First detection of Leishmania major in dogs living in an endemic area of Zoonotic Cutaneous Leishmaniasis in Tunisia

Abstract Background Dogs are considered the main domestic animals that may be reservoir for Leishmania infantum, the agent of Zoonotic Visceral Leishmaniasis (ZVL) in several countries of the world. Dog may host other Leishmania species but its epidemiological role in the maintaining and spreading of these parasites is not completely elucidated. Zoonotic Cutaneous Leishmaniasis (ZCL), caused by Leishmania major, affect thousands of people every year and is particularly diffused in many countries of North Africa and Middle East Asia. In ZCL endemic countries few reports of L. major positive dogs have been reported, probably because most human cases occur in poor rural areas where the social role of the dog and its medical management is not well considered. The aim of the present study is to better understand the possible involvement of domestic dogs in the epidemiology of ZCL. Methods Our research focused on a well-established endemic focus of ZCL, in the area of Echrarda, Kairouan Governorate, central Tunisia. Fifty-one dogs with no apparent clinical signs of vector borne diseases, were selected in small villages where human cases of ZCL are yearly present. All dogs were sampled for the Leishmania spp. diagnosis, by using the following procedures: blood sample for serology and buffy coat qPCR, popliteal fine needle aspiration and cutaneous biopsy punch for lymph node and skin qPCR. Results The results demonstrated a high percentage (21.6%) of dogs positive at least at one or more test, the most sensitive technique was the lymph node qPCR that detected 8/11 positive dogs. Nine, out of the eleven positive dogs, resulted infected by Leishmania infantum; ITS1-PCR-sequencing allowed Leishmania major identification in the remaining two cases, both from the popliteal lymph node samples, that can suggest a possible visceral spread of a cutaneous Leishmania species in dog. Interestingly, one of the two L. major positive dogs was living in the same house where 6-year-old children showed cutaneous lesions referred to ZCL. Conclusions To our knowledge, this is the first report of L. major positive dogs in Tunisia, the epidemiological role of which remains under investigation.