News Releases

September 24, 2012

Second Vermont Horse Tests Positive for Eastern Equine Encephalomyelitis (EEE)

The Vermont Agency of Agriculture, Food and Markets was notified on September 21 that a horse located in Pittsford, Vermont has tested positive for EEE. The horse began showing signs of illness on September 16 and was euthanized the next day. The horse was not vaccinated for EEE. This is the second horse that tested positive for EEE in Vermont, and this is the first time EEE virus has been detected in the town of Pittsford.

People who live in Pittsford and the surrounding communities may be at increased risk for infection and should take precautions to prevent mosquito bites. The area where this horse lives was not treated with pesticide during the aerial spray that occurred the first week in September.

EEE is a mosquito-borne, viral infection that can cause severe neurologic disease in horses, with mortality rates approaching 100 percent. Although horses are the animals most susceptible to EEE, the virus can also cause disease in other mammals such as llamas and alpacas and in emus. In animals, the onset of clinical signs is generally three to 10 days after a bite by an infected mosquito.

Mammals infected with EEE most commonly exhibit neurologic signs including ataxia or incoordination, inability to stand, limb weakness or paralysis, seizures and death, while infected emus often develop hemorrhagic diarrhea. Mammals infected with EEE generally do not transmit EEE to other animals or to people. Vermont cases of EEE in animals are required to be reported to the Office of the State Veterinarian.

“All horses in Vermont should be vaccinated for EEE, regardless of their travel frequency” stated Dr. Shelley Mehlenbacher, Vermont Assistant State Veterinarian. “Even horses that spend the majority of their time on isolated properties are susceptible, and those horses should be vaccinated. Horse owners and veterinarians should work together to develop appropriate vaccination plans.”

While vaccination is the most effective tool for preventing EEE in horses, owners may also protect their horses from infection by using an acceptable insect repellent seasonally and mechanical barriers such as fly sheets and face nets. Changing out water troughs regularly and removing other items that hold water will help to reduce mosquito breeding areas.

Because humans are also susceptible to EEE, Vermonters are encouraged to take the following actions to protect themselves from mosquito bites and risk of infection from EEE:

• Limit the amount of time spent outdoors at dawn and dusk.

• Wear long-sleeved shirts and long pants outside when mosquitoes are active.

• Use insect repellents labeled as being effective against mosquitoes.

• Remove standing water around from around your house.

“With the onset of cold weather the risk of mosquito bites is decreasing, but this recent equine case of EEE is a reminder that people need to continue to take steps to reduce their risk of exposure until there have been a few good frosts,” said Erica Berl, infectious disease epidemiologist for the Vermont Department of Health.

Source: Department of Health
Last Updated at: September 24, 2012 08:18:41