World Health Organisation warns about deadly West Nile virus rapidly spreading through European countries popular with British holidaymakers

By SHAUN WOOLLER, EXECUTIVE HEALTH EDITOR Published: 15:20, 24 July 2026 | Updated: 15:22, 24 July 2026 Potentially fatal West Nile virus is rapidly spreading across European countries popular with British holidaymakers, the World Health Organisation has warned. Officials are urging tourists and locals to take precautions to avoid being bitten by mosquitoes, who acquire the disease by feeding on infected birds. There is no licensed vaccine for humans and no specific antiviral drugs, with care limited to managing symptoms and supportive treatment in hospital for severe cases where it has infected the central nervous system. It can cause high fever, neck stiffness, disorientation, tremors, convulsions, muscle weakness, paralysis or coma. Greece has recorded the steepest recent rise, with 21 human cases of West Nile virus confirmed by national health authorities as of July 22 - 14 of them in the past week alone. Twenty of the 21 patients developed neuro-invasive disease, including encephalitis or meningitis, and 13 remain hospitalised. Italy has the widest geographic spread, with 21 cases confirmed in 17 separate areas as of July 15, the latest data available. Multiple locally acquired human cases have also been reported in Spain, Romania and North Macedonia. Officials are urging tourists and locals to take precautions to avoid being bitten by mosquitoes, who acquire the disease by feeding on infected birds. Most people who catch the disease will do so as a result of being bitten by an infected mosquito, although transmission through organ transplant, blood transfusion, pregnancy and breastfeeding has also been documented. The WHO said: ‘For most people the risk remains low, but anyone living in or travelling to an affected area should take basic steps to avoid mosquito bites and know the signs of severe illness in case they or someone close to them falls ill.’ In Europe, most human infections occur during the mosquito season, typically from late spring through autumn, with the highest transmission usually observed between July and September. Dr Hans Henri P Kluge, WHO regional director for Europe, said: ‘West Nile virus is not a new threat, but the conditions that make it spread are changing rapidly. ‘Warmer temperatures and longer summers are giving mosquitoes more time and territory to transmit this virus. ‘Most infections are mild, but roughly 1 in 150 people who contract it will develop a severe infection affecting the central nervous system which can be life-threatening. ‘Simple steps like covering up, using insect repellent, and clearing stagnant water around the home, can make a real difference. ‘Anyone who develops a high fever, rash or neck stiffness after a mosquito bite should see a doctor without delay.’ Dr Hans Henri P Kluge, WHO regional director for Europe, said West Nile virus is not a new threat but the conditions that make it spread are 'changing rapidly'. Between 70 per cent and 80 per cent of people with West Nile virus infection will not develop any symptoms. Those who do may experience fever, headache, tiredness, body aches, nausea or vomiting, and sometimes a rash or swollen lymph glands. The WHO said anyone developing symptoms after returning from an area where West Nile virus is circulating should seek medical care ‘promptly’, while those with severe symptoms should do so ‘immediately’. Care focuses on rest, fluids, pain relief and, in severe cases, hospital-based supportive treatment. West Nile virus infection can be confirmed by laboratory testing, including detection of virus-specific antibodies or viral RNA, depending on the timing of illness. The World Health Organisation Regional Office for Europe is urging countries to strengthen mosquito surveillance and public knowledge of protective measures. It advises wearing light clothing covering most of the body, including long sleeves and trousers; using mosquito repellent containing approved active ingredients; and limiting time outdoors at dawn and dusk, when mosquitoes are most active. Windows and doors should be fitted with screens to keep mosquitoes out of the home, with mosquito nets over beds and babies’ cots. Stagnant water, which is a common breeding site, should be removed from around the home and in public places, it adds.