DC Battles Dengue Surge as Cases Triple Year-Over-Year

Dengue fever, a potentially life-threatening disease spread by Aedes mosquitoes, has emerged as a growing public health concern in Washington, D.C. The 2024 caseload represents a 117 percent increase from 2023, reflecting a broader national trend. Across the United States, dengue cases surged to 3,561 in 2024—an 88 percent jump from the previous year—according to the DC Department of Health's latest Health Alert Network notice issued in April 2025.

The disease, caused by one of four closely related viruses, presents with symptoms including high fever, severe headache, pain behind the eyes, joint pain, muscle and bone pain, and rash. Most infected individuals—roughly 75 percent—experience mild or no symptoms, complicating early detection and containment efforts. Severe cases can progress to dengue hemorrhagic fever, where the high fever persists for two to seven days before potentially declining into a more dangerous phase.

DC Health has issued explicit guidance to healthcare providers across the District, urging them to consider dengue fever as a diagnosis in patients with recent travel history and to utilize CDC DENV-1-4 RT-PCR assays when dengue is the primary diagnostic suspicion. Healthcare providers must report suspected or confirmed cases to DC Health within 24 hours of provisional diagnosis. The department has also emphasized the importance of testing for related illnesses—zika, chikungunya, and oropouche—which share similar symptoms and often circulate in the same geographic areas.

With warmer weather accelerating mosquito breeding season, DC Health is urging District residents to eliminate standing water in flower pots, bird baths, clogged gutters, and other areas where Aedes mosquitoes breed. The mosquitoes that transmit dengue typically thrive in areas below 6,500 feet elevation, making Washington, D.C.'s climate conducive to transmission. Public health officials stress that community action to reduce mosquito habitats, combined with heightened clinical awareness among providers, remains the District's strongest defense against further spread.