The West Nile virus outbreak in Greece has reached an alarming level, with Attica at the epicenter of this year's surge. As of August 12, 2026, the National Public Health Organization of Greece (EODY) has recorded a staggering 110 domestically acquired cases, a significant increase in just one week. This rapid rise in cases is a cause for grave concern, especially given the virus's impact on the central nervous system (CNS).
Among the 110 confirmed cases, 81 involved severe CNS manifestations, such as encephalitis, meningitis, meningoencephalitis, or acute flaccid paralysis. This highlights the virus's potential for severe neurological complications. The median age of these patients is 73, with a range from 19 to 91, indicating that older individuals are more susceptible to severe outcomes. Moreover, the virus's rapid spread is evident in the last week's report, which recorded 45 new cases, a substantial portion of the total cases since the transmission season began.
The situation is further exacerbated by the tragic loss of life. As of the report's publication, nine deaths have been attributed to West Nile virus infections, all occurring in patients over 65 years old, with a median age of 82. This grim statistic underscores the virus's deadly potential, particularly in older populations.
The true scale of infections may be far greater than the reported figures suggest. EODY's 2010 seroepidemiological study revealed that for every confirmed case with CNS involvement, there are approximately 140 infected individuals who either exhibit mild symptoms or remain asymptomatic. This means that the actual number of infected people could be significantly higher than the reported cases.
Attica, a region in Greece, has borne the brunt of this year's viral outbreak. By August 12, cases had been recorded in 39 municipalities across 14 regional units and four regions, including Attica, Thessaly, Central Macedonia, and the Peloponnese. Within Attica, East Attica and the North, West, Central, and South Sectors of Athens, as well as Piraeus, have been particularly affected. Outside Attica, cases have been reported in Karditsa, Larissa, Trikala, Imathia, Thessaloniki, Pella, Serres, and Laconia.
The impact is most severe in certain municipalities within East Attica. Spata-Artemida and Markopoulo Mesogaias have seen a high burden of cases, with 11 and 8 patients, respectively, exhibiting CNS manifestations. The rate of severe cases in these areas is alarming, with 31.5 and 36.8 cases per 100,000 inhabitants, respectively.
Despite the current focus on affected areas, health authorities are also identifying 'high-risk' municipalities that have not yet reported human cases. These areas are selected based on epidemiological and geomorphological factors, such as proximity to affected regions and historical data. Kifisia, Iraklio, Filothei-Psychiko, Metamorfosi, Kallithea, Nea Smyrni, Nea Filadelfeia-Nea Chalkidona, Dafni-Ymittos, Amfipoli, Heroic City of Naousa, and Delta are among the high-risk areas.
The virus's geographical reach extends beyond human cases, as evidenced by veterinary surveillance. By August 12, recent West Nile virus infections had been detected in equines in five settlements across East Attica, Drama, Preveza, and Thessaloniki. This further emphasizes the virus's widespread circulation in the region.
To combat the outbreak, EODY has implemented an enhanced epidemiological surveillance system, ensuring that every reported case is investigated within 24 hours. This includes contact with treating doctors and patient interviews to determine exposure sites, risk factors, and disease severity. Additionally, daily communication with laboratories and specialized guidance for health professionals have been crucial in identifying and managing suspected cases.
Mosquito control programs have been stepped up as a central prevention strategy. The Ministry of Health issued a circular in March 2026, outlining integrated mosquito management programs. EODY has also installed mosquito traps as an early-warning system, monitoring mosquito populations for the presence of the virus. When virus circulation is detected, targeted control measures are implemented, and local authorities are advised to intensify mosquito control and public information efforts.
In conclusion, the West Nile virus outbreak in Greece is a complex and evolving situation. The rapid increase in cases, severe complications, and geographical spread highlight the need for continued vigilance and proactive measures. EODY's recommendations emphasize the importance of epidemiological surveillance, integrated mosquito control, and individual protection against mosquitoes. As the virus continues to circulate, further cases are expected, underscoring the need for a comprehensive and coordinated response to protect public health.
