Do the rodents have a role in transmission of cutaneous leishmaniasis in Turkey?

Abstract

Leishmaniasis is a zoonotic/anthroponotic vector borne parasitic infection which is caused by Leishmania species and transmitted by sand flies (Phlebotomus spp.) The reservoirs of Leishmania species in nature are various wild and domestic carnivores, rodents and human. The aim of this study was to investigate whether the rodents in genera Meriones, Mesocricetus, Rattus and Mus which inhabit in the natural habitat of our country could be natural reservoirs of Leishmania tropica, Leishmania infantum, Leishmania major and Leishmania donovani for cutaneous Leishmaniasis (CL)., The rodents Mus musculus (Balb/C mouse), Mesocricetus auratus (hamster), Meriones unguiculatus (gerbil) and Rattus norvegicus (rat) which are part of the natural habitat in Turkey were used in the study. L.tropica, L.infantum, L.major and L.donovani promastigote isolates obtained from CL patients and cultured in enriched media were injected in the footpads of the animals intradermally using the density of 108 promastigote/ml. The scale of the lesions on the footpads of the animals were measured for 12 weeks. At the end of the experiment, the animals were sacrificed and "touch preparations" were prepared using footpad, liver, spleen and testicles of the sacrified animals and were examined using Giemsa stained slides following culturing in enriched NNN medium. Leishmania amastigotes were seen in the slides prepared from the footpads of the all experimental animals and all cultures were positive for promastigotes prepared from the same clinical material. But not all the experiment groups were positive for the liver, spleen and testicle preparations. According to these results it was concluded that while all rodents in the experiment groups were positive for CL, only a part of the experiment groups were positive for internal organ involvement. Accordingly, (a) All Leishmania strains caused both CL and internal organ involvement in M.unguiculatus and M.musculus, (b) only L.tropica caused CL and internal organ involvement in R.norvegicus, while other Leishmania strains only caused CL in this group, (c) in M.auratus only L.donovani caused CL while other strains caused both CL and internal organ involvement. In our study, it was determined that the rodents Meriones, Mesocricetus, Rattus and Mus genera which are part of our country's natural habitat could serve as natural reservoirs of L.tropica, L.infantum, L.major and L.donovani, thus having the potential for the spreading of Leishmaniasis in our country and important information were gathered concerning the clinical aspects of the infection caused by Leishmania species in their potential reservoir hosts.