Emergence of leishmaniasis in northern Italy

Background – Canine leishmaniasis (CanL) is traditionally endemic in central-south Italy, whereas northern regions (Padana plane and Alpine territories) have been considered Leishmania-free (Pozio et al., 1985) until early 1990’s, when CanL foci were firstly identified in Veneto and Piedmont. Because of the appearance of autochthonous human cases (VL), a national project was launched in 2003 to systematically collect CanL and sandfly data in 5 northern regions of Italy: Valle d’Aosta, Piedmont, Lombardy, Veneto, Trentino-Alto Adige and Emilia Romagna. A 2.7% seroprevalence was revealed among some 6,500 dogs from 18 scattered foci, with 118 proven autochthonous infections. Phlebotomus perniciosus was recorded in almost all new foci, characterized by hilly sub-Apennine and sub-Alpine environments. P. neglectus, P. ariasi and P. perfiliewi showed more limited diffusion in the territories investigated (Capelli et al., 2004; Rossi et al., 2005; Ferroglio et al., 2005). In the frame of the subproject EDEN-LEI we aimed to study and monitor leishmaniasis spreading in two selected areas of the northern Italy, trying to answer the following questions: (i) Is Leishmania transmission spreading northward into Alpine valleys? and (ii) Which environmental conditions limit the diffusion of P. ariasi and P. perfiliewi towards northern latitudes and, in general, the spreading of all Leishmania vectors in the large Padana plane?