Detecting the High Prevalence of Leishmania Infantum in Asymptomatic Stray Dogs of Shiraz by PCR Technique

Leishmania infantum is the cause of visceral leishmaniasis (Kalaazar). This protozoan has zoonotic importance and causes disease in dogs and humans. Our country is one of the major foci of leishmaniasis, such that visceral leishmaniasis and cutaneous leishmaniasis have been reported in most regions of the country. Fars province and Shiraz city are considered as the foci of leishmaniasis (cutaneous and visceral). Therefore, this study was conducted with the aim of identifying Leishmania infantum in asymptomatic stray dogs in Shiraz city using Semi Nested PCR technique.  

Routine methods of Leishmania parasite identification are performed by parasitological technique, which is based on microscopic observation of the parasite in infected tissues. One of the main disadvantages of the mentioned method is that it is not able to detect the parasite species. Therefore, Semi Nested PCR molecular method was used in the present study. In this study, 100 stray dogs ​​ without leishmaniasis symptoms were randomly selected from different areas of Shiraz city and their central blood was sampled. The samples were subjected to the above molecular detection test.

Thirty five samples (35%) were identified as positive for Leishmania infantum infection. All leishmaniasis positive dogs had no clinical signs of the disease.

Considering that leishmaniasis positive dogs did not have any clear clinical signs of the disease, therefore, all points of control and prevention of the disease, including the control of stray dogs and vector Phlebotomus, education to community members and compliance with personal and public health should be observed. Emphasis is considering the ease, speed and high accuracy of the technique used in the present study, it is suggested.