The New York State Department of Health confirmed a locally acquired case of chikungunya virus in an individual living in Nassau County on Long Island. State health officials said it’s the first reported transmission of the illness within the United States since 2019. Rare Mosquito-Borne Virus Reportedly Detected In United States The individual started experiencing symptoms in August after traveling outside of the region but not the country, the Associated Press noted. "Chikungunya is a virus that's spread by mosquitoes. You can't get it from another person, but mosquitoes do get it from biting a person who is infected. Chikungunya symptoms typically include fever and joint pain, as well as headache, nausea, red eyes, a rash, and fatigue," WebMD stated. A resident of Long Island in New York State has tested positive for Chikungunya virus, marking the first locally acquired case in the United States in six years, according to the New York State Department of Health.⁠⁠Chikungunya is a virus that's spread by mosquitoes. You… pic.twitter.com/dJ7XopPfsO — WebMD (@WebMD) October 16, 2025 More from the Associated Press: It’s not clear how exactly the person, whom authorities have not named, contracted the virus. Health officials say the person was likely bit by an infected mosquito, but they also say the virus has not been detected in local mosquito pools and there is no evidence of ongoing transmission. The type of mosquito known to carry chikungunya is present in parts of the New York City metropolitan area, including suburban Long Island. The disease cannot be spread directly from one person to another. Since mosquitoes are less active during the fall’s cooler temperatures, the current risk of transmission is “very low,” said state Health Commissioner James McDonald. “While the case is classified as locally acquired based on current information, the precise source of exposure is not known," health officials said, according to ABC News. 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.… pic.twitter.com/ndqYWGoKAQ — Yahoo News (@YahooNews) October 15, 2025 ABC News shared further info: 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.