Detection of Leishmania DNA in Ticks and Fleas from Dogs and Domestic Animals in Endemic Algerian Provinces

Background: Leishmaniasis is a zoonotic vector-borne disease and a significant global public health concern worldwide and in Algeria. In this study, we investigated the potential role of ticks and fleas as carriers of Leishmania in endemic regions of Algeria. Methods: Adult ectoparasites were collected from reservoir dogs and cohabiting animals across three provinces: Tizi-Ouzou (northeast), M&rsquo:Sila (southeast), and T&eacute:bessa (extreme east). A subset of 247 ectoparasites was randomly selected for Leishmania DNA screening using ITS1-PCR. Results: Morphological identification revealed two tick species, Rhipicephalus turanicus (378 specimens) and Rhipicephalus sanguineus s.l (127 specimens), and one flea species, Ctenocephalides felis (94 specimens). Dogs were the most heavily infested hosts (74.12%), followed by sheep (9.51%) and cats (9.34%). Leishmania DNA was detected in 36.43% (90/247) of the tested specimens, with higher positivity in ticks (41.32%) compared to fleas (17.64%). Infection rates varied by host species, with dogs harboring the majority of positive ectoparasites (62/90), primarily R. sanguineus s.l (19/30) and R. turanicus (40/115). Leishmania DNA was also detected in ectoparasites collected from cats and sheep, whereas goats and rabbits were free from Leishmania DNA. Conclusions: This investigation highlights the high detection rate of Leishmania DNA in ticks and fleas from animals in Algerian endemic regions, indicating exposure to infected hosts. Together with previous reports, these findings support the view that ticks and fleas may act as incidental hosts or mechanical carriers of the parasite. However, their role in parasite transmission remains unconfirmed and warrant further investigation, particularly through studies assessing vector competence. These results emphasize the need for additional research to clarify the contribution of these ectoparasites to Leishmania transmission and multi-host dynamics.