A high prevalence of dogs seropositive to Leishmania in Zambia

Domestic dogs are the main reservoir of Leishmania infantum, a causative agent of visceral leishmaniasis in humans. Although the disease is widespread in the world, the burden of visceral or any other disease form of leishmaniasis is poorly documented in Zambia, largely due to lack of surveillance. Recently, three cases of autochthonous canine leishmaniasis (CanL) were reported in Zambia following decades of presumed disease absence. This finding intimated probable disease emergence, raising the need for the identification of infection foci. Thus, in this study, we conducted the first mass serological survey for Leishmania infections in domestic dogs from two densely populated urban areas of Zambia in July 2022. In some of the study sites, seropositivity was up to ∼17 %, suggesting probable presence of Leishmania transmission hot spots. Moreover, on follow-up surveys of seropositive dogs, presence of antileishmanial antibodies was a risk factor for dog survival (relative risk = 7.9; odds ratio = 42.5). Our findings implies that Leishmania infection can be a health issue in domestic dogs in Zambia. Considering the risk of zoonotic transmission, the need for improved disease diagnosis and surveillance in both humans, dogs and sand fly vectors is highlighted in Zambia.