Authors

M Pareyn³; E Van den Bosch³; N Girma¹; N van Houtte³; G Van der Auwera²; H Leirs³;  ¹ Arba Minch University, Ethiopia;  ² Institute of Tropical Medicine, Antwerp, Belgium;  ³ University of Antwerp, Belgium

Discussion

Ochollo is a village in the mid-highlands of Southern Ethiopia where cutaneous leishmaniasis (CL) forms a major health concern. The past decades, the high CL burden attracted several researchers to this area, conducting basic research on the players of transmission. The assigned vector for transmitting Leishmania aethiopica in Ochollo is Phlebotomus pedifer. Hyraxes, living on cliffs and in caves near human settlements in close contact with P. pedifer, are suspected to be the reservoir hosts. Since the transmission dynamic of Leishmania is somewhat unique to every region, a detailed description on the ecology of the different players of transmission needs to be established prior to attempting a control program to decrease the disease burden.

The general aim of this study is to extensively investigate the ecology of CL in Ochollo. More specific, the potential small mammal reservoirs, vectors and parasites of CL and the environmental characteristics (biotic and abiotic) they are associated with will be established.

A monthly sand fly sample collection was carried out from March 2017 until February 2018 in different habitats (caves, stone fences, tree crevices, ...) using CDC miniature light traps and sticky traps. Temperature and humidity data were recorded by loggers on an hourly basis for one year in the different habitats. Furthermore, hyraxes and rodents were trapped at different locations and ear, spleen and blood samples were taken. The presence of Leishmania DNA among the different sand fly, hyrax and rodent species was demonstrated by screening for kDNA using a real-time PCR. To determine the Leishmania, sand fly and small mammal species of the kDNA positive specimens, conventional PCRs targeting ITS-1, COI and CytB were performed respectively. PCR products were sequenced and examined by BLAST.

17% of the hyraxes was found infected with L. aethiopica, while only one out of 196 rodents, Mus mahomet, was kDNA positive. The prevalence of the (different) Leishmania species will be established among the variety of sand fly species and the potential seasonal dynamics in infectivity of different sand fly species and their ecological niche will be obtained. Finally, blood meal sources of fresh fed sand flies will be determined to establish the feeding preferences of the sand fly species.

This study will provide information about the sand fly and small mammal species that might play a role in CL transmission in Southern Ethiopia. Accordingly, the epidemiological relevance of the potential vectors and reservoirs will be assessed, as well as their ecological niche. This information will be used to prepare ecological niche models that will make predictions of the CL distribution at present and under changing environmental and land use circumstances, based on all players of transmission in this area.