The Centers for Disease Control and Prevention issued a Level 1 travel advisory Friday warning that higher-than-expected rates of dengue fever have been identified among U.S. travelers returning from 16 countries. The advisory covers Afghanistan, Bangladesh, Bolivia, Colombia, Cook Islands, Cuba, Guyana, Maldives, Mali, Mauritania, New Caledonia, Pakistan, Samoa, Sudan, Timor-Leste, and Vietnam. More than 525 dengue cases have been reported in the United States in 2026 so far, according to the CDC. Fox News covered the advisory as a spring break health warning; local television affiliates and public health outlets confirmed the 16-country list and case count.

Dengue fever is a mosquito-borne viral illness spread by Aedes mosquitoes active year-round in tropical and subtropical climates. Symptoms typically appear within two weeks of infection and include high fever, severe headache, pain behind the eyes, muscle and joint pain, nausea, vomiting, and rash. The CDC notes that roughly 1 in 20 people who contract dengue will develop severe dengue, characterized by abdominal pain, persistent vomiting, rapid breathing, bleeding gums, or blood in vomit — symptoms that require immediate medical attention. Approximately 20,000 people die from dengue globally each year.

The Level 1 designation — Practice Usual Precautions — is the CDC's lowest travel advisory tier, intended to raise awareness rather than discourage travel. The advisory urges travelers to use EPA-registered insect repellents containing DEET, picaridin, or oil of lemon eucalyptus; wear long-sleeved shirts and pants; stay in air-conditioned or well-screened accommodations; and eliminate standing water that serves as mosquito breeding habitat. A dengue vaccine exists but is currently approved only for U.S. children ages 9-16 who have had a confirmed prior dengue infection and live in an endemic area.

The timing of the advisory — during spring break, when millions of Americans travel to tropical destinations — made the alert particularly notable. Many of the 16 countries, including Colombia, Cuba, and Guyana, are popular American tourist destinations. Fox News framed the alert as a practical spring break safety guide. Public health advocates noted that dengue is one of several mosquito-borne illnesses — including Zika and chikungunya — that travelers to these regions should be aware of. Both right- and left-leaning health coverage agreed the CDC advisory represents factual public health guidance consistent with elevated case trends.