To date this year, the EEE virus has been found in 65 mosquito samples and WNV in 87 mosquito samples, including in species of mosquitoes capable of spreading the virus to people.
Last year, the Commonwealth experienced its most active EEE season since 1956, with 12 human cases and 6 deaths. EEE is a rare but serious disease caused by a virus that can affect people of all ages. EEE is generally spread to humans through the bite of a mosquito infected with the virus. EEE can cause severe illness and possibly lead to death in any age group; however, people under age 15 are at particular risk. EEE does not occur every year, but based on mosquito sampling, a high risk of occurrence of human cases currently exists in MA. The majority of people who are infected with WNV (approximately 80%) will have no symptoms.
Less than 1% of people infected with WNV will develop severe illness, including encephalitis or meningitis. Persons older than 50 years of age have a higher risk of developing severe illness from WNV.
In Middlesex County, Pepperell still remains the only location where a EEE positive mosquito was detected on July 29th. In Middlesex County, WNV positive mosquitoes have been detected in Arlington, Belmont, Everett, Malden, Medford, Newton, Wakefield, and Watertown. Based on where the WNV positive cases live and visited prior to diagnosis, MDPH recently raised the WNV risk level to Moderate for the following communities: Concord, Lexington, Lincoln, Sudbury, Waltham, Wayland, Weston, Winchester, Dighton, Fall River, and Swansea. MDPH has raised the WNV risk level to HIGH for the following communities: Cambridge, Newton, Somerville, and Watertown.
No EEE or WNV positive mosquitoes have been detected in Bedford to date, as such, Bedford is currently designated as a low-risk community for EEE and WNV transmission.
EEE positive mosquitoes were trapped in Bedford last season, generating an elevated EEE risk level and, as of September 7, 2019, implementation of restrictions on outdoor activities between dusk and dawn as part of a town-wide disease prevention strategy. There were no human cases of EEE in Bedford last year.
Mosquito Control in Bedford
The Bedford Board of Health (BOH) continues to work with the MDPH and the Eastern Middlesex Mosquito Control Project (EMMCP) to monitor local mosquito populations for WNV and EEE. Bedford has a robust mosquito control program that includes an annual helicopter application of biological larvicide to wetland areas in town by EMMCP and each summer the Bedford DPW treats catch basins in town. Additionally, based on acquired surveillance data from five mosquito trap locations in town, the EMMCP will conduct truck-mounted spraying events in Bedford to reduce populations of biting adult mosquitoes. EMMCP will continue to trap and test mosquitos in and around Bedford until the end of September.
Reduce Your Risk for Mosquito Bites
Residents have an important role to play in reducing the risk of WNV and EEE and protecting themselves and their loved ones by taking a few, common-sense precautions. The best protection is prevention.
- Mosquito proof your property – Limit the number of places around your home for mosquitoes to develop 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 the water in birdbaths frequently. Install or Repair Screens – Some mosquitoes like to come indoors. Keep them outside by having tightly-fitting screens on all windows and doors.
- 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 the evening or early morning. Otherwise, take extra care to use repellent and protective clothing.
- 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.
- 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 the skin.
Information about mosquito activity in Massachusetts during 2020 can be found on the Mosquito-borne Disease page on the MDPH website at https://www.mass.gov/mosquito-borne-diseases. Facts sheets on WNV, EEE, and other mosquito-related materials are available by contacting the Bedford BOH at 781-275-6507 or by accessing the Board of Health website at http://www.bedfordma.gov/health.