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Tropical Medicine and Infectious Disease Nov 2022Schistosomiasis is a neglected tropical disease affecting 40 million women of childbearing age worldwide. Its global disease prevalence among pregnant women is still... (Review)
Review
Schistosomiasis is a neglected tropical disease affecting 40 million women of childbearing age worldwide. Its global disease prevalence among pregnant women is still unknown. This meta-analysis determined the pooled prevalence of schistosomiasis among pregnant women globally. Additionally, this study also determined the pooled prevalence based on infection intensity based on eggs per gram. Observational studies on the prevalence of schistosomiasis among pregnant patients were obtained from Medline, Scopus, and CINAHL from January 2001 until August 2020. A review of titles and abstracts was done independently by six reviewers. The quality of the included studies was assessed using the Newcastle-Ottawa Scale for case-control, cohort, and cross-sectional studies. A total of 27 studies were included in the meta-analysis and meta-regression. The pooled prevalence of was 13.44 (CI: 8.90-19.80) per 100 observations, while the pooled prevalence of was 12.18 (CI: 4.47-29.12) per 100 observations. The prevalence of infection in one study was 53.54 (CI: 43.23-63.62) per 100 observations. Our results showed a prevailing health problem of schistosomiasis during pregnancy in various countries worldwide. This strengthens the need to conduct more schistosomiasis research, prevention, and control programs in pregnant women.
PubMed: 36355896
DOI: 10.3390/tropicalmed7110354 -
PLoS Neglected Tropical Diseases Oct 2022Schistosomiasis is a parasitic disease that is endemic in 78 countries and affects almost 240 million people worldwide. It has been acknowledged that an integrated...
BACKGROUND
Schistosomiasis is a parasitic disease that is endemic in 78 countries and affects almost 240 million people worldwide. It has been acknowledged that an integrated approach that goes beyond drug treatment is needed to achieve control and eventual elimination of the disease. Improving hygiene has been encouraged by World Health Organisation, and one aspect of good hygiene is using soap during water-contact activities, such as bathing and doing laundry. This hygiene practice might directly reduce the skin exposure to cercariae at transmission sites. A systematic review was carried out to investigate the efficacy of soap against schistosome cercariae and to identify the knowledge gaps surrounding this topic.
METHODOLOGY
Six online databases were searched between 5th and 8th July of 2021. Records returned from these databases were screened to remove duplicates, and the remaining records were classified by reading titles, abstracts, and full texts to identify the included studies. The results were categorised into two groups based on two different protective mechanisms of soap (namely, damage to cercariae and protection of skin).
CONCLUSIONS
Limited research has been conducted on the efficacy of soap against schistosome cercariae and only 11 studies met the criteria to be included in this review. The review demonstrates that soap has the potential of protecting people against schistosome cercariae and there are two protective aspects: (1) soap affects cercariae adversely; (2) soap on the skin prevents cercariae from penetrating the skin, developing into adult worms and producing eggs. Both aspects of protection were influenced by many factors, but the differences in the reported experimental conditions, such as the cercarial endpoint measurement used and the cercaria numbers used per water sample, lead to low comparability between the previous studies. This review indicates that more evidence is needed to inform hygiene advice for people living in schistosomiasis endemic areas.
Topics: Animals; Cercaria; Schistosoma; Schistosomiasis; Soaps; Water
PubMed: 36191022
DOI: 10.1371/journal.pntd.0010820 -
PloS One 2023Traditional diagnostic tests for schistosome infections are suboptimal, particularly when the parasite burden is low. In the present review we sought to identify...
Diagnostic performances of Schistosoma haematobium and Schistosoma mansoni recombinant proteins, peptides and chimeric proteins antibody based tests. Systematic scoping review.
BACKGROUND
Traditional diagnostic tests for schistosome infections are suboptimal, particularly when the parasite burden is low. In the present review we sought to identify recombinant proteins, peptides, and chimeric proteins with potential to be used as sensitive and specific diagnostic tools for schistosomiasis.
METHODS
The review was guided by PRISMA-ScR guidelines, Arksey and O'Malley's framework, and guidelines from the Joanna Briggs Institute. Five databases were searched: Cochrane library, PubMed, EMBASE, PsycInfo and CINAHL, alongside preprints. Identified literature were assessed by two reviewers for inclusion. A narrative summary was used to interpret the tabulated results.
RESULTS
Diagnostic performances were reported as specificities, sensitivities, and AUC. The AUC for S. haematobium recombinant antigens ranged from 0.65 to 0.98, and 0.69 to 0.96 for urine IgG ELISA. S. mansoni recombinant antigens had sensitivities ranging from 65.3% to 100% and specificities ranging from 57.4% to 100%. Except for 4 peptides which had poor diagnostic performances, most peptides had sensitivities ranging from 67.71% to 96.15% and specificities ranging from 69.23% to 100%. S. mansoni chimeric protein was reported to have a sensitivity of 86.8% and a specificity of 94.2%.
CONCLUSION
The tetraspanin CD63 antigen had the best diagnostic performance for S. haematobium. The tetraspanin CD63 antigen Serum IgG POC-ICTs had a sensitivity of 89% and a specificity of 100%. Peptide Smp_150390.1 (216-230) serum based IgG ELISA had the best diagnostic performance for S. mansoni with a sensitivity of 96.15% and a specificity of 100%. Peptides were reported to demonstrate good to excellent diagnostic performances. S. mansoni multi-peptide chimeric protein further improved the diagnostic accuracy of synthetic peptides. Together with the advantages associated with urine sampling technique, we recommend development of multi-peptide chimeric proteins urine based point of care tools.
Topics: Animals; Schistosoma haematobium; Schistosoma mansoni; Tetraspanin 30; Peptides; Blood Group Antigens; Recombinant Proteins; Recombinant Fusion Proteins; Immunoglobulin G
PubMed: 36862712
DOI: 10.1371/journal.pone.0282233 -
PLoS Pathogens May 2021Although a growing number of studies suggest interactions between Schistosoma parasites and viral infections, the effects of schistosome infections on the host response...
Although a growing number of studies suggest interactions between Schistosoma parasites and viral infections, the effects of schistosome infections on the host response to viruses have not been evaluated comprehensively. In this systematic review, we investigated how schistosomes impact incidence, virulence, and prevention of viral infections in humans and animals. We also evaluated immune effects of schistosomes in those coinfected with viruses. We screened 4,730 studies and included 103. Schistosomes may increase susceptibility to some viruses, including HIV and Kaposi's sarcoma-associated herpesvirus, and virulence of hepatitis B and C viruses. In contrast, schistosome infection may be protective in chronic HIV, Human T-cell Lymphotropic Virus-Type 1, and respiratory viruses, though further research is needed. Schistosome infections were consistently reported to impair immune responses to hepatitis B and possibly measles vaccines. Understanding the interplay between schistosomes and viruses has ramifications for anti-viral vaccination strategies and global control of viral infections.
Topics: Animals; Antiviral Agents; Coinfection; Humans; Immunity; Schistosoma; Schistosomiasis; Virus Diseases; Viruses
PubMed: 34015063
DOI: 10.1371/journal.ppat.1009555 -
Parasites & Vectors Feb 2021Ethiopia has set the ambitious national targets of eliminating soil-transmitted helminths (STH) and schistosomiasis (SCH) as public health problems by 2020, and breaking...
BACKGROUND
Ethiopia has set the ambitious national targets of eliminating soil-transmitted helminths (STH) and schistosomiasis (SCH) as public health problems by 2020, and breaking their transmission by 2025. This systematic review was performed to provide insight into the progress made by the national STH and SCH control programme purposed with reaching these targets.
METHODS
Studies published on STH and SCH in Ethiopia were searched for using Web of Science, PubMed, Scopus, and the resulting references of selected studies. Prevalence and intensity were analysed, stratified by region, age, and diagnostics.
RESULTS
A total of 231 papers published between 2000 and 2020 were included. Over the past two decades, Trichuris trichiura (TT) infection has shown the most statistically significant decrease (93%, p < 0.0001), followed by Schistosoma mansoni (SM) (69%, p < 0.0001), Ascaris lumbricoides (AL) (67%, p < 0.0001) and Schistosoma haematobium (83%, p = 0.038) infections. Geographically, parasite burden has only consistently shown a significant reduction in the Southern Nations, Nationalities and Peoples' Region of Ethiopia, where AL, TT, hookworm and SM significantly decreased by 80% (p = 0.006), 95% (p = 0.005), 98% (p = 0.009) and 87% (p = 0.031), respectively. Prevalence of STH was highest among adults across all species, contrary to typical age-infection profiles for TT and AL that peak among school-aged children. Expanding treatment to the whole community would target reservoirs of adult and preschool-aged infection within the community, assisting Ethiopia in reaching their national transmission break targets. There was substantial heterogeneity in diagnostic methods used across studies, the majority of which predominantly used single-slide Kato-Katz. This low slide frequency provides poor diagnostic sensitivity, particularly in low endemic settings.
CONCLUSION
The prevalence of STH and SCH in Ethiopia has decreased over time due to the strategic use of anthelmintics. Both standardising and increasing the sensitivity of the diagnostics used, alongside the ubiquitous use of parasite intensity with prevalence, would enable a more accurate and comparable understanding of Ethiopia's epidemiological progress. Further work is needed on community-wide surveillance in order to understand the burden and subsequent need for treatment among those outside of the standard school-based control program.
Topics: Cross-Sectional Studies; Ethiopia; Feces; Helminthiasis; Humans; Prevalence; Schistosomiasis; Soil; World Health Organization
PubMed: 33546757
DOI: 10.1186/s13071-021-04600-0 -
PLoS Neglected Tropical Diseases Dec 2016Spatial modelling of STH and schistosomiasis epidemiology is now commonplace. Spatial epidemiological studies help inform decisions regarding the number of people at... (Review)
Review
BACKGROUND
Spatial modelling of STH and schistosomiasis epidemiology is now commonplace. Spatial epidemiological studies help inform decisions regarding the number of people at risk as well as the geographic areas that need to be targeted with mass drug administration; however, limited attention has been given to propagated uncertainties, their interpretation, and consequences for the mapped values. Using currently published literature on the spatial epidemiology of helminth infections we identified: (1) the main uncertainty sources, their definition and quantification and (2) how uncertainty is informative for STH programme managers and scientists working in this domain.
METHODOLOGY/PRINCIPAL FINDINGS
We performed a systematic literature search using the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) protocol. We searched Web of Knowledge and PubMed using a combination of uncertainty, geographic and disease terms. A total of 73 papers fulfilled the inclusion criteria for the systematic review. Only 9% of the studies did not address any element of uncertainty, while 91% of studies quantified uncertainty in the predicted morbidity indicators and 23% of studies mapped it. In addition, 57% of the studies quantified uncertainty in the regression coefficients but only 7% incorporated it in the regression response variable (morbidity indicator). Fifty percent of the studies discussed uncertainty in the covariates but did not quantify it. Uncertainty was mostly defined as precision, and quantified using credible intervals by means of Bayesian approaches.
CONCLUSION/SIGNIFICANCE
None of the studies considered adequately all sources of uncertainties. We highlighted the need for uncertainty in the morbidity indicator and predictor variable to be incorporated into the modelling framework. Study design and spatial support require further attention and uncertainty associated with Earth observation data should be quantified. Finally, more attention should be given to mapping and interpreting uncertainty, since they are relevant to inform decisions regarding the number of people at risk as well as the geographic areas that need to be targeted with mass drug administration.
Topics: Animals; Bayes Theorem; Health Services Research; Helminthiasis; Helminths; Humans; Models, Statistical; Schistosoma; Schistosomiasis; Soil
PubMed: 28005901
DOI: 10.1371/journal.pntd.0005208 -
Infectious Diseases of Poverty Jul 2018Schistosomiasis is a serious public health burden in sub-Saharan Africa. Praziquantel is the only drug recommended by the World Health Organization to treat both... (Review)
Review
BACKGROUND
Schistosomiasis is a serious public health burden in sub-Saharan Africa. Praziquantel is the only drug recommended by the World Health Organization to treat both urogenital and intestinal schistosomiasis. The reliance on a single drug to treat a disease with such a huge burden has raised concerns of possible drug resistance mainly in endemic areas. This systematic review was conducted to identify gaps and recent progress on the efficacy of different regimens of praziquantel in treating schistosomiasis among children in sub-Saharan Africa where Schistosoma mansoni and S. haematobium are endemic.
MAIN TEXT
A literature search of peer-reviewed journals was done on Google Scholar, MEDLINE (under EBSCOhost) and PubMed databases using pre-defined search terms and Boolean operators. The search included studies published from 2008 to 2017 (August) with emphasis on the efficacy of praziquantel on S. haematobium and S. mansoni infections among preschool and school children. Nineteen publications satisfied the inclusion criteria for the review. The studies reviewed were from 10 sub-Saharan African countries and 7/19 of the studies (37%) were conducted in Uganda. Seven studies (37%) focused on Schistosoma mansoni, 6/19 (31.5%) on S. haematobium and another 6 on mixed infection. A single standard dose of 40 mg/kg body weight was the most used regimen (9) followed by the repeated single standard dose assessed for efficacy at 3-4 weeks post-treatment.
CONCLUSIONS
A repeated standard dose of 40 mg/kg achieved satisfactory efficacy compared to a single dose against both parasite species. However, findings on efficacy of repeated doses in co-infection of S. mansoni and S. haematobium were not conclusive. Praziquantel administrated at 60 mg/kg was slightly more efficacious than the 40 mg/kg standard dose. Minor and transitory side-effects were reported for both regimens. The review indicates that further investigations are necessary to conclusively determine efficacy of praziquantel on coinfection of S. haematobium and S. mansoni to formulate concrete guidelines on the use of repeated doses at 40 or 60 mg/kg for treating schistosomiasis. We recommend the use of the egg reduction rate (ERR) formula recommended by the WHO for assessing praziquantel efficacy in order for the results to be comparable for different regions.
Topics: Africa South of the Sahara; Animals; Anthelmintics; Child; Child, Preschool; Humans; Praziquantel; Schistosoma haematobium; Schistosoma mansoni; Schistosomiasis
PubMed: 29986763
DOI: 10.1186/s40249-018-0448-x -
PloS One 2015Schistosomiasis japonica has been resurging in certain areas of China where its transmission was previously well controlled or interrupted. Several factors may be... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Schistosomiasis japonica has been resurging in certain areas of China where its transmission was previously well controlled or interrupted. Several factors may be contributing to this, including mobile populations, which if infected, may spread the disease. A wide range of estimates have been published for S. japonicum infections in mobile populations, and a synthesis of these data will elucidate the relative risk presented from these groups.
METHODS
A literature search for publications up to Oct 31, 2014 on S. japonicum infection in mobile populations in previously endemic but now non-endemic regions was conducted using four bibliographic databases: China National Knowledge Infrastructure, WanFang, VIP Chinese Journal Databases, and PubMed. A meta-analysis was conducted by pooling one arm binary data with MetaAnalyst Beta 3.13. The protocol is available on PROSPERO (No. CRD42013005967).
RESULTS
A total of 41 studies in Chinese met the inclusion criteria, covering seven provinces of China. The time of post-interruption surveillance ranged from the first year to the 31st year. After employing a random-effects model, from 1992 to 2013 the pooled seroprevalence ranged from 0.9% (95% CI: 0.5-1.6%) in 2003 to 2.3% (95% CI: 1.5-3.4) in 1995; from the first year after the disease had been interrupted to the 31st year, the pooled seroprevalence ranged from 0.6% (95% CI: 0.2-2.1%) in the 27th year to 4.0% (95%CI: 1.3-11.3%) in the second year. The pooled seroprevalence in mobile populations each year was significantly lower than among the residents of endemic regions, whilst four papers reported a lower level of infection in the mobile populations than in the local residents out of only 13 papers which included this data.
CONCLUSIONS
The re-emergence of S. japonicum in areas which had previously interrupted transmission might be due to other factors, although risk from re-introduction from mobile populations could not be excluded.
Topics: Animals; China; Endemic Diseases; Humans; Movement; Prevalence; Publication Bias; Schistosoma japonicum; Schistosomiasis japonica; Seroepidemiologic Studies
PubMed: 26043190
DOI: 10.1371/journal.pone.0128896 -
Host determinants of reinfection with schistosomes in humans: a systematic review and meta-analysis.PLoS Neglected Tropical Diseases Sep 2014Schistosomiasis is still a major public health burden in the tropics and subtropics. Although there is an effective chemotherapy (Praziquantel) for this disease,... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Schistosomiasis is still a major public health burden in the tropics and subtropics. Although there is an effective chemotherapy (Praziquantel) for this disease, reinfection occurs rapidly after mass drug administration (MDA). Because the entire population do not get reinfected at the same rate, it is possible that host factors may play a dominant role in determining resistance or susceptibility to reinfection with schistosomes. Here, we systematically reviewed and meta-analyzed studies that reported associations between reinfection with the principal human-infecting species (S. mansoni, S. japonicum and S. haematobium) and host socio-demographic, epidemiological, immunological and genetic factors.
METHODOLOGY/PRINCIPAL FINDINGS
PubMed, Scopus, Google Scholar, Cochrane Review Library and African Journals Online public databases were searched in October 2013 to retrieve studies assessing association of host factors with reinfection with schistosomes. Meta-analysis was performed to generate pooled odds ratios and standardized mean differences as overall effect estimates for dichotomous and continuous variables, respectively. Quality assessment of included studies, heterogeneity between studies and publication bias were also assessed. Out of the initial 2739 records, 109 studies were included in the analyses, of which only 32 studies with 37 data sets were eligible for quantitative data synthesis. Among several host factors identified, strong positive association was found with age and pre-treatment intensity, and only slightly for gender. These factors are major determinants of exposure and disease transmission. Significant positive association was found with anti-SWA IgG4 level, and a negative overall effect for association with IgE levels. This reconfirmed the concept that IgE/IgG4 balance is a major determinant of protective immunity against schistosomiasis. Other identified determinants were reported by a small number of studies to enable interpretation.
CONCLUSIONS
Our data contribute to the understanding of host-parasite interaction as it affects reinfection, and is a potential tool to guide planning and tailoring of community interventions to target high-risk groups.
Topics: Animals; Disease Susceptibility; Host-Parasite Interactions; Humans; Recurrence; Schistosoma; Schistosomiasis
PubMed: 25211227
DOI: 10.1371/journal.pntd.0003164 -
PLoS Neglected Tropical Diseases Oct 2019Schistosomiasis is a widespread public health concern in the poorest regions of the world. The principal control strategy is regular praziquantel administration to... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Schistosomiasis is a widespread public health concern in the poorest regions of the world. The principal control strategy is regular praziquantel administration to school-aged children in endemic areas. With calls for the elimination of schistosomiasis as a public health problem, expanding praziquantel delivery to all community members has been advocated. This systematic review and meta-analysis compares the impact of community-wide and child-targeted praziquantel distribution on schistosomiasis prevalence and intensity in school-aged children.
METHODOLOGY/PRINCIPAL FINDINGS
We searched MEDLINE, Embase and Web of Science to identify papers that reported schistosome prevalence before and after praziquantel administration, either to children only or to all community members. Extracted data included Schistosoma species, drug administration strategy, number of treatment rounds, follow-up interval and prevalence and intensity before and after treatment. We used inverse variance weighted generalised linear models to examine the impact of mass versus targeted drug administration on prevalence reduction, and weighted boxplots to examine the impact on infection intensity reduction. This study is registered with PROSPERO, number CRD42018095377. In total, 34 articles were eligible for systematic review and 28 for meta-analysis. Schistosoma mansoni was reported in 20 studies; Schistosoma haematobium in 19 studies, and Schistosoma japonicum in two studies. Results of generalised linear models showed no detectable difference between mass and targeted treatment strategies on prevalence reduction in school-aged children for S. mansoni (odds ratio 0.47, 95%CI 0.13-1.68, p = 0.227) and S. haematobium (0.41, 95%CI 0.06-3.03, p = 0.358). Box plots also showed no apparent differences in intensity reduction between the two treatment strategies.
CONCLUSIONS/SIGNIFICANCE
The results of this meta-analysis do not support the hypothesis that community-wide treatment is more effective than targeted treatment at reducing schistosomiasis infections in children. This may be due to the relatively small number of included studies, insufficient treatment coverage, persistent infection hotspots and unmeasured confounders. Further field-based studies comparing mass and targeted treatment are required.
Topics: Animals; Child; Databases, Factual; Humans; Praziquantel; Prevalence; Schistosoma haematobium; Schistosoma japonicum; Schistosoma mansoni; Schistosomatidae; Schistosomiasis; Schools
PubMed: 31603895
DOI: 10.1371/journal.pntd.0007808