The Centers for Disease Control and Prevention (CDC) has issued a travel advisory for Mexico and 19 other countries due to a surge in dengue fever cases. Updated in May 2025, the alert urges travelers to take extra precautions in regions where the mosquito-borne virus is spreading rapidly. Health officials reported over 13 million dengue cases across North, Central, and South America, as well as the Caribbean in 2024.

Dengue transmission remains dangerously high in 2025. The CDC warns that travelers returning from affected areas risk bringing the virus back to the U.S., where Aedes mosquitoes, the main dengue carriers, live in several states. Experts stress that dengue is now a year-round threat in many parts of the world, with large outbreaks happening every 2 to 5 years.

Countries On The CDC Dengue Fever Warning List

Mexico is among the 20 countries with widespread dengue outbreaks. Others include Brazil, Colombia, Comoros, Cuba, Ecuador (including the Galápagos), Fiji, French Polynesia, Guadeloupe, Guatemala, Iran, Pakistan, Panama, the Philippines, Saint Lucia, Samoa, Sudan, and Tonga. Risk levels in Mexico vary by region.

Some areas report constant or frequent transmission, while others see only occasional cases. Dengue fever, or “breakbone fever,” can cause intense joint and muscle pain. Four related viruses cause the illness, all spread by bites from infected Aedes mosquitoes. Symptoms range from mild fever to severe illness. The most dangerous cases occur when a person infected with one strain is later infected by another. This can lead to severe dengue, including internal bleeding and dengue shock syndrome.

How To Stay Safe While Traveling

The CDC advises travelers to take strong precautions against mosquito bites. Use EPA-approved insect repellent; wear long sleeves and pants; and choose hotels with air conditioning or screened windows. Aedes mosquitoes bite during the day — especially in the morning and late afternoon — so protection is needed all day.