Leishmaniases survey in the Awash Valley: The magnitude of positive leishmanin reaction and its pattern in the Middle Awash

Abstract

Background: Both visceral and cutaneous leishmaniasis are reckoned to be endemic in Ethiopia in magnitudes of undetermined prevalence and distribution. There is considerable information pertaining to the public health importance of leishmaniases in the lower course of the Rift Valley of Ethiopia. Nevertheless, there is evident gap of knowledge on these disease entities in the middle course of the Valley, where the current investigation has been carried out.

Objectives: The study was conducted to get pertinent information regarding exposure to leishmanial parasites and to screen study subjects in the delineated course of the Valley for possible occurrence of clinical cases.

Methods: Following screening for overt cases of leishmaniasis, a cross-sectional leishmanin skin test was undertaken in 926 individuals. The overall prevalence of leishmanin positivity in 889 (96%) of those who returned for reading of the test was about 40%. Nearly 60% of the males and about 25% of the females tested positive for the antigen. Positivity appeared to be increasing with age in both sexes. Variation in leishmanin response among the study localities was evident and this appeared to be influenced very much by the duration of stay in the area. This difference was found to be statistically significnt (X2=13.7; P<0.005).

Conclusion: the leishmanin response profile of the study area is typical of an endemic locality, with positivity building up with age as experienced in other endemic sites. This suggests an outdoor exposure to infection. The implication of this finding will be further discussed.

[Ethiop.J.Health Dev. 2002;16(2):157-163]