Critical Information about Mosquito-Borne Illnesses: Schools Advised to Take Action to Mitigate Risk

September 18, 2024

For more information contact: Hillary Peterson at: hillary.peterson@maine.gov

Dear IPM Coordinators,

We are writing today in partnership with the Maine Center for Disease Control and Prevention (Maine CDC), and the Maine Department of Agriculture, Conservation and Forestry (DACF), to bring to your attention that Maine is currently experiencing significantly elevated risks of mosquito-borne illness. We are strongly advising that precautions be taken to mitigate that risk.

Current Situation

In recent weeks, the Maine CDC has reported:

  • West Nile virus (WNV) in 15 wild birds and in one human
  • Eastern Equine Encephalitis (EEE) virus in 4 horses, 2 emus, 1 llama, and 1 wild turkey
  • Jamestown Canyon Virus (JCV) in 4 mosquito pools (groups of up to 50 mosquitoes regularly tested as part of routine surveillance)

Presence of these viruses in animals indicates that mosquitos in certain regions of our state do carry the viruses and therefore pose a risk to humans.

Maine CDC has identified the following counties as being high risk: Cumberland, Kennebec, Penobscot, Somerset, and Waldo counties. All other counties are at an elevated risk at this time. All three of these viruses are spread through the bite of an infected mosquito and usually start with flu-like symptoms in humans. Severe symptoms can include brain swelling (encephalitis) and spinal cord inflammation (meningitis).

EEE is a deadly virus that has an approximate mortality rate of 30 percent for those who develop severe disease and, if survived, often has serious, lifelong neurological impacts. West Nile Virus causes serious, sometimes fatal, illness in approximately one out of 150 people. For survivors, recovery may take several weeks to months, and some will have lifelong impacts. If you experience flu-like symptoms, severe headache, behavior changes, or serious drowsiness, call a health care provider, especially if a COVID-19 test is negative.

Prevention strategies are critical to keep students, staff, and families safe when participating in outdoor activities, including recess, games, practices, spectator sports, outdoor classes and field trips.

The risk for getting a mosquito-borne disease is highest from dusk to dawn and when temperatures are above 50F (especially above 60F), since this is when mosquitoes are most active. Risk from mosquito bites is expected to continue until two hard frosts kill the mosquitoes this fall/winter. The best way to prevent mosquito-borne diseases is to prevent mosquito bites.

Schools can take and/or encourage the following actions to reduce the existing risk:

  • Use repellent. Use an EPA-approved repellent containing DEET, picaridin, IR3535 (ethyl butylacetylaminopropionate), or oil of lemon eucalyptus on skin and clothing. Permethrin can also be used on clothing only and is effective through several washes.
    • School employees and volunteers must have authorization from parents/guardians to apply repellents to minor children (CMR 01-026, Chapter 10, Section 2.I.4.iii - PDF).
    • Schools that schedule practices or other after-school activities at dusk/evening should encourage the use of EPA-approved repellents for all participants. This includes students, coaches, and observers.
  • Wear protective clothing. Children and others at outdoor after-school activities, practices, or outdoor field trips should be encouraged to wear protective clothing that covers skin. This includes long-sleeved shirts, pants, and socks.
  • Identify any stagnant water sources and drain them. Items such as tires, buckets, rain gutters, pools, tarps, play equipment, overturned traffic cones present opportunities for mosquito breeding habitat. Seek out those sources around the school and any other outdoor venues used by students or staff, and dry out those potential mosquito habitats. Prevent these sources from refilling by removing items, drilling holes, etc.
  • Check all windows for intact and tight-fitting screens. Patch any holes in screens, as necessary.

As an IPM Coordinator: Expect folks to be reaching out to you as the Integrated Pest Management (IPM) coordinator about strategies to improve safety of school grounds and reviewing your IPM policy. Maine's School IPM Program is expected to help identify strategies schools can use to minimize mosquito-borne disease risk.

Schools in counties (Cumberland, Kennebec, Penobscot, Somerset, and Waldo) with detected mosquito-borne disease activity may also want to consider taking additional precautions around outdoor activities, such as:

  • Limiting or rescheduling evening outdoor activities when temperatures at dusk are 50F or greater.
  • Raise awareness and provide education for families in the school administrative unit about the risk, and personal protections they can take for themselves and their families.
  • Implementing your school administrative units IPM strategy.

Resources Available

The Maine DOE, the Maine CDC, and DACF will continue to monitor the situation and appreciate your help to keep the people of Maine safe.

Please feel free to reach out with any questions:

Hillary Peterson, Ph.D.
IPM Entomologist
Maine Department of Agriculture, Conservation and Forestry
28 State House Station
Augusta, ME 04333-0028
hillary.peterson@maine.gov / www.maine.gov/ipm
207-215-4793