The World Health Organization (WHO) said in an outbreak notice last week that some countries are reporting a resurgence in the chikungunya virus, which is transmitted via mosquitoes, and warned that the virus could spread further.
In a notice issued on Oct. 3, the U.N.-backed health body said that the chikungunya virus saw “a resurgence” in 2025, including in countries “that had not reported substantial case numbers in recent years.”





