Assessment of leishmania donovani infection among children in Rashid village in eastern Sudan

Abstract

Sudan is one of five countries where more than 90 % of visceral leishmaniasis occurs Little data is available on the immune epidemiology of VL in Sudan. A descriptive longitudinal study was conducted in Rashid village in Gadraref state — eastern Sudan, during the period between January and November 2006. Informed consents were obtained from parent and guardian of children before been enrolled in the study. 741 of School age ( 17-5 years) children were selected to participate in the study. The study aimed to determine the immune responses of children living in VL endemic area . Three surveys were conducted in January, May and November 2006, and three tests ( LST, DAT, and PCR) were done. 6.9 % of the children were reactive in LST during the three surveys , and non of these children had a significant antibody titer ( DAT> 3200) , despite that some of them had past history of VL. The highest LST reaction was detected mostly in older children. Conversion from — ye LST to + ye LST was observed in about 0.7 % participant in the second survey (May) and also in 1.3 % of them in the third one (November). About 6.1 % of the participants were DAT + ye during the three surveys ,although no one of them had VL clinical symptoms . Conversion from — ye DAT to + ye DAT was observed in 1.1 % of the participant in the second survey (May ) and also in 0.3 % of them in the third one (November) with out development of VL clinical symptoms. The phenomena of negative conversion in both LST and DAT need to be further investigated. No circulating parasite DNA was detected by PCR technique in peripheral blood of all participants, and no infected sand fly was captured in the study area during the study indicating low transmission rate.