The conquest of the north continues: Baylisascaris procyonis in free-ranging invasive raccoons (Procyon lotor) from Germany, including a first report in the northeastern state of Mecklenburg-Western Pomerania

With exception of the Northeast, the raccoon roundworm (Baylisascaris procyonis) is widespread in Germany. This zoonotic parasite can cause neurological disease in paratenic and aberrant hosts, like humans. As the name indicates, raccoons are the definitive host of B. procyonis. However, and despite the successful expansion of the raccoon population, parasite and host ranges do not always overlap. B. procyonis has been largely absent from the northeastern part of the country, notwithstanding the stable presence of raccoons in this area. In this study, faecal and intestinal samples were opportunistically collected from 166 free-ranging raccoons from 9 federal states in Germany. In 68 animals (41.0 %), B. procyonis was identified either through PCR or morphological identification of adult worms. The positive raccoons originated from 6 federal states, including for the first time animals from the northern state of Mecklenburg-Western Pomerania. The results of this study highlight the dissemination of the parasite in the north of the country, while maintaining its presence in the rest of Germany.