Autochthonous canine and feline dirofilariosis in central Italy: microscopic and molecular evidence.

In Italy Dirofilaria repens is distributed nationwide with different prevalence rates according to the geographical regions, while Dirofilaria immitis is mainly present in hyperendemic foci in the North. Nonetheless, D. immitis has recently spread toward central Italy, where the parasite is now considered endemic. In order to enhance the knowledge of the presence of these filarial nematodes in the central area of Italy (Abruzzo region) individual blood samples were collected random in 2008 from 300 autochthonous animals (i.e. 175 dogs and 125 cats). All samples were subjected to the Knott method and to two PCRs specific for the cox1 and 12S mitochondrial genes of canine and feline filariae. Sixteen dogs were microscopically and molecularly positive for D. repens (n.13), for both D. repens and D. immitis (n.2) and for Dipetalonema reconditum (n.1), while 1 more animal was positive for D. repens only at the PCRs (9.7% overall infection rate). Three and one cats were microscopically and molecularly positive for D. repens and D. immitis respectively (3.2% overall infection rate). Even though the infection rate by Dirofilaria spp. seems to still be low in central Italy, mainly for D. immitis, both parasites are present and likely spreading southward in our Country. It is thus advisable that dirofilariosis is included into the differential diagnosis of canine and feline cardiopulmonary and skin diseases in southern/central Italy, where the prophylaxis against the vectors should also be implemented. Finally, given the zoonotic potential of these filariae, such scenario represents an important risk factor also for humans.