Human visceral (VL, also known as Kala-azar) and cutaneous (CL) leishmaniasis are important infectious diseases affecting countries in East Africa that remain endemic in several regions of Ethiopia. The transmission and epidemiology of the disease is complicated due to the complex life cycle of the parasites and the involvement of various Leishmania spp., sand fly vectors, and reservoir animals besides human hosts. Particularly in East Africa, the role of animals as reservoirs for human VL remains unclear. Isolation of Leishmania donovani parasites from naturally infected rodents has been reported in several endemic countries; however, the status of rodents as reservoirs in Ethiopia remains unclear. Here, we demonstrated natural Leishmania infections in rodents. Animals were trapped in 41 localities of endemic and non-endemic areas in eight geographical regions of Ethiopia and DNA was isolated from spleens of 586 rodents belonging to 21 genera and 38 species. Leishmania infection was evaluated by real-time PCR of kinetoplast (k)DNA and confirmed by sequencing of the PCR products. Subsequently, parasite species identification was confirmed by PCR and DNA sequencing of the 18S ribosomal RNA internal transcribed spacer one (ITS1) gene. Out of fifty (8.2%) rodent specimens positive for Leishmania kDNA-PCR and sequencing, 10 were subsequently identified by sequencing of the ITS1 showing that five belonged to the L. donovani complex and five to L. tropica. Forty nine kDNA-positive rodents were found in the endemic localities of southern and eastern Ethiopia while only one was identified from northwestern Ethiopia. Moreover, all the ten ITS1-positive rodents were captured in areas where human leishmaniasis cases have been reported and potential sand fly vectors occur. Our findings suggest the eco-epidemiological importance of rodents in these foci of leishmaniasis and indicate that rodents are likely to play a role in the transmission of leishmaniasis in Ethiopia, possibly as reservoir hosts.
Bibliographical noteFunding Information:
We would like to thank Radim Sumbera and Josef Bryja for providing additional rodent sample; Yaarit Biala, Jana Radrova, and staffs of the leishmaniasis research and diagnostic laboratory (Medical school, Addis Ababa University) for their technical assistance. This project was funded by grants from the Bill and Melinda Gates Foundation Global Health Program ( OPPGH5336 ), Grant Agency of the Charles University in Prague ( GAUK 9108/2013 ), Czech Science Foundation ( GACR P506-10-0983 ) and the EU grant 2011-261504 EDENext (the paper is cataloged as EDENext 319). The funding agencies had no role in study design, data collection and analysis, decision to publish, or preparation of manuscript.
© 2015 The Authors.
- L. tropica
- Leishmania donovani
- Phlebotomine sand fly