Prevalence of tick-borne encephalitis virus (TBEV) in samples of raw milk taken randomly from cows, goats and sheep in eastern Poland.

A total of 119 unpasteurized milk samples taken from 63 cows, 29 goats and 27 sheep bred on 8 farms situated on the territory of the Lublin province (eastern Poland), an area of risk of tick-borne encephalitis (TBE), were examined for the presence of RNA of tick-borne encephalitis virus (TBEV) by the nested RT-PCR method. Milk samples were also tested for the presence of anti-TBEV antibodies by ELISA test. By RT-PCR, the greatest prevalence of TBE virus was found in the milk of sheep (22.2%), followed by milk of goats (20.7%) and cows (11.1%). By ELISA, the greatest prevalence of anti- TBEV antibodies was found also in the milk of sheep (14.8%), followed by milk of cows (3.2%) and goats (0%). The results suggest a potential risk of infection with TBEV by drinking raw milk on endemic areas of TBE, and indicate a need for milk pasteurization before consumption.