For the first time in 2023, mosquitoes in Vermont have tested positive for West Nile virus. The disease was detected through an interagency surveillance effort by the Agency of Agriculture, Food and Markets and the Department of Health.
The virus was found in mosquito pools from Alburgh and Vergennes, according to a health department press release issued Tuesday. The West Nile virus is typically detected in all 14 Vermont counties from June through October, but “the risk is highest in late summer and early autumn,” according to the release.
Since 2002, 17 human cases of West Nile virus have been reported in Vermont, with the last confirmed case in 2021. No cases of West Nile virus in humans or animals have been reported this year. There have been no human cases of the more deadly Eastern equine encephalitis, also transmitted through bites from infected mosquitoes, since 2012.
“Fortunately, most people infected will never have symptoms, and cases of West Nile virus have been rare in Vermont,” said Natalie Kwit, the state’s public health veterinarian. “But West Nile virus and other diseases spread by mosquitoes can be serious for some people, and there’s no vaccine or specific medicines available for West Nile virus infection.”
The virus may have symptoms such as fever, headache, body aches, joint pains, vomiting, diarrhea or rash. Particularly for people over age 60 and those with certain medical conditions, the virus can pose a risk for more serious illness, such as encephalitis — inflammation of the brain.
“The best protection is to take simple measures to protect yourself and family from mosquito bites,” which is how the virus is transmitted, said Kwit. She advised people to contact their health provider if they feel unwell.
The health department recommends that Vermont residents wear long-sleeved shirts and long pants outdoors; limit time outside at dawn and dusk, when mosquitoes are most likely to bite; and use an effective insect repellent. They can consult a repellent finder tool provided by the Environmental Protection Agency.
The department also suggests clearing any standing water from gutters, tires or play pools; covering strollers and outdoor playpens with mosquito netting; and fixing holes in screens and ensuring they are fixed to doors and windows properly.
Horse owners should ensure their animals are up to date on vaccinations for the West Nile virus and other diseases transmitted by infected insects or ticks, the department said. While horses cannot spread the virus to humans or other horses, it can be fatal to unvaccinated animals.
