among males. The study was conducted to investigate the prevalence of MGS, sexual and reproductive health problems that could be caused by MGS among adult males in Mtama district. A community-based cross-sectional study using quantitative methods was carried out among males aged ≥ 18 years in selected households. Semen and urine samples were collected from each participant to establish the prevalence of MGS and urogenital schistosomiasis respectively. Semen quality was macroscopically and microscopically assessed. Urine samples were analyzed using filtration technique. A structured questionnaire interview was carried out to collect socio-demographic data, sexual and reproductive health information. Descriptive statistics were used to provide a summary of each variable. The prevalence (proportions) were presented in percentages and their respective 95% confidence intervals. A total of 223 adult males participated in this study. The prevalence of MGS and urogenital schistosomiasis were 5.8% (95% CI; 3.1%-9.0%) and 22.4% (95% CI; 16.6%-27.8%) respectively. The prevalence of Schistosoma haematobium eggs in semen was found high among young adults 12/129 (9.3%, 95% CI; 4.9%-15.7%), who never attended to school 6/35 (17.1%, 95% CI; 6.6%-33.6%), petty traders 4/26 (15.4%, 95% CI; 4.4%-34.9%), never impregnated woman 9/70 (12.9%, 95% CI: 6.6%-33.6%), experienced pain during ejaculation 4/17 (23.5%, 95% CI; 4.9%-15.7%), and with brownish semen 2/5 (40%, 95% CI; 4.9%-15.7%). According to the findings, MGS, like urogenital schistosomiasis, is prevalent in southern Tanzania. The disease is prevalent among males with some reproductive and sexual issues. This highlight the need for more research to investigate the association of MGS and male reproductive and sexual health for improved health services among males.
PubMed: 38536825
DOI: 10.1371/journal.pgph.0002533 -
Biosensors Mar 2024The rapid and accurate identification of parasites is crucial for prompt therapeutic intervention in parasitosis and effective epidemiological surveillance. For accurate... (Review)
Review
The rapid and accurate identification of parasites is crucial for prompt therapeutic intervention in parasitosis and effective epidemiological surveillance. For accurate and effective clinical diagnosis, it is imperative to develop a nucleic-acid-based diagnostic tool that combines the sensitivity and specificity of nucleic acid amplification tests (NAATs) with the speed, cost-effectiveness, and convenience of isothermal amplification methods. A new nucleic acid detection method, utilizing the clustered regularly interspaced short palindromic repeats (CRISPR)-associated (Cas) nuclease, holds promise in point-of-care testing (POCT). CRISPR/Cas12a is presently employed for the detection of , , , and other parasites in blood, urine, or feces. Compared to traditional assays, the CRISPR assay has demonstrated notable advantages, including comparable sensitivity and specificity, simple observation of reaction results, easy and stable transportation conditions, and low equipment dependence. However, a common issue arises as both amplification and cis-cleavage compete in one-pot assays, leading to an extended reaction time. The use of suboptimal crRNA, light-activated crRNA, and spatial separation can potentially weaken or entirely eliminate the competition between amplification and cis-cleavage. This could lead to enhanced sensitivity and reduced reaction times in one-pot assays. Nevertheless, higher costs and complex pre-test genome extraction have hindered the popularization of CRISPR/Cas12a in POCT.
Topics: Animals; Parasites; CRISPR-Cas Systems; RNA, Guide, CRISPR-Cas Systems; Biological Assay; Body Fluids; Nucleic Acid Amplification Techniques
PubMed: 38534252
DOI: 10.3390/bios14030145 -
European Journal of Microbiology &... May 2024Schistosomiasis is a neglected tropical disease that is prevalent in low- and middle-income countries. There are five human pathogenic species, of which Schistosoma... (Review)
Review
Schistosomiasis is a neglected tropical disease that is prevalent in low- and middle-income countries. There are five human pathogenic species, of which Schistosoma haematobium, Schistosoma mansoni and Schistosoma japonicum are the most prevalent worldwide and cause the greatest burden of disease in terms of mortality and morbidity. In addition, hybrid schistosomes have been identified through molecular analysis. Human infection occurs when cercariae, the larval form of the parasite, penetrate the skin of people while bathing in contaminated waters such as lakes and rivers. Schistosomiasis can cause both urogenital and intestinal symptoms. Urogenital symptoms include haematuria, bladder fibrosis, kidney damage, and an increased risk of bladder cancer. Intestinal symptoms may include abdominal pain, sometimes accompanied by diarrhoea and blood in the stool. Schistosomiasis affects more than 250 million people and causes approximately 70 million Disability-Adjusted Life Years (DALYs), mainly in Africa, South America, and Asia. To control infection, it is essential to establish sensitive and specific diagnostic tests for epidemiological surveillance and morbidity reduction. This review provides an overview of schistosomiasis, with a focus on available diagnostic tools for Schistosoma spp. Current molecular detection methods and progress in the development of new diagnostics for schistosomiasis infection are also discussed.
PubMed: 38498078
DOI: 10.1556/1886.2024.00013 -
International Journal For Parasitology.... Apr 2024The freshwater amphibious snail commonly occurs in eastern Asia, on certain Pacific islands and more importantly has recently dispersed into Europe. Since this snail is...
The freshwater amphibious snail commonly occurs in eastern Asia, on certain Pacific islands and more importantly has recently dispersed into Europe. Since this snail is now considered an invasive species, its distribution is of growing parasitological interest as an alien intermediate host for various trematodes, particularly liver flukes. As part of ongoing surveillance for snail-borne diseases in Malawi, a population of was first observed in May 2023, alongside an alarming presence of a human schistosome cercaria. This snail population later underwent detailed morphological characterisation with both snail and parasite identities confirmed upon DNA barcoding. This seminal observation triggered more extensive local snail surveys, finding 3 further populations in separated rice paddies, with further field-caught snails (n = 465) screened for infection and a selection used for repeated experimental challenges with miracidia from and . Although no field-caught (and experimentally exposed) snail was seen to shed schistosome cercariae, molecular xenomonitoring for schistosomiasis provided tangible evidence of putative transmission potential. Our first report of here in Malawi, and more broadly in Africa, flags a need for increased vigilance for this invasive species alongside local clarification(s) of its transmission potential for trematodiases of either medical and/or veterinary importance.
PubMed: 38495311
DOI: 10.1016/j.ijppaw.2024.100919 -
Parasites & Vectors Mar 2024Schistosomiasis is a water-based parasitic disease that affects humans, livestock and wild animals. While considerable resources are dedicated to the surveillance,...
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.
Topics: Adult; Cattle; Humans; Animals; Cote d'Ivoire; Schistosomiasis; Schistosoma haematobium; Animals, Wild; Prevalence
PubMed: 38475876
DOI: 10.1186/s13071-024-06221-9 -
The Lancet. Microbe Apr 2024Accurate diagnosis is pivotal for implementing strategies for surveillance, control, and elimination of schistosomiasis. Despite their low sensitivity in low-endemicity... (Meta-Analysis)
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 (I>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.
Topics: Child; Child, Preschool; Adult; Animals; Humans; Adolescent; Schistosoma mansoni; Schistosoma haematobium; Hematuria; Reagent Strips; Microscopy; Bayes Theorem; Feces; Antigens, Helminth; Urinalysis; Schistosomiasis haematobia; Diagnostic Tests, Routine
PubMed: 38467130
DOI: 10.1016/S2666-5247(23)00377-4 -
PLoS Neglected Tropical Diseases Mar 2024Schistosoma haematobium, the parasite that causes urogenital schistosomiasis, is widely prevalent in Tanzania. In addition to well-known effects on the urinary tract, S.... (Review)
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.
Topics: Animals; Female; Humans; Tanzania; Public Health; Retrospective Studies; Early Detection of Cancer; Uterine Cervical Neoplasms; Genitalia, Female; Schistosomiasis haematobia; Schistosoma haematobium; Genital Diseases, Female
PubMed: 38466660
DOI: 10.1371/journal.pntd.0011954 -
PloS One 2024Schistosoma mansoni and S. haematobium infections have been public health problems in Ethiopia, S. mansoni being more prevalent. To reduce the burden of schistosomiasis,...
Efficacy and safety of prazequantel for the treatment of Schistosoma mansoni infection across different transmission settings in Amhara Regional State, northwest Ethiopia.
BACKGROUND
Schistosoma mansoni and S. haematobium infections have been public health problems in Ethiopia, S. mansoni being more prevalent. To reduce the burden of schistosomiasis, a national school-based prazequantel (PZQ) mass drug administration (MDA) program has been implemented since November 2015. Nevertheless, S. mansoni infection is still a major public health problem throughout the country. Reduced efficacy of PZQ is reported by a few studies in Ethiopia, but adequate data in different geographical settings is lacking. Hence, this study aimed to assess the efficacy and safety of PZQ for the treatment of S. mansoni infection across different transmission settings in Amhara Regional State, northwest Ethiopia.
METHODS
A school-based single-arm prospective cohort study was conducted from February to June, 2023 among 130 S. mansoni-infected school-aged children (SAC). Forty-two, 37, and 51 S. mansoni-infected SAC were recruited from purposely selected schools located in low, moderate, and high transmission districts, respectively. School-aged children who were tested positive both by Kato Katz (KK) using stool samples and by the point of care circulating cathodic antigen (POC-CCA) test using urine samples at baseline were treated with a standard dose of PZQ and followed for 21 days for the occurrence of adverse events. After three weeks post-treatment, stool and urine samples were re-tested using KK and POC-CCA. Then the cure rate (CR), egg reduction rate (ERR), and treatment-associated adverse events were determined. The data were analyzed using SPSS version 21.
RESULTS
Out of the total 130 study participants, 110 completed the follow-up. The CR and ERR of PZQ treatment were 88.2% (95%CI: 82.7-93.6) and 93.5% (95%CI: 85.4-98.5), respectively, by KK. The CR of PZQ based on the POC-CCA test was 70.9% (95%CI: 62.7-79.1) and 75.5% (95%CI: 67.3-83.6) depending on whether the interpretation of 'trace' results was made as positive or negative, respectively. After treatment on the 21st day, 78 and 83 participants tested negative both by KK and POC-CCA, with respective interpretations of 'trace' POC-CCA test results as positive or negative. The CR in low, moderate and high transmission settings was 91.7%, 91.2% and 82.5%, respectively (p = 0.377) when evaluated by KK. The CR among SAC with a light infection at baseline (95.7%) by KK was higher than that of moderate (81.5%) and heavy (64.3%) infections (χ2 = 12.53, p = 0.002). Twenty-six (23.6%) participants manifested at least one adverse event. Eleven (10.0%), eight (7.3%), six (5.5%), and three (2.7%) participants complained about abdominal pain, nausea, headache, and anorexia, respectively. All adverse events were mild, needing no intervention. Occurrence of adverse events was slightly higher in high endemic areas (32.5%) than moderate (23.5%) and low endemic areas (p = 0.279).
CONCLUSIONS
A single dose of 40 mg/kg PZQ was efficacious and safe for the treatment of S. mansoni infection when it was evaluated by the KK test, but a lower efficacy was recorded when it was evaluated by the POC-CCA test. However, the POC-CCA test's specificity, clearance time of CCA from urine after treatment, and interpretation of weakly reactive (trace) test results need further research.
Topics: Child; Animals; Humans; Schistosomiasis mansoni; Ethiopia; Prospective Studies; Public Health; Schistosoma mansoni
PubMed: 38437215
DOI: 10.1371/journal.pone.0298332 -
Annals of Parasitology 2024Schistosomiasis is a common neglected helminthic disease in the tropics and sub-tropics particularly in sub-Saharan countries including Burkina Faso. It is the second... (Review)
Review
Schistosomiasis is a common neglected helminthic disease in the tropics and sub-tropics particularly in sub-Saharan countries including Burkina Faso. It is the second world parasitic endemic disease after malaria. The two prevalent species infecting human in Burkina Faso are are Schistosoma haematobium and Schistosoma mansoni which cause respectively the urogenital schistosomiasis and the intestinal schistosomiasis. This review aimed at providing an historical perspective of research on schistosomiasis from 1960 to 2020 and shedding some light on the gaps in knowledge useful for the disease control and the elimination efforts in Burkina Faso. Formal systematic review was not followed for this review. Published studies on the schistosomiasis in Burkina Faso over the period from 1960 to 2020, were search in Medline, PubMed, Google Scholar, EMBASE and the libraries of main universities in Burkina Faso namely: Joseph KI-ZERBO University and Nazi BONI University. The following key words used were: Schistosomiasis, Bilharzia, Bulinus, Biomphalaria, Upper-Volta and Burkina Faso. Over a period of 60 years, a total of 87 scientific research documents were identified. The original scientific research articles represent the majority of the scientific documents found (65.52%). Urinary schistosomiasis was the most common from the documentation. There has been a gradual decrease in the prevalence, more significantly since the implementation of the National Schistosomiasis Control Program (NSCP). The effectiveness of the NSCP could therefore contribute to the elimination of schistosomiasis in Burkina Faso.
Topics: Humans; Animals; Burkina Faso; Schistosomiasis haematobia; Schistosomiasis mansoni; Schistosoma haematobium
PubMed: 38423519
DOI: 10.17420/ap6903/4.514