Middlesex County Elevated to 'High' Risk of West Nile Virus

mosquito

The Massachusetts Department of Public Health (DPH) has announced the first animal case of West Nile virus (WNV) in the state this year. WNV infection was diagnosed in an alpaca exposed to WNV in Middlesex County.

Last week, DPH announced the first four human cases of WNV in Massachusetts this year. Boston and adjacent areas in Essex and Middlesex counties, and several towns in Bristol, Hampden, and Worcester counties are already at moderate risk for WNV.

But based on the occurrence of both animal and human cases, above-average populations of the Culex mosquitoes that carry WNV, recent rainfall, and continued weather favorable for mosquito activity, the WNV risk level is being raised in 27 communities, including Lexington, from moderate to high.

While we advise everyone to take steps to avoid mosquito bites, this is especially important if you are over the age of 50 or have an immune compromising condition.

Preventing Mosquito Bites

There are simple steps you can take to prevent mosquito bites and avoid WNV.

  • Apply Insect Repellent when you go outdoors. Use a repellent with DEET (N, N-diethyl-m-toluamide), permethrin, picaridin (KBR 3023), IR3535 or oil of lemon eucalyptus [p-methane 3, 8-diol (PMD)] 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.  Permethrin products are intended for use on items such as clothing, shoes, bed nets and camping gear and should not be applied to skin. 
  • Clothing Can Help reduce mosquito bites. Although it may be difficult to do when it’s hot, wearing long-sleeves, long pants and socks when outdoors will help keep mosquitoes away from your skin.
  • Be Aware of Peak Mosquito Hours - The hours from dusk to dawn are peak biting times for many mosquitoes. When risk is increased, consider rescheduling outdoor activities that occur during evening or early morning. If you are outdoors at any time and notice mosquitoes around you, take steps to avoid being bitten by moving indoors, covering up and/or wearing repellant.

Mosquito-Proof Your Home

  • Drain Standing Water – Many mosquitoes lay their eggs in standing water. Limit the number of places around your home for mosquitoes to breed by either draining or getting rid of 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 - Some mosquitoes like to come indoors. Keep them outside by having tightly-fitting screens on all your windows and doors.

The Lexington Office of  Public  Health will continue to work closely with MDPH and with  East Middlesex  Mosquito Control.  If there are any additional updates or   specific   actions   taken  due to  WNV in our area, the Office of Public Health will notify the residents of Lexington.

Information about WNV and reports of current and historical WNV virus activity in Massachusetts can be found on the MDPH website at www.mass.gov/dph/mosquito.