The U.S. Virgin Islands and Puerto Rico remain in the grip of active dengue virus (DENV) outbreaks, prompting renewed public health warnings from the Centers for Disease Control and Prevention as the United States braces for a potentially severe dengue season.
In a Health Alert Network (HAN) update issued a few days ago, the CDC reported sustained dengue activity in the Americas and rising case numbers across multiple regions. The warning includes updated testing recommendations and prevention guidelines for healthcare providers, health departments, and the general public.
Outbreak Status in the USVI and Puerto Rico
In Puerto Rico, health officials have reported 936 dengue cases as of March 7, 2025—more than double the number during the same period in 2024, marking a 113% year-over-year increase. The island remains under a public health emergency first declared in March 2024. Last year, 6,291 dengue cases were reported in Puerto Rico, 52% of which required hospitalization, with 13 fatalities.
The U.S. Virgin Islands declared its own dengue outbreak in August 2024. By year’s end, 208 locally acquired cases were confirmed. So far in 2025, the territory has reported 30 additional cases.
Dengue activity remains high throughout the Americas, with over 13 million cases and 8,200 deaths recorded in 2024 alone. That number followed 4.6 million cases and 2,400 deaths reported in 2023. As of March 6, 2025, more than 760,000 cases have already been reported—representing a 15% increase over the five-year average. DENV-3 has re-emerged across multiple countries, while DENV-4, which had been less common, now accounts for half of recent travel-associated U.S. cases.
The surge in global travel coinciding with peak dengue season is contributing to both imported and locally transmitted infections in the continental U.S., with Florida, California, and Texas reporting a combined 110 locally acquired cases in 2024. Travel-associated infections spiked to 3,483 that year—an 84% increase over the previous year—with Florida (1,016), California (648), and New York (327) reporting the highest numbers.
The CDC is urging healthcare professionals to maintain heightened suspicion for dengue in patients with fever who recently traveled to areas with ongoing dengue transmission.
The CDC continues to emphasize mosquito bite prevention as a first line of defense against dengue and other vector-borne illnesses. Travelers to areas with ongoing transmission—including the Caribbean, Central America, and parts of South America—should use insect repellent, wear long sleeves and pants, and stay in places with air conditioning or screened windows. Upon return, travelers should continue bite prevention measures for three weeks to reduce the risk of local spread.
The CDC also warns that repeat infections with different dengue serotypes can lead to more severe illness, especially among vulnerable groups such as infants, pregnant women, seniors, and those with chronic health conditions.
