News Release

West Nile Virus Detected at the William Floyd Estate, Followed by Negative Detection

Date: August 20, 2025
Contact: Fire Island National Seashore

Patchogue, NY – West Nile Virus (WNV) has been detected in a mosquito sample for the first time this year in Fire Island National Seashore's William Floyd Estate. The William Floyd Estate is located in Mastic Beach, NY, and is managed by the National Seashore.

The mosquitoes were collected on July 29, 2025, from a trap set by Seashore as part of its mosquito monitoring program. This program is a collaborative effort between the National Park Service and Suffolk County Department of Health Services – Arthropod-Borne Disease Laboratory that helps the park assess risk levels and select actions for public safety. 

A mosquito sample from August 5, 2025, returned no results of West Nile Virus. National Park Service staff collects weekly samples of mosquitoes to test for WNV. Despite a negative result, WNV may still be present among the mosquito population and members of the public should take precautions to prevent mosquito bites.

WNV is transmitted to humans through the bite of an infected mosquito. Visitors should take precautions to reduce exposure to the virus by avoiding areas with high densities of mosquitoes. If contact with mosquitoes is unavoidable, it is advisable to minimize outdoor activities when mosquitoes are active, wear protective clothing (long sleeved shirts, socks, and long pants) and use effective insect repellent, such as one containing at least 30% DEET. People most at risk of becoming ill are those over 60 years of age or whose health is impaired.  

The National Park Service, along with Suffolk County, will continue its weekly surveillance program to monitor the severity and extent of WNV within the boundaries of the Seashore. Consistent with Fire Island National Seashore’s mosquito monitoring protocols, there will be increased surveillance at the William Floyd Estate, where West Nile Virus was detected. If significant threats to human health are identified, actions to protect the public may need to include control methods such as larviciding, spraying, or area closures. The National Park Service works closely with the Centers for Disease Control and Prevention (CDC), the New York State Department of Environmental Conservation (DEC), Suffolk County Department of Health Services – Arthropod-Borne Disease Laboratory, Suffolk County Vector Control, and local Fire Island and Long Island municipalities to determine the best course of action to protect residents, visitors, and employees of the Seashore. The public will be notified 24 hours in advance of any spray event. 

West Nile Virus was first confirmed in New York State in 1999. For general information on West Nile Virus, please contact your local health department or the CDC, New York State, or Suffolk County WNV websites. If you have information or questions for the park, please contact us at e-mail us.

PREVENTION

• Reducing exposure to mosquitoes is the best prevention method for mosquito-borne diseases, especially in warmer months when mosquitoes are most abundant. To help prevent getting mosquito-borne illness:
• Wear insect repellents that contain DEET, IR3535, Picaridin, or oil of lemon eucalyptus (Para-menthane-dio); follow label instructions and reapply as needed.
• Use this EPA resource to find the repellent that is right for you.
• Wear long sleeves, long pants, and socks outdoors when weather permits.
• Treat clothing and gear with products containing permethrin.
• Use screens on windows and doors and repair holes in screens to keep mosquitoes outdoors.
• Use air conditioning, if available.
• Help reduce the number of mosquitoes around your home or work area by emptying standing water.
• See the NPS Pest & Invasive Species Management Page for additional details.