Whilst the infection rate in Germany remained moderate until early September, the number of cases in birds and horses increased significantly by the end of October.
By 26 October, the National Reference Laboratory for West Nile Virus (WNV) infections at the FLI had confirmed 17 cases in horses and 25 cases in wild and zoo birds. The virus occurred sporadically, but was widespread across the known endemic areas, including Berlin, Brandenburg, Hamburg, Lower Saxony, Saxony-Anhalt, Saxony and Thuringia. A cluster of confirmed cases in horses and birds was identified in south-west Germany, particularly in the Upper Rhine Graben (Upper Rhine Plain). It is highly likely that the virus has become permanently established in these new areas.
The WNV season is not yet over, so infection with West Nile virus should continue to be investigated as an important differential diagnosis in the event of neurological symptoms in birds and horses.
Nevertheless, the incidence of WNV infection in Germany this year remains moderate compared to the significant increase in case numbers in other European countries, such as Italy, Greece and France. In neighbouring countries to the west, such as Belgium and the Netherlands, infection rates in both animals and humans are significantly higher.
According to the European Centre for Disease Prevention and Control (ECDC) and the European Food Safety Authority (EFSA), WNV is reaching unprecedented levels in Europe in 2026, affecting a larger geographical area than in any previous season. The number of human infections and animal outbreaks also exceeds previous years' figures (https://www.efsa.europa.eu/en/efsajournal/pub/10410).
