Rhode Island’s first case of West Nile Virus this year has been detected in an East Providence mosquito sample, state health officials announced Thursday.
A mosquito sample collected on July 21 as part of routine trapping work by the Rhode Island Department of Environmental Management (DEM) later tested positive for West Nile Virus at state laboratories.
According to the state’s mosquito surveillance data, the positive mosquito was Aedes albopictus, also known as the Asian tiger mosquito, which federal disease control officials classify as among the “Most (un)Wanted Mosquitoes” when it comes to spreading disease.
This is the first mosquito to test positive in Rhode Island in 2025 — comparable to the 2024 mosquito season, when the first positive sample emerged around July 15.
The other 192 mosquito samples tested — representing a total of 2,838 mosquitoes — were free of other diseases like Eastern Equine Encephalitis (EEE) or Jamestown Canyon Virus, according to the Rhode Island Department of Health.
West Nile Virus is the most common mosquito-borne disease in the country. While it tends to be asymptomatic, about one in five people develop West Nile fever, which includes symptoms like headache, body aches or other flu-like symptoms.
A small number of infections lead to neuroinvasive illness, such as encephalitis or meningitis. About 10% of these severe cases can be fatal, according to the U.S. Centers for Disease Control (CDC). Most of those fatal cases are among adults over 60 and immunocompromised people.
Preliminary CDC data for 2025 points to 53 cases of neuroinvasive West Nile nationwide, out of 98 West Nile Virus cases recorded overall.
The CDC notes, however, that the national database relies on county-level data, meaning under-reporting is common. People who don’t contract neuroinvasive illness are less likely to be reported, which can skew data to represent more severe cases.
Between 1999 and 2024, CDC recorded 60,992 West Nile Virus cases in humans, with 3,134 deaths.
Rhode Island health officials advise residents to take caution and wear insect repellent, long sleeves, and pants when outside at dusk and dawn, when mosquitoes are most active. Getting rid of standing water, which attracts mosquitoes, also limits the areas where they can breed.
Weekly mosquito testing data is available on the health department’s website, and more prevention tips and resources can be found at health.ri.gov/mosquito and dem.ri.gov/mosquito.
This story was originally published by the Rhode Island Current.
