Cutaneous leishmaniasis in south-western Ethiopia: Ocholo revisited.

The borough of Ocholo, on the western side of the Ethiopian Rift Valley, is an endemic focus for Leishmania aethiopica infection and has been surveyed thrice between 1987 and 1990. In 1989, 3022 inhabitants (> 95% of the population) were interviewed and examined. The overall prevalence of localized cutaneous leishmaniasis (LCL) was 3.6-4.0%, with a peak value of 8.5% in the 0-10 years old age group. In half of the patients the active disease was estimated to last for 9.6 +/- 6 months; in 10%, it exceeded 3 years. Scars of LCL were present in 34.3% of the residents. Leishmanin skin tests were positive in 54% of 120 school-children without signs of the disease. Therefore, in Ocholo a minimum of 71.6% of the population has been exposed to L. aethiopica infection. Two cases of the diffuse form of cutaneous leishmaniasis were observed. In this highland biotope, Phlebotomus pedifer was found to be the major, and possibly the only, vector for L. aethiopica.