Parasites in brains of wild rodents (Arvicolinae and Murinae) in the city of Leipzig, Germany.

Small rodents serve as intermediate or paratenic hosts for a variety of parasites and may participate in the transmission of these parasites into synanthropic cycles. Parasites with neuroinvasive stages, such as or , can cause detrimental damage in the brain of intermediate or paratenic hosts. Therefore, the occurrence of neuroinvasive parasite stages was evaluated in brains of wild rodents captured in the city of Leipzig, Germany. In addition, a few specimens from the cities of Hanover, Germany, and Vienna, Austria were included, resulting in a total of 716 rodents collected between 2011 and 2016. Brains were investigated for parasitic stages by microscopic examination of native tissue, artificially digested tissue as well as Giemsa-stained digestion solution to verify positive results. Infective stages of zoonotic ascarids or other helminths were not detected in any sample, while coccidian cysts were found in 10.1% (95% CI: 7.9-12.5%; 72/716) of examined brains. The most abundant rodent species in the study was the bank vole (; Arvicolinae), showing an infection rate with cerebral cysts of 13.9% (95% CI: 11.0-17.8%; 62/445), while 2.7% (95% CI: 1.0-5.8%; 6/222) of yellow-necked mice (; Murinae) were infected. Generalized linear modelling revealed a statistically significant difference in prevalence between and , significant local differences as well as an effect of increasing body mass on cyst prevalence. Coccidian cysts were differentiated by amplification of the gene and subsequent sequencing. The majority of identifiable cysts (97.9%) were determined as , a coccidian species mainly circulating between as intermediate and buzzards ( spp.) as definitive hosts. The zoonotic pathogen was confirmed in one originating from the city of Leipzig. Overall, it can be concluded that neuroinvasion of zoonotic parasites seems to be rare in and .