West Nile Virus Detected in Addison County Mosquito Pool

Jul 22, 2013

A mosquito carrying West Nile virus was among those caught in a trap in Leicester earlier this month. This is the first time the virus has been detected in Vermont in 2013.

The Vermont Agency of Agriculture, Food & Markets has been trapping mosquitoes in southern Addison and northern Rutland Counties since the middle of June. The infected mosquito was found in a trap on July 10. The Eastern Equine Encephalitis virus, also known as EEE, has not been detected so far this year.

“Although West Nile virus tends to be less severe than Eastern equine encephalitis, it can still cause significant illness,” said Erica Berl, an epidemiologist for the Health Department.

West Nile virus and EEE are spread through the bite of an infected mosquito. Three people in Vermont became ill with West Nile Virus in 2012, and two people died after becoming infected with EEE.

The State of Vermont has increased Mosquito surveillance this summer in response to last year's two fatal human cases of Eastern Equine Encephalitis, according to a press release from the Vermont Department of Health. The State has not announced any plans for insecticide spraying.

A total of 110 batches of mosquitoes have been tested for both viruses so far this year. Limited trapping and testing is also being done in Franklin County.

The state will also help arrange testing for people or horses with symptoms consistent with a West Nile virus infection.

There is a West Nile virus vaccine for horses, but a vaccine has yet to be developed for humans.

Symptoms of West Nile virus are often mild, but can include high fever, muscle aches, headache and fatigue. Approximately 1 percent of people who are infected develop severe illness affecting the central nervous system, which can be fatal.

According to the Vermont Department of Health, since Vermont’s first human case of West Nile virus was reported in 2002 the virus has been detected in mosquito pools in every county in the state.

The Health Department recommends the following precautions to avoid mosquito bites:

  • Wear long sleeves and pants and avoid outdoor activities at dusk and dawn when mosquitoes are active.
  • Reduce mosquito breeding habitats by getting rid of standing water, and by draining areas where water can pool such as rain gutters, wading pools, and old tires.
  • Use insect repellents that are safe and effective against mosquitoes. Products with a registration number from the Environmental Protection Agency on the label have been evaluated for safety and effectiveness. Repellents containing DEET in concentrations up to 30%, picaridin, oil of lemon eucalyptus, or IR3535 can be used to prevent mosquito bites.
  • Install or repair screens on windows and doors to keep mosquitoes out.