12 countries in Europe report cases of West Nile virus

This year, twelve European countries have reported cases of West Nile virus, compared to nine countries last year, according to the European Union's health agency. West Nile virus is transmitted by mosquitoes and can cause symptoms similar to the flu, but in severe cases, it can lead to tremors, fever, comas, and brain swelling known as encephalitis.

Meningitis is another potential complication. There are no approved vaccines or specific treatments for the virus; management involves symptom control and supportive hospital care for severe cases.

The twelve European countries reporting cases are Spain, France, Germany, Greece, Italy, the Netherlands, Albania, Austria, Kosovo, North Macedonia, Romania, and Serbia. These nations have identified infections in 99 regions, as reported by the European Centre for Disease Prevention and Control (ECDC). Italy and Greece have the highest number of cases, with 311 and 157 cases respectively. Twenty-one regions across Europe reported their first cases this year.

This increase in West Nile virus transmission, along with the spread of invasive mosquito species, highlights the need for European countries to enhance their mosquito-control capabilities. ECDC executive Celine Gossner emphasized the importance of close cooperation and an integrated approach to mosquito monitoring, community engagement, and targeted control methods that consider environmental impacts.

In Europe, human infections typically occur during mosquito season, which runs from late spring to autumn, with peak transmission between July and September. Mosquitoes that spread West Nile virus, primarily Culex mosquitoes, are already widespread in Europe. However, the Asian tiger mosquito (Aedes albopictus), which can transmit dengue and chikungunya viruses, has established itself in 16 European countries, double the number from twelve years ago, according to the ECDC.