Greek public health authorities are grappling with a sharp surge in West Nile virus infections, with 45 new locally transmitted cases reported in the final week of surveillance alone. The National Public Health Organization of Greece, EODY, has recorded 110 domestically acquired cases by 12 August 2026, with the outbreak concentrated heavily in Attica and raising urgent questions about mosquito control programmes, public health preparedness, and the protection of elderly and vulnerable populations.
Nine people have died from the virus, all over 65 years of age. The median age of those who died was 82, with ages ranging from 66 to 91 years. The virus has hit older Greeks particularly hard: the median age of patients with central nervous system manifestations is 73 years, though cases span from 19 to 91 years. Of the 110 confirmed cases, 81 involved severe manifestations affecting the central nervous system, including encephalitis, meningitis, meningoencephalitis or acute flaccid paralysis. The remaining 29 cases had milder symptoms or no central nervous system involvement.
Hospitals Under Pressure
By 12 August, 35 patients remained hospitalised. Sixteen were in Intensive Care Units, while 19 were in ordinary hospital wards. None were in High Dependency Units. In total, 61 patients had been discharged, and five cases didn't require hospitalisation. The concentration of severe cases in ICUs underscores the strain on public health infrastructure during a summer already marked by heat stress and stretched emergency services.
EODY has warned that the 110 laboratory-confirmed cases don't reflect the true scale of infection. According to a 2010 seroepidemiological study, for every single case of West Nile virus with central nervous system involvement there are around 140 infected people who either develop mild symptoms or remain asymptomatic. That suggests thousands of Greeks may have been exposed.
East Attica Hit Hardest
The outbreak has been particularly intense in East Attica. In the municipality of Spata-Artemida, 11 patients with central nervous system manifestations and two without have been recorded. In Markopoulo Mesogaias, eight patients with central nervous system involvement and three without have been reported. Vari-Voula-Vouliagmeni recorded five cases with central nervous system manifestations and two without. Pallini reported five cases with central nervous system involvement, Agia Paraskevi six, and Acharnes, Chalandri, Glyfada and the municipality of Athens three each.
The proportion of severe cases is strikingly high in some municipalities. In Markopoulo Mesogaias there are 36.8 cases with central nervous system manifestations per 100,000 inhabitants. In Spata-Artemida the rate stands at 31.5 per 100,000 inhabitants.
Beyond Attica, cases have been recorded in 39 municipalities across 14 regional units in four regions: Attica, Thessaly, Central Macedonia and the Peloponnese. Outside Attica, cases have appeared in the regional units of Karditsa, Larissa, Trikala, Imathia, Thessaloniki, Pella, Serres and Laconia.
Mosquito Control Under Scrutiny
EODY has classified additional municipalities as high-risk areas based on epidemiological and geomorphological data: Kifisia, Iraklio, Filothei-Psychiko and Metamorfosi in the North Sector of Athens, Kallithea and Nea Smyrni in the South Sector, Nea Filadelfeia-Nea Chalkidona and Dafni-Ymittos in the Central Sector, as well as Amfipoli in Serres, Heroic City of Naousa in Imathia and Delta in the Metropolitan Unit of Thessaloniki. No human cases had been recorded in these municipalities by the time the report was published.
Veterinary surveillance showed recent West Nile virus infections in equines at five sites or settlements in the regional units of East Attica, Drama and Preveza, as well as in the Metropolitan Unit of Thessaloniki. EODY said every reported case is investigated within 24 hours, with daily communication with laboratories and support for suspected cases.
In March 2026, about 5 months ago, the Ministry of Health issued a circular on integrated mosquito management programmes. EODY has asked regions and municipalities for the timely launch, proper organisation and effective implementation of mosquito-control programmes. In May 2026, about 3 months ago, an information letter was sent to all health facilities and medical associations in the country. For 2026, an enhanced entomological surveillance network has been set up, with EODY installing mosquito traps in different parts of Greece.
According to EODY, cases have been recorded in Greece during the periods from 2010 to 2014 and from 2017 to 2025, mainly in the summer and autumn months. The almost annual occurrence of cases since 2010 indicates that West Nile virus has become established in Greece, as it has in other European countries. EODY said additional cases are considered likely in the coming weeks, both in areas where the virus is already circulating and potentially in new areas.
Why This Matters:
This outbreak exposes the vulnerability of ageing populations to climate-sensitive diseases and raises hard questions about municipal capacity to implement effective mosquito control. Nine deaths, all among people over 65, highlight the need for targeted public health interventions that protect the elderly and those with underlying conditions. The gap between central government circulars issued in March and May and the reality on the ground in August suggests coordination failures between national authorities and local municipalities. With climate change expanding the range and season of disease-carrying mosquitoes across Southern Europe, Greece's experience is a warning for the continent. Effective vector control, early warning systems, and adequately funded public health infrastructure aren't optional — they're essential to protecting the most vulnerable in a warming world.