Greece is facing a heightened public health alert as the West Nile virus continues to spread across the country, with 63 municipalities now identified as either affected or at high risk. The region of Attica remains the epicenter of the outbreak, reporting the highest number of confirmed cases — 34 out of its 66 municipalities have recorded infections so far.
Latest Data from EODY
The National Public Health Organization (EODY) has updated its list of affected areas following new case confirmations between 21 and 24 August 2026. During that period, six additional municipalities were added to the list — two in Attica (Kifissia and Filothei–Psychiko), two in the Thessaloniki regional unit (Thessaloniki and Delta), one in Dio-Olympos (Pieria), and one in Thasos. However, the Thasos case remains under investigation due to the patient’s complex travel history; while most of the incubation period was spent on the island, epidemiologists are still verifying local transmission.
National Spread and Risk Assessment
In total, the virus has been confirmed in:
- 34 municipalities in Attica (out of 66)
- At least 22 municipalities elsewhere in Greece (excluding Thasos; the rest of the country comprises 266 municipalities)
Additionally, six more municipalities have been classified as high-risk zones — meaning they meet criteria such as geographic proximity to affected areas, elevated mosquito breeding potential, documented virus circulation in local mosquito or animal populations, or a known epidemiological burden. These areas are not yet confirmed as having human cases but are being closely monitored and prioritized for preventive measures.
Public Health Response
Ongoing vector control efforts — including targeted mosquito spraying — continue across affected and high-risk regions. A key distinction is made between affected municipalities (with at least one confirmed human case) and high-risk municipalities, as this classification triggers specific interventions — notably enhanced blood donation screening protocols to prevent transfusion-related transmission.
Epidemiological Snapshot
As of 19 August 2026, Greece had reported 157 locally acquired cases of West Nile virus infection — meaning all were contracted domestically via infected mosquito bites. Thirteen patients have died, all aged between 66 and 91 years. Most severe cases presented with neurological complications, including meningitis and encephalitis. For every symptomatic case, an estimated 140 additional infections are believed to be asymptomatic or mild — underscoring the virus’s broad but often silent circulation.
A revised EODY report detailing the exact distribution and breakdown of cases by municipality is expected shortly.