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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 -
BioMed Research International 2023Schistosomiasis is causing high morbidity and significant mortality in endemic areas. Kato-Katz stool examination and urine filtration techniques are the conventional... (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
Schistosomiasis is causing high morbidity and significant mortality in endemic areas. Kato-Katz stool examination and urine filtration techniques are the conventional methods for the detection of intestinal and urinary schistosomiasis. The most appropriate diagnostic tools for the detection of schistosomiasis especially in low-prevalence settings should be used. Therefore, this study is aimed at investigating the diagnostic accuracy of and diagnostic tools in sub-Saharan Africa.
METHODS
Electronic databases such as PubMed, PubMed Central/Medline, HINARI, Scopus, EMBASE, Science Direct, Google Scholar, and Cochrane Library were reviewed. The pooled estimates and heterogeneity were determined using Midas in Stata 14.0. The diagnostic accuracy of index tests was compared using the hierarchical summary of the receiver operating characteristic (HSROC) curve in Stata 14.0.
RESULTS
Twenty-four studies consisting of 12,370 individuals were tested to evaluate the accuracy of antigen, antibody, and molecular test methods for the detection of and . The pooled estimate of sensitivity and specificity of CCA was 88% (95% CI: 83-92) and 72 (95% CI: 62-80), respectively, when it is compared with parasitological stool examination for detection. On the other hand, ELISA showed a pooled estimate of sensitivity and specificity of 95% (95% CI: 93-96) and 35% (95% CI: 21-52), respectively, for the examination of using stool examination as a reference test. With regard to , the pooled estimate of sensitivity and specificity of polymerase chain reaction was 97% (95% CI: 78-100) and 94% (95% CI: 74-99), respectively. Moreover, the sensitivity and specificity of urine CCA vary between 41-80% and 55-91%, respectively, compared to urine microscopy.
CONCLUSION
The effort of schistosomiasis elimination requires accurate case identification especially in low-intensity infections. This study showed that CCA had the highest sensitivity and moderate specificity for the diagnosis of . Similarly, the sensitivity of ELISA was excellent, but its specificity was low. The diagnostic accuracy of PCR for the detection of was excellent compared to urine microscopic examination.
Topics: Humans; Animals; Microscopy; Schistosoma mansoni; Urinalysis; Africa South of the Sahara; Diagnostic Tests, Routine
PubMed: 37621699
DOI: 10.1155/2023/3769931 -
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 -
Journal of Parasitic Diseases :... Jun 2024are intermediate snail hosts of . Despite their vectorial role, the transmission dynamics and infectivity of these intermediate snail hosts remain understudied in the...
are intermediate snail hosts of . Despite their vectorial role, the transmission dynamics and infectivity of these intermediate snail hosts remain understudied in the Ase River. This longitudinal study evaluated the geospatial and seasonal transmission patterns and infectivity of three vectors between November 2020 and October 2022 in the Ase River catchment, Delta State, Nigeria. Eleven (11) geospatial water contact coordinates were mapped for monthly spatiotemporal collection of species along the Ase River and its catchment, for two years. Snail sampling was performed for 45 min at each study site using scooping/hand-picking techniques and subsequently counted, identified and recorded. Snails of the genus were individually placed in a beaker containing distilled water and exposed to light to shed cercariae which were identified to be human schistosome type. The number of infected snails for each month and season was also documented to analyze the spatiotemporal and seasonal transmission dynamics of infectivity. Out of the 2345 snails collected, a total of 41.45% were found to be infected with . The monthly infectivity of snails varied significantly ( < 0.05) throughout the study period ( = < 0.0001; F = 23.11; df = 11). Further analysis showed a strong significant association (χ = 23.57; df = 11; = 0.015) between the study years. The Principal Component Analysis (PCA) results suggest that infectivity within the Ase River catchment area was primarily associated with the months of February and January. consistently had the highest transmission potential, followed by and . ANOVA confirms that the monthly/study site infectivity and transmission potential in , and were statistically, significant ( < 0.05). These results demonstrated a clear distinction in the patterns and relationships between the different months in terms of snail infectivity and seasonal transmission potential. This understanding will help in the continuous monitoring and targeted interventions to control schistosomiasis transmission in Ase River.
PubMed: 38840869
DOI: 10.1007/s12639-024-01656-4 -
Pulmonary Circulation Jan 2024Whether all Schistosoma species cause pulmonary hypertension (PH) is unclear. Experimentally exposing mice to Schistosoma haematobium eggs caused PH, which was less...
Whether all Schistosoma species cause pulmonary hypertension (PH) is unclear. Experimentally exposing mice to Schistosoma haematobium eggs caused PH, which was less severe than that induced by S. mansoni exposure. These findings align with the relatively uncommon reports of pulmonary arterial hypertension associated with S. haematobium.
PubMed: 38312832
DOI: 10.1002/pul2.12336 -
Infectious Diseases of Poverty May 2024The three most important genera of snails for the transmission of schistosomes are Bulinus, Biomphalaria and Oncomelania. Each of these genera, found in two distantly...
The three most important genera of snails for the transmission of schistosomes are Bulinus, Biomphalaria and Oncomelania. Each of these genera, found in two distantly related families, includes species that act as the intermediate host for one of the three most widespread schistosome species infecting humans, Schistosoma haematobium, S. mansoni and S. japonicum, respectively. An important step in the fight against schistosomiasis in Asia has been taken with the publication of the article "Chromosome-level genome assembly of Oncomelania hupensis: the intermediate snail host of Schistosoma japonicum", which means that genomes for all three major genera, including species across three continents, are now available in the public domain. This includes the first genomes of African snail vectors, namely Biomphalaria sudanica, Bi. pfeifferi and Bulinus truncatus, as well as high-quality chromosome level assemblies for South American Bi. glabrata. Most importantly, the wealth of new genomic and transcriptomic data is helping to establish the specific molecular mechanisms that underly compatibility between snails and their schistosomes, which although diverse and complex, may help to identify potential targets dictating host parasite interactions that can be utilised in future transmission control strategies. This new work on Oncomelania hupensis and indeed studies on other snail vectors, which provide deep insights into the genome, will stimulate research that may well lead to new and much needed control interventions.
Topics: Animals; Humans; Disease Vectors; Genomics; Host-Parasite Interactions; Schistosomiasis; Snails
PubMed: 38711151
DOI: 10.1186/s40249-024-01199-z -
Acta Tropica Aug 2024The World Health Organization calls for schistosomiasis endemic countries to regularly monitor the efficacy of Praziquantel (PZQ) drug, the only antischistosomal drug...
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.
Topics: Praziquantel; Tanzania; Humans; Schistosomiasis haematobia; Child; Animals; Child, Preschool; Female; Male; Sensitivity and Specificity; Anthelmintics; Schistosoma haematobium; Adolescent; Reagent Strips; Prevalence; Urine; Treatment Outcome; Parasite Egg Count
PubMed: 38729329
DOI: 10.1016/j.actatropica.2024.107232 -
Medicina (Kaunas, Lithuania) Aug 2023Gynecological fistulae are a rare but severe complication of radiation therapy, pelvic surgery, prolonged labor, cesarean deliveries, or inflammatory bowel diseases. A... (Review)
Review
Gynecological fistulae are a rare but severe complication of radiation therapy, pelvic surgery, prolonged labor, cesarean deliveries, or inflammatory bowel diseases. A gynecological fistula is an abnormal pathway formed between the urinary and gynecological tract, most commonly located between the urinary bladder and vagina. Vesico-uterine and vesicovaginal fistulae are an important health issue, common in women of reproductive age in developing countries with limited access to obstetrical care. Various surgical techniques have been described for VVF repair, depending on the location, severity, and cause of the fistula and the surgeon's experience. The purpose of our review was to evaluate the present state of knowledge about the prevalence and treatment of gynecological fistulae. The PubMed scientific database was searched for original articles on the subject of gynecological fistulae that had been published between 2013 and 2023.
Topics: Pregnancy; Female; Humans; Fistula; Obstetrics; Urinary Bladder; Cesarean Section; Databases, Factual
PubMed: 37629745
DOI: 10.3390/medicina59081455 -
Molecules (Basel, Switzerland) Sep 2023It is estimated that 250 million people worldwide are affected by schistosomiasis. Disease transmission is related to the poor sanitation and hygiene habits that affect... (Review)
Review
It is estimated that 250 million people worldwide are affected by schistosomiasis. Disease transmission is related to the poor sanitation and hygiene habits that affect residents of impoverished regions in tropical and subtropical countries. The main species responsible for causing disease in humans are , , and , each with different geographic distributions. Praziquantel is the drug predominantly used to treat this disease, which offers low effectiveness against immature and juvenile parasite forms. In addition, reports of drug resistance prompt the development of novel therapeutic approaches. Natural products represent an important source of new compounds, especially those obtained from plant sources. This review compiles data from several in vitro and in vivo studies evaluating various compounds and essential oils derived from plants with cercaricidal and molluscicidal activities against both juvenile and adult forms of the parasite. Finally, this review provides an important discussion on recent advances in molecular and computational tools deemed fundamental for more rapid and effective screening of new compounds, allowing for the optimization of time and resources.
Topics: Humans; Animals; Anthelmintics; Schistosoma haematobium; Biological Products; Schistosomiasis; Praziquantel; Schistosoma mansoni
PubMed: 37836650
DOI: 10.3390/molecules28196807