National mapping of schistosomiasis, soil-transmitted helminthiasis and anaemia in Yemen: Towards better national control and elimination.

BACKGROUND: Schistosomiasis (SCH) and soil-transmitted helminthiasis (STH) are known to be endemic in Yemen. However, the distribution of both diseases had not previously been assessed by a well-structured national mapping study covering all governorates. The main aim of this study was, therefore, to map the prevalence of SCH and STH in Yemen in order to better inform implementation of effective national control and elimination interventions. The assessment of the distribution of anaemia was also included as a well-known consequence of infection with both SCH and STH. Secondarily, the study aimed to provide a broad indication of the impact of large-scale treatment on the distribution of infection. METHODOLOGY AND PRINCIPAL FINDINGS: To achive these aims, 80,432 children (10-14 years old) from 2,664 schools in 332 of Yemen's 333 districts were included, in 2014, into this national cross-sectional survey. Countrywide, 63.3% (210/332) and 75.6% (251/332) of districts were found to be endemic for SCH and STH respectively. More districts were affected by intestinal than urogenital SCH (54.2% and 31.6% respectively). SCH infection was mostly mild and moderate, with no districts reporting high infection. One quarter (24.4%) of Yemeni districts had high or moderate levels of Ascaris lumbricoides infection. Infection with Trichuris trichiura was the second most common STH (44.9% of districts infected) after A. lumbricoides (68.1%). Hookworm was the least prevalent STH (9.0%). Anaemia was prevalent in 96.4% of districts; it represented a severe public health problem (prevalence ≥ 40%) in 26.5% of districts, and a mild to moderate problem in two thirds of the districts (33.7% and 36.1% respectively). CONCLUSION: This study provided the first comprehensive mapping of SCH, STH, and anaemia across the country. This formed the basis for evaluating and continuing the national control and elimination programme for these neglected tropical diseases in Yemen.

Towards nationwide control of schistosomiasis in Yemen: a pilot project to expand treatment to the whole community.

Both the urinary and intestinal forms of schistosomiasis are thought to be widespread in the Republic of Yemen, with estimates of 3 million people infected and 600 000 suffering clinical morbidity. Sub-national control has been ongoing since 2006 via the distribution of praziquantel (PZQ) against schistosomiasis and albendazole (ALB) against soil-transmitted helminths using school-based treatment. In preparation for a 6-year nationwide control programme with the aim of expanding treatment to the wider community, a new programmatic approach of complementing school-based distribution with community-based treatment was trialled in 10 highly endemic districts in three governorates in December 2009. The new approach achieved coverage of 90.1% of non-enrolled children: a 40% increase compared with the same districts in 2008, and coverage of 97.9% of enrolled children: a 2% increase compared to 2008. Coverage of females (children and adults) was 81.8%, and of adults in general was 73.9%. The total cost per person treated was US$0.66 (US$0.79 in 2008), which includes training, health education, social mobilization, distribution and drugs. These results provide hope that a combined school and community-based approach can be successfully implemented on a wider scale during the main control programme in 2010-2015, with approximately 10 million people targeted in the first year alone.