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Diagnosis of Schistosoma infection in non-human animal hosts: A systematic review and meta-analysis.PLoS Neglected Tropical Diseases May 2022Reliable and field-applicable diagnosis of schistosome infections in non-human animals is important for surveillance, control, and verification of interruption of human... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Reliable and field-applicable diagnosis of schistosome infections in non-human animals is important for surveillance, control, and verification of interruption of human schistosomiasis transmission. This study aimed to summarize uses of available diagnostic techniques through a systematic review and meta-analysis.
METHODOLOGY AND PRINCIPAL FINDINGS
We systematically searched the literature and reports comparing two or more diagnostic tests in non-human animals for schistosome infection. Out of 4,909 articles and reports screened, 19 met our inclusion criteria, four of which were considered in the meta-analysis. A total of 14 techniques (parasitologic, immunologic, and molecular) and nine types of non-human animals were involved in the studies. Notably, four studies compared parasitologic tests (miracidium hatching test (MHT), Kato-Katz (KK), the Danish Bilharziasis Laboratory technique (DBL), and formalin-ethyl acetate sedimentation-digestion (FEA-SD)) with quantitative polymerase chain reaction (qPCR), and sensitivity estimates (using qPCR as the reference) were extracted and included in the meta-analyses, showing significant heterogeneity across studies and animal hosts. The pooled estimate of sensitivity was 0.21 (95% confidence interval (CI): 0.03-0.48) with FEA-SD showing highest sensitivity (0.89, 95% CI: 0.65-1.00).
CONCLUSIONS/SIGNIFICANCE
Our findings suggest that the parasitologic technique FEA-SD and the molecular technique qPCR are the most promising techniques for schistosome diagnosis in non-human animal hosts. Future studies are needed for validation and standardization of the techniques for real-world field applications.
Topics: Animals; Feces; Prevalence; Reference Standards; Schistosoma; Schistosomiasis; Sensitivity and Specificity
PubMed: 35522699
DOI: 10.1371/journal.pntd.0010389 -
Tropical Diseases, Travel Medicine and... Dec 2021Schistosomiasis is a neglected tropical disease caused by mainly Schistosoma mansoni and Schistosoma hematobium. The disease is very common in Africa including Ethiopia....
BACKGROUND
Schistosomiasis is a neglected tropical disease caused by mainly Schistosoma mansoni and Schistosoma hematobium. The disease is very common in Africa including Ethiopia. Schistosoma mansoni is a major public health problem in Ethiopia especially among children. This review is aimed to indicate the prevalence of Schistosoma mansoni among children at the national and regional levels.
METHODS AND MATERIAL
The PRISMA guidelines were followed. An electronic search of PubMed, Google Scholar, Web of Science, Scopus, MEDLINE, and Google search were carried out using key terms. Articles published from the proceeding of professional associations such as the Ethiopian medical laboratory association, the Ethiopian public health association, and annual national research conferences were also searched to find additional eligible studies. Data were extracted independently by two investigators, and cross-checked by a third reviewer. The quality of included studies was assessed using JBI quality assessment criteria. Data were extracted using Microsoft excel and finally analyzed using STATA version 12. The pooled prevalence was done using a random-effects model.
RESULT
Overall 49 studies involving 20,493 children (10,572 male and 9, 921 females) were included in this meta-analysis. The pooled prevalence of Schistosoma mansoni infection was 37.13% (95%CI:30.02-44.24). High heterogeneity was observed with I of 99.4%, P < 0.000. According to subgroup analysis, the pooled prevalence was high in the SNNPR (41.49%: 95%CI: 19.52-63.46) followed by the Amhara region (41.11%: 95%CI: 30.41-51.8), the Tigray region (31.40%: 95%CI:11.72-51.09), and the Oromia region (28.98%: 95%CI: 18.85-39.1). Year from 2011 to 2015 contributed to the highest prevalence of Schistosoma mansoni infection among children (46.31%: 95%:34.21-59.05).
CONCLUSION
This study revealed a 37.13% prevalence of Schistosoma mansoni infection among children. This is an alert to improve and implement appropriate control strategies such as mass drug administration in Ethiopia.
PubMed: 34847958
DOI: 10.1186/s40794-021-00156-0 -
PLoS Neglected Tropical Diseases Feb 2021Schistosomiasis is a parasitic disease caused by trematode worms of the genus Schistosoma and belongs to the neglected tropical diseases. The disease has been reported...
BACKGROUND
Schistosomiasis is a parasitic disease caused by trematode worms of the genus Schistosoma and belongs to the neglected tropical diseases. The disease has been reported in 78 countries, with around 290.8 million people in need of treatment in 2018. Schistosomiasis is predominantly considered a rural disease with a subsequent focus of research and control activities in rural settings. Over the past decades, occurrence and even expansion of schistosomiasis foci in peri-urban and urban settings have increasingly been observed. Rural-urban migration in low- and middle-income countries and subsequent rapid and unplanned urbanization are thought to explain these observations. Fifty-five percent (55%) of the world population is already estimated to live in urban areas, with a projected increase to 68% by 2050. In light of rapid urbanization and the efforts to control morbidity and ultimately achieve elimination of schistosomiasis, it is important to deepen our understanding of the occurrence, prevalence, and transmission of schistosomiasis in urban and peri-urban settings. A systematic literature review looking at urban and peri-urban schistosomiasis was therefore carried out as a first step to address the research and mapping gap.
METHODOLOGY
Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic computer-aided literature review was carried out using PubMed, ScienceDirect, and the World Health Organization Database in November 2019, which was updated in March 2020. Only papers for which at least the abstract was available in English were used. Relevant publications were screened, duplicates were removed, guidelines for eligibility were applied, and eligible studies were reviewed. Studies looking at human Schistosoma infections, prevalence, and intensity of infection in urban and peri-urban settings were included as well as those focusing on the intermediate host snails.
PRINCIPAL FINDINGS
A total of 248 publications met the inclusion criteria. The selected studies confirm that schistosomiasis is prevalent in peri-urban and urban areas in the countries assessed. Earlier studies report higher prevalence levels in urban settings compared to data extracted from more recent publications, yet the challenge of migration, rapid uncontrolled urbanization, and resulting poor living conditions highlight the potential for continuous or even newly established transmission to take place.
CONCLUSIONS
The review indicates that schistosomiasis has long existed in urban and peri-urban areas and remains a public health problem. There is, however, a challenge of comparability of settings due to the lack of a clear definition of what constitutes urban and peri-urban. There is a pressing need for improved monitoring of schistosomiasis in urban communities and consideration of treatment strategies.
Topics: Animals; Humans; Schistosoma; Schistosomiasis; Snails; Suburban Population; Urban Population
PubMed: 33630833
DOI: 10.1371/journal.pntd.0008995 -
Open Journal of Epidemiology Feb 2023Tuberculosis disease stands for the second leading cause of death worldwide after COVID-19, most active tuberculosis cases result from the reactivation of latent TB...
Tuberculosis disease stands for the second leading cause of death worldwide after COVID-19, most active tuberculosis cases result from the reactivation of latent TB infection through impairment of immune response. Several factors are known to sustain that process. , a parasite of the helminth genus that possesses switching power from an immune profile type Th1 to Th2 that favors reactivation of latent TB bacteria. The aim of the study was to assess the prevalence of the co-infection between the two endemic infections. Systematic literature was contacted at the University Clinical Research Center at the University of Sciences, Techniques, and Technologies of Bamako in Mali. Original articles were included, and full texts were reviewed to assess the prevalence and better understand the immunological changes that occur during the co-infection. In total, 3530 original articles were retrieved through database search, 53 were included in the qualitative analysis, and data from 10 were included in the meta-analysis. Prevalence of the co-infection ranged from 4% to 34% in the literature. Most of the articles reported that immunity against infection with helminth parasite and more specifically infection enhances latent TB reactivation through Th1/Th2. In sum, the impact of co-infection with is under-investigated. Understanding the role of this endemic tropical parasite as a contributing factor to TB epidemiology and burden could help integrate its elimination as one of the strategies to achieve the END-TB objectives by the year 2035.
PubMed: 36910425
DOI: 10.4236/ojepi.2023.131008 -
Parasites & Vectors Mar 2021Schistosomiasis is a highly prevalent parasitic disease that can lead to adverse maternal and perinatal outcomes. To our knowledge, there has been no systematic review... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Schistosomiasis is a highly prevalent parasitic disease that can lead to adverse maternal and perinatal outcomes. To our knowledge, there has been no systematic review and meta-analysis of schistosomiasis during pregnancy.
METHODS
We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Relevant published studies were searched in international databases (PubMed, Science Direct, Scopus, Web of Science, and Google Scholar), from their inception until May 31, 2020. The retrieved studies were assessed for quality using the Modified Newcastle-Ottawa Scale. OpenMeta Analyst software was used for the statistical analysis.
RESULTS
Thirty-two studies enrolling 21024 pregnant women were included in this meta-analysis. All 32 of these studies were conducted in Africa. Of these studies, 19, 11, and 2 investigated S. mansoni, S. haematobium, and combined S. mansoni and S. haematobium infections, respectively. The pooled prevalence estimate of schistosomiasis during pregnancy was 13.2% (95 CI 11.0-15.4). A random model was used because of high heterogeneity (Q = 99.14; P < 0.001). In subgroup analyses, the pooled prevalence estimate of S. haematobium was significantly higher than the pooled prevalence estimates of S. mansoni [22.5% (95% CI 1.6-43.5) vs 8.7% (95% CI 6.0-11.3, P = 0.016), respectively]. The results of meta-regression analyses showed a non-significant difference in the prevalence of schistosomiasis during pregnancy according to the study sample sizes and year of publication. Only six studies evaluated the association between schistosomiasis during pregnancy and anemia. Schistosomiasis was associated with anemia in these six studies (OR = 3.02, 95% = 1.25‒7.28, P = 0.014).
CONCLUSION
The present meta-analysis suggests that schistosomiasis during pregnancy is an existing health problem. This meta-analysis also highlights the lack of data on the determinants and outcomes of schistosomiasis during pregnancy. Preventive measures are needed and could be part of antenatal care in areas endemic with schistosomiasis.
Topics: Africa; Anemia; Female; Humans; Pregnancy; Prevalence; Schistosomiasis; Schistosomiasis haematobia
PubMed: 33653391
DOI: 10.1186/s13071-021-04642-4 -
PloS One 2020While praziquantel mass drug administration is currently the most widely used method in the control of human schistosomiasis, it does not prevent subsequent reinfection... (Meta-Analysis)
Meta-Analysis
While praziquantel mass drug administration is currently the most widely used method in the control of human schistosomiasis, it does not prevent subsequent reinfection hence persistent transmission. Towards schistosomiasis elimination, understanding the reinfection rate is crucial in planning for the future interventions. However, there is scarcity of information on the global reinfection rate of schistosomiasis. This systematic review and meta-analysis aimed at summarizing studies that estimated the reinfection rate of human schistosomiasis. Three data bases (PubMed, Hinari and Google Scholar) were thoroughly searched to retrieve original research articles presenting data on reinfection rate of human schistosomiasis. Study quality and risk of bias was assessed based on Joanna Briggs Institute critical appraisal checklist. Meta-analysis was conducted using statistical R version 3.6.2 and R Studio using "meta" and "metafor" packages. Random effect model was employed to estimate pooled reinfection rates. Heterogeneity was determined using Cochran's Q (chi-square)-test and Higgins I2 statistics. A total of 29 studies met inclusion criteria to be included in this review. All studies had at least satisfactory (5-9 scores) quality. The overal mean and pooled reinfection rates of schistosomiasis were 36.1% (±23.3%) and 33.2% (95% CI, 26.5-40.5%) respectively. For intestinal schistosomiasis, the mean and pooled reinfection rates were 43.9% (±20.6%) and 43.4% (95% CI, 35.8-51.4%), and that for urogenital schistosomiasis were 17.6% (±10.8%) and 19.4% (95% CI, 12.3%- 29.2%) respectively. Cochran's Q (chi-square)-test and Higgins I2 statistic indicated significant heterogeneity across studies (p-values < 0.001, I2 values > 95%). Results of subgroup analysis showed that, the type of Schistosoma species, participants' age group, sample size and geographical area had influence on disparity variation in reinfection rate of schistosomiasis (p < 0.1). Despite the control measures in place, the re-infection rate is still high, specifically on intestinal schistosomiasis as compared to urogenital schistosomiasis. Achieving 2030 sustainable development goal 3 on good health and wellbeing intensive programmatic strategies for schistosomiasis elimination should be implemented. Among such strategies to be used at national level are repeated mass drug administration at least every six months, intensive snails control and health education.
Topics: Animals; Biometry; Humans; Praziquantel; Reinfection; Schistosoma; Schistosomiasis
PubMed: 33270752
DOI: 10.1371/journal.pone.0243224 -
The Lancet. Planetary Health Jul 2020Agrochemical pollution of surface waters is a growing global environmental challenge, especially in areas where agriculture is rapidly expanding and intensifying.... (Review)
Review
BACKGROUND
Agrochemical pollution of surface waters is a growing global environmental challenge, especially in areas where agriculture is rapidly expanding and intensifying. Agrochemicals might affect schistosomiasis transmission through direct and indirect effects on Schistosoma parasites, their intermediate snail hosts, snail predators, and snail algal resources. We aimed to review and summarise the effects of these agrochemicals on schistosomiasis transmission dynamics.
METHODS
We did a systematic review of agrochemical effects on the lifecycle of Schistosoma spp and fitted dose-response models to data regarding the association between components of the lifecycle and agrochemical concentrations. We incorporated these dose-response functions and environmentally relevant concentrations of agrochemicals into a mathematical model to estimate agrochemical effects on schistosomiasis transmission. Dose-response functions were used to estimate individual agrochemical effects on estimates of the agrochemically influenced basic reproduction number, R, for Schistosoma haematobium. We incorporated time series of environmentally relevant agrochemical concentrations into the model and simulated mass drug administration control efforts in the presence of agrochemicals.
FINDINGS
We derived 120 dose-response functions describing the effects of agrochemicals on schistosome lifecycle components. The median estimate of the basic reproduction number under agrochemical-free conditions, was 1·65 (IQR 1·47-1·79). Agrochemical effects on estimates of R for S haematobium ranged from a median three-times increase (R 5·05, IQR 4·06-5·97) to transmission elimination (R 0). Simulations of transmission dynamics subject to interacting annual mass drug administration and agrochemical pollution yielded a median estimate of 64·82 disability-adjusted life-years (DALYs) lost per 100 000 people per year (IQR 62·52-67·68) attributable to atrazine use. In areas where aquatic arthropod predators of intermediate host snails suppress transmission, the insecticides chlorpyrifos (6·82 DALYs lost per 100 000 people per year, IQR 4·13-8·69) and profenofos (103·06 DALYs lost per 100 000 people per year, IQR 89·63-104·90) might also increase the disability burden through their toxic effects on arthropods.
INTERPRETATION
Expected environmental concentrations of agrochemicals alter schistosomiasis transmission through direct and indirect effects on intermediate host and parasite densities. As industrial agricultural practices expand in areas where schistosomiasis is endemic, strategies to prevent increases in transmission due to agrochemical pollution should be developed and pursued.
FUNDING
National Science Foundation, National Institutes of Health.
Topics: Agrochemicals; Animals; Environmental Pollutants; Environmental Pollution; Food Chain; Host-Parasite Interactions; Humans; Schistosoma; Schistosomiasis
PubMed: 32681899
DOI: 10.1016/S2542-5196(20)30105-4 -
Journal of Tropical Medicine 2020Schistosomiasis is caused by and in Africa. These schistosome parasites use freshwater snail intermediate hosts to complete their lifecycle. Varied prevalence rates of... (Review)
Review
BACKGROUND
Schistosomiasis is caused by and in Africa. These schistosome parasites use freshwater snail intermediate hosts to complete their lifecycle. Varied prevalence rates of these parasites in the snail intermediate hosts were reported from several African countries, but there were no summarized data for policymakers. Therefore, this study was aimed to systematically summarize the prevalence and geographical distribution of and among freshwater snails in Africa.
METHODS
Literature search was carried out from PubMed, Science Direct, and Scopus which reported the prevalence of and among freshwater snails in Africa. The pooled prevalence was determined using a random-effect model, while heterogeneities between studies were evaluated by test. The meta-analyses were conducted using Stata software, metan command.
RESULTS
A total of 273,643 snails were examined for the presence of and cercaria in the eligible studies. The pooled prevalence of schistosome cercaria among freshwater snails was 5.5% (95% CI: 4.9-6.1%). The pooled prevalence of and cercaria was 5.6% (95% CI: 4.9-6.3%) and 5.2% (95% CI: 4.6-5.7%), respectively. The highest pooled prevalence was observed from Nigeria (19.0%; 95% CI: 12.7-25.3%), while the lowest prevalence was reported from Chad (0.05%; 95% CI: 0.03-0.13). Higher prevalence of schistosome cercaria was observed from (12.3%; 95% CI: 6.2-18.3%) followed by (6.7%; 95% CI: 4.5-9.0%) and (5.1%; 95% CI: 4.1-6.2%). The pooled prevalence of schistosome cercaria obtained using PCR was 26.7% in contrast to 4.5% obtained by shedding cercariae.
CONCLUSION
This study revealed that nearly 6% of freshwater snails in Africa were infected by either or . The high prevalence of schistosomes among freshwater snails highlights the importance of appropriate snail control strategies in Africa.
PubMed: 32963554
DOI: 10.1155/2020/8850840 -
Pathogens and Global Health Oct 2023Praziquantel (PZQ) has been extensively used as the drug of choice for the treatment of schistosomiasis on account of its safety and effectiveness against all major...
Praziquantel (PZQ) has been extensively used as the drug of choice for the treatment of schistosomiasis on account of its safety and effectiveness against all major forms of schistosomiasis. However, low cure rate, reduced susceptibility of to PZQ and treatment failures in . infections have been reported, raising concerns about its efficacy. Using the search terms, 'praziquantel efficacy, schistosomiasis, school children, reinfection' as well as defined inclusion criteria, and guided by the PRISMA guidelines, articles from 2001 to 2022 were selected from the PubMed and Google Scholar databases and reviewed to assess their importance to the research question. This review assessed the efficacy of PZQ against schistosomiasis and reinfection rates following treatment of infections in children. Majority of both intestinal and urinary schistosomiasis studies reported comparable egg reduction rates (ERRs) of 94.2% to 99.9% and 91.9% to 98%, respectively. However, ERRs suggestive of sub-optimal PZQ efficacy as well as generally high and comparable cure rates for intestinal (81.2%-99.1%) and urinary (79%-93.7%) schistosomiasis studies were reported. Schistosomiasis reinfection rates varied widely for urinary (8.1%-39.6%) and intestinal (13.9%-63.4%) studies within eight to 28 weeks following PZQ treatment. Praziquantel treatment of urinary and intestinal schistosomiasis should be accompanied by the provision of potable water, toilet, and recreational facilities to reduce reinfection and egg reduction rates and increase cure rate to expedite schistosomiasis elimination.
Topics: Child; Humans; Praziquantel; Schistosomiasis mansoni; Anthelmintics; Reinfection; Treatment Outcome; Schistosomiasis haematobia
PubMed: 36394218
DOI: 10.1080/20477724.2022.2145070 -
PLoS Neglected Tropical Diseases Mar 2021Most of national schistosomiasis elimination programmes in Asia are relying on stool examination, particularly Kato Katz stool examination technique for regular... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Most of national schistosomiasis elimination programmes in Asia are relying on stool examination, particularly Kato Katz stool examination technique for regular transmission monitoring. However, the Kato-Katz technique has shown low sensitivity for the detection of light-intensity infections, and therefore highly sensitive diagnostic tools are urgently required to monitor prevalence of infection in low transmission settings. The objective of this systematic review was to evaluate and synthesize the performance of diagnostic tests for detecting Schistosoma japonicum and S. mekongi infection in people living in endemic areas.
METHODOLOGY/PRINCIPAL FINDINGS
We comprehensively searched these nine electronic databases and other resources until July 2019, with no language or publication limits: PubMed, EMBASE, MEDLINE, Web of Science, BIOSIS Citation Index, HTA, CINAHL PLUS, The Cochrane Library, and PsycINFO. We included original studies that assessed diagnostic performance using antibody, antigen, and molecular tests with stool examination test as a reference standard. Two reviewers independently extracted a standard set of data and assessed study quality. We estimated the pooled estimates of sensitivity and specificity for each index test. We used diagnostic odds ratio to determine the overall accuracy and hierarchical summary receiver operating characteristics (HSROC) curve to assess the index tests performance. Fifteen studies (S. japonicum [n = 13] and S. mekongi [n = 2]) testing 15,303 participants were included in the review. Five studies reported performance of enzyme-linked immunosorbent assay (ELISA), seven studies reported indirect hemagglutination assay (IHA), and four studies reported polymerase chain reaction (PCR) for detecting S. japonicum. The pooled sensitivity and specificity were 0.93 (95% CI: 0.84-0.98) and 0.40 (95% CI: 0.29-0.53) for ELISA, 0.97 (95% CI: 0.90-0.99) and 0.66 (95% CI: 0.58-0.73) for IHA, and 0.89 (95% CI: 0.71-0.96) and 0.49 (95% CI: 0.29-0.69) for PCR respectively. A global summary indicated the best performance for IHA, closely followed by ELISA. We were unable to perform meta-analysis for S. mekongi due to insufficient number of studies.
CONCLUSIONS/SIGNIFICANCE
IHA showed the highest detection accuracy for S. japonicum. Further studies are needed to determine the suitable diagnostic methods to verify the absence of transmission of S. mekongi and also to compare detection accuracy against more sensitive reference standards such as PCR.
Topics: Animals; Enzyme-Linked Immunosorbent Assay; Fluorescent Antibody Technique, Indirect; Humans; Polymerase Chain Reaction; Schistosoma; Schistosoma japonicum
PubMed: 33730048
DOI: 10.1371/journal.pntd.0009244