A Newport County resident in their 60s is one of two new probable human cases of West Nile Virus (WNV) announced by Rhode Island health officials. The other case involves a Providence County resident in their 50s.
These new cases bring the state’s total WNV count to six for the season, with three confirmed and three probable cases.
The Rhode Island Department of Environmental Management (DEM) and Rhode Island Department of Health (RIDOH) are reminding the public that it’s a particularly active mosquito season in Southern New England. Recent human cases of both Eastern Equine Encephalitis (EEE) virus and WNV indicate a high risk level statewide.
“Our fibers, food, and medications would not exist without pollinators. So we need to protect them,” said a health official, emphasizing the importance of mosquito control measures.
Despite the new cases, the most recent mosquito samples tested by the Rhode Island State Health Laboratories have not shown positive findings of EEE virus or WNV. These results come from 72 samples collected from 28 traps set statewide by DEM on Sept. 23, 24, and 25.
Due to the high risk level, RIDOH and DEM are urging schools and organizations to consider rescheduling outdoor activities scheduled during early morning or dusk hours. These are peak times for mosquito activity.
While adult mosquitoes are not killed until a hard frost, they become less active at temperatures below 58 degrees and largely inactive below 50 degrees.
Health officials stress the importance of taking precautions to limit exposure to mosquitoes and prevent bites. This includes using EPA-approved insect repellent and wearing long sleeves and pants when outdoors.
Previously this season, Rhode Island has reported 18 EEE virus findings in mosquito samples, 14 WNV findings, one confirmed human case of EEE virus, and three confirmed human cases of WNV.
Neighboring states have also reported significant mosquito activity. Connecticut has announced 66 EEE virus findings and 308 WNV findings, while Massachusetts has reported 333 WNV findings and 96 EEE findings.
On Aug. 29-30, DEM conducted an aerial application of mosquito larvicide across 3,000 acres of Chapman Swamp in Westerly and Great Swamp in South Kingstown to reduce mosquito populations and related disease risk.
Although extremely rare in humans, EEE virus is very serious and has a much higher human mortality rate than WNV. Approximately 30% of people with EEE virus die, and many survivors have ongoing neurological problems.
WNV is more prevalent in Rhode Island every year. Most people infected with WNV do not feel sick, but about one in five develop a fever and other symptoms. About one out of 150 infected people develop a serious, sometimes fatal, illness.
Residents can help control mosquitoes by removing backyard breeding grounds. The Asian Tiger Mosquito, a daytime biter common in Rhode Island urban environments, develops from eggs laid in artificial containers.
Health officials advise removing standing water from containers such as buckets, pots, wheelbarrows, boats, and pools. Clogged rain gutters and puddles formed on tarps can also support the larvae of this species.
Additional protective measures include:
- Putting screens on windows and doors
- Using EPA-approved bug spray with active ingredients like DEET, picaridin, IR3535, or oil of lemon eucalyptus
- Putting mosquito netting over playpens and baby carriages
- Cleaning and changing water in birdbaths at least once a week
Horse owners are advised to vaccinate their animals early in the season and take precautions such as avoiding putting animals outside during peak mosquito hours and insect-proofing facilities where possible.
For more information on mosquito prevention and local data, residents can visit health.ri.gov/mosquito. DEM will continue to trap and test mosquitoes weekly until the first hard frost of the season, typically occurring in mid-October.
