ABSTRACT
Visceral leishmaniasis (VL), or kala-azar, is mainly caused by two closely related Leishmania species, Leishmania infantum and Leishmania donovani Leishmania infantum is responsible for zoonotic VL, with dogs as the main reservoir host in the Mediterranean, the Middle East, Asia, and South America. In the Indian subcontinent, VL is caused by L. donovani and is considered anthroponotic, although the only known vector, the sand fly, is zoophilic in nature. The role of domestic and stray dogs in VL transmission is still unclear in this area. We screened 50 stray dogs from VL-endemic areas of Bangladesh for serological and molecular evidence of Leishmania infection. We detected anti-Leishmania antibodies in six (12%) dog serum samples using rK39 immunochromatographic tests. We observed Leishmania kinetoplast DNA in 10 (20%) buffy coat DNA samples by real-time polymerase chain reaction (PCR), five of which were positive based on internal transcribed spacer 1-PCR. A sequencing analysis of the amplified products confirmed that the parasitic DNA was derived from L. donovani Our findings support the hypothesis that stray dogs are an animal reservoir for L. donovani in this endemic region. Further studies are required to determine the precise role of dogs in the epidemiology of VL in Bangladesh.
Subject(s)
Dog Diseases/epidemiology , Leishmania donovani/immunology , Leishmania infantum/immunology , Leishmaniasis/veterinary , Psychodidae/parasitology , Animals , Bangladesh/epidemiology , Chromatography, Affinity/veterinary , DNA, Kinetoplast/blood , DNA, Kinetoplast/genetics , DNA, Kinetoplast/isolation & purification , Disease Reservoirs/parasitology , Dog Diseases/diagnosis , Dog Diseases/parasitology , Dogs , Endemic Diseases/veterinary , Female , Geography , Humans , Leishmania donovani/genetics , Leishmania donovani/isolation & purification , Leishmania infantum/genetics , Leishmania infantum/isolation & purification , Leishmaniasis/diagnosis , Leishmaniasis/epidemiology , Leishmaniasis, Visceral/diagnosis , Leishmaniasis, Visceral/epidemiology , Leishmaniasis, Visceral/veterinary , Male , Polymerase Chain Reaction/veterinaryABSTRACT
Although Phlebotomus argentipes as the only known vector of visceral leishmaniasis (VL) is zoophilic in nature, VL is considered to be anthroponotic in the Indian subcontinent. Peripheral blood samples from 85 stray dogs were examined for any molecular evidence of Leishmania infection in VL endemic areas of Bangladesh. Parasite DNA was detected in a blood sample from 1 of 85 (1.2%) stray dogs using ITS1-PCR, and PCR sequencing of the rRNA-ITS and cytochrome b gene confirmed that the parasitic DNA was Leishmania donovani. The results support the assumption that dogs are a probable animal reservoir for the Leishmania parasite in Bangladesh. It will be important to investigate the possible epidemiological role of dogs in domestic foci of VL endemic areas in Bangladesh.
