Chikungunya detected in United States as New York investigates possible locally acquired case

A mosquito-borne chikungunya virus case in the United States has prompted public health officials to monitor for possible local transmission after a woman on Long Island was diagnosed with the disease in August. New York health authorities said the patient had not traveled off the island, which is home to more than 8 million people and includes the Hamptons, a pattern that has prompted investigators to consider a locally acquired infection for the first time in New York since records began. The New York State Department of Health said it is investigating the case and coordinating with local Long Island health authorities to confirm the results. Local mosquito surveillance in the area has not detected chikungunya virus in the insect population, and officials emphasized that the overall risk to the public remains very low while the inquiry continues.

The chikungunya virus is spread primarily by Aedes mosquitoes and can cause abrupt fever and severe joint pain, sometimes crippling, that can last for weeks or months. The incubation period is typically three to seven days, and the most common symptoms include a sudden fever over 102 degrees Fahrenheit (38.9 Celsius) and intense joint pain in the hands and feet. In rare cases, infections can lead to severe complications affecting the heart or brain. The virus does not spread from person to person through casual contact or saliva; transmission requires a bite from an infected mosquito. There is no specific antiviral treatment for chikungunya; management focuses on relieving symptoms and preventing dehydration, with prevention centered on avoiding mosquito bites and eliminating standing water where mosquitoes breed. While two chikungunya vaccines exist, they are not part of routine U.S. immunization programs and are generally reserved for travelers to outbreak zones or people at higher risk during localized outbreaks.

Since the start of 2025, authorities have recorded more than 317,000 chikungunya cases and about 135 related deaths in 16 countries, with outbreaks reported across the Americas, Africa, Asia and Europe. In China, a severe outbreak in the Guangdong Province prompted a Level 2 travel warning from the CDC and led to Covid-era–style restrictions in the epicenter region, including quarantines for patients in hospitals and curbs on power and movement for residents who did not comply with public health protocols. The global rise in cases has underscored the ongoing risk of chikungunya as international travel resumes to pre-pandemic levels.

Public health officials note that chikungunya is a nationally notifiable disease in the United States, meaning health authorities can voluntarily report cases for tracking and monitoring. U.S. health authorities typically see a small number of travel-associated cases each year, and there have historically been no locally acquired transmissions in New York State prior to this recent inquiry. A spokesperson for the New York State Department of Health told NTD News that investigators are determining whether the case is locally acquired and that, at this stage, the risk to the public remains very low. The department is working with local Long Island health authorities to confirm the patient’s test results and to expand surveillance for any additional cases in the area.

The case also comes as a reminder of the ongoing need for mosquito-control efforts. Aedes mosquitoes bite primarily during the daytime, making personal protective measures essential for residents and visitors in affected areas. Officials advise using EPA-registered insect repellents, wearing long sleeves and pants, and ensuring that doors and screens are intact to prevent entry of mosquitoes. Communities are encouraged to remove standing water from containers and to monitor for signs of increased mosquito activity, especially during warm months when the insects are most active.

The broader context includes geographic data from Europe’s disease agency, which shows varying chikungunya notification rates around the world. The European Centre for Disease Prevention and Control provides a 12-month view of case notification rates per 100,000 people, illustrating how outbreaks have shifted across regions in recent years. Health experts also caution that roughly 15 to 35 percent of people infected with chikungunya may be asymptomatic, underscoring the need for vigilance even when no fever is observed.

As travel continues to rebound and global travel volumes remain high, health authorities stress the importance of early recognition of symptoms such as fever and joint pain, particularly for people who have visited areas with known outbreaks in the preceding weeks. People experiencing sudden high fever, intense joint pain, or other flu-like symptoms after mosquito exposure should seek medical care promptly, both to receive supportive treatment and to help public health officials track potential transmission.