During the U.S. Virgin Islands’ first dengue outbreak in about a decade, doctors waited one to two months for lab results because no local testing existed and every sample had to be shipped off the islands. The finding comes from a report by the Centers for Disease Control and Prevention published Oct. 15 in the Morbidity and Mortality Weekly Report.
Once the territory began running dengue tests at its own public health laboratory in October 2024, results came back in less than a week. The outbreak, which ran from January 2024 to June 2025, included 263 confirmed cases and the territory’s first confirmed dengue-related death since 2005.
The lesson reaches beyond the Caribbean. When a test takes weeks, a feverish patient has usually recovered or worsened long before the answer arrives, and health officials lose the ability to see where the virus is spreading. That matters on the mainland, too, where Florida is now dealing with its own wave of locally acquired cases.
A Two-Month Wait for Answers
CDC and the Virgin Islands Department of Health found two major barriers during an assessment in August and September 2024. Many clinicians had seen few suspected dengue patients in the previous decade and said they needed training on diagnosis, testing, and reporting. In addition, the territory had no local diagnostic testing for dengue.
Without fast results, case counts tell only part of the story. In August 2024, Chief Medical Officer Dr. Tai Hunte-Ceasar warned that many residents were not seeking care or testing. “Our true dengue burden is unknown,” she said at a Government House press briefing, the VI Consortium reported.
The confirmed cases were spread across the three main islands, with 118 on St. Croix, 105 on St. Thomas, and 40 on St. John. Nearly all patients, 97%, had not traveled in the two weeks before symptoms began, meaning the virus was spreading locally. Fifteen people were hospitalized, staying an average of 4.3 days.
The patient who died was a 63-year-old woman with diabetes. Of the 105 cases with a known virus type, 101 were dengue type 2. Three of the four type 3 cases involved people who had recently traveled to Puerto Rico, a reminder that short trips can move new strains between islands.
Inside the Territory’s Fix
The response went beyond the lab. Health officials visited 30 clinics, held 20 clinical trainings in fall 2024, and launched a dengue telephone hotline for medical providers in October 2024. They also rolled out a web-based electronic reporting system so cases could reach the health department faster.
Mosquito control teams, working with CDC and the Puerto Rico Vector Control Unit, went door to door in 25 communities. They inspected 256 yards for mosquito breeding sites, applied outdoor larvicide at 167 homes, and handed out roughly 900 passive repellent devices that slowly release insecticide indoors. Outreach reached 420 households and 54 schools.
The CDC authors stressed that these gains need upkeep. “Maintaining capacity for dengue case management, surveillance, and vector control is imperative,” they wrote, to allow quick responses to future outbreaks. The report adds that keeping lab testing, surveillance, mosquito control, and staff training in place between outbreaks can strengthen preparedness for the next one.
Local Spread in Tampa Bay Shows the Mainland Risk
Dengue is not limited to U.S. territories. Florida had reported 368 locally acquired dengue cases in 2026 as of Oct. 10, according to the Florida Department of Health’s weekly arbovirus report. Of those, 310 were linked to exposure in Hillsborough County and 37 to Pinellas County. The state had also logged 288 travel-associated cases, including 182 reported in Miami-Dade County.
Nationally, CDC data updated Sept. 23 counted 2,008 cases across 40 states and territories this year, including 916 in Puerto Rico, WWSB reported. CDC describes those figures as provisional. MedicalDaily previously reported that U.S. dengue cases had passed 500 earlier in 2026 as the Aedes aegypti mosquito expands its range.
About 1 in 4 people infected with dengue get sick, and about 1 in 20 people who get sick develop severe dengue, according to CDC’s dengue symptoms guidance. Symptoms typically start 5 to 7 days after a bite, though the range is 3 to 10 days, and can include fever, nausea, vomiting, rash, and pain behind the eyes or in the muscles, joints, or bones.
Warning signs usually begin 24 to 48 hours after the fever goes away. Belly pain or tenderness, vomiting at least three times in 24 hours, bleeding from the nose or gums, vomiting blood, blood in the stool, or feeling extremely tired or restless need immediate care at a clinic or emergency room. CDC advises people with suspected dengue to take acetaminophen for fever and pain and to avoid aspirin and ibuprofen.
Residents and travelers can lower their risk by using EPA-registered insect repellent, wearing long sleeves, and emptying containers that hold water around the home. Anyone who develops a fever after visiting Puerto Rico, the Virgin Islands, or another area with dengue should tell a clinician about the trip and ask about testing.
Key Questions Answered
What did the CDC report find? The U.S. Virgin Islands had 263 confirmed dengue cases from January 2024 to June 2025, and test results took one to two months before local lab testing began.
How fast are results now? After testing started at the Territorial Public Health Laboratory in October 2024, turnaround time dropped to less than a week.
What should someone with suspected dengue take for pain? CDC recommends acetaminophen for fever and pain. People should avoid aspirin and ibuprofen and see a health care provider.
What symptoms should people watch for? Fever with nausea, vomiting, rash, or aches. Belly pain, repeated vomiting, bleeding, or extreme tiredness after the fever fades need immediate care.
Is dengue spreading in the mainland U.S.? Yes. Florida has reported 368 locally acquired cases in 2026 as of Oct. 10, most of them linked to Hillsborough County.
How can families protect themselves? Use insect repellent, cover skin, remove standing water, and tell a doctor about recent travel if a fever develops.
Published by Medicaldaily.com