Epidemiology of Leishmania donovani infection in high-transmission foci in Nepal : Epidemiology of Leishmania donovani

Nepal reports a visceral leishmaniasis (VL) incidence of 5 per 10 000 per year on the basis of notification by health facilities, but little community-based epidemiological information exists. We report data on prevalence rates of Leishmania donovani infection in ten communities in East Nepal. Ten clusters with highest VL incidence rates were purposefully selected in Nepal.

All households were mapped and socio-demographic data and data on past VL incidence were collected. An exhaustive serological survey was performed of individuals aged >2 years, by collecting finger prick blood on filter paper in November-December 2006. The samples were tested by direct agglutination, and a titre >or=1:1600 was taken as marker of infection.

A generalized estimating equation (GEE) model was used to assess risk factors for Direct Agglutination Test (DAT) positivity taking into account the clustering at household and village level. The sero-survey (n = 5397) showed an infection prevalence rate of 9%, (range 5-15% per cluster) with higher prevalence in men (9.9%) than in women (8.3%) (P = 0.049).

Male gender, increasing age and poverty were significant risk factors in the final GEE model. Leishmania infection rate in high-transmission areas in Nepal is associated with gender, age and socio-economic status.