Geographic Distribution and Prevalence of Schistosomiasis and Soil-Transmitted Helminths among Schoolchildren in Mozambique

Schistosomiasis and soil-transmitted helminths (STHs) are most prevalent in developing countries. In Mozambique, the first and only national survey of the distribution and prevalence of schistosomiasis and STHs was conducted in 1952 and 1957. Only occasional surveys in restricted areas have been conducted since the 1950s. The objective of our survey was to update information on the geographic distribution and prevalence of schistosomiasis and STHs in this country. During August 2005-June 2007, the Schistosomiasis and STH Laboratory of National Institutes of Health of the Ministry of Health undertook an epidemiologic survey among schoolchildren. A total of 83,331 persons attending primary schools were sampled. The mean age was 11.36 years (range: 7-22 years). Stool and urine samples were collected and examined by using Kato-Katz and filtration and Ritchie and Willis techniques. Results indicate a widespread occurrence of Schistosoma haematobium (overall prevalence = 47.0%) and STHs (prevalence = 53.5%). Prevalence varied dramatically across the country, with the highest prevalence in districts in northern provinces (Cabo Delgado, Niassa, Nampula, and Zambezia) and in certain provincial capital cities. Districts in the southern region of the country were less affected. Schistosoma mansoni was less common, with prevalence of 1%. We conclude that schistosomiasis and STHs are widely distributed in Mozambique and confirm the need for a national helminth control program.