Human Case of West Nile Virus Confirmed in Wayland

Town of Wayland, October 7, 2021

The Massachusetts Department of Public Health (MDPH) announced today a human case of West Nile virus (WNV) in Middlesex County with potential exposure in or near Wayland.  The case involves a male resident between 50 and 59 years of age.  Wayland will remain at “moderate” risk level due to this being so late in the season.

Although serious illness caused by WNV is uncommon, there have been 216 cases of WNV in Massachusetts between 2001 and 2020. There were eleven human cases of WNV in 2020 and five human cases in 2019.  In addition to the case just identified, there have been 7 other human WNV cases identified in Massachusetts this year. WNV is most commonly transmitted to humans by the bite of an infected mosquito.  The mosquitoes that carry this virus are common throughout the state and are found in urban as well as more rural areas.  While WNV can infect people of all ages, people over the age of 50 are at higher risk for severe infection.

With no sign of the first frost in the weather forecast we urge residents to take precautions to protect themselves from mosquito bites.  The risk for WNV is beginning to decline but remains until the first frost when mosquitoes die off.  As we get into mid-October there will cooler weather, less day light and less hatching of new mosquitoes.

By taking a few, common sense precautions, people can help to protect themselves and their loved ones:

Avoid Mosquito Bites

  • 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.

While the Town of Wayland continues to work closely with the MDPH and other agencies, locally we have treated our catch basins with larvicide which was completed in early June and we receive services provided by the East Middlesex Mosquito Control Project including surveillance testing of mosquitoes for diseases.  Testing mosquitoes for West Nile Virus and Eastern Equine Encephalitis was done on September 9th and all mosquitoes tested negative for mosquito-borne illness.

Information about WNV and reports of current and historical WNV virus activity in Massachusetts can be found on the MDPH website at

Julia Junghanns, R.S., C.H.O.
Director of Public Health


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