For Immediate Release - September 20, 2013

State Health Officials Announce Additional Horse Cases of Mosquito Borne Illness in Massachusetts

Residents urged to take precautions against mosquito bites until first hard frost

BOSTON — The Massachusetts Department of Public Health (DPH) today confirmed another case of Eastern Equine Encephalitis (EEE) in a horse, stabled in Middleborough in Plymouth County. As a result of this finding, the EEE threat level has been raised to “Critical” in Middleborough. The adjacent town of Plympton is being moved to “High” risk. All other surrounding towns are currently at moderate risk and will remain there. DPH urges communities designated as “High” and “Critical” to cancel evening outdoor events for the remainder of the mosquito season.

DPH also confirmed the first case of West Nile Virus (WNV) in a horse this year, in an animal which was stabled in Dartmouth. The town is already considered to be at moderate risk for WNV so no additional risk changes are needed.

“Infected mosquitoes continue to be present in our environment and will be around until the first hard frost. Everyone needs to continue to take precautions to avoid getting bitten,” said DPH State Public Health Veterinarian Dr. Catherine Brown. “With cooler nighttime temperatures, mosquitoes tend to be less active. But the next few days in particular are still warm enough for them to be out looking for food during the dusk to dawn hours, and humans are a source of food for them.”

There have been three human cases of WNV and one human case of EEE so far this year. This is the fourth case of EEE in a horse this year. EEE is usually spread to humans through the bite of an infected mosquito. EEE is a serious disease in all ages and can even cause death. While WNV can infect people of all ages, people over the age of 50 are at higher risk for severe disease. WNV is usually transmitted to humans through the bite of an infected mosquito. Most people infected with WNV will have no symptoms. When present, WNV symptoms tend to include fever and flu-like illness. In rare cases, more severe illness can occur.

People have an important role to play in protecting themselves and their loved ones from illnesses caused by mosquitoes.

Avoid Mosquito Bites

  • Apply Insect Repellent when Outdoors. Use a repellent with DEET (N, N-diethyl-m-toluamide), permethrin, picaridin (KBR 3023), oil of lemon eucalyptus [p-methane 3, 8-diol (PMD)] or IR3535 according to the instructions on the product label. DEET products should not be used on infants under two months of age and should be used in concentrations of 30% or less on older children. Oil of lemon eucalyptus should not be used on children under three years of age.
  • Be Aware of Peak Mosquito Hours. The hours from dusk to dawn are peak biting times for many mosquitoes. Consider rescheduling outdoor activities that occur during evening or early morning
  • Clothing Can Help Reduce Mosquito Bites. Wearing long-sleeves, long pants and socks when outdoors will help keep mosquitoes away from your skin.

Mosquito-Proof Your Home

  • Drain Standing Water. Mosquitoes lay their eggs in standing water. Limit the number of places around your home for mosquitoes to breed by either draining or discarding items that hold water. Check rain gutters and drains. Empty any unused flowerpots and wading pools, and change water in birdbaths frequently.
  • Install or Repair Screens. Keep mosquitoes outside by having tightly-fitting screens on all of your windows and doors.

Protect Your Animals

Animal owners should reduce potential mosquito breeding sites on their property by eliminating standing water from containers such as buckets, tires, and wading pools – especially after heavy rains. Water troughs provide excellent mosquito breeding habitats and should be flushed out at least once a week during the summer months to reduce mosquitoes near paddock areas. Horse owners should keep horses in indoor stalls at night to reduce their risk of exposure to mosquitoes. If an animal is diagnosed with WNV or EEE, owners are required to report to Department of Agriculture (DAR), Division of Animal Health by calling 617-626-1795 and to the Department of Public Health (DPH) by calling 617-983-6800.

More information, including all WNV and EEE positive results from 2013, can be found on the Arbovirus Surveillance Information web page at www.mass.gov/dph/mosquito or by calling the DPH Epidemiology Program at 617-983-6800.

DPH has produced a series of 30-second videos on how to prevent mosquito and tick bites and the illnesses that can result. All videos can be found at www.mass.gov/MosquitoesAndTicks. Media outlets are encouraged to share these videos on their websites. Instructions on how to embed the videos into external websites are included on this webpage.

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