West Nile Virus Cases Rise Across Europe as Greece Reports 21 Infections

The 2026 West Nile virus transmission season is underway across Europe, with locally acquired infections reported in Greece, Italy, Spain, Romania, and North Macedonia, according to the European Centre for Disease Prevention and Control (ECDC).

In Greece, the National Public Health Organisation (EODY) has confirmed 21 locally transmitted cases of West Nile virus infection between the start of the surveillance season and July 22. Twenty patients developed severe neurological complications, including encephalitis, meningitis, or acute flaccid paralysis, while one patient experienced only mild symptoms. No deaths have been reported, and 13 patients remain hospitalized.

Fourteen of the confirmed infections were identified during the past week, indicating a rapid increase in transmission. An additional case involving a traveler with a complex travel history is still under investigation and has not been included in Greece's official epidemiological assessment.

According to ECDC data available through July 15, a total of 33 locally acquired cases had been reported across five European countries and neighboring regions.

Italy has recorded the largest number of infections, with 20 cases spread across 16 affected areas. The highest numbers were reported in Novara, followed by Cremona and Verona, while additional cases have been identified in cities including Milan, Florence, Naples, Padua, Modena, and Ferrara.

Romania, Spain, and North Macedonia have each reported two locally acquired cases. ECDC notes that the number of affected areas in Italy expanded significantly within a single week, reflecting the rapid geographic spread of the virus.

In Greece, most infections have occurred in the Attica region, particularly in the municipalities of Spata-Artemida, Markopoulo Mesogaias, Pallini, Agia Paraskevi, and several other communities. Additional cases have been detected in Larissa and the municipality of Palamas.

Although no human infections have yet been confirmed in several neighboring municipalities, Greek health authorities have classified these areas as high risk based on epidemiological evidence, environmental conditions, and their proximity to locations where the virus is already circulating.

EODY notes that the almost annual occurrence of West Nile virus cases since 2010 suggests the virus has become established in Greece, similar to several other European countries.

Health officials emphasize that predicting exactly where new cases will appear remains impossible. They recommend that residents and travelers throughout Greece take preventive measures against mosquito bites during the summer, including using insect repellent, wearing protective clothing, and eliminating standing water where mosquitoes breed.