The Vermont Department of Health has confirmed the year’s first case of human illness due to West Nile virus. The Windsor County resident became ill in mid-June, and was diagnosed with West Nile neuroinvasive disease, a more serious form of the illness that affects the nervous system.


West Nile virus is spread through the bite of an infected mosquito. Mosquitos that carry West Nile virus can be found throughout the state. The Vermont Agency of Agriculture, Food & Markets began conducting mosquito surveillance throughout the state in June. So far this season no mosquito pools have tested positive for West Nile virus or Eastern Equine Encephalitis.

While most people who are infected do not become ill, about 20 percent develop symptoms including high fever, muscle aches, headache and fatigue. Fewer than 1 percent who are infected develop the more severe illness that affects the nervous system and can be fatal. When the nervous system is involved, symptoms may include disorientation, coma, tremors, seizures, or paralysis.

There have been nine human cases of West Nile virus reported in Vermont since 2003. This newest case is the first since 2013. Health officials said the risk of illness is typically highest in late summer, so seeing a case this early in the season is unusual.

“This case is notable because of how early it occurred in the summer,” said Bradley Tompkins, infectious disease epidemiologist. “It is important for people to take steps now to protect themselves from getting a mosquito bite.”

What you can do to avoid mosquito bites:

  • Limit your time outside from dusk to dawn when mosquitoes are most active.
  • Wear long sleeves and long pants when outdoors while mosquitoes are biting.
  • Use EPA-registered insect repellents that are labeled as effective against mosquitoes. Use repellents that contain no more than 30 percent DEET for adults and children. Do not use DEET on infants younger than 2 months of age. Repellants with picaridin and lemon eucalyptus are also effective.
  • Get rid of standing water, and drain areas where water can pool: rain gutters, wading pools, old tires, etc. This is where mosquitoes breed.
  • Install or repair screens on windows and doors to keep mosquitoes out.