The Austrian ministry of health announced on Wednesday that a Viennese woman had been tested while donating plasma, and a positive test result was found for the virus. Such screening is routinely performed, to prevent contamination of blood being stored for transfusion.
It has spread inexorably around the world wherever mosquitos may be found, due to the travelers coming from infected areas. It arrived in New York in 1999, and has subsequently spread across the USA, Canada and into Western Europe.
While not as directly dangerous as Ebola or even Malaria, the West Nile virus can in rare cases lead to a debilitating illness with a neurological basis, including meningitis and encephalitis.
There is currently no vaccine to protect against WNV, therefore prevention is the best defense.
Now that a case has officially been detected in Austria, public health officials will step up efforts at screening. In 2012, WNV killed 286 people in the United States, with Texas being especially hard hit.
The disease is relatively unknown in Europe, with Greece, Serbia and Russia reporting cases in 2014.