WNV Cases Reported in Nine European Countries

According to a surveillance report from The European Centre for Disease Prevention and Control, 429 locally acquired cases of West Nile virus infection have been reported in 9 countries. This is for the period up until August 13, 2026. There have been 12 deaths.

The majority have occurred in Italy (224). Cases have also been reported in Greece (105), Spain (42), North Macedonia (30), Romania (18), France (6), Serbia (2), Germany (1) and Kosovo (1).

A map showing affected areas can be found on the ECDC website.

Newly affected areas are identified.

A similar outbreak was reported in August 2025. There were more than 1,100 cases in 2025 with Italy (779), and Greece (96) reporting almost 80% of cases. There were 97 deaths.

Major migratory bird pathways exist between Africa and southern Europe and are thought to be the reason for the high case numbers in Italy and Greece. It was introduced into the USA in 1999 and is now found throughout North America.

What is West Nile Virus (WNV)?

West Nile virus (WNV) is a vector-borne disease. It is a viral infection transmitted by the bite of an infected mosquito. Mosquitoes carry the virus after feeding on infected birds and transmit the disease to humans.

It is not spread from humans to humans. Humans are incidental hosts.

Many bird species are susceptible to WNV. It can also be transmitted from mosquitoes to horses, dogs and other mammals. Horses can also contract serious disease. Humans, horses and dogs are dead-end hosts as they cannot transmit the virus back to other mosquitoes.

Studies show that 8 in 10 infected people are asymptomatic (experience no symptoms), 1 in 5 infected people develop a mild flu-like illness. Symptoms can include fever, headache, tiredness, muscle aches, nausea, vomiting, and a rash.

1 in 150 people infected with WNV will develop more severe disease (WHO, 2017), such as encephalitis (inflammation of the brain) or meningitis (inflammation of the lining of the brain and spinal cord) (CDC, 2023). Recovery from severe illness may take several months. Among those who experience severe central nervous system illness, 1 in 10 people have a fatal outcome.

How to protect yourself from West Nile Virus

Anyone who resides in or travels to regions with WNV activity is at risk of infection. In tropical climates, cases occur throughout the year. In Europe, the United States and other temperate Northern Hemisphere climates, WNV occurs through June and November, peaking around July and September.

In the U.S., WNV is endemic (native) in New York State, and is considered a seasonal infection, with cases peaking in some parts of the state each Summer.

Individual Risk Factors for WNV

• Those over the age of 50 years are at higher risk for severe illness, however, serious infections can occur in people of any age (WHO, 2017).
• Immunocompromised people, for example, people living with HIV or transplant recipients, are at the highest risk for becoming severely ill with WNV infections (ECDC, 2023).
• Those with underlying illnesses, such as diabetes, cancer, and kidney disease, are also associated with more severe disease.

Precautions

The species of mosquito responsible for the vast majority of WNV transmission to humans is the Culex species. These mosquitoes are mainly active during the evening, but their peak activity occurs at dusk and dawn.

The best way to prevent infection is to protect yourself against mosquito bites. See Insect-Borne Disease Prevention.