Socio-economic and environmental factors associated with Montenegro skin test positivity in an endemic area of visceral leishmaniasis in northern Morocco

In Marocco, many aspects of human asymptomatic visceral leishmaniasis (VL) still have to be clarified and little information is available about the factors that predispose individuals to asymptomatic infection. A prospective study was carried out in 889 healthy children under the age of 15 years living in two provinces in the endemic area in northern Morocco (the provinces of Taounate and My Yacoub) from April to May 2010. The aim of the study was to evaluate the prevalence and the socio-economic and environmental characteristics associated with infection by Leishmania infantum. The Montenegro skin test (MST) was used to detect asymptomatic infection. The prevalence of transmission of infection was 11.4% and approximately 2 times higher in Taounate than in My Yacoub, as measured by MST. Asymptomatic infection was associated with gender, age, presence of familial links, proximity to chickens, and the number of people in the house and locality, but it was not associated to education status, presence of dogs, livestock waste, sewage disposal, water supply system or use of insecticides