← All diseases

West Nile Virus

Watch rising
Vector-borne
Current NYS Status

Mosquito season underway. First WNV-positive mosquito pools detected in Nassau and Suffolk counties. Human case season peaks August-September.

Source: NYSDOH arboviral surveillance, updated weekly (seasonal)

What is it?

West Nile Virus (WNV) is a mosquito-borne virus present in New York State every summer. The vast majority of infected people experience no symptoms or mild flu-like illness. A small fraction develop serious neurological disease.

How it spreads

Transmitted by the bite of infected Culex mosquitoes, which are most active from dusk to dawn. Not spread person-to-person. Rarely transmitted through blood transfusion, organ transplant, or from mother to baby.

Symptoms

Most people (80%) have no symptoms. About 20% develop West Nile Fever: headache, body aches, fever, fatigue, and sometimes rash. Less than 1% develop serious neurological illness (meningitis or encephalitis).

Who is at risk?

Everyone is at risk of infection during mosquito season. Adults over 50 and immunocompromised individuals are at higher risk for severe neurological disease.

What you can do

🛡Use EPA-registered insect repellent with DEET, picaridin, or oil of lemon eucalyptus
🛡Wear long sleeves and pants during peak mosquito hours (dusk to dawn)
🛡Eliminate standing water around your home — mosquitoes breed in as little as a bottle cap of water
🛡Make sure window and door screens are intact
Tier AReal-time tracking

Surveillance data updated from government sources daily or weekly. Threat level reflects current wastewater signal or clinical reports.

Seasonality: summer

This information is for general public health awareness and is not a substitute for professional medical advice, diagnosis, or treatment.