Tracking Emerging Public Health Challenges – January 1, 2026 – Chikungunya
“As of December 29, 2025, this Rapid Risk Assessment says WHO regions have seen declines in cases compared to 2024, others are experiencing sharp increases, and the mosquito-transmitted virus is emerging in previously unaffected populations.
This uneven pattern makes it challenging to assess the overall global trend, but points to localized outbreaks and resurgences in specific areas.
The Region of the Americas recorded the highest number of confirmed cases, closely followed by the European Region, where the majority stem from French Overseas Departments in the Indian Ocean.
The WHO warns that the risk of further geographic spread remains high as infected travelers can introduce the virus to new areas, where local transmission can establish if competent Aedes mosquitoes are present.
In the United States, the leading states reporting travel-related chikungunya cases include southeast Florida (250) and Texas (6).” (2)
1.Global chikungunya 2025, by Robert Herriman, https://outbreaknewstoday.substack.com/p/global-chikungunya-2025
2.186 Chikungunya Associated Fatalities Confirmed in 2025, by Don Hackett, https://www.vax-before-travel.com/2025/12/30/186-chikungunya-associated-fatalities-confirmed-2025
curated by Jonathan M. Metsch, Dr.P.H.
Clinical Professor of Environmental Medicine, Icahn School of Medicine at Mount Sinai