New York health officials confirmed the first locally acquired case of chikungunya in the state since 2017 and the first documented U.S. transmission since 2019. The patient, a Nassau County resident, fell ill in late August after traveling within the region but not leaving the country, according to the Associated Press. Laboratory work at the Wadsworth Center verified the infection more than two weeks after clinical samples were taken.
Investigators have not determined how the woman contracted the virus, though they suspect a bite from an Aedes albopictus mosquito that previously fed on an infected traveler. “The case is interesting because the source of exposure for this individual is unclear,” said infectious-disease expert Dr. Amesh Adalja, according to the Economic Times.
State officials said dropping night-time temperatures and declining mosquito activity kept the overall public threat low, and no virus-positive mosquitoes had been found in Nassau County. “The possibility of the chikungunya virus spreading in New York is very remote,” said Dr. James McDonald, the state health commissioner, according to People.
The Centers for Disease Control and Prevention counted 152 chikungunya cases in the United States this year, nearly all linked to international travel. New York recorded three additional cases in 2023, each tied to trips abroad. Globally, the European Centre for Disease Prevention and Control logged roughly 317,000 infections and 135 deaths in 16 nations and territories since January.
Aedes albopictus, the mosquito capable of carrying chikungunya, has lived in New York City and its suburbs for decades and recently expanded across the state’s southern tier. Warmer temperatures and urban expansion have already allowed local transmission of dengue and Zika in Florida and Texas. “All it takes is an infected traveler to seed local mosquitoes,” Adalja said.
Chikungunya usually causes sudden fever, severe joint pain, headache, muscle aches, nausea, fatigue, and rash three to seven days after a mosquito bite. Most patients recover within one to two weeks, though joint pain can persist for months or years. Newborns, adults over 65, and people with hypertension, diabetes, or heart disease face greater risks.
No antiviral treatment exists; care centers on rest, fluids, and fever-reducing drugs such as acetaminophen. Aspirin and other NSAIDs should be avoided until dengue is ruled out. A live-attenuated vaccine is available for travelers but is not part of routine immunization schedules.
Because chikungunya spreads only through mosquitoes—aside from rare mother-to-fetus transmission—public-health advice focuses on mosquito control. Officials urged residents to empty standing water from containers, fix window screens, use EPA-registered repellents, and wear long sleeves, long pants, and socks outdoors. Aedes mosquitoes thrive in urban environments and bite mostly during daylight, especially in early morning and late afternoon.
While the Long Island patient recovers, county and state teams are tracing her recent movements and expanding mosquito surveillance. So far, all collected mosquito pools have tested negative, though Adalja cautioned that unsampled areas “could harbor the virus,” the Associated Press reported.
Written with the help of a news-analysis system.