Visceral Leishmaniasis in Communities of Hamer and Benna-Tsemai Districts, Lower Omo Valley Southwest Ethiopia: Sero-Epidemiological and Leishmanin Skin Test Survey.

Abstract

Background: Visceral leishmaniasis is a systemic disease which is usually caused by Leishmania donovani or L. infantum, protozoan parasites that are transmitted by phlebotomine sandflies when blood-feeding on human and animal hosts. Eastern Africa is one of the world’s main endemic areas, where it occurs in numerous foci in Eritrea, Ethiopia, Kenya, Somalia, Sudan and Uganda. In Ethiopia, Hamer and Benna-Tsemai districts in SNNPR-S are one of the areas which are presumed to be endemic for visceral leishmaniasis. Objectives: The objective of the study was to determine the prevalence of asymptomatic and symptomatic visceral leishmaniasis and also to determine the level of exposure (infection) to leishmania parasites in Hamer and Bena Tsemai districts in south western Ethiopia. Methods: Between 25th of July and August14th of 2013, we conducted a community based crosssectional survey in selected villages of Hamer and Benna Tsemai districts in SNNPR-S. A total of 1760 individuals living in 440 households were included in the study. Socio-demographic and clinical data were collected from each of the participants; and venous blood was also collected for the detection of antibodies to visceral leishmaniasis using DAT. LST (Leishmanin Skin Test, also known as the Montenegro test) was performed to detect the exposure to the parasite. Results: A statistically significant variation in the rate of positive LST response was observed in different study sites and age groups. Positive LST response has shown an increasing trend with age. The DAT also showed a statistically significant variation among different study sites and age groups. High DAT positivity was observed in lower age groups. In general, the overall LST and DAT positivity were 8.6 and 1.8% respectively. Conclusion and Recommendations: Our study showed that asymptomatic VL infection in the study area is not negligible and could have a great contribution for anthropnotic transmission of the disease; thus, the regional health bureau specifically and MOH at large should take into consideration the implementation of a prevention and control strategy for VL. In addition to that we recommend an exhaustive survey, including a study of incidence and risk factors, which includes both sandfly investigation and epidemiology of the disease in one of the study kebele called cherkeka, represented by Ayro and Wisna villages in this study