A stable focus of canine leishmaniosis in the Bologna Province, Italy

During an epidemiological survey carried out for two consecutive years (2001-2002), autochthonous cases of canine leishmaniosis (CanL) were reported in Communes of the Bologna Province (Emilia-Romagna Region, northern Italy), involved in the past (1971-1972) in a severe outbreak of human visceral leishmaniosis (VL). Serological controls, carried out by immunofluorescence antibody test on a sample of owned dogs, detected a mean prevalence of 2.5% in the first year in 4 Communes, and of 11.2% in the second year in only one Commune, where an incidence value of 9.3% was assessed. The autochthonous origin of the infection was confirmed in 11 out of 13 positive animals in the first year and in 5 out of 6 new cases in the second year. In one case the parasitological examinations led to the isolation of leishmaniae characterized as Leishmania infantum zymodeme MON 1. Entomological surveys carried out during two sandfly seasons in one of the areas concerned by the VL outbreak showed the presence of Phlebotomus perfiliewi and, to a lesser extent, of P perniciosus, both proven vectors of L. infantum in Italy. The results obtained seem to suggest the presence of a stable focus of CanL in the territory involved in the previous VL outbreak of 1971-1972, within which the infection in the canine population had been assessed only serologically. Such an epidemiological situation may be seen either as the persistence of an old focus or as a new imported one.