U.S. health officials are urging travelers to take additional precautions after a series of chikungunya outbreaks were confirmed across several tropical regions. The Centers for Disease Control and Prevention announced new Level 2 travel advisories on Friday for Cuba, Bangladesh, Sri Lanka and China’s Guangdong Province, citing rising case numbers and the absence of medical treatments for the mosquito-borne disease.
Chikungunya is transmitted through the bite of infected mosquitoes, and while no antiviral treatment exists, experts emphasize that the illness is preventable through vaccination. The CDC now recommends that travelers headed to affected areas consider immunization, especially those who may face prolonged exposure outdoors.
The virus typically causes fever and intense joint pain, but patients may also experience headaches, muscle aches, swelling or rash. Symptoms often appear within one week of infection, with most people recovering in several days. However, the World Health Organization warns that some cases can lead to lingering joint pain that lasts months or even years. More severe infections may require hospitalization due to the risk of organ damage.
Multiple regions report significant spikes
The outbreaks have varied widely in scale. Bangladesh has recorded the highest concentration of suspected cases, with the WHO reporting 700 infections in the capital city of Dhaka between January and September 2025. In China’s Guangdong Province, officials have confirmed 16,000 locally transmitted cases, marking the largest chikungunya outbreak ever documented within the country.
Cuba has reported 34 confirmed cases during the same period, prompting public health authorities to deploy targeted mosquito-control measures. In Sri Lanka, 150 laboratory-confirmed cases were recorded between January and mid-March, with infections reportedly peaking in June. Regional health agencies have warned that environmental factors, including rainfall patterns and rising temperatures, may be contributing to mosquito population growth.
According to WHO data, global chikungunya activity has been unusually high this year. Between January and September 2025, more than 445,000 suspected and confirmed cases were documented worldwide, along with 155 deaths attributed to the disease.
CDC lists additional countries with elevated risk
While the latest advisories focus on four locations experiencing active outbreaks, the CDC cautions that travelers to Brazil, Colombia, India, Mexico, Nigeria, Pakistan, the Philippines and Thailand may also face an elevated risk. In these countries, chikungunya transmission remains possible even without formal outbreak declarations.
Public health officials stress that travelers should remain vigilant during peak mosquito hours and use multiple layers of protection. Preventive measures include wearing long sleeves, applying EPA-approved insect repellent and staying in accommodations with window screens or air conditioning. For vaccinated travelers, these precautions remain important because no measure offers complete protection.
The U.S. has not documented any locally transmitted chikungunya infections since 2019. Cases reported within the country have been linked exclusively to travel, underscoring the importance of pre-trip preparation and post-travel monitoring. The CDC advises individuals returning from outbreak areas to seek medical evaluation if they develop symptoms consistent with the virus.
Growing concern over expanding mosquito-borne threats
Health authorities note that the rise in chikungunya cases mirrors broader global patterns in mosquito-borne diseases, including dengue and Zika. Warmer temperatures and urbanization have expanded mosquito habitats, increasing the likelihood of transmission in densely populated areas. Experts expect continued fluctuation in outbreak intensity as climate conditions evolve.
Researchers are also monitoring how travel patterns may influence regional spread. Increased international mobility, combined with limited treatment options, complicates containment efforts. While chikungunya is rarely fatal, its potential for long-term disability places significant strain on local health systems during widespread outbreaks.
The CDC advises travelers to stay informed through official health bulletins and consult medical professionals ahead of international trips. With seasonal tourism to tropical regions expected to rise, health agencies emphasize that preparation is key to reducing risk.