Dengue fever cases have been rising among U.S. travelers and are expected to climb this year, according to a warning from the Centers for Disease Control and Prevention (CDC).
A “record number” of dengue fever cases were identified among U.S. travelers last year — a total of 3,484, an 84 percent increase compared to the year before.
“This trend is expected to continue with increased dengue activity in endemic areas in 2025,” the warning from the CDC reads.
Dengue activity remains high in some parts of the United States and around the world, and transmission of the disease remains high in the Americas and the U.S. territories of Puerto Rico and the U.S. Virgin Islands.
Dengue is more easily spread during the warmer months, placing spring and summer travelers at an increased risk of contracting the disease.
Cases of the virus have increased during the past five years, particularly in the Americas, according to the World Health Organization (WHO).
There were 7.6 million cases of the virus reported to the WHO in 2024 alone, including 3.4 million confirmed cases, more than 16,000 severe cases and more than 3,000 deaths from the virus.
In Puerto Rico, dengue fever cases have been above the outbreak threshold since February of last year. A public health emergency was declared in March 2024 and remains in effect.
The island reported 6,291 cases of dengue in 2024, with more than 52 percent requiring hospitalization and 13 resulting in death, according to the CDC.
A dengue outbreak also was declared in August 2024 on the U.S. Virgin Islands and remains in effect.
A total of 208 cases were identified in 2024 and 30 in 2025 as of early March. The highest numbers of travel-associated dengue cases in 2024 were reported in Florida, California and New York, according to the CDC.
