An update on the prevalence of Echinococcus multilocularis in red foxes (Vulpes vulpes) in a Central European focus: Northern and northeastern Poland (2022-2024).

Knowing Echinococcus multilocularis prevalence in wild canids helps us assess the risk of zoonotic spillover. In this study, we updated the infection statistics among red foxes in northern and northeastern Poland since the last monitoring effort at the district (Polish: powiat) level (2001-2004). We collected faecal samples from 192 red foxes from the districts of Słupsk, Puck, Wejherowo, Kościerzyna, and Kartuzy (Pomorskie Voivodship); 200 individuals from the districts of Bartoszyce, Kętrzyn, Gołdap, Iława, and Węgorzewo (Warmińsko-Mazurskie Voivodship); and 47 individuals from the district of Augustów (Podlaskie Voivodship). Based on nested PCR testing confirmed by Sanger sequencing, we calculated the prevalence with a 95 % confidence interval and compared the results to previous reports. We recorded the highest proportion of infected red foxes in Gołdap District (21/40, 52.5 %, 95 % CI: 37.5 %-67.1 %). The shared prevalence in Puck, Wejherowo, Kościerzyna, and Kartuzy Districts was 10.4 % (19/182, 95 % CI: 6.7 %-15.8 %). One red fox tested positive in Iława District (1/48, 2.1 %, 95 % CI: -0.6 %-11.9 %). We found no statistically significant changes in prevalence in the sampled areas. Our results indicate that E. multilocularis prevalence has remained stable in red fox populations throughout the region over the past 20 years.