Four dead from West Nile virus in Greece as 21 new cases reported in one week

Rising case numbers and fatalities

In its weekly epidemiological update published on 29 July 2026, Greece's National Public Health Organization (EODY) reported a total of 42 domestically acquired West Nile virus infections since the beginning of the 2026 surveillance season. Among these, 37 patients showed evidence of central nervous system involvement, encephalitis, meningitis or acute flaccid paralysis, while the remaining five experienced milder illness. During the previous week alone, 21 new cases were diagnosed or declared, driving the cumulative figure to 42. Four individuals, all older than 65, have died after developing neuroinvasive disease. EODY cautioned that additional cases are likely in the coming weeks, both in already affected areas and in new locations that cannot be predicted with precision.

Clinical burden and hospitalisations

As of 29 July, 13 patients remained hospitalised: eight in standard care and five in intensive care units. Twenty-five people have been discharged since the start of the season. The age profile of the fatalities matches historical observations for West Nile fever, where older adults face the highest risk of severe neurological complications. The agency did not provide granular data on the ages or pre-existing conditions of those still under treatment.

Attica's intense transmission and the geography of cases

The outbreak has been overwhelmingly concentrated in the Attica region, with EODY describing the circulation of the virus as particularly intense this year. Cases have been confirmed in 21 municipalities within eight regional units, East Attica, North Athens, Central Athens, South Athens, West Attica, Karditsa, Larissa and Pella, spanning the administrative regions of Attica, Thessaly and Central Macedonia. The municipality of Spata-Artemidos recorded nine infections, the highest count; Pallini and Markopoulo Mesogeas each reported four, Larissa three, and Vari-Voula-Vouliagmeni, Kropia, Agia Paraskevi and Glyfada two cases apiece. Thirteen other municipalities logged a single case: Lavreotiki, Paiania, Rafina-Pikermi, Nea Ionia, Chalandri, Papagou-Cholargou, the 6th municipal community of Athens, Ilioupoli, Fyli, Palama, Tempi, Pella, and Skydra.

High-risk zones and protective measures

Alongside the 21 affected municipalities, EODY maintains a separate list of high-risk areas. Under the agency's categorisation, a municipality is designated affected once it records at least one human case in the current transmission season, while high-risk status is assigned to locations where no human infections have yet occurred but where the coincidence of several indicators, proximity to affected communities, local geomorphology, historical epidemiological data and findings from mosquito and animal surveillance, points to a heightened probability of spillover. The high-risk list, updated as of 27 July, covers the municipalities of Amarousio, Heraklio, Filothei-Psychiko, and the 1st and 4th municipal communities of the city of Athens. These designations trigger enhanced blood safety measures and other public health precautions even before human cases appear. All four high-risk zones remain free of confirmed human infections for now, but the seasonal trend and the already heavy burden in neighbouring districts suggest that their status may change in the coming weeks.