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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 -
PLoS Neglected Tropical Diseases Mar 2016In 2012 the World Health Assembly adopted resolution WHA65.21 on elimination of schistosomiasis, calling for increased investment in schistosomiasis control and support... (Review)
Review
Schistosomiasis Prevalence and Intensity of Infection in Latin America and the Caribbean Countries, 1942-2014: A Systematic Review in the Context of a Regional Elimination Goal.
BACKGROUND
In 2012 the World Health Assembly adopted resolution WHA65.21 on elimination of schistosomiasis, calling for increased investment in schistosomiasis control and support for countries to initiate elimination programs. This study aims to analyze prevalence and intensity of Schistosoma mansoni infection in children in Latin America and the Caribbean countries and territories (LAC), at the second administrative level or lower.
METHODOLOGY
A systematic review of schistosomiasis prevalence and intensity of infection was conducted by searching at PubMed, LILACS and EMBASE. Experts on the topic were informally consulted and institutional web pages were reviewed (PAHO/WHO, Ministries of Health). Only SCH infection among children was registered because it can be a 'proxi-indicator' of recent transmission by the time the study is conducted.
PRINCIPAL FINDINGS
One hundred thirty two full-text articles met the inclusion criteria and provided 1,242 prevalence and 199 intensity of infection data points. Most of them were from Brazil (69.7%). Only Brazil published studies after 2001, showing several 'hot spots' with high prevalence. Brazil, Venezuela, Suriname and Saint Lucia need to update the epidemiological status of schistosomiasis to re-design their national programs and target the elimination of Schistosoma mansoni transmission by 2020. In Antigua and Barbuda, Dominican Republic, Guadeloupe, Martinique, Montserrat and Puerto Rico schistosomiasis transmission may be interrupted. However the compilation of an elimination dossier and follow-up surveys, per WHO recommendations, are needed to verify that status. Hence, the burden of subtle SCH chronic infection may be still present and even high in countries that may have eliminated transmission. Heterogeneity in the methodologies used for monitoring and evaluating the progress of the schistosomiasis programs was found, making cross-national and chronological comparisons difficult.
CONCLUSIONS
There is a need for updating the schistosomiasis status in the historically endemic countries and territories in LAC to address the required public health interventions for control and elimination programs or to verify the elimination of transmission of Schistosoma mansoni. Improved reporting and standardization of the monitoring and evaluation methodologies used are recommended, while using available WHO guidelines. Meeting a regional elimination goal will require additional and improved epidemiological data by age group and sex.
Topics: Anthelmintics; Disease Eradication; Humans; Latin America; Praziquantel; Schistosomiasis
PubMed: 27007193
DOI: 10.1371/journal.pntd.0004493 -
The Lancet. Global Health Feb 2019Global migration from regions where strongyloidiasis and schistosomiasis are endemic to non-endemic countries has increased the potential individual and public health... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Global migration from regions where strongyloidiasis and schistosomiasis are endemic to non-endemic countries has increased the potential individual and public health effect of these parasitic diseases. We aimed to estimate the prevalence of these infections among migrants to establish which groups are at highest risk and who could benefit from screening.
METHODS
We did a systematic review and meta-analysis of strongyloidiasis and schistosomiasis prevalence among migrants born in endemic countries. Original studies that included data for the prevalence of Strongyloides or Schistosoma antibodies in serum or the prevalence of larvae or eggs in stool or urine samples among migrants originating from countries endemic for these parasites and arriving or living in host countries with low endemicity-specifically the USA, Canada, Australia, New Zealand, Israel, and 23 western European countries-were eligible for inclusion. Pooled estimates of the prevalence of strongyloidiasis and schistosomiasis by stool or urine microscopy for larvae or eggs or serum antibodies were calculated with a random-effects model. Heterogeneity was explored by stratification by age, region of origin, migrant class, period of study, and type of serological antigen used.
FINDINGS
88 studies were included. Pooled strongyloidiasis seroprevalence was 12·2% (95% CI 9·0-15·9%; I 96%) and stool-based prevalence was 1·8% (1·2-2·6%; 98%). Migrants from east Asia and the Pacific (17·3% [95% CI 4·1-37·0]), sub-Saharan Africa (14·6% [7·1-24·2]), and Latin America and the Caribbean (11·4% [7·8-15·7]) had the highest seroprevalence. Pooled schistosomiasis seroprevalence was 18·4% (95% CI 13·1-24·5; I 97%) and stool-based prevalence was 0·9% (0·2-1·9; 99%). Sub-Saharan African migrants had the highest seroprevalence (24·1·% [95% CI 16·4-32·7]).
INTERPRETATION
Strongyloidiasis affects migrants from all global regions, whereas schistosomiasis is focused in specific regions and most common among sub-Saharan African migrants. Serological prevalence estimates were several times higher than stool estimates for both parasites. These data can be used to inform screening decisions for migrants and support the use of serological screening, which is more sensitive and easier than stool testing.
FUNDING
None.
Topics: Africa South of the Sahara; Australia; Canada; Caribbean Region; Emigrants and Immigrants; Endemic Diseases; Europe; Asia, Eastern; Feces; Humans; Israel; Latin America; Mass Screening; New Zealand; Pacific Islands; Prevalence; Schistosomiasis; Seroepidemiologic Studies; Serologic Tests; Strongyloidiasis; United States
PubMed: 30683241
DOI: 10.1016/S2214-109X(18)30490-X -
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 -
PLoS Neglected Tropical Diseases Feb 2017Since 1984, WHO has endorsed drug treatment to reduce Schistosoma infection and its consequent morbidity. Cross-sectional studies suggest pre-treatment correlation... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Since 1984, WHO has endorsed drug treatment to reduce Schistosoma infection and its consequent morbidity. Cross-sectional studies suggest pre-treatment correlation between infection intensity and risk for Schistosoma-related pathology. However, evidence also suggests that post-treatment reduction in intensity may not reverse morbidity because some morbidities occur at all levels of infection, and some reflect permanent tissue damage. The aim of this project was to systematically review evidence on drug-based control of schistosomiasis and to develop a quantitative estimate of the impact of post-treatment reductions in infection intensity on prevalence of infection-associated morbidity.
METHODOLOGY/PRINCIPAL FINDINGS
This review was registered at inception with PROSPERO (CRD42015026080). Studies that evaluated morbidity before and after treatment were identified by online searches and searches of private archives. Post-treatment odds ratios or standardized mean differences were calculated for each outcome, and these were correlated to treatment-related egg count reduction ratios (ERRs) by meta-regression. A greater ERR correlated with greater reduction in odds of most morbidities. Random effects meta-analysis was used to derive summary estimates: after treatment of S. mansoni and S. japonicum, left-sided hepatomegaly was reduced by 54%, right-sided hepatomegaly by 47%, splenomegaly by 37%, periportal fibrosis by 52%, diarrhea by 53%, and blood in stools by 75%. For S. haematobium, hematuria was reduced by 92%, proteinuria by 90%, bladder lesions by 86%, and upper urinary tract lesions by 72%. There were no consistent changes in portal dilation or hemoglobin levels. In sub-group analysis, age, infection status, region, parasite species, and interval to follow-up were associated with meaningful differences in outcome.
CONCLUSION/SIGNIFICANCE
While there are challenges to implementing therapy for schistosomiasis, and praziquantel therapy is not fully curative, reductions in egg output are significantly correlated with decreased morbidity and can be used to project diminution in disease burden when contemplating more aggressive strategies to minimize infection intensity.
Topics: Animals; Anthelmintics; Humans; Praziquantel; Schistosoma; Schistosomiasis
PubMed: 28212414
DOI: 10.1371/journal.pntd.0005372 -
PLoS Neglected Tropical Diseases Jan 2018Evidence of an adverse influence of soil transmitted helminth (STH) infections on cognitive function and educational loss is equivocal. Prior meta-analyses have focused... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Evidence of an adverse influence of soil transmitted helminth (STH) infections on cognitive function and educational loss is equivocal. Prior meta-analyses have focused on randomized controlled trials only and have not sufficiently explored the potential for disparate influence of STH infection by cognitive domain. We re-examine the hypothesis that STH infection is associated with cognitive deficit and educational loss using data from all primary epidemiologic studies published between 1992 and 2016.
METHODS
Medline, Biosis and Web of Science were searched for original studies published in the English language. Cognitive function was defined in four domains (learning, memory, reaction time and innate intelligence) and educational loss in two domains (attendance and scholastic achievement). Pooled effect across studies were calculated as standardized mean differences (SMD) to compare cognitive and educational measures for STH infected/non-dewormed children versus STH uninfected /dewormed children using Review Manager 5.3. Sub-group analyses were implemented by study design, risk of bias (ROB) and co-prevalence of Schistosoma species infection. Influential studies were excluded in sensitivity analysis to examine stability of pooled estimates.
FINDINGS
We included 36 studies of 12,920 children. STH infected/non-dewormed children had small to moderate deficits in three domains-learning, memory and intelligence (SMD: -0.44 to -0.27, P<0.01-0.03) compared to STH-uninfected/dewormed children. There were no differences by infection/treatment status for reaction time, school attendance and scholastic achievement (SMD: -0.26 to -0.16, P = 0.06-0.19). Heterogeneity of the pooled effects in all six domains was high (P<0.01; I2 = 66-99%). Application of outlier treatment reduced heterogeneity in learning domain (P = 0.12; I2 = 33%) and strengthened STH-related associations in all domains but intelligence (SMD: -0.20, P = 0.09). Results varied by study design and ROB. Among experimental intervention studies, there was no association between STH treatment and educational loss/performance in tests of memory, reaction time and innate intelligence (SMD: -0.27 to 0.17, P = 0.18-0.69). Infection-related deficits in learning persisted within design/ROB levels (SMD: -0.37 to -52, P<0.01) except for pre-vs post intervention design (n = 3 studies, SMD = -0.43, P = 0.47). Deficits in memory, reaction time and innate intelligence persisted within observational studies (SMD: -0.23 to -0.38, all P<0.01) and high ROB strata (SMD:-0.37 to -0.83, P = 0.07 to <0.01). Further, in Schistosoma infection co-prevalent settings, associations were generally stronger and statistically robust for STH-related deficits in learning, memory and reaction time tests(SMD:-0.36 to -0.55, P = 0.003-0.02). STH-related deficits in school attendance and scholastic achievement was noted in low (SMD:-0.57, P = 0.05) and high ROB strata respectively.
INTERPRETATION
We provide evidence of superior performance in five of six educational and cognitive domains assessed for STH uninfected/dewormed versus STH infected/not-dewormed school-aged children from helminth endemic regions. Cautious interpretation is warranted due to high ROB in some of the primary literature and high between study variability in most domains. Notwithstanding, this synthesis provides empirical support for a cognitive and educational benefit of deworming. The benefit of deworming will be enhanced by strategically employing, integrated interventions. Thus, multi-pronged inter-sectoral strategies that holistically address the environmental and structural roots of child cognitive impairment and educational loss in the developing world may be needed to fully realize the benefit of mass deworming programs.
Topics: Adolescent; Albendazole; Animals; Anthelmintics; Child; Child, Preschool; Cognition; Cognitive Dysfunction; Educational Measurement; Executive Function; Humans; Mebendazole; Memory and Learning Tests; Schistosoma; Schistosomiasis; Soil
PubMed: 29329288
DOI: 10.1371/journal.pntd.0005523 -
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