First record of Calodium hepaticum and Taenia taeniaeformis liver infection in wild Norway rats (Rattus norvegicus) in Serbia

The nematode Calodium hepaticum and the cestode Taenia taeniaeformis are zoonotic helminths primarly found in the liver of common wild rats. Most reports on these helminth species with cosmopolitan distribution are from Asia, and there is paucity of data for Europe. Wild Norway rats (Rattus norvegicus) from urban and suburban habitats of the Belgrade area were examined for the presence of Calodium hepaticum and Taenia taeniaeformis larvae liver infections. The presence of visible cysts and a histomorphology of parasite-related inflammatory liver responses were sought as signs of infection. The total prevalence of infection was 10.9% (C. hepaticum) and 29.9% (T. taeniaeformis), with no differences between the sexes. No difference in the annual prevalence of both helminth species was noted. Data obtained in this study provide new information relevant to wild Norway rats as sources of C. hepaticum and T. taeniaeformis liver infection in this geographic area, and, in a wider context, in Europe.