-
PLoS Neglected Tropical Diseases Sep 2011Controversy persists about the optimal approach to drug-based control of schistosomiasis in high-risk communities. In a systematic review of published studies, we... (Review)
Review
BACKGROUND
Controversy persists about the optimal approach to drug-based control of schistosomiasis in high-risk communities. In a systematic review of published studies, we examined evidence for incremental benefits from repeated praziquantel dosing, given 2 to 8 weeks after an initial dose, in Schistosoma-endemic areas of Africa.
METHODOLOGY/PRINCIPAL FINDINGS
We performed systematic searches of electronic databases PubMed and EMBASE for relevant data using search terms 'schistosomiasis', 'dosing' and 'praziquantel' and hand searches of personal collections and bibliographies of recovered articles. In 10 reports meeting study criteria, improvements in parasitological treatment outcomes after two doses of praziquantel were greater for S. mansoni infection than for S. haematobium infection. Observed cure rates (positive to negative conversion in egg detection assays) were, for S. mansoni, 69-91% cure after two doses vs. 42-79% after one dose and, for S. haematobium, 46-99% cure after two doses vs. 37-93% after a single dose. Treatment benefits in terms of reduction in intensity (mean egg count) were also different for the two species-for S. mansoni, the 2-dose regimen yielded an weighted average 89% reduction in standardized egg counts compared to a 83% reduction after one dose; for S. haematobium, two doses gave a 93% reduction compared to a 94% reduction with a single dose. Cost-effectiveness analysis was performed based on Markov life path modeling.
CONCLUSIONS/SIGNIFICANCE
Although schedules for repeated treatment with praziquantel require greater inputs in terms of direct costs and community participation, there are incremental benefits to this approach at an estimated cost of $153 (S. mansoni)-$211 (S. haematobium) per additional lifetime QALY gained by double treatment in school-based programs. More rapid reduction of infection-related disease may improve program adherence, and if, as an externality of the program, transmission can be reduced through more effective coverage, significant additional benefits are expected to accrue in the targeted communities.
Topics: Adolescent; Adult; Africa; Animals; Anthelmintics; Child; Child, Preschool; Humans; Middle Aged; Praziquantel; Quality of Life; Schistosoma haematobium; Schistosoma mansoni; Schistosomiasis; Time Factors; Treatment Outcome; Young Adult
PubMed: 21949893
DOI: 10.1371/journal.pntd.0001321 -
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 -
The Cochrane Database of Systematic... 2000Schistosomiasis is a parasite that is carried by freshwater snails. The intestinal form infects the intestine, liver and spleen and can be fatal. (Review)
Review
BACKGROUND
Schistosomiasis is a parasite that is carried by freshwater snails. The intestinal form infects the intestine, liver and spleen and can be fatal.
OBJECTIVES
The objective of this review was to assess the effects of oxamniquine or praziquantel for treating Schistosomiasis mansoni
SEARCH STRATEGY
We searched the Cochrane Infectious Diseases Group trials register, the Cochrane Controlled Trials Register, Medline, Lilacs and reference lists of articles. The Revista da Sociedade Brasileira de Medicina Tropical and Brazilian Tropical Medicine Congress abstracts were handsearched
SELECTION CRITERIA
Randomised and quasi-randomised trials comparing oxamniquine and/or praziquantel to placebo for the treatment of Schistosomiasis mansoni.
DATA COLLECTION AND ANALYSIS
Two reviewers independently assessed trial quality and extracted data.
MAIN RESULTS
Thirteen trials met the inclusion criteria. Praziquantel and oxamniquine were effective in curing Schistosoma mansoni infection when compared to placebo. In Africa, praziquantel 40 mg/Kg is more effective than oxamniquine 15 mg/Kg in individuals older than 14 years (OR 3.54, 95%CI 1.70, 7.38), but no difference was found when compared with oxamniquine 30 mg/Kg (OR 0.29, 95%CI 0.08, 1.01). In Brazil, praziquantel was equally effective when compared with oxamniquine in individuals older than 14 years (OR 1.70, 95%CI 0.83, 3.49). Both drugs appear safe. There was no difference in reinfection rate between zinc supplementation and placebo (OR 0.82, 95%CI 0.47, 1.41).
REVIEWER'S CONCLUSIONS
IPraziquantel and oxamniquine both appear to be effective for the treatment of Schistosomiasis mansoni, although lower doses of oxamniquine (less than 30 milligrams per kilogram) may not be as effective.
Topics: Humans; Oxamniquine; Praziquantel; Schistosomiasis mansoni; Schistosomicides
PubMed: 10796552
DOI: 10.1002/14651858.CD000528 -
International Journal of Epidemiology Aug 2023Schistosomiasis is a water-borne parasitic disease estimated to have infected >140 million people globally in 2019, mostly in sub-Saharan Africa. Within the goal of...
BACKGROUND
Schistosomiasis is a water-borne parasitic disease estimated to have infected >140 million people globally in 2019, mostly in sub-Saharan Africa. Within the goal of eliminating schistosomiasis as a public health problem by 2030 in the World Health Organization (WHO) Roadmap for neglected tropical diseases, other regions cannot be neglected. Empirical estimates of the disease burden in Southeast Asia largely remain unavailable.
METHODS
We undertook a systematic review to identify empirical survey data on schistosomiasis prevalence in Southeast Asia using the Web of Science, ScienceDirect, PubMed and the Global Atlas of Helminth Infections, from inception to 5 February 2021. We then conducted advanced Bayesian geostatistical analysis to assess the geographical distribution of infection risk at a high spatial resolution (5 × 5 km) using the prevalence, number of infected individuals and doses needed for preventive chemotherapy.
RESULTS
We identified 494 Schistosoma japonicum surveys in the Philippines and Indonesia, and 285 in Cambodia and Laos for S. mekongi. The latest estimates suggest that 225 [95% credible interval (CrI): 168-285] thousand in the endemic areas of Southeast Asian population were infected in 2018. The highest prevalence of schistosomiasis was 3.86% (95% CrI: 3.40-4.31) in Laos whereas the lowest was 0.29% in Cambodia (95% CrI: 0.22-0.36). The estimated number of praziquantel doses needed per year was 1.99 million (95% CrI: 1.92-2.03 million) for the entire population in endemic areas of Southeast Asia.
CONCLUSIONS
The burden of schistosomiasis remains far from the WHO goal and our estimates highlighted areas to target with strengthened interventions against schistosomiasis.
Topics: Humans; Bayes Theorem; Schistosomiasis; Helminthiasis; Prevalence; Cambodia
PubMed: 36478466
DOI: 10.1093/ije/dyac227 -
The Lancet. Infectious Diseases Aug 2015Schistosomiasis affects more than 200 million individuals, mostly in sub-Saharan Africa, but empirical estimates of the disease burden in this region are unavailable. We... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Schistosomiasis affects more than 200 million individuals, mostly in sub-Saharan Africa, but empirical estimates of the disease burden in this region are unavailable. We used geostatistical modelling to produce high-resolution risk estimates of infection with Schistosoma spp and of the number of doses of praziquantel treatment needed to prevent morbidity at different administrative levels in 44 countries.
METHODS
We did a systematic review to identify surveys including schistosomiasis prevalence data in sub-Saharan Africa via PubMed, ISI Web of Science, and African Journals Online, from inception to May 2, 2014, with no restriction of language, survey date, or study design. We used Bayesian geostatistical meta-analysis and rigorous variable selection to predict infection risk over a grid of 1 155 818 pixels at 5 × 5 km, on the basis of environmental and socioeconomic predictors and to calculate the number of doses of praziquantel needed for prevention of morbidity.
FINDINGS
The literature search identified Schistosoma haematobium and Schistosoma mansoni surveys done in, respectively, 9318 and 9140 unique locations. Infection risk decreased from 2000 onwards, yet estimates suggest that 163 million (95% Bayesian credible interval [CrI] 155 million to 172 million; 18·5%, 17·6-19·5) of the sub-Saharan African population was infected in 2012. Mozambique had the highest prevalence of schistosomiasis in school-aged children (52·8%, 95% CrI 48·7-57·8). Low-risk countries (prevalence among school-aged children lower than 10%) included Burundi, Equatorial Guinea, Eritrea, and Rwanda. The numbers of doses of praziquantel needed per year were estimated to be 123 million (95% CrI 121 million to 125 million) for school-aged children and 247 million (239 million to 256 million) for the entire population.
INTERPRETATION
Our results will inform policy makers about the number of treatments needed at different levels and will guide the spatial targeting of schistosomiasis control interventions.
FUNDING
European Research Council, China Scholarship Council, UBS Optimus Foundation, and Swiss National Science Foundation.
Topics: Adolescent; Africa South of the Sahara; Animals; Bayes Theorem; Child; Child, Preschool; Health Services Needs and Demand; Humans; Morbidity; Mozambique; Praziquantel; Prevalence; Schistosoma haematobium; Schistosoma mansoni; Schistosomiasis
PubMed: 26004859
DOI: 10.1016/S1473-3099(15)00066-3 -
Parasites & Vectors Mar 2015Schistosomiasis is a disease caused by infection with blood flukes of the genus Schistosoma. Transmission of, and exposure to, the parasite result from faecal or urinary... (Review)
Review
Schistosomiasis is a disease caused by infection with blood flukes of the genus Schistosoma. Transmission of, and exposure to, the parasite result from faecal or urinary contamination of freshwater containing intermediate host snails, and dermal contact with the same water. The World Health Assembly resolution 65.21 from May 2012 urges member states to eliminate schistosomiasis through preventive chemotherapy (i.e. periodic large-scale administration of the antischistosomal drug praziquantel to school-aged children and other high-risk groups), provision of water, sanitation and hygiene (WASH) and snail control. However, control measures focus almost exclusively on preventive chemotherapy, while only few studies made an attempt to determine the impact of upgraded access to safe water, adequate sanitation and good hygiene on schistosome transmission. We recently completed a systematic review and meta-analysis pertaining to WASH and schistosomiasis and found that people with safe water and adequate sanitation have significantly lower odds of a Schistosoma infection. Importantly though, the transmission of schistosomiasis is deeply entrenched in social-ecological systems, and hence is governed by setting-specific cultural and environmental factors that determine human behaviour and snail populations. Here, we provide a comprehensive review of the literature, which explores the transmission routes of schistosomes, particularly focussing on how these might be disrupted with WASH-related technologies and human behaviour. Additionally, future research directions in this area are highlighted.
Topics: Animals; Child; Fresh Water; Global Health; Humans; Hygiene; Male; Praziquantel; Sanitation; Schistosoma; Schistosomiasis; Snails; Water
PubMed: 25884172
DOI: 10.1186/s13071-015-0766-9 -
The American Journal of Tropical... Apr 2020Schistosomiasis is an acute and chronic parasitic disease caused by blood flukes of the genus More than 220 million people worldwide were estimated to have active...
Schistosomiasis is an acute and chronic parasitic disease caused by blood flukes of the genus More than 220 million people worldwide were estimated to have active schistosomiasis in 2017, 90% of whom live on the African continent, but only 102 million were reported to have received treatment. Africa is also disproportionately burdened by HIV, with an estimated 26 million people living with HIV in 2017. Given these overlapping epidemics, we conducted a systematic review to ascertain the contribution of schistosomes to HIV acquisition risk, the contribution of HIV to schistosome acquisition, the impact of HIV on schistosomiasis-related morbidity, the impact of schistosomes on HIV disease progression and immune response, the impact of HIV on the efficacy of praziquantel treatment, and the impact of HIV on egg shedding. We reviewed studies of people living in sub-Saharan Africa coinfected with HIV and spp. between January 1996 and July 2018. We found that 1) infection with increases the risk of HIV acquisition, 2) there is currently a lack of data on whether HIV infection increases the risk of acquisition, 3a) HIV coinfection was not an accelerating factor for adverse outcomes, 3b) schistosomiasis may be an important contributor to immune activation in HIV coinfected people, 4) praziquantel use in coinfected people may improve immune reconstitution on antiretroviral therapy for HIV, and 5) there is evidence that HIV infection reduces egg excretion in individuals infected with .
Topics: Africa South of the Sahara; Animals; HIV Infections; HIV-1; Schistosoma; Schistosomiasis
PubMed: 32043458
DOI: 10.4269/ajtmh.19-0494 -
Infectious Diseases of Poverty Feb 2023
PubMed: 36814337
DOI: 10.1186/s40249-023-01064-5 -
Journal of Travel Medicine Oct 2019Schistosomiasis affects more than 260 million people worldwide, mostly in sub-Saharan Africa, where more than 280 000 deaths per year are estimated. In the past few...
BACKGROUND
Schistosomiasis affects more than 260 million people worldwide, mostly in sub-Saharan Africa, where more than 280 000 deaths per year are estimated. In the past few years, the increasing flow of migrants from endemic areas and the upward number of international travels have caused the emergence of the disease also in non-endemic areas. A single course of praziquantel (PZQ) 40 mg/kg is the first-line treatment recommended by the World Health Organization, mainly based on clinical trials conducted in endemic countries. No trials have been performed in non-endemic areas.
METHODS
We carried out a systematic review of case reports and case series published between 1956 and August 2017 on cases of chronic schistosomiasis (infection acquired >3 months before) diagnosed in non-endemic areas and treated with PZQ. Primary outcome was to assess the number of different therapeutic regimens deployed and their frequency of use, calculated as the number of reports for each regimen over the total number of included cases.
RESULTS
The final database included 99 case reports and 51 case series, for a total of 1433 patients. In 57 of the 150 records (38%) the administered treatment was different from the one recommended by the World Health Organization. The proportion of 'alternative' regimens included increased doses of PZQ (up to 80 mg/kg) and/or prolonged duration of treatment and/or doses repeated some days/weeks apart. About 50% of the records regarding Western short-term travellers reported a non-standard treatment.
CONCLUSION
This is the first complete catalogue of the published experience with PZQ outside of endemic areas in the situation where reinfection is not an issue. We found a wide heterogeneity of the therapeutic regimens reported. Multicenter clinical trials conducted in non-endemic areas and guidelines specifically addressing the treatment of imported cases of chronic schistosomiasis are needed.
Topics: Anthelmintics; Dose-Response Relationship, Drug; Global Health; Humans; Incidence; Praziquantel; Schistosomiasis
PubMed: 31309979
DOI: 10.1093/jtm/taz050 -
The Cochrane Database of Systematic... Mar 2010Neurocysticercosis is an infection of the brain by the larval stage of the pork tapeworm. In endemic areas it is a common cause of epilepsy. Anthelmintics (albendazole... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Neurocysticercosis is an infection of the brain by the larval stage of the pork tapeworm. In endemic areas it is a common cause of epilepsy. Anthelmintics (albendazole or praziquantel) may be given to kill the parasites. However, there are potential adverse effects, and the parasites may eventually die without treatment.
OBJECTIVES
To assess the effectiveness and safety of anthelmintics for people with neurocysticercosis.
SEARCH STRATEGY
In May 2009 we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2009, Issue 2), MEDLINE, EMBASE, LILACS, and the mRCT.
SELECTION CRITERIA
Randomized controlled trials comparing anthelmintics with placebo, no anthelmintic, or other anthelmintic regimen for people with neurocysticercosis.
DATA COLLECTION AND ANALYSIS
Two authors independently selected trials, extracted data, and assessed each trial's risk of bias. We calculated risk ratios (RR) for dichotomous variables, with 95% confidence intervals (CI). We pooled data from trials with similar interventions and outcomes.
MAIN RESULTS
For viable lesions in children, there were no trials. For viable lesions in adults, no difference was detected for albendazole compared with no treatment for recurrence of seizures (116 participants, one trial); but fewer participants with albendazole had lesions at follow up (RR 0.56, 95% CI 0.45 to 0.70; 192 participants, two trials).For non-viable lesions in children, seizures recurrence was less common with albendazole compared with no treatment (RR 0.49, 95% CI 0.32 to 0.75; 329 participants, four trials). There was no difference detected in the persistence of lesions at follow up (570 participants, six trials). For non-viable lesions in adults, there were no trials.In trials including viable, non-viable or mixed lesions (in both children and adults), headaches were more common with albendazole alone (RR 9.49, 95% CI 1.40 to 64.45; 106 participants, two trials), but no difference was detected in one trial giving albendazole with corticosteroids (116 participants, one trial).
AUTHORS' CONCLUSIONS
In patients with viable lesions, evidence from trials of adults suggests albendazole may reduce the number of lesions. In trials of non-viable lesions, seizure recurrence was substantially lower with albendazole, which is counter-intuitive. It may be that steroids influence headache during treatment, but further research is needed to test this.
Topics: Adrenal Cortex Hormones; Adult; Albendazole; Anticestodal Agents; Brain Diseases; Child; Humans; Neurocysticercosis; Praziquantel; Randomized Controlled Trials as Topic; Trichlorfon
PubMed: 20238309
DOI: 10.1002/14651858.CD000215.pub4