Echinococcus multilocularis infection in horses in Poland.

A cross-sectional survey was performed to obtain first information on the prevalence of Echinococcus multilocularis infection in slaughter horses from central, eastern and southern Poland, a country with a highly endemic occurrence of this tapeworm in red foxes. White tough nodular lesions being 3-10 mm in size, sharply demarcated and spherically or irregularly shaped were found in 54 of 365 livers examined. Histologically, focal granulomatous necrotizing inflammations and sometimes PAS-positive acellular lamellar structures being characteristic of the E. multilocularis metacestode stage were visible; protoscoleces were not found. E. multilocularis DNA was detected in six of 19 hepatic lesions examined by nested PCR. Our results from molecular and morphological diagnostics suggest an overall prevalence of alveolar echinococcosis between 4.7% and 14.8% in the horse population studied. Horses as dead-end hosts do not play any role in the life cycle of E. multilocularis but may serve as additional sentinel animals in monitoring the environmental contamination with tapeworm eggs.