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 thetransmission of these parasites into synanthropic cycles. Parasites with neuroinvasive stages, such asToxoplasmagondiiorToxocara canis, 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 inthe 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 in-vestigated for parasitic stages by microscopic examination of native tissue, artificially digested tissue as well asGiemsa-stained digestion solution to verify positive results. Infective stages of zoonotic ascarids or other hel-minths 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 (Myodes glareolus;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 (Apodemusflavicollis; Murinae) were infected. Generalizedlinear modelling revealed a statistically significant difference in prevalence betweenM. glareolusandA.flavi-collis, significant local differences as well as an effect of increasing body mass on cyst prevalence. Coccidian cystswere differentiated by amplification of the18S rRNAgene and subsequent sequencing. The majority of iden-tifiable cysts (97.9%) were determined asFrenkelia glareoli, a coccidian species mainly circulating betweenM.glareolusas intermediate and buzzards (Buteospp.) as definitive hosts. The zoonotic pathogenToxoplasma gondiiwas confirmed in oneM. glareolusoriginating from the city of Leipzig. Overall, it can be concluded that neu-roinvasion of zoonotic parasites seems to be rare inM. glareolusandA.flavicollis