Retrospective identification of human cases of West Nile virus infection in Austria (2009 to 2010) by serological differentiation from Usutu and other flavivirus infections Stiasny, K and Aberle, S W and Heinz, F X, Eurosurveillance, 18, 20614 (2013), https://doi.org/10.2807/1560-7917.ES2013.18.43.20614