Evora district as a new focus for canine leishmaniasis in Portugal

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Abstract
On the basis of information acquired from local health authorities in Evora district of Portugal on cases of visceral leishmaniasis (VL), an epidemiology survey study was conducted. To determine the prevalence of anti-Leishmania antibodies in the local human and canine populations residing in Evora twon and 14 adjacent villages, blood samples collected from 885 children and 3,614 dogs were tested in a direct agglutination test (DAT). Seropositivity forLeishmania parasite obtained by DAT in both endemic populations was further confirmed by an enzymelinked immunosorbent assay (ELISA) and immunofluorescence test (IFAT). For identification of the responsible sandfly vector, 79 biotopes within the study areas were surveyed. In the infantile population assessed, none of the children screened showed an antibody level indicative (titer, >=1:3200) of visceral leishmaniasis in the DAT. However, agglutinating antibody rates ranging from 0.7% to 6.9% were obtained in dogs residing in Evora and 11 adjacent villages. Concordant seropositivity of 94.04% was obtained by ELISA and IFAT in the same canine population (141) identified by DAT. Of the 159 sandflies captured, 67 were identified asPhlebotomus sergenti; 15, asP. ariasi; 58, asP. perniciosus; and 19, asSergentomyia minuta. Unlike the results previously reported in Alto-Douro and Algarve districts of Portugal, as compared with the other three species,P. sergenti appears to be more abundant in Evora district. Considering the overall seroprevalence rate of 3.9% obtained among the local dog population and its absence in the human at risk, it may be concluded that the endemic manifestation ofL. infantum infection in Evora district is largely, if not solely, maintained in the canine host.