Cost-effectiveness of a successful schistosomiasis control programme in Cambodia (1995–2006)

Croce, Davide; Porazzi, Emanuele; Foglia, Emanuela; Restelli, Umberto; Muth, Sinuon; Socheat, Duong; Montresor, Antonio

doi:10.1016/j.actatropica.2009.11.011

Cited by 28 publications

(44 citation statements)

References 27 publications

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“…We assumed that praziquantel has a S. haematobium curative rate of 55% (range 37%–90%), as is consistent with epidemiological data (19,21,23–26). For women who received praziquantel as a child and those without established FGS, we assumed that they have a reduced risk of 50% (range 40%–70%) of developing FGS (20).…”

Section: Methodssupporting

confidence: 64%

Evaluating the potential impact of mass praziquantel administration for HIV prevention in Schistosoma haematobium high-risk communities

2014

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Genital infection with Schistosoma haematobium is prevalent in sub-Saharan Africa. Epidemiological studies have observed that genital schistosomiasis is associated with an increased odd of HIV infection among women. We used mathematical modeling to explore the potential impact of mass preventive chemotherapy against schistosomiasis on HIV transmission in three sub-Saharan Africa countries: Angola, Kenya, and Zambia. We developed a model of female genital schistosomiasis (FGS) and HIV transmission dynamics, fitting it to data of HIV and S. haematobium prevalences as well as co-infection. We simulated targeted mass drug administration (MDA) with praziquantel to school-age children and mass treatment of the entire community. We estimated that, in S. haematobium high-risk communities, targeted annual treatment of school-age children could reduce HIV prevalence by 20% (95% CI: 12%–31%) in Angola, 16% (95% CI: 10%–32%) in Kenya, and 6% (95% CI: 3%–18%) in Zambia after the first twenty years of intervention; and would reduce HIV incidence by 15% (95% CI: 13–32) in Angola, 22% (95% CI: 18–42) in Kenya, and 9% (95% CI: 3–22) in Zambia. Extending the intervention to adults could reduce HIV prevalence by an additional 2.2% (95% CI: 0.2%–12.0%) in Angola, 1.8% (95% CI: 0.1%–5.2%) in Kenya, and 0.3% (95% CI: 0.1%–2.1%) in Zambia; and would reduce HIV incidence by an additional 1.8% (95% CI: 0.0–14.4) in Angola, 6.1% (95% CI: 0.5–12.6) in Kenya, and 0.8% (95% CI: 0.0–2.7) in Zambia. We showed that the exacerbation of HIV transmission due to FGS and the probability of developing FGS as a result of childhood infection with S. haematobium, were the most important factors in determining the effectiveness of praziquantel MDA for reducing HIV transmission. Praziquantel MDA may be an innovative measure for reducing schistosomiasis and HIV transmissionin sub-Saharan Africa, the effectiveness of which varies with HIV prevalence.

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Section: Methodssupporting

confidence: 64%

Evaluating the potential impact of mass praziquantel administration for HIV prevention in Schistosoma haematobium high-risk communities

2014

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“…We included 84 English studies and six French studies. One study (Colley 2013), which was retrieved through an updated search, provided recent data for studies retrieved previously (Coulibaly 2011; Shane 2011; Tchuente 2012). In this case, we gathered data for the 2 × 2 tables from the most recent publication (Colley 2013).…”

Section: Resultsmentioning

confidence: 99%

“…The absence of a suitable gold standard for active schistosomiasis is reflected in the existing literature, where different reference standards are used with subsequent variation in accuracy (especially with specificity) of the index test (Koukounari 2009; Coulibaly 2011; Tchuente 2012; Colley 2013; Erko 2013; King 2013;Lodh 2013; Sousa-Figueiredo 2013). …”

Section: Discussionmentioning

confidence: 99%

“…A more reliable way of evaluating whether an index test can replace microscopy would be to compare the accuracy of microscopy, urine reagent strips, and circulating antigen tests against other proposed reference standards in the same set of participants (direct comparison studies). A few studies have compared the accuracy of one or more KK smears and CCA POC against a reference standard comprising six or more KK smears (Coulibaly 2011; Tchuente 2012; Erko 2013) or against PCR as the reference test (Lodh 2013) (see comparisons in Appendix 17). All of these studies have shown the CCA POC test to be more sensitive but less specific than single or double KK.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Circulating antigen tests and urine reagent strips for diagnosis of active schistosomiasis in endemic areas

Ochodo

Gopalakrishna

Spek

et al. 2015

Cochrane Database of Systematic Reviews

131

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Background Point‐of‐care (POC) tests for diagnosing schistosomiasis include tests based on circulating antigen detection and urine reagent strip tests. If they had sufficient diagnostic accuracy they could replace conventional microscopy as they provide a quicker answer and are easier to use. Objectives To summarise the diagnostic accuracy of: a) urine reagent strip tests in detecting active Schistosoma haematobium infection, with microscopy as the reference standard; and b) circulating antigen tests for detecting active Schistosoma infection in geographical regions endemic for Schistosoma mansoni or S. haematobium or both , with microscopy as the reference standard. Search methods We searched the electronic databases MEDLINE, EMBASE, BIOSIS, MEDION, and Health Technology Assessment (HTA) without language restriction up to 30 June 2014. Selection criteria We included studies that used microscopy as the reference standard: for S. haematobium , microscopy of urine prepared by filtration, centrifugation, or sedimentation methods; and for S. mansoni , microscopy of stool by Kato‐Katz thick smear. We included studies on participants residing in endemic areas only. Data collection and analysis Two review authors independently extracted data, assessed quality of the data using QUADAS‐2, and performed meta‐analysis where appropriate. Using the variability of test thresholds, we used the hierarchical summary receiver operating characteristic (HSROC) model for all eligible tests (except the circulating cathodic antigen (CCA) POC for S. mansoni , where the bivariate random‐effects model was more appropriate). We investigated heterogeneity, and carried out indirect comparisons where data were sufficient. Results for sensitivity and specificity are presented as percentages with 95% confidence intervals (CI). Main results We included 90 studies; 88 from field settings in Africa. The median S. haematobium infection prevalence was 41% (range 1% to 89%) and 36% for S. mansoni (range 8% to 95%). Study design and conduct were poorly reported against current standards. Tests for S. haematobium Urine reagent test strips versus microscopy Compared to microscopy, the detection of microhaematuria on test strips had the highest sensitivity and specificity (sensitivity 75%, 95% CI 71% to 79%; specificity 87%, 95% CI 84% to 90%; 74 studies, 102,447 participants). For proteinuria, sensitivity was 61% and specificity was 82% (82,113 participants); and for leukocyturia, sensitivity was 58% and specificity 61% (1532 participants). Howeve...

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“…Also, evidence demonstrating the ability of MDA to control the transmission of schistosomiasis in high prevalence areas is mixed, in part because the impact of MDA will vary across different epidemiological settings. There are many regions, such as the Mekong River in Cambodia, where excellent progress has been made, with heavy-intensity infections reduced to below 1% [5, 6]. However, several recent studies in Africa have demonstrated limited progress in reducing prevalence in localized high-transmission areas, despite high MDA coverage [7–9].…”

Section: Introductionmentioning

confidence: 99%

Vaccination or mass drug administration against schistosomiasis: a hypothetical cost-effectiveness modelling comparison

et al. 2019

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BackgroundSchistosomiasis is a neglected tropical disease, targeted by the World Health Organization for reduction in morbidity by 2020. It is caused by parasitic flukes that spread through contamination of local water sources. Traditional control focuses on mass drug administration, which kills the majority of adult worms, targeted at school-aged children. However, these drugs do not confer long-term protection and there are concerns over the emergence of drug resistance. The development of a vaccine against schistosomiasis opens the potential for control methods that could generate long-lasting population-level immunity if they are cost-effective.MethodsUsing an individual-based transmission model, matched to epidemiological data, we compared the cost-effectiveness of a range of vaccination programmes against mass drug administration, across three transmission settings. Health benefit was measured by calculating the heavy-intensity infection years averted by each intervention, while vaccine costs were assessed against robust estimates for the costs of mass drug administration obtained from data. We also calculated a critical vaccination cost, a cost beyond which vaccination might not be economically favorable, by benchmarking the cost-effectiveness of potential vaccines against the cost-effectiveness of mass drug administration, and examined the effect of different vaccine protection durations.ResultsWe found that sufficiently low-priced vaccines can be more cost-effective than traditional drugs in high prevalence settings, and can lead to a greater reduction in morbidity over shorter time-scales. MDA or vaccination programmes that target the whole community generate the most health benefits, but are generally less cost-effective than those targeting children, due to lower prevalence of schistosomiasis in adults.ConclusionsThe ultimate cost-effectiveness of vaccination will be highly dependent on multiple vaccine characteristics, such as the efficacy, cost, safety and duration of protection, as well as the subset of population targeted for vaccination. However, our results indicate that if a vaccine could be developed with reasonable characteristics and for a sufficiently low cost, then vaccination programmes can be a highly cost-effective method of controlling schistosomiasis in high-transmission areas. The population-level immunity generated by vaccination will also inevitably improve the chances of interrupting transmission of the disease, which is the long-term epidemiological goal.

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Cost-effectiveness of a successful schistosomiasis control programme in Cambodia (1995–2006)

Cited by 28 publications

References 27 publications

Evaluating the potential impact of mass praziquantel administration for HIV prevention in Schistosoma haematobium high-risk communities

Evaluating the potential impact of mass praziquantel administration for HIV prevention in Schistosoma haematobium high-risk communities

Circulating antigen tests and urine reagent strips for diagnosis of active schistosomiasis in endemic areas

Vaccination or mass drug administration against schistosomiasis: a hypothetical cost-effectiveness modelling comparison

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