Water, Sanitation and Hygiene (WASH) and environmental risk factors for soil-transmitted helminth intensity of infection in Timor-Leste, using real time PCR

Abstract

BackgroundNo investigations have been undertaken of risk factors for intensity of soil-transmitted helminth (STH) infection in Timor-Leste. This study provides the first analysis of risk factors for intensity of STH infection, as determined by quantitative PCR (qPCR), examining a broad range of water, sanitation and hygiene (WASH) and environmental factors, among communities in Manufahi District, Timor-Leste.MethodsA baseline cross-sectional survey of 18 communities was undertaken as part of a cluster randomised controlled trial, with additional identically-collected data from six other communities. qPCR was used to assess STH infection from stool samples, and questionnaires administered to collect WASH, demographic, and socioeconomic data. Environmental information was obtained from open-access sources and linked to infection outcomes. Mixed-effects multinomial logistic regression was undertaken to assess risk factors for intensity of Necator americanus and Ascaris infection.Results2152 participants provided stool and questionnaire information for this analysis. In adjusted models incorporating WASH, demographic and environmental variables, environmental variables were generally associated with infection intensity for both N. americanus and Ascaris spp. Precipitation (in centimetres) was associated with increased risk of moderate-intensity (adjusted relative risk [ARR] 6.1; 95% confidence interval [CI] 1.9–19.3) and heavy-intensity (ARR 6.6; 95% CI 3.1–14.1) N. americanus infection, as was sandy-loam soil around households (moderate-intensity ARR 2.1; 95% CI 1.0–4.3; heavy-intensity ARR 2.7; 95% CI 1.6–4.5; compared to no infection). For Ascaris, alkaline soil around the household was associated with reduced risk of moderate-intensity infection (ARR 0.21; 95% CI 0.09–0.51), and heavy-intensity infection (ARR 0.04; 95% CI 0.01–0.25). Few WASH risk factors were significant.ConclusionIn this high-prevalence setting, strong risk associations with environmental factors indicate that anthelmintic treatment alone will be insufficient to interrupt STH transmission, as conditions are favourable for ongoing environmental transmission. Integrated STH control strategies should be explored as a priority.

WASH for WORMS: A Cluster-Randomized Controlled Trial of the Impact of a Community Integrated Water, Sanitation, and Hygiene and Deworming Intervention on Soil-Transmitted Helminth Infections

“…Detailed characterization of participants at baseline, including environmental and WASH risk factors for STH infection, and intensity of infection are described elsewhere. 20,[30][31][32] Participation rates at each study time point were similar in the intervention and control arms and are shown in Supplemental Table 1. In total, 2,141 individuals (1,033 in the intervention arm and 1,108 in the control arm) participated in at least one follow-up time point, by completing a questionnaire and/or providing stool samples.…”

Tailoring Water, Sanitation, and Hygiene (WASH) Targets for Soil-Transmitted Helminthiasis and Schistosomiasis Control

“…Absence of evidence does not imply evidence of lack of WASH and helminth connection. The soil or aquatic life cycle requirements of STH and schistosomiasis leave no doubt that WASH is a key causal pathway to reduce environmental contamination and eventually break transmission [23]. New research should not try to re-establish this unassailable link, but rather should examine which WASH interventions are most effective at reducing exposure to infection, in which settings.…”

Tingginya angka kecacingan pasca pengobatan massal filariasis (DEC dan Albendazole) di SDN Juku Eja Pagatan

“…Oleh karena itu, program intervensi, preventif dan promosi kecacingan juga sangat perlu untuk dilaksanakan di tingkat desa untuk memberikan pemahaman kepada masyarakat tentang kerugian yang ditimbulkan oleh kecacingan. Perbaikan WASH (Water, Sanitation and Hygiene) yang diterapkan bersamaan dengan pemberian drug mass administration dinyatakan mampu memutuskan siklus hidup STH ledakan kasus tidak akan mampu diatasi hanya dengan pemberian anthelminthik, 14 hal ini dikarenakan obat cacing hanya mengurangi angka kesakitan sementara dan tidak memberikan efek pencegahan terhadap reinfeksi. 22…”

“…WHO sendiri menargetkan peningkatan cakupan pemberian obat cacing dari 50% menjadi 75% pada tahun 2020 mendatang 3. dalam tubuh manusia 14,15. Infeksi A. lumbricoides dan T. trichiura menyebar melalui transmisi fecal-oral yang dimediasi oleh lingkungan yaitu melalui konsumsi telur/larva yang mengkontaminasi tanah.…”