A first nation-wide assessment of soil-transmitted helminthiasis in Fijian primary schools, and factors associated with the infection, using a lymphatic filariasis transmission assessment survey as surveillance platform

Abstract

Background Soil-transmitted helminthiasis (STH) is endemic in Fiji but its prevalence is not known and likely to have changed after a decade of mass drug administration (MDA) for lymphatic filariasis (LF). By linking with LF transmission assessment surveys (LF-TAS), we undertook the first nation-wide assessment of STH in Fijian primary schools, as well as an analysis of factors associated with STH infections. Methodology/Principal findings A cross-sectional assessment for STH was conducted in all four Divisions of Fiji from 2014 to 2015. In the Western, Central, and Northern Divisions, schools were sub-sampled after LF-TAS, while, in the Eastern Division, schools were selected via simple random sampling. For the diagnosis of STH, stool samples were examined by coproscopy with a single Kato-Katz thick smear (KK) and the formol-ether-acetate concentration technique, except for the samples from the Eastern Division where only KK was used. Mean prevalence of any STH among class 1-2 students at the national level was 10.5% (95% CI: 6.9-15.5). Across the three Divisions via LF-TAS, the prevalence levels for ascariasis were 8.7% (95% CI: 4.3-16.6), hookworm 3.9% (95% CI: 2.3-6.6) and trichuriasis 0%. In the Eastern Division, ascariasis prevalence was 13.3% (95% CI: 6.4-25.6), and hookworm 0.7% (95% CI: 0.2-2.5), with one case of trichuriasis. Among class 3-8 students, ascariasis prevalence was lower. Lower risk of any STH was associated with wearing shoes (adjusted OR 0.54, 95% CI: 0.32-0.90) and having piped water from the Fiji Water Authority at home (adjusted OR 0.48, 95% CI: 0.25-0.92). Conclusions After a decade of community-based LF-MDA, STH in school-age children in Fiji is now close to 10%, but localities of endemicity remain. Preventive chemotherapy should be maintained in areas with elevated STH prevalence alongside targeted delivery of integrated WASH interventions. LF-TAS has provided an opportunity to develop future public health surveillance platforms. Author summary Soil-transmitted helminth infections (STH) are common in school-age children in the developing world and can cause morbidity to affected human beings depending on the intensity and duration of infection. In Fiji, where there has been a long history of implementing a program for eliminating lymphatic filariasis (LF) due to inadequate sanitation conditions, there is a need to assess the current epidemiological profile of STH since the LF mass drug administration (MDA) as a community-based intervention may soon stop. By linking with ongoing LF-transmission assessment surveys (LF-TAS), we undertook the first nation-wide assessment of STH in Fijian primary schools. Mean prevalence of STH across three Divisions of Fiji in class 1-2 students chosen for LF-TAS was 12.1% (ascariasis 8.7%, hookworm 3.9%, and trichuriasis 0%). In the remaining Division, the Eastern, ascariasis prevalence was 13.3%, and hookworm 0.7%. Wearing shoes and use of piped water reduced the prevalence of STH. It is concluded that STH in school-age children in Fiji is at low levels, but hot spot localities of elevated STH endemicity remain. Therefore, preventive chemotherapy should be maintained in these localities alongside targeted delivery of appropriate integrated water, sanitation and hygiene interventions.