Health officials in New York City have announced the first human case of West Nile virus (WNV) for 2026. Residents are urged to protect themselves from mosquito bites during the summer. The New York City Department of Health indicated the individual contracted the virus after spending time outdoors in both the city and other locations.
Mosquitoes carrying WNV have been identified in all five boroughs since June, with over 1,000 mosquito pools testing positive citywide.
Understanding West Nile Virus
West Nile virus is transmitted to humans through the bite of an infected mosquito. It does not spread from person to person. As the leading cause of mosquito-borne disease in the continental US, its activity peaks during warmer months when mosquitoes are most active.
In NYC, West Nile virus is present every year from June through October, with peak activity in August and September.
States Reporting West Nile Cases
The CDC has reported 222 human cases nationwide in 2026 across 32 states, now 33 including New York’s recent case. Arizona, Texas, and California have the most cases.
Symptoms of West Nile Virus
Most infected people show no symptoms. Those who develop mild illness may experience:
- Fever
- Headache
- Muscle aches
- Fatigue
- Skin rash
These symptoms can persist for days or weeks and may resemble other viral infections.
From 2012 to 2021, NYC averaged 16 cases of West Nile neuroinvasive disease annually, increasing to 31 cases annually between 2022 and 2025.
A small percentage develop West Nile neuroinvasive disease, a severe condition affecting the brain and spinal cord. The CDC reports 156 neuroinvasive cases in the US in 2026. Approximately one in 150 infected individuals may develop this life-threatening illness requiring hospitalization.
While many recover fully, some face long-term health complications or permanent disability.
Who Is Most at Risk?
Older adults and those with weakened immune systems are at greater risk. People aged 65 and older are three times more likely to develop neurological disease from WNV compared to younger individuals. Those with cancer, diabetes, hypertension, and kidney disease face higher risks as well.
What to Do If You Have Symptoms
The NYC Health Department advises contacting a healthcare provider if symptoms appear. Immediate medical attention is recommended for serious symptoms like confusion, severe weakness, or neurological issues.
Preventing West Nile Virus
As there is no specific treatment or vaccine for West Nile virus, prevention is crucial. Health officials recommend:
- Using EPA-registered insect repellents with DEET, picaridin, IR3535, or oil of lemon eucalyptus
- Wearing long-sleeved shirts, long pants, socks, and shoes outdoors
- Limiting outdoor activities around dawn and dusk
- Installing and repairing window and door screens
- Eliminating standing water in containers like buckets, flowerpots, and gutters
- Maintaining swimming pools, hot tubs, and ponds
Dr. Alister F. Martin, NYC Health Commissioner, emphasized the importance of precaution during mosquito season, noting that while most infections are mild, severe cases can occur.
The recent case serves as a reminder of the virus’s potential to cause serious illness in vulnerable individuals, highlighting the importance of preventive measures as summer ends.
Newsweek has contacted the New York Department of Health for comment.
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