de Heus et al.
West Nile virus and tick-borne encephalitis virus are endemic in equids in Eastern Austria
Viruses. 2021;13(9):1873. doi: 10.3390/v13091873
Some arthropod-borne pathogens such as West Nile virus (WNV), Usutu virus (USUV) and TBE virus are emerging in some regions of Europe, e.g., WNV has been reported in Austria since 2008 and USUV since 2001. TBE cases have been on a rise in Austria in 2020 despite a mass vaccination program.
The prevalence of WNV and USUV is unknown amongst the horse population in Austria, and a study has been carried out in 2017 to determine the seroprevalence of WNV, USUV and TBE virus in equids (334 horses and 14 donkeys analyzed) in eastern Austria (Vienna, Burgenland, Lower Austria, Upper Austria and Styria).
The prevalence for neutralizing antibodies was 5.3% for WNV, 15.5% for TBE virus and 0% for USUV. Among the donkeys, TBE seroprevalence was 28.6% and these animals were from Lower Austria and Styria.
It is noteworthy to mention that TBE virus infections in horses usually remain subclinical. An exception has recently been discussed in Snapshot week 37/2021. No TBE case in horses has been recorded at the University Equine Hospital, Vienna, during 2017. Continuous surveillance of horses may be used as a predictor for flavivirus circulation.