Domestic dogs as reservoir hosts for Leishmania donovani in the southernmost Western Ghats in India

The peripheral blood samples from domestic dogs (n=47) and wild rats (n=25) in the Kani Tribe settlements, located southernmost part of the Western Ghats, Thiruvananthapuram district, Kerala, India were examined for Leishmania infection. This area is known for cases of leishmaniasis with cutaneous manifestations and sandfly abundance. The tribes domesticate dogs to protect them from untoward activities of wild animals. Leishmania donovani parasite DNA was detected only from 6.4% (n=3) of the blood samples collected from the domestic dogs by amplification of the diagnostic kinetoplast mini-circle DNA and PCR-RFLP analysis of the UTR region of heat shock protein 70 (hsp70) gene. None of the blood samples collected from rats was positive. Through sequencing, L. donovani infection among dogs was confirmed. The DNA sequences generated for hsp70 were deposited with the GenBank. The GenBank accession numbers of these samples are KR905363, KR905364 and KR905365 for hsp70 genes. The results indicated that the DNA isolates from dog blood samples matched precisely with that of our earlier isolates from skin lesions of Kani tribes and also from P. argentipes vector. Thus, the role of dogs as reservoirs for L. donovani parasite in the Kani tribe settlements is confirmed.