The US Centers for Disease Control and Prevention (CDC) has issued a Level 1 Global Travel Alert for dengue fever as the mosquito-borne virus spreads across more than a dozen countries.
This “Practice Usual Precautions” notice is currently active for 16 nations throughout the Americas, Asia, Africa and the Pacific.
Health officials are sounding the alarm because “dengue is a year-round risk in many parts of the world” with transmission often surging in tropical climates.
Since the start of 2026, over 500,000 cases have been reported globally.
While most infections are mild, the CDC warns that for about one in 20 people, the illness can become life-threatening causing internal bleeding or shock.
Currently, there is no widely available vaccine for most US travelers, making prevention the primary defense.
The agency emphasised that “the best way to prevent dengue is by avoiding mosquito bites.” Travelers are urged to use EPA-registered insect repellents and wear protective clothing.
The virus is spread by Aedes mosquitoes which bite during the day and night, the CDC notes that “anyone who lives in or travels to an area with risk of dengue is at risk for infection.”
