Seroprevalence of Tick-Borne Encephalitis (TBE) Virus Antibodies in Wild Rodents from Two Natural TBE Foci in Bavaria, Germany

Abstract

Tick-borne encephalitis (TBE) is Eurasia’s most important tick-borne viral disease. Rodents play an important role as natural hosts. Longitudinal studies on the dynamics of the seroprevalence rates in wild rodents in natural foci over the year are rare, and the dynamics of the transmission cycle still need to be understood. To better understand the infection dynamics, rodents were captured in a capture-mark-release-recapture-study in two natural foci in Bavaria, Germany, monthly from March 2019 to October 2022. Overall, 651 blood and thoracic lavage samples from 478 different wild rodents (Clethrionomys glareolus and Apodemus flavicollis) were analyzed for antibodies against tick-borne encephalitis virus (TBEV) by indirect immunofluorescence assay (IIFA) and confirmed using a serum neutralization test (SNT). Furthermore, a generalized linear mixed model (GLMM) analysis was performed to investigate ecological and individual factors for the probability of infection in rodents. Clethrionomys glareolus (19.4%) had a higher seroprevalence than A. flavicollis (10.5%). Within Cl. glareolus, more males (40.4%) than females (15.6%) were affected, and more adults (25.4%) than juveniles (9.8%). The probability of infection of rodents rather depends on factors such as species, sex, and age than on the study site of a natural focus, year, and season. The high incidence rates of rodents, particularly male adult bank voles, highlight their critical role in the transmission cycle of TBEV in a natural focus and demonstrate that serologically positive rodents can be reliably detected in a natural focus regardless of season or year. In addition, these data contribute to a better understanding of the TBEV cycle and thus could improve preventive strategies for human infections.

The Prevalence of Tick-Borne Encephalitis Virus in Wild Rodents Captured in Tick-Borne Encephalitis Foci in Highly Endemic Lithuania

“…Furthermore, a thermosensitive RNA switch has been proposed as significant for virus propagation in ticks [ 48 ]. However, other factors such as duration of photoperiod, relative humidity [ 8 , 26 ], age and sex [ 49 ], reproductive and immune status [ 50 ], and tick burden load on rodents [ 51 ], which are also at least partially related to the average air temperature, might be influential. Moreover, a rapid fall in ground-level temperatures in August and October is associated with the synchrony of larval-nymphal questing (and therefore co-feeding) in early spring, which was observed in TBEV foci and not elsewhere [ 6 ].…”

Tick Activity, Host Range, and Tick-Borne Pathogen Prevalence in Mountain Habitats of the Western Carpathians, Poland

“…Wild-living rodents play an important role as TBP reservoir animals in nature [ 73 ]. Our study showed the presence of the genetic material of Borrelia spp., Ehrlichia spp., Bartonella spp., and Mycoplasma spp.…”

Biting Back: Advances in Fighting Ticks and Understanding Tick-Borne Pathogens

“…Natural TBE Foci in Bavaria, Germany-By Brandenburg et al [13] While B. miyamotoi discussed above [11] is an emerging disease tick-borne encephalitis (TBE) is one of the most important TBD in areas of Asia and Europe. TBE has been a notifiable disease in the European Union since 2012.…”