Canine Visceral Leishmaniasis in Kerman, Southeast of Iran: A Seroepidemiological, Histopathological and Molecular Study

Background: Canine visceral leishmaniasis (CVL) is a systemic disease with a high mortality rate, caused by a diphasic protozoan parasite, Leishmania infantum/chagasi in the world. The objective of the present study was to determine the presence of CVL in the city and suburbs of Kerman, using a range of serological, histopathological and molecular methods. Methods: Blood samples were taken from 80 clinically symptomatic stray dogs All the collected blood samples were tested by direct agglutination test (DAT) to detect the anti-Leishmania antibodies in dogs, using a cut-off value of >= 1: 320. Pathological specimens including spleen, liver and lymph nodes were prepared for paraffin blocks, sectioning, staining and final microscopic examination in the pathology laboratory. PCR amplification of kDNA from 9 samples of DAT positive stray dogs was studied. Results: The anti-Leishmania antibody was detected in 9 dogs (11.25 %) of the total 80 studied dogs. No significant difference was found between VL infection and gender. In contrast, there was a significant difference between seropositivity and age (P<0.05). Pathological samples showed changes including hyperplasia of infected macrophages and inflammatory cells that occupied sinusoids and splenic cords. Among the samples which was characterized by PCR, only one specimen revealed to be mixed infection between L. infantum and L. tropica. Conclusion: The results revealed a high prevalence of L. infantum infection in stray dogs in Kerman. This kind of information is needed for implementation of future control programs.