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 transmitted by infected Culex mosquitoes and is present in New York State every summer. NYS reported 69 cases in 2024. The vast majority of infected people have no symptoms or mild 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 pregnant person to baby.

Symptoms

Most people (about 80%) have no symptoms. About 1 in 5 develop West Nile Fever: headache, body aches, fever, fatigue, and sometimes rash. Less than 1% develop serious neurological illness — meningitis, encephalitis, or acute flaccid paralysis.

Who is at risk?

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

What you can do

🛡Use EPA-registered insect repellent containing DEET, picaridin, IR3535, or oil of lemon eucalyptus

🛡Wear long sleeves and pants during peak mosquito hours (dusk to dawn)

🛡Eliminate standing water around your home — mosquitoes can breed in as little as a bottle cap of water

🛡Make sure window and door screens are in good repair

Tier A — Real-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.