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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 -
The Cochrane Database of Systematic... Jun 2021Neurocysticercosis is a parasitic infection of the central nervous system by the larval stage of the pork tapeworm and is a common cause of seizures and epilepsy in... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Neurocysticercosis is a parasitic infection of the central nervous system by the larval stage of the pork tapeworm and is a common cause of seizures and epilepsy in endemic areas. Anthelmintics (albendazole or praziquantel) may be given alongside supportive treatment (antiepileptics/analgesia) with the aim of killing these larvae (cysticerci), with or without corticosteroid treatment. However, there are potential adverse effects of these drugs, and the cysticerci may eventually die without directed anthelminthic treatment.
OBJECTIVES
To assess the effects of anthelmintics on people with neurocysticercosis.
SEARCH METHODS
We searched the Cochrane Infectious Diseases Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, LILACS, the WHO ICTRP, and ClinicalTrials.gov, up to 21 October 2020.
SELECTION CRITERIA
Randomized controlled trials comparing anthelmintics and supportive treatment (+/- corticosteroids) with supportive treatment alone (+/- corticosteroids) for people with neurocysticercosis.
DATA COLLECTION AND ANALYSIS
Two review authors independently screened the title and abstract of all articles identified by the search. We obtained full-text articles to confirm the eligibility of all studies that passed screening. One review author extracted data, which a second review author checked. Two review authors assessed the risk of bias of each trial and performed GRADE assessments. In cases of disagreement at consensus discussion stage between review authors, we consulted a third review author. We calculated risk ratios (RR) for dichotomous variables, with 95% confidence intervals (CIs) for pooled data from studies with similar interventions and outcomes.
MAIN RESULTS
We included 16 studies in the review. Only two studies investigated praziquantel and did not report data in a format that could contribute to meta-analysis. Most results in this review are therefore applicable to albendazole versus placebo or no anthelmintic. The aggregate analysis across all participants with neurocysticercosis did not demonstrate a difference between groups in seizure recurrence, but heterogeneity was marked (RR 0.94, 95% CI 0.78 to 1.14; 10 trials, 1054 participants; I = 67%; low-certainty evidence). When stratified by participants with a single cyst or multiple cysts, pooled analysis suggests that albendazole probably improves seizure recurrence for participants with a single cyst (RR 0.61, 95% CI 0.4 to 0.91; 5 trials, 396 participants; moderate-certainty evidence). All studies contributing to this analysis recruited participants with non-viable, intraparenchymal cysts only, and most participants were children. We are uncertain whether or not albendazole reduces seizure recurrence in participants with multiple cysts, as the certainty of the evidence is very low, although the direction of effect is towards albendazole causing harm (RR 2.05, 95% CI 1.28 to 3.31; 2 trials, 321 participants; very low-certainty evidence). This analysis included a large study containing a highly heterogeneous population that received an assessment of unclear risk for multiple 'Risk of bias' domains. Regarding radiological outcomes, albendazole probably slightly improves the complete radiological clearance of lesions (RR 1.22, 95% CI 1.07 to 1.39; 13 trials, 1324 participants; moderate-certainty evidence) and the evolution of cysts (RR 1.27, 95% CI 1.10 to 1.47; 6 trials, 434 participants; moderate-certainty evidence). More adverse events appeared to be observed in participants treated with either albendazole or praziquantel compared to those receiving placebo or no anthelmintic. The most commonly reported side effects were headache, abdominal pain, and nausea/vomiting.
AUTHORS' CONCLUSIONS
For participants with a single cyst, there was less seizure recurrence in the albendazole group compared to the placebo/no anthelmintic group. The studies contributing to this evidence only recruited participants with a non-viable intraparenchymal cyst. We are uncertain whether albendazole reduces seizure recurrence for participants with multiple cysts. We also found that albendazole probably increases radiological clearance and evolution of lesions. There were very few studies reporting praziquantel outcomes, and these findings apply to albendazole only.
Topics: Adult; Albendazole; Anticestodal Agents; Bias; Brain Diseases; Child; Humans; Neurocysticercosis; Placebos; Praziquantel; Randomized Controlled Trials as Topic; Seizures
PubMed: 34060667
DOI: 10.1002/14651858.CD000215.pub5 -
Neurology Jan 2013The effectiveness of anthelminthic and corticosteroid drug therapy in parenchymal neurocysticercosis is well established. The treatment of parenchymal solitary... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
The effectiveness of anthelminthic and corticosteroid drug therapy in parenchymal neurocysticercosis is well established. The treatment of parenchymal solitary cysticercus granuloma (SCG), however, remains controversial. We attempted to obtain a consistent estimate of the efficacy of anthelminthic and corticosteroid drug treatment in SCG.
METHODS
Randomized-controlled trials (RCTs) comparing rates of seizure freedom, granuloma resolution, and residual calcification in individuals with SCG treated with anthelminthic or corticosteroid drugs with those treated with antiepileptic drugs (AEDs) alone were systematically reviewed and quantified using fixed- or random-effects meta-analysis.
RESULTS
Fifteen RCTs were identified for inclusion. Ten RCTs assigned 765 people with SCG to AED treatment with or without anthelminthic drug (albendazole) treatment. A further 5 RCTs assigned 457 people with SCG to AED treatment with or without corticosteroid drugs. Anthelminthic treatment was associated with significantly increased rates of seizure freedom (nonevent odds ratio: 2.45; 95% confidence interval: 1.49-4.03; p = 0.0004) and significantly higher rates of granuloma resolution (odds ratio: 2.09; 95% confidence interval: 1.41-3.00; p = 0.0003), but did not alter the risk of residual calcification. Corticosteroid treatment was not significantly associated with any outcome.
CONCLUSIONS
Anthelminthic treatment with albendazole provides improved rates of seizure freedom and hastens resolution of the granuloma. The role of corticosteroid treatment remains uncertain. The benefits (or lack thereof in the case of corticosteroids) are consistent when measured across different time points after treatment.
Topics: Adolescent; Albendazole; Anthelmintics; Anti-Inflammatory Agents; Calcinosis; Child; Child, Preschool; Female; Granuloma; Humans; Infant; Male; Neurocysticercosis; Odds Ratio; Praziquantel; Prednisolone; Randomized Controlled Trials as Topic; Seizures; Treatment Outcome; Young Adult
PubMed: 23269591
DOI: 10.1212/WNL.0b013e31827b90a8 -
International Journal of Environmental... Dec 2018We aimed to evaluate the evidence on screening and treatment for two parasitic infections-schistosomiasis and strongyloidiasis-among migrants from endemic countries...
Effectiveness of Screening and Treatment Approaches for Schistosomiasis and Strongyloidiasis in Newly-Arrived Migrants from Endemic Countries in the EU/EEA: A Systematic Review.
We aimed to evaluate the evidence on screening and treatment for two parasitic infections-schistosomiasis and strongyloidiasis-among migrants from endemic countries arriving in the European Union and European Economic Area (EU/EEA). We conducted a systematic search of multiple databases to identify systematic reviews and meta-analyses published between 1 January 1993 and 30 May 2016 presenting evidence on diagnostic and treatment efficacy and cost-effectiveness. We conducted additional systematic search for individual studies published between 2010 and 2017. We assessed the methodological quality of reviews and studies using the AMSTAR, Newcastle⁻Ottawa Scale and QUADAS-II tools. Study synthesis and assessment of the certainty of the evidence was performed using GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. We included 28 systematic reviews and individual studies in this review. The GRADE certainty of evidence was low for the effectiveness of screening techniques and moderate to high for treatment efficacy. Antibody-detecting serological tests are the most effective screening tests for detection of both schistosomiasis and strongyloidiasis in low-endemicity settings, because they have higher sensitivity than conventional parasitological methods. Short courses of praziquantel and ivermectin were safe and highly effective and cost-effective in treating schistosomiasis and strongyloidiasis, respectively. Economic modelling suggests presumptive single-dose treatment of strongyloidiasis with ivermectin for all migrants is likely cost-effective, but feasibility of this strategy has yet to be demonstrated in clinical studies. The evidence supports screening and treatment for schistosomiasis and strongyloidiasis in migrants from endemic countries, to reduce morbidity and mortality.
Topics: Cost-Benefit Analysis; Endemic Diseases; European Union; Humans; Mass Screening; Schistosomiasis; Serologic Tests; Strongyloidiasis; Transients and Migrants
PubMed: 30577567
DOI: 10.3390/ijerph16010011 -
Parasitology Nov 2009Guidelines recommend praziquantel (PZQ) for the treatment and control of schistosomiasis, with no real alternative. Metrifonate was still widely used against Schistosoma... (Review)
Review
Guidelines recommend praziquantel (PZQ) for the treatment and control of schistosomiasis, with no real alternative. Metrifonate was still widely used against Schistosoma haematobium in the 1990s, and then withdrawn. Experimental studies and clinical trials suggest that artemisinin compounds are active against S. haematobium. In a Cochrane systematic review assessing the efficacy and safety of drugs for treating urinary schistosomiasis, 24 randomized controlled trials (n=6315 individuals) met our inclusion criteria. These trials compared a variety of single agent and combination regimens with PZQ, metrifonate or artemisinin derivatives. The review confirmed that both the standard recommended doses of PZQ (single 40 mg/kg oral dose) and metrifonate (3x7.5-10 mg/kg oral doses administered fortnightly) are efficacious and safe in treating urinary schistosomiasis, but there is no study comparing these two regimens head-to-head. There is currently not enough evidence to evaluate artemisinin compounds. Most of the studies included in the Cochrane systematic review were insufficiently powered, lacked standardization in assessing and reporting outcomes, and had a number of methodological limitations. In this paper we discuss the implications of these findings with respect to public health and research methodology and propose priority research needs.
Topics: Humans; Public Health; Public Policy; Schistosomiasis haematobia; Schistosomicides
PubMed: 19493363
DOI: 10.1017/S0031182009005939 -
PLoS Neglected Tropical Diseases Oct 2017The mainstay of current schistosomiasis control programs is mass preventive chemotherapy of school-aged children with praziquantel. This treatment is delivered through... (Review)
Review
Systematic review of community-based, school-based, and combined delivery modes for reaching school-aged children in mass drug administration programs for schistosomiasis.
BACKGROUND
The mainstay of current schistosomiasis control programs is mass preventive chemotherapy of school-aged children with praziquantel. This treatment is delivered through school-based, community-based, or combined school- and community-based systems. Attaining very high coverage rates for children is essential in mass schistosomiasis treatment programs, as is ensuring that there are no persistently untreated subpopulations, a potential challenge for school-based programs in areas with low school enrollment. This review sought to compare the different treatment delivery methods based both on their coverage of school-aged children overall and on their coverage specifically of non-enrolled children. In addition, qualitative community or programmatic factors associated with high or low coverage rates were identified, with suggestions for overall coverage improvement.
METHODOLOGY/PRINCIPAL FINDINGS
This review was registered prospectively with PROSPERO (CRD 42015017656). Five hundred forty-nine publication of potential relevance were identified through database searches, reference lists, and personal communications. Eligible studies included those published before October 2015, written in English or French, containing quantitative or qualitative data about coverage rates for MDA of school-aged children with praziquantel. Among the 22 selected studies, combined community- and school-based programs achieved the highest median coverage rates (89%), followed by community-based programs (72%). School-based programs had both the lowest median coverage of children overall (49%) and the lowest coverage of the non-enrolled subpopulation of children. Qualitatively, major factors affecting program success included fear of side effects, inadequate education about schistosomiasis, lack of incentives for drug distributors, and inequitable distribution to minority groups.
CONCLUSIONS/SIGNIFICANCE
This review provides an evidence-based framework for the development of future schistosomiasis control programs. Based on our results, a combined community and school-based delivery system should maximize coverage for both in- and out-of-school children, especially when combined with interventions such as snacks for treated children, educational campaigns, incentives for drug distributors, and active inclusion of marginalized groups.
TRIAL REGISTRATION
ClinicalTrials.gov CRD42015017656.
Topics: Chemoprevention; Child; Clinical Trials as Topic; Community Health Services; Delivery of Health Care; Disease Transmission, Infectious; Drug Administration Schedule; Humans; Praziquantel; Schistosomiasis; Schistosomicides; Schools
PubMed: 29077723
DOI: 10.1371/journal.pntd.0006043 -
Acta Tropica Apr 2020
Comparative Study Meta-Analysis
Topics: Adjuvants, Immunologic; Animals; Anthelmintics; Immunologic Factors; Mice; Models, Animal; Praziquantel; Schistosoma mansoni; Schistosomiasis mansoni; Schistosomicides
PubMed: 31987779
DOI: 10.1016/j.actatropica.2020.105359 -
PLoS Neglected Tropical Diseases Jun 2016Schistosomiasis control mainly relies on preventive chemotherapy with praziquantel (PZQ) distributed through mass drug administration. With a target of 260 million... (Review)
Review
The Schistosomiasis Clinical Trials Landscape: A Systematic Review of Antischistosomal Treatment Efficacy Studies and a Case for Sharing Individual Participant-Level Data (IPD).
BACKGROUND
Schistosomiasis control mainly relies on preventive chemotherapy with praziquantel (PZQ) distributed through mass drug administration. With a target of 260 million treatments yearly, reliably assessing and monitoring efficacy is all-important. Recommendations for treatment and control of schistosomiasis are supported by systematic reviews and meta-analyses of aggregated data, which however also point to limitations due to heterogeneity in trial design, analyses and reporting. Some such limitations could be corrected through access to individual participant-level data (IPD), which facilitates standardised analyses.
METHODOLOGY
A systematic literature review was conducted to identify antischistosomal drug efficacy studies performed since 2000; including electronic searches of the Cochrane Infectious Diseases Group specialised register and the Cochrane Library, PubMed, CENTRAL and Embase; complemented with a manual search for articles listed in past reviews. Antischistosomal treatment studies with assessment of outcome within 60 days post-treatment were eligible. Meta-data, i.e. study-level characteristics (Schistosoma species, number of patients, drug administered, country, etc.) and efficacy parameters were extracted from published documents to evaluate the scope of an individual-level data sharing platform.
PRINCIPAL FINDINGS
Out of 914 documents screened, 90 studies from 26 countries were included, enrolling 20,517 participants infected with Schistosoma spp. and treated with different PZQ regimens or other drugs. Methodologies varied in terms of diagnostic approaches (number of samples and test repeats), time of outcome assessment, and outcome measure (cure rate or egg reduction rate, as an arithmetic or geometric mean), making direct comparison of published data difficult.
CONCLUSIONS
This review describes the landscape of schistosomiasis clinical research. The volume of data and the methodological and reporting heterogeneity identified all indicate that there is scope for an individual participant-level database, to allow for standardised analyses.
Topics: Anthelmintics; Data Interpretation, Statistical; Humans; Randomized Controlled Trials as Topic; Schistosomiasis
PubMed: 27347678
DOI: 10.1371/journal.pntd.0004784 -
Infectious Diseases of Poverty May 2018Cholangiocarcinoma (CCA) is a fatal bile duct cancer associated with infection by the liver fluke, Opisthorchis viverrini, in the lower Mekong region. Numerous public... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Cholangiocarcinoma (CCA) is a fatal bile duct cancer associated with infection by the liver fluke, Opisthorchis viverrini, in the lower Mekong region. Numerous public health interventions have focused on reducing exposure to O. viverrini, but incidence of CCA in the region remains high. While this may indicate the inefficacy of public health interventions due to complex social and cultural factors, it may further indicate other risk factors or interactions with the parasite are important in pathogenesis of CCA. This systematic review aims to provide a comprehensive analysis of described risk factors for CCA in addition to O. viverrini to guide future integrative interventions.
MAIN BODY
We searched five international and seven Thai research databases to identify studies relevant to risk factors for CCA in the lower Mekong region. Selected studies were assessed for risk of bias and quality in terms of study design, population, CCA diagnostic methods, and statistical methods. The final 18 included studies reported numerous risk factors which were grouped into behaviors, socioeconomics, diet, genetics, gender, immune response, other infections, and treatment for O. viverrini. Seventeen risk factors were reported by two or more studies and were assessed with random effects models during meta-analysis. This meta-analysis indicates that the combination of alcohol and smoking (OR = 11.1, 95% CI: 5.63-21.92, P < 0.0001) is most significantly associated with increased risk for CCA and is an even greater risk factor than O. viverrini exposure. This analysis also suggests that family history of cancer, consumption of raw cyprinoid fish, consumption of high nitrate foods, and praziquantel treatment are associated with significantly increased risk. These risk factors may have complex relationships with the host, parasite, or pathogenesis of CCA, and many of these risk factors were found to interact with each other in one or more studies.
CONCLUSIONS
Our findings suggest that a complex variety of risk factors in addition to O. viverrini infection should be addressed in future public health interventions to reduce CCA in affected regions. In particular, smoking and alcohol use, dietary patterns, and socioeconomic factors should be considered when developing intervention programs to reduce CCA.
Topics: Animals; Asia, Southeastern; Cholangiocarcinoma; Incidence; Opisthorchiasis; Opisthorchis; Prevalence; Risk Factors; Thailand
PubMed: 29769113
DOI: 10.1186/s40249-018-0434-3 -
Iranian Red Crescent Medical Journal Oct 2014Praziquantel, an antischistosomal compound, is used as first-line drug for chemotherapy of Schistosoma japonicum since 1984. In this article, we conducted a systematic...
BACKGROUND
Praziquantel, an antischistosomal compound, is used as first-line drug for chemotherapy of Schistosoma japonicum since 1984. In this article, we conducted a systematic review and mete-analysis to evaluate the efficacy and safety of different dosages of praziquantel (PZQ) for treatment of Schistosoma japonicum.
EVIDENCE ACQUISITION
A number of six articles published in peer-reviewed journals before December 2012 were selected for analysis after searching the following literature databases: PubMed/Medline, the Chinese WanFang Literature Database, China National Knowledge Infrastructure (1994-2012.12), and the Chinese Biomedical Literature (1978-2012.12).
RESULTS
The meta-analyses showed that there is no statistically significant difference of the negative rate on the egg using 40 mg/kg compared to 60 mg/kg PZQ for S. japonicum treatment (RR 0.79, 95% CI 0.46 1.35; P < 0.39). The meta-analysis showed that there is no statistically significant difference of the side effects using 30 mg/kg compared with 40 mg/kg (RR 0.97, 95% CI 0.68 1.38; P = 0.87), 40 mg/kg compared with 60 mg/kg (RR 0.79, 95% CI 0.46 1.35; P = 0.39) and 50 mg/kg compared with 60 mg/kg (RR 0.89, 95% CI 0.56 1.42; P = 0.63).
CONCLUSIONS
According to the results, there is no statistically significant difference in different doses of PZQ for treating S. japonicum.
PubMed: 25558390
DOI: 10.5812/ircmj.9600