Schistosomiasis in school-age children in Burkina Faso after a decade of preventive chemotherapy.

Introduction Human schistosomiasis is endemic in 78 countries or territories. (1,2) It has been estimated that, in 2013, there were nearly 261 million people--including about 240 million in Africa--who required preventive chemotherapy because they were at risk of schistosome infection. (1) Following the 2001 World Health Assembly resolution WHA54.19, (3) several endemic countries in Africa launched national programmes for the control of schistosomiasis. (4,5) These programmes are largely based on preventive chemotherapy with praziquantel and are targeted at school-age children and adults at risk. (6) In resolution WHA65.21, the World Health Assembly called on all countries with endemic schistosomiasis to intensify their control programmes and, where appropriate, to initiate campaigns for the elimination of schistosomiasis. (7) The West African country of Burkina Faso is divided into 13 administrative regions (Fig. 1). Some form of human schistosomiasis is thought to be endemic in every one of the country's 63 health districts. (9-11) Although urogenital schistosomiasis --caused by Schistosoma haematobium--occurs throughout the country, intestinal schistosomiasis--caused by Schistisoma mansoni--is mainly confined to the southwest of the country. (9,11) Surveys conducted before the 1980s, showed that the prevalence of S. haematobium was very high, with focal prevalence up to 100% of people surveyed in the eastern part of the country. (9) Over the same period, S. mansoni infection was found in up to 79% of people surveyed in the Hauts Bassins and Sud-Ouest regions. (9) Burkina Faso established a national programme for the control of schistosomiasis and soil-transmitted helminths in 2004, with funding from the Schistosomiasis Control Initiative. (5,12,13) This programme's main objective was to use mass administration of praziquantel to prevent human schistosomiasis. National mapping surveys (14) led to the country being divided into a hyper-endemic zone--comprising the 19 health districts that make up the Boucle du Mouhoun, Nord, Sahel and Sud-Ouest regions--and a meso-endemic zone--comprising the country's other 44 health districts. In 2004, baseline data were collected from children attending 16 randomly-selected primary schools in the four regions of the hyperendemic zone. Depending on the study region, the observed prevalence of S. haematobium infection varied from 18.4% to 84.2% and the observed intensity of such infection--among all children investigated--varied from 39.4-126.9 eggs per 10 ml urine sample. (15) Biennial mass administration of praziquantel to school-age children began in the hyper-endemic zone in 2004 and in the meso-endemic zone in 2005. (13,15) Since 2006, adults who are considered to be at risk have also been targeted. In 2007, Burkina Faso's national programme for the control of schistosomiasis and soil-transmitted helminths became part of a national integrated programme against neglected tropical diseases. The integrated programme was initially supported by the Schistosomiasis Control Initiative and Reseau International Schistosomiases--Environnement Amenagements et Lutte, with funding from the United States Agency for International Development's (USAID) Neglected Tropical Disease Control Programme, managed by RTI International. (16) Since 2011, the programme has been supported by Helen Keller International, with funding from the USAID's End Neglected Tropical Diseases in Africa Project, managed by Family Health International 360. At the beginning of 2013, four and five rounds of mass praziquantel administration were done in the mesoendemic and hyper-endemic zones, respectively. To assess the impact of these rounds and plan for the next phase, primary-school children at 22 sentinel sites were tested for schistosomiasis in 2013. Here we present the results of the assessment and discusses possible future strategies for thp elimination of all forms of schistosomiasis from Burkina Faso. …