West Nile virus in Europe 2026: what you need to know

Of the mosquito-borne diseases that recur in Europe every summer, West Nile virus (WNV) is the one that asks the narrowest question of a household in Italy, Greece, Romania, Spain, or North Macedonia between July and September: can a Culex mosquito reach the bedroom between dusk and dawn? The protection answer is structural, not pharmaceutical, and it is the same answer in every affected country. This hub is the entry point to the Mosticare 2026 West Nile virus coverage: it describes the disease, the vector, the 2026 season so far, the protection layer that sits in the home, and the consumer-protection framing that is the only available line of defence for a pathogen with no human vaccine and no specific antiviral.

The page is intentionally evergreen. The country sections, the vector behaviour, the clinical spectrum, and the household protection logic do not change with the headline case counts. The week-by-week surveillance signal changes, and the ECDC weekly West Nile virus monitoring carries the live numbers. The durable piece is this page; the moving piece is the data.

What West Nile virus is

West Nile virus is a flavivirus maintained in a bird-mosquito-bird transmission cycle. Culex mosquitoes, chiefly Cx. pipiens in continental Europe and Cx. molestus in urban environments, pick up the virus when they feed on infected birds and pass it on when they subsequently feed on humans, horses, and other incidental hosts. Humans and horses are dead-end hosts: they do not sustain transmission. The disease is not contagious person-to-person, is not food-borne, and is not water-borne [ECDC WNV infection page; WHO WNV fact sheet].

Three things West Nile virus is not, and the misreads cost households real protection:

• Not a tropical disease. It is established endemically across southern and southeast Europe. The ECDC factsheet records the first major European outbreak in Romania in 1996, when about 400 cases were identified. Greece recorded a large outbreak in 2010, with 262 human cases and 35 deaths in Central Macedonia. Every year since, the ECDC weekly West Nile virus monitoring has had something to record.
• Not dengue, not chikungunya. Those two are Aedes albopictus viruses, day-biting, container-breeding, with different geography and different protection patterns. Mixing them up is one of the more common errors in European consumer press. The protection logic for Aedes-borne viruses (daytime terrace and garden) and Culex-borne WNV (night-time bedroom) is different.
• Not preventable by vaccines available to the public. The WHO fact sheet states that no vaccine is available for humans, and the ECDC factsheet states that no vaccine exists against the disease in humans. Equine vaccines exist and are used in horses; that is a separate programme run by national veterinary authorities. The protection layer for people sits in the household, not in the clinic.

The 2026 season in one paragraph

The first European signal of the 2026 season came in spring, and by 5 August the season's shape was clear. In their joint monthly report covering data submitted up to that date, ECDC and EFSA record 245 locally acquired human cases across seven countries: Italy 139, Greece 65, Spain 17, North Macedonia 13, Romania 6, France 4 and Germany 1. The earliest date of onset was 12 May. The report notes that the 2026 total is below the average for the corresponding period over the past decade, and that reporting delays may understate the burden.

The joint report also describes where transmission is most intense. It records cases in 58 NUTS 3 regions across seven countries and notes that the geographical spread so far is below the final extent of recent seasons. Six regions reported locally acquired cases for the first time. ECDC and EFSA add that they expect further cases given favourable weather conditions, and that transmission has typically peaked in August and September [ECDC and EFSA monthly report, 5 August 2026].

The vector: Culex pipiens and the dusk-to-dawn window

The species doing the work in continental Europe is Culex pipiens, the common house mosquito. It is small, brown, unremarkable, and, unlike Aedes albopictus, it is nocturnal. The ECDC factsheet states that Culex mosquitoes mainly bite between dusk and dawn, indoors and outdoors. The same species will rest during the day in shaded vegetation, cellars, sheds, and the cooler corners of inhabited buildings.

Three behavioural facts about Cx. pipiens drive the household protection logic:

1. It is a dusk and night feeder. This is the critical distinction from Ae. albopictus. An open bedroom window at 22:00 in August in Pavia, Thessaloniki, Bucharest, Plovdiv, or Slavonski Brod is an open invitation.
2. It breeds in standing water that is not container-sized. Where Ae. albopictus uses small container water (a flowerpot saucer, a bottle cap), the ECDC Culex pipiens factsheet describes Cx. pipiens as using larger accumulations: blocked drains, flooded cellars, irrigation overflow, neglected ponds, used tyres laid flat, and any organically rich standing water in urban and peri-urban settings. Source reduction works on Culex but looks different from Aedes source reduction.
3. It enters the house. Unlike Ae. albopictus, which tends to feed outdoors, Cx. pipiens readily enters bedrooms through open windows, doors left ajar for ventilation in summer, and unsealed gaps around window frames. Indoor biting is the rule, not the exception, for WNV-relevant transmission.

The corollary, for every household in the seven-country 2026 footprint: the protection question for July through September is not "what do I put on my skin during the day." It is "what is between me and a Culex mosquito between dusk and dawn."

The countries where this matters in 2026

The ECDC and EFSA monthly report of 5 August 2026 records locally acquired human cases in seven countries. Five of them have a long documented history of WNV transmission and their own national surveillance infrastructure: Italy, Greece, Spain, North Macedonia and Romania, with France and Germany also on the 2026 list. The country landings linked from this hub carry the per-country detail; the table below is the overview.

The joint report places the 2026 total below the ten-year average, which the report says is shaped by intense seasons such as 2018, 2022 and 2024. Italy remains the most affected country, and Greece has reported more cases in 2026 than at the same point in 2025. Six regions across Europe reported locally acquired cases for the first time [ECDC and EFSA monthly report, 5 August 2026].

Symptom spectrum and when to call a doctor

About 80 percent of human WNV infections are asymptomatic, and about 20 percent develop West Nile fever, with fever, headache and body aches, and sometimes a rash, per the WHO fact sheet. The ECDC factsheet puts the incubation period at usually two to six days and describes most patients as recovering within one week.

The ECDC factsheet states that fewer than 1 percent of infected individuals develop neuroinvasive disease, West Nile neuroinvasive disease (WNND), which presents as meningitis, encephalitis, or acute flaccid paralysis. The factsheet states that older adults and immunocompromised people are at higher risk, and lists hypertension, diabetes and renal disease among the risk factors. A 2026 clinical review from Rome's Spallanzani Institute, published in Reviews in Medical Virology (PMID 42431607), reports that the neuroinvasive form carries a case-fatality rate as high as 17 percent. There is no specific antiviral treatment for WNV; clinical management is supportive [Spallanzani Institute review, 2026; ECDC WNV factsheet; WHO WNV fact sheet].

The clinical decision point is therefore early recognition, particularly in older or immunocompromised household members developing high fever, neck stiffness, confusion, weakness, or seizures within the typical transmission season, and prompt presentation to emergency services.

The protection layer that exists in your house tonight

The protection layer for WNV in a SE EU household is built from four components. None of them is new. All of them are physical, and none relies on a new chemical exposure.

1. A mosquito net over the bed. For sleeping adults and children in the WNV transmission season, an untreated mosquito net draped over the bed is the single most reliable chemical-free barrier to Culex bites. Properly tucked under the mattress or with a framed canopy, the net eliminates indoor-biting exposure for the hours when Cx. pipiens is most active.
2. Screens on bedroom windows and doors. Tight-fitting insect screens on the bedroom windows and on any door left open for cross-ventilation in summer prevent Culex from entering the room in the first place. The ECDC factsheet lists screened or air-conditioned rooms among the personal protective measures against Culex bites.
3. Elimination of Culex breeding sites in the immediate vicinity. This is different from Aedes source reduction. The ECDC Culex pipiens factsheet describes Cx. pipiens as breeding in larger and more organically rich standing water: blocked roof gutters, neglected ponds, water-filled containers that have been in place for weeks, used tyres stored flat, flooded cellars, and water left in place across the breeding cycle. A weekly walk around the house and garden to drain, dry, or treat these accumulations reduces the local biting pressure.
4. Personal protection during outdoor evening hours. Where presence on the terrace, in the garden, or at an outdoor event during the dusk-to-dawn window is unavoidable, personal protection (long sleeves, long trousers, light-coloured clothing, and an age-appropriate skin repellent applied according to label) is the third line of defence. The first line is the bedroom net; this is the supplementary one.

What the protection layer is not: it is not a prescription, not a vaccination, not a chemical indoor treatment. The chemical layer (residual indoor spraying, outdoor ultra-low-volume adulticiding, larviciding of standing water with Bacillus thuringiensis israelensis or insect growth regulators) is a public-health tool used by municipal vector control. It complements, but does not replace, the household physical-barrier layer.

Why bedroom nets, and the regulatory frame around them

For households in the SE EU transmission zone, the relevant barrier products sit in two regulatory families.

Untreated nets, the polyester or cotton mosquito nets, framed canopies, and gazebo nets used over beds and around outdoor seating, are general textile products. They make no chemical claims. They carry no biocidal-product registration. They are the simplest, longest-lasting, and most easily maintained part of the household barrier. They are what a family with a baby, a toddler, an elderly relative, or an allergic individual can deploy tonight.

Treated nets, insecticide-treated nets (ITNs), are a different product family. They carry a permethrin or other pyrethroid treatment and fall under the European Biocidal Products Regulation (BPR, Regulation (EU) No 528/2012). In the global public-health context, WHO prequalifies insecticidal vector-control products and their active ingredients for procurement against malaria vectors in endemic tropical settings. WHO prequalification and BPR conformity apply only to treated nets, never to untreated household products. Untreated bed canopies, gazebo nets, and baby or crib canopies are not WHO-prequalified products, are not BPR-registered biocidal products, and do not claim to be [Regulation (EU) No 528/2012; WHO prequalification of vector control products].

For households in the SE EU WNV zone, untreated nets over the bed, plus screened windows, plus source reduction around the house, are the complete physical-barrier layer. Where a household has a specific need for additional protection (immunocompromised family members, very elderly relatives, prior history of severe mosquito-borne illness) the conversation about treated products is one to have with the treating physician and with reference to the locally labelled BPR-registered products.

Frequently asked questions

Question: Is West Nile virus dangerous? About 80 percent of infections cause no symptoms at all, per the WHO fact sheet. Of those that do, most are a self-limiting fever. The ECDC factsheet states that fewer than 1 percent become neuroinvasive, but that form can be severe, and the Spallanzani Institute 2026 review reports a case-fatality rate as high as 17 percent for the neuroinvasive form. Older adults and immunocompromised household members are at higher risk of severe disease.

Question: Can I be vaccinated against West Nile virus? No. The WHO fact sheet states that no vaccine is available for humans, and the ECDC factsheet states that no vaccine exists against the disease in humans. Equine vaccines exist for horses. The protection layer for people is household-level physical barriers plus source reduction.

Question: When is the West Nile virus season in Europe? The ECDC factsheet states that most human infections in Europe are observed between July and September, and the joint ECDC and EFSA report states that transmission has typically peaked in August and September.

Question: Where in Europe is West Nile virus circulating in 2026? In the ECDC and EFSA monthly report of 5 August 2026, seven countries had reported locally acquired cases: Italy 139, Greece 65, Spain 17, North Macedonia 13, Romania 6, France 4 and Germany 1.

Question: Is a mosquito net enough to protect my family? An untreated mosquito net over the bed, plus tight-fitting window and door screens, plus elimination of Culex breeding sites around the home, plus age-appropriate repellent use during outdoor evening hours, is the complete household protection layer for the WNV season. Each component adds to the others; the combination is what works.

Question: Does DEET work against the mosquitoes that carry West Nile virus? The US CDC lists DEET and picaridin among the EPA-registered repellent active ingredients it recommends for use on exposed skin, and the ECDC factsheet recommends applying mosquito repellent to exposed skin during evening and night-time exposure. They are an effective supplement to a physical barrier, not a replacement for one.

Question: Is the 2026 season bigger than usual? The ECDC and EFSA report states that seasonal weather conditions are favourable for transmission and that more cases are expected. The same report places the 2026 total so far below the ten-year average, and notes that six regions reported locally acquired cases for the first time. Whether the season ends above or below the multi-year average will only be known at season close.

How to use this hub

This page is the entry point to the Mosticare 2026 West Nile virus coverage. It does not change with the case count of any single week. The country landings (Italy 2026, Greece 2026, Romania 2026) carry the per-country case data and the per-country household guidance. The protection guide (How to protect yourself from West Nile virus mosquito bites) carries the household-layer detail. For the live weekly figures, the right place to look is the ECDC West Nile virus weekly monitoring for the EU/EEA aggregate, the national reference (ISS for Italy, EODY for Greece, INSP for Romania, the national authorities for Spain and North Macedonia) for country-specific case counts and affected-area updates.

The structural facts do not change. Culex pipiens bites at dusk and through the night. WNV transmits through that bite. An untreated net over the bed breaks the chain. A screened window keeps the mosquito out in the first place. Source reduction around the house lowers the local biting pressure. These four moves, deployed every summer in the SE EU WNV window, are what every household in the affected region has under its own control.

Sources

• European Centre for Disease Prevention and Control. West Nile virus infection, surveillance and disease data, current 2026 season.
• European Centre for Disease Prevention and Control. West Nile virus weekly case-data report, 2026 season.
• European Centre for Disease Prevention and Control. West Nile fever factsheet for experts.
• European Centre for Disease Prevention and Control. Culex pipiens factsheet for experts.
• European Centre for Disease Prevention and Control and European Food Safety Authority. Surveillance of West Nile virus infections in humans and animals in Europe, monthly report, data submitted up to 5 August 2026. PMID 42614799.
• World Health Organization. West Nile virus fact sheet, continuously updated.
• World Health Organization. Prequalification of vector control products.
• Istituto Superiore di Sanità, EpiCentro. Arbovirosi in Italia: sorveglianza integrata nazionale, national plan extended through 2026.
• Hellenic National Public Health Organization (EODY). Weekly West Nile virus epidemiological surveillance reports.
• National Institute of Public Health, Romania (INSP). West Nile virus surveillance updates.
• Spallanzani Institute, Rome. West Nile neuroinvasive disease: current management, emerging therapies and future clinical trial priorities, Reviews in Medical Virology, 2026. PMID 42431607.
• United States Centers for Disease Control and Prevention. Preventing mosquito bites, EPA-registered repellent active ingredients and age advice.
• European Commission. Regulation (EU) No 528/2012 concerning the making available on the market and use of biocidal products (BPR).