New York City health officials have reported the city’s first human case of West Nile virus (WNV) in 2026. They urge residents to protect themselves from mosquito bites during the peak summer season. According to the New York City Department of Health, the infection occurred after the person spent time outdoors in New York City and various locations beyond the city limits. Mosquitoes carrying WNV have been detected across all five boroughs since June, with over 1,000 mosquito pools testing positive for the virus this year.
Understanding West Nile Virus
West Nile virus is transmitted by mosquitoes. It spreads to humans through bites from infected mosquitoes but does not transmit from person to person. WNV is a leading cause of mosquito-borne disease in the continental United States. It typically circulates during the warmer months, when mosquito numbers are highest. In New York City, mosquitoes carrying the virus are found from June through October, with the greatest activity in August and September.
West Nile Virus Cases Across the U.S.
The Centers for Disease Control and Prevention (CDC) report 222 human cases of WNV nationwide in 2026 across 32 states. The recent case in New York brings that total to 33 states. Arizona, Texas, and California have the most cases.
Symptoms of West Nile Virus
Many people infected with WNV show no symptoms. Some people develop mild symptoms, such as:
- Fever
- Headache
- Muscle aches
- Fatigue
- Skin rash
Symptoms can persist for days or weeks and resemble other viral infections. From 2012 to 2021, an average of 16 New Yorkers were diagnosed yearly with West Nile neuroinvasive disease. From 2022 to 2025, that average increased to 31 cases annually. A small percentage of those infected develop a more severe form, known as West Nile neuroinvasive disease, affecting the brain and spinal cord. The CDC reports 156 neuroinvasive cases in the U.S. in 2026. About one in 150 people infected can develop this potentially life-threatening condition.
While some cases can be fatal, many patients recover fully. However, some experience ongoing health issues or permanent disability.
Who Is Most at Risk?
Older adults and those with weakened immune systems are at higher risk for severe illness. People aged 65 and older are three times more likely to develop neurologic disease from WNV than younger individuals. Those with chronic health conditions such as cancer, diabetes, hypertension, and kidney disease also face increased risk.
What to Do If You Have Symptoms
The NYC Health Department advises anyone with symptoms of WNV to contact a healthcare provider. Serious symptoms, particularly confusion, severe weakness, or neurological issues, require immediate medical attention. Early diagnosis can help rule out other illnesses and enable supportive treatment if needed.
Protecting Yourself Against Mosquito Bites
Without a specific treatment or vaccine for WNV available to the general public, prevention remains key. Health officials recommend:
- Using EPA-registered insect repellents containing DEET, picaridin, IR3535, or oil of lemon eucalyptus.
- Wearing long-sleeved shirts, long pants, socks, and shoes when outdoors.
- Limiting outdoor activity at dawn and dusk, when mosquitoes are most active.
- Installing and repairing window and door screens.
- Eliminating standing water from buckets, flowerpots, birdbaths, gutters, and containers where mosquitoes breed.
- Maintaining swimming pools, hot tubs, and ornamental ponds to prevent mosquito reproduction.
“West Nile virus is spread by mosquito bites and cannot spread from person to person. The good news is it’s preventable,” stated NYC Health Commissioner Dr. Alister F. Martin, urging precautions during mosquito season.
The latest case in the city highlights the need for vigilance as the summer ends. While most infections are mild or symptom-free, WNV can cause severe illness in vulnerable individuals. Preventing mosquito bites is crucial during this season.