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mosquito-2The calendar says September, but the Department of Public Health, in conjunction with the Boston Public Health Commission, has announced the 12th human case of West Nile virus in Massachusetts.   Health officials say even though it may no longer feel like summertime, it still makes sense to review precautions for avoiding mosquito bites.

“Labor Day is often considered to be the unofficial end of summer,” says DPH State Epidemiologist Dr. Catherine Brown. “But it is not the end of the mosquito season. September is still the peak of the transmission season and additional cases of WNV infection are likely to occur.

In fact, the risk from West Nile virus continues until the first hard frost. That’s why it is important to continue using insect repellents, covering exposed skin, and moving indoors when mosquitos are biting.

West Nile virus is usually transmitted to humans through the bite of an infected mosquito. While WNV can infect people of all ages, people over the age of 50 are at higher risk for severe disease. Most people infected with WNV will have no symptoms. When the virus is present, 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. Here’s how:

  • 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 mosquitos. Consider rescheduling outdoor activities that occur during evening or early morning.
  • Clothing Can Help Reduce Mosquito Bites. Wear long-sleeves, long pants, and socks when outdoors to help keep mosquitos away from your skin.
  • Drain Standing Water. Mosquitos lay their eggs in standing water. Limit the number of places around your home for mosquitos 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 the water in birdbaths frequently.
  • Install or Repair Screens.Keep mosquitos outside by having tightly-fitting screens on all of your windows and doors.

It is also important for animal owners to 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. Horse owners should keep horses in indoor stalls at night to reduce their risk of exposure to mosquitos. Pet owners should also speak with their veterinarian about mosquito repellents and vaccinations approved for use in animals.

To learn more about the West Nile virus, visit the DPH web page.

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