The Rhode Island Department of Health confirmed Tuesday that two more Rhode Island residents have been diagnosed with Eastern Equine Encephalitis, a rare but potentially fatal mosquito-borne disease.
These diagnoses bring the state’s total number of human cases this year to three. A West Warwick resident diagnosed with the virus died Sept. 8, which marked the first EEE fatality in the state since 2007, according to a Rhode Island government press release. A child younger than ten years old from Coventry, R.I. and a person in their 50s from Charlestown, R.I. were also diagnosed with the illness.
Before this year, only one person had been diagnosed with EEE in Rhode Island since 2010.
According to the Centers for Disease Control, the virus can either result in a systemic or encephalitic illness; while people can recover from the former in one to two weeks, approximately a third of those who experience encephalitic symptoms — swelling of the brain — die, and many who survive continue to have neurological problems.
Though an individual’s chance of contracting EEE is small, “when it does happen people can become very, very ill,” wrote Vanessa Britto, executive director of Health and Wellness at the University, in an email to The Herald. “Because the risk is not nonexistent we want everyone to be smart about protecting themselves as much as possible.”
On average, there are “about seven cases per year nationwide” of EEE, said Howard Ginsberg, an insect ecologist who sits on the Rhode Island Mosquito Advisory Board. “This year, we’re already above that,” he added, with cases also reported in Michigan, Massachusetts and Connecticut.
EEE is initially transmitted to birds by mosquitoes that do not bite humans. The infected birds are then bitten by another type of mosquito that feeds on both birds and other mammals, potentially passing along the disease to people, Ginsberg said. He added that “areas near swamps are a special risk,” as mosquitoes primarily reside there.
In response to this uptick, RIDOH has treated higher-risk areas with a low concentration of the aerial pesticide spray Anvil 10+10, aimed at killing adult mosquitoes, according to a Rhode Island government press release. The aerial pesticide should not be a cause for human health concerns, Britto wrote, adding that it has been “used for decades worldwide and is highly effective against adult mosquitoes.” The pesticide is not absorbed well through the skin and breaks down “fairly quickly” in sunlight, she added.
To date, RIDOH has treated four “critical risk areas,” covering parts of 21 communities with the aerial pesticide spray. RIDOH also conducted a “larviciding” campaign in at-risk areas using a bacterium called Bti. Bti “produces toxins that specifically affect the larvae of only mosquitoes, black flies and fungus gnats,” according to a RIDOH press release posted Sept. 4.
For precautionary measures, Britto, Ginsberg and RIDOH all recommend limiting time outdoors at dusk, since that is when most of the mosquito species that transmit EEE are active. “You just want to minimize your exposure,” Ginsberg said. People should limit their outdoor activity at those hours“for the remainder of the mosquito season, which typically ends in mid-October (after the first hard frost),” according to the RIDOH press release.
Students can also wear long-sleeved shirts and pants, ensure window screens are intact and use insect repellent when outdoors to limit exposure, Britto wrote.
Arden Orwicz ’21 said that she is “concerned” about EEE, “but maybe not concerned enough to act that much.” Orwicz first heard about the illness from a news report in her home state of Connecticut, but said that at the University, she feels “like no one knows about it, which is kind of scary.”
The Department of Environmental Management and RIDOH are “considering the next steps” to combat EEE, which include the possibility of additional aerial spraying in the state, according to a state press release.
