Capillaria hepatica infection in wild brown rats (Rattus norvegicus) from the urban area of Milan, Italy

Forty-seven wild brown rats (Rattus norvegicus) collected from the urban ar ea of Milan (Italy) were screened for Capillaria hepatica liver infection. The liver of each rat was grossly and histologically examined for the prese nce of C. hepatica adults, eggs and typical C. hepatica-induced lesions. In 17 rats (36%) liver lesions consistent with C hepatica infection were dete cted. Grossly, white-yellow nodules of 1-5 mm in diameter were present, eit her scattered on the liver surface or localized in a single lobe. Histologi cally, granulomatous liver lesions associated with eggs and/or worms were o bserved. The degree of gross liver involvement was moderate in most of the positive cases (71%). About 30 cases of C. hepatica infection in humans hav e been documented world-wide, most of which are reported in children from 1 to 5 years of age. Our results suggest that the potential transmission of C. hepatica to children in the study area should be considered an important health issue.