Detection of TBEV antibodies in small rodents
We analysed 448 serum samples from 249 M. glareolus and 381 from 274 A. flavicollis . Overall, 4.2% [95% CI: 2.6 – 6.3] of individuals and 2.8% [95% CI: 1.8 – 4.1] of rodent-sessions were seropositive for TBEV. This proportion did not differ significantly between years (Fisher’s exact test, p-value =0.43), varying from 1.3 % [95% CI: 0.0 – 7.1] in 2014 (n=76 individuals) to 4.7% [95% CI: 2.9 – 7.2] in 2012 (n=422 individuals). Seroprevalence levels were similar between seasons in 2012 (3.2-5.2%, Fisher’s exact test, p-value =0.53) (Table 1), with TBEV antibodies detected from April to October. In 2013 and 2014, TBEV antibodies were inconsistently detected throughout the year (Table 1).
Among the 22 seropositive rodents, three and one rodents were re-captured respectively one and two months after the detection of their seroconversion. TBEV antibodies were detected in two consecutive months for only one individual. Two juvenile yellow-necked mice (out of 61 juveniles of both species tested) with a body mass of 11 g and 15 g tested seropositive.
None of the variables included in the logistic model — species, year and season — had a significant effect on the probability that a rodent would be seropositive.