West Nile virus detected in Vermont mosquitoes, health department reports

A sample of mosquitoes collected in Alburgh tested positive for the West Nile virus, a virus that can cause severe illness in humans, the Vermont Department of Health reported Monday.

The sample was the first of nearly 1,000 taken so far this year that tested positive for the virus. 

There have been 14 human cases of the virus in Vermont since 2003 and none so far this year, the department said. The most recent confirmed human case was in 2021.

West Nile virus is spread through bites from an infected mosquito. Typical symptoms include fever, headaches and other flu-like symptoms, but in rare instances the virus can cause more severe complications, such as encephalitis. It is particularly dangerous for people 50 years and older.

Over 50 human cases have been reported nationally so far this year, according to the U.S. Centers for Disease Control and Prevention. The disease is most prevalent in southern and midwestern states.

“West Nile virus has been circulating throughout Vermont for years now, and we expect to find positive pools each season,” State Epidemiologist Patsy Kelso said in a press release. “We have been fortunate that not many people have developed serious illness.”

The department advised that Vermonters take steps to prevent getting bitten by mosquitoes, which include wearing long-sleeved clothing, using effective insect repellent and getting rid of standing water near your home. The department has more tips on avoiding mosquito bites on its website.

No vaccine for the West Nile virus is available for humans, but the health department encouraged Vermont horse owners to vaccinate their animals. A horse died of West Nile virus in Vermont in 2018.

— Erin Petenko