The New York State Department of Health has confirmed a case of locally acquired chikungunya on Long Island, marking the first case of the virus reported to be locally acquired in New York and the first locally acquired case to be reported in the United States since 2019.

Laboratory testing at the department’s Wadsworth Center confirmed the case in Nassau County on Long Island, according to health officials.

“An investigation suggests that the individual likely contracted the virus following a bite from an infected mosquito,” officials said. “While the case is classified as locally acquired based on current information, the precise source of exposure is not known.”

Chikungunya is a mosquito-borne disease most common in tropical and subtropical regions and symptoms include fever and joint pain, headache, muscle pain, joint swelling, or rash, officials said.

The disease cannot be spread directly from one person to another, authorities said, and the risk to the public is low.

The illness is rarely fatal, and most patients recover within a week, though some may experience persistent joint pain, authorities continued.

“People at higher risk for severe disease include newborns infected around the time of birth, adults aged 65 and older, and individuals with chronic conditions such as high blood pressure, diabetes or heart disease,” according to the New York State Department of Health.

The Aedes albopictus mosquito, which is known to transmit chikungunya, is present in parts of downstate New York and local transmission can occur when an A. albopictus mosquito bites an infected traveler, becomes infected and bites another person.

“Our Wadsworth Center has confirmed this test result, which is the first known case of locally acquired Chikungunya in New York State. Given the much colder nighttime temperatures, the current risk in New York is very low.” State Health Commissioner Dr. James McDonald said. “We urge everyone to take simple precautions to protect themselves and their families from mosquito bites.”

In 2025, there have been three additional chikungunya cases outside New York City that were all linked to international travel to regions with active chikungunya infections, according to health officials.

“Routine mosquito testing conducted by the Department’s Wadsworth Center and the New York City Department of Health and Mental Hygiene (DOHMH) has not detected chikungunya virus in any New York mosquito samples to date,” said the New York State Department of Health.

Health officials said that all New Yorkers should take precautions to reduce the risk of mosquito bites by using EPA-registered insect repellents, wearing long sleeves, long pants and socks outdoors when possible, removing standing water around homes, such as in flowerpots, buckets and gutters, and by repairing or patching holes in window and door screens to keep mosquitoes out.