Prevalence of Capillaria hepatica in Norway rats (Rattus norvegicus) in Croatia

An analytical cross-sectional study of Capillaria hepatica in 307 Norway (brown) rats (Rattus norvegicus) was performed. Rats were trapped in two rural regions in Croatia. The prevalence of adult C. hepatica was 1.95%. The parasite was observed in 6 rats. Of these, 3 out of 189 (1.59%) were male and 3 out of 118 (2.54%) female. The adult parasite was a more common finding in large rats and was observed in 5 (1.95%) large rats and in one (2.17%) intermediate rat. Adult C. hepatica was not found among 4 examined young rats. Positive rats were derived from only four households. Clustering of adult parasites found among examined 17 households was significant (P<0.001). Eggs of C. hepatica were found in 12 (3.91%) rats. The majority of positive rats with adult C. hepatica had parasite eggs (P<0.001) and having adult parasite in livers, increases of 210 × odds of having parasite eggs in intestines (OR=210, P<0.001).