Published: 15:29 BST, 20 August 2026 | Updated: 21:41 BST, 20 August 2026
New York City health officials have confirmed the city's first case of brain-swelling West Nile virus this year.
The New York City Health Department announced Wednesday that a resident contracted West Nile virus after spending time outdoors in areas around and outside the city.
No other details were released about the person's identity or how they became ill.
It's the city's first case of West Nile virus so far in 2026, with 222 cases reported nationwide, primarily in Arizona, Texas and California.
According to the health department, mosquitoes carrying West Nile virus are present in NYC every year from June through October, with peak season between August and September.
The city said it has intensified mosquito surveillance and expanded control efforts after detecting the virus in mosquito samples in all five boroughs since June, twice as many samples as last summer.
While most patients have few or mild symptoms, about one in 150 suffer potentially life-threatening brain swelling, along with infections and paralysis.
'The good news is it's preventable,' Alister Martin, NYC health commissioner, said in a statement. 'With mosquito season in full swing, we’re encouraging New Yorkers to take extra precautions to minimize the risk of mosquito bites.'
West Nile virus is caused by a bite from Culex mosquitoes (pictured above) and is most common in Great Plains states
He added that the best steps 'to protect yourself are simple: wear insect repellent, cover up during dawn and dusk, and get rid of standing water around your home.'
West Nile virus is caused by a bite from Culex mosquitoes and is most common in Great Plains states like North Dakota, South Dakota, Nebraska and Colorado, though cities like Los Angeles, Chicago and Dallas-Fort Worth also record high levels due to large populations.
Many of these states have also extended mosquito season – which runs from late spring through early fall – due to the increases in mosquito prevalence later in the year.
The disease usually causes no symptoms, but in one in five patients, it can lead to fever, headaches, nausea, diarrhea, joint pain and pain behind the eyes.
About one in 150 cases are neuroinvasive, meaning the virus penetrates the blood-brain barrier and travels to the meninges, causing meningitis and potential paralysis.