The V.I. Department of Health’s Epidemiology Division says 2025 brought the territory’s highest influenza case count in the past five years. Photo: Internet Source

The annual report also details new reporting requirements for several health conditions, the launch of an online food and water illness complaint portal, and growing use of wastewater monitoring to track both respiratory disease and substance-use trends.

In its summary of nationally notifiable diseases handled by the Epidemiology Division in 2025, the report lists 378 laboratory-confirmed influenza cases, 140 confirmed COVID-19 cases, 47 confirmed dengue cases, 9 confirmed and 3 probable cases of elevated lead in blood, 4 confirmed and 1 probable case of legionellosis, 3 confirmed cases each of campylobacteriosis and giardiasis, 7 confirmed cases of salmonellosis, 1 confirmed case each of shigellosis and vibriosis, 3 probable cases of varicella, 2 probable acute hepatitis B cases, 9 confirmed or probable chronic hepatitis B cases, 2 confirmed acute hepatitis C cases, 8 confirmed chronic or resolved hepatitis C cases, and 1 confirmed Lyme disease case tied to off-island exposure. The report excludes cases under the Communicable Diseases Division for sexually transmitted infections, HIV, and tuberculosis or latent tuberculosis infection.

Respiratory illness

Respiratory disease surveillance remained a central part of the division’s work. The report says influenza-like illness surveillance identified 766 visits among 47,869 total outpatient visits, or 1.6 per cent of all visits. 

The report also details a territory-wide outbreak of hand, foot, and mouth disease between February and April 2025. According to the report, 247 cases were identified.

Dengue remained under close watch following the territory’s 2024 outbreak. The report states that there were no active cases of Zika, chikungunya, or yellow fever in the territory in 2025, and that dengue trends steadily declined after the 2024 outbreak.

Lead & legionella 

Lead exposure surveillance was expanded in 2025, with “Lead in Blood” officially added as a Category A notifiable condition requiring immediate reporting of elevated blood lead levels. The report documents nine confirmed, three probable, and three suspect cases of elevated blood lead. 

Legionellosis investigations also continued throughout the year. The report says the division investigated 10 suspected cases in 2025, identifying four as confirmed and one as probable. 

Water surveillance

Wastewater surveillance also expanded as a public health tool. Working with the Virgin Islands Waste Management Authority, the department collected weekly wastewater samples from five sites across St. Croix, St. Thomas, and St. John for respiratory disease and substance surveillance. According to the report, 204 samples tested from October 2023 through December 2024 detected cocaine, benzoylecgonine, and a nicotine metabolite in almost every sample. Fentanyl and norfentanyl were detected less frequently, and xylazine biomarkers were not detected during the study period. 

Beyond surveillance and case tracking, the report points to workforce and systems development efforts, including the territory’s participation in the Council of State and Territorial Epidemiologists Data Science Team Training Program, a CDC Foundation site visit tied to workforce acceleration, and updates to the public epidemiology dashboard launched in 2024.