Description:
<jats:title>Abstract</jats:title><jats:p>The apicomplexan parasite <jats:italic>Sarcocystis calchasi</jats:italic> (<jats:italic>S. calchasi</jats:italic>) triggers pigeon protozoal encephalitis, a neurologic disease in columbids. <jats:italic>Accipiter</jats:italic> hawks have been identified as the final host, and Columbidae and Psittaciformes as intermediate hosts. In this study, 368 free-ranging <jats:italic>Accipiter</jats:italic> hawks and 647 free-ranging common woodpigeons were sampled in a country-wide study in order to identify the prevalence of <jats:italic>S. calchasi</jats:italic> in these populations. A semi-nested PCR specific for <jats:italic>S. calchasi</jats:italic> tested positive in 7.3% (4.9–10.5) of submitted samples from <jats:italic>Accipiter</jats:italic> hawks. Juvenile <jats:italic>Accipiter</jats:italic> hawks (13.7%; 7.7–22.0) had a significantly higher infection rate with <jats:italic>S. calchasi</jats:italic> than adult <jats:italic>Accipiter</jats:italic> hawks (5.8%; 2.7–9.3). The prevalence of <jats:italic>S. calchasi</jats:italic> in common woodpigeons was 3.3% (5.4–9.7). Positive pigeons were identified in 14/16 federal states, and a region-dependency was detected, with higher rates of infection in the eastern parts of Germany. The results of this study suggest that the common woodpigeon is a natural reservoir for <jats:italic>S. calchasi</jats:italic>. In a study of one region for four consecutive years, an increase in prevalence was not detected. Findings indicate that the parasite is not newly introduced to Germany, but rather long established. The prevalence suggests that there is a substantial risk of <jats:italic>S. calchasi</jats:italic> infections in other free-ranging as well as captive host species.</jats:p>