West Nile Virus in Westchester: What You Need to Know

By Joseph Kaczmarek, MD

Westchester County this week confirmed its first human case of West Nile Virus for 2025. This news, while not unexpected for the season, often sparks questions and a degree of concern among residents. The truth is, for most, it's not as dangerous as it sounds.

Here is what you need to know about West Nile Virus, and how to protect yourself and your family.

What is West Nile virus?

West Nile Virus is a mosquito-borne illness that primarily circulates between birds and mosquitoes. Humans can become infected if bitten by an infected mosquito, but the virus cannot spread from person to person or from other animals to people. It's a seasonal threat, typically emerging during the warmer months when mosquito populations are active.

What to watch for

The good news is that about eight out of 10 people infected with West Nile Virus will not experience any symptoms at all. For the roughly 20% who do, symptoms are usually mild, often referred to as West Nile Fever. Symptoms can appear two to 14 days after a mosquito bite and typically include:

• Fever
• Headache
• Body aches
• Joint pain
• Vomiting
• Diarrhea
• Rash

Less than 1% of those infected develop a severe neurological illness, meaning the virus affects the brain or spinal cord. Symptoms of severe illness can include:

• High fever
• Severe headache
• Neck stiffness
• Disorientation or confusion
• Tremors
• Seizures
• Paralysis
• Coma

Individuals 65 years and older and those with weakened immune systems are at a higher risk for developing severe illness. If you or a loved one develops these severe symptoms, seek immediate medical attention.

Preventing West Nile Virus

There is currently no specific antiviral treatment for West Nile Virus, nor is there a vaccine for humans. Treatment for severe cases focuses on supportive care, helping patients manage symptoms and complications. This makes prevention our most powerful tool. Here’s what you can do:

Eliminate standing water: Mosquitoes breed in stagnant water; even a bottle cap is enough.

• Tip and toss: Weekly, empty water from flowerpots, bird baths (change water twice weekly), pet dishes, wading pools, and children's toys.
• Maintain your yard: Remove old tires, buckets, and anything that collects water. Drill holes in outdoor recycling containers.
• Check drainage: Ensure proper property drainage, and clear gutters and storm drains.
• Pools: Keep pools, spas, and hot tubs chlorinated. Drain water from covers.

Protect yourself outdoors:

• Use repellent: Apply EPA-registered insect repellents (DEET, picaridin, etc.), following instructions. It's important to choose the right repellent, especially for infants and children; consult the EPA's website (epa.gov/insect-repellents) for guidance. For infants over two months, apply to your hands first, then rub onto the child, avoiding their hands, eyes, and mouth.
• Dress appropriately: During dawn and dusk (peak mosquito times), wear long sleeves, long pants, and socks.
• Repair screens: Ensure window and door screens are in good condition.
• Utilize fans: An outdoor fan's breeze helps repel mosquitoes.

Community awareness:

• Report dead birds and large standing water on public property to the county health department (914-813-5000).
• Stay informed about local mosquito surveillance.

By understanding the virus, recognizing potential symptoms, and taking simple, proactive steps to eliminate mosquito breeding grounds and protect ourselves, we can significantly reduce our risk of infection. I urge you to stay informed, take preventative measures seriously, and seek medical attention if you experience severe symptoms. Together, we can help keep our community safe and healthy this season.

About the author

Joseph Kaczmarek, MD, is associate medical director of emergency medicine at Northwell's Northern Westchester Hospital.