Molecular Identification of Leishmania infantum kDNA in Naturally Infected Dogs and Their Fleas in an Endemic Focus of Canine Visceral Leishmaniasis in Iran.

Background: Fleas (Insecta: Siphonaptera) are considered as highly specialized bloodsucking on mammals such as dogs. The existence of three factors, namely a vast distribution area, different hosts, and digestive system with a specific mechanism for digesting blood has led to species of fleas who nourish from mammals be introduced as the potential vectors of diseases. The aim of this study was to assess Leishmania infantum natural infection of dog fleas in northwest Iran in 2018.

Methods: A total of 20 infested domestic dogs (Canis lupus familiaris) were randomly selected from 5 villages. Fleas were collected using brushing against dog hairs and fine forceps. Then, they were morphologically identified and preserved in ethanol for molecular assay. The kinetoplast DNA of the parasite was used for detection of Leishmania infantum using a semi-nested polymerase chain reaction (PCR) assay.

Results: The human flea, Pulex irritans, and the cat flea, Ctenocephalides felis were identified on 40% and 35% of dogs, respectively. The results of PCR indicated that L. infantum was found in the Ctenocephalides canis (75%) and C. felis (66.7%) collected from infected dogs. No leishmanial infection was observed in P. irritans.

Conclusion: It is concluded that fleas could be infected by Leishmania infantum, but maintenance of the parasite and their vectorial competence needs to be determined.