A step forward in the understanding of the presence and expansion of Echinococcus multilocularis in Eastern Europe using microsatellite EmsB genotyping in Poland.

Alveolar echinococcosis is a severe zoonotic disease caused by the parasite Echinococcus multilocularis. In Europe, the lifecycle of this cestode is mainly sylvatic based on a prey-predator interaction between the red fox and small rodents as definitive and intermediate hosts, respectively. National surveillance of E. multilocularis in red foxes in Poland has reported a clear distinction between low endemic areas (from 2 to 5.7%) in the western half and high endemic areas (11.8 to 50.0%) in the eastern half of the country. A drastic increase of prevalence has been observed in the eastern half of Poland since the 2000's. Microsatellite EmsB genotyping was performed on 301 E. multilocularis worms from 87 foxes sampled throughout Poland, leading to identification of 29 EmsB profiles. The main profile, Pol19, was identified across the country and accounted for 44.9% of the worms collected. The conformity of 18 Polish profiles was established by comparison with previous profiles identified in Europe, but none corresponded to the most common European profiles. Poland was confirmed as a peripheral area of the main European focus, with more recent colonization by the parasite. The sharing of common profiles mainly by neighboring provinces was confirmed by a clustering analysis identifying four main groups. Expansion of the parasite in Poland in these four groups appears to be influenced by the situation in neighboring countries. Acquiring EmsB genotyping data from eastern European countries, for which very few data are reported, is necessary to understand the expansion of the parasite in the whole of Europe.