Locally Acquired Eastern Equine Encephalitis Virus Identified in Maine Resident

Sep 09, 2025

The Maine CDC urges protections against mosquito bites

AUGUSTA-- The Department of Health and Human Services' (DHHS) Maine Center for Disease Control and Prevention (Maine CDC) announced today the detection of a locally-acquired case of Eastern Equine Encephalitis virus (EEE) in a Maine resident. This is the first Maine resident to become infected with EEE this year.

The Maine resident became ill with severe symptoms in late August and remains hospitalized. The EEE results are considered presumptive positive while the Maine CDC awaits confirmation by the U.S. Centers for Disease Control and Prevention.

Particularly with heavy rains, the risk of mosquito-borne disease across the state is high. For Penobscot, Piscataquis, Somerset, and Waldo Counties, the risk for EEE is considered severe given evidence of virus prevalence and the ideal habitat for the types of mosquitoes that carry EEE. The risk for other mosquito-borne viruses remains high across the state as different species of mosquitoes can successfully breed in varied environments, including in more residential areas and areas with smaller volumes of standing water.

EEE, along with Jamestown Canyon virus (JCV) and West Nile virus (WNV), all spread through the bite of an infected mosquito. The viruses cannot spread from human to human, or between human and animal.

"Recent heavy rainfall likely means more mosquitoes in the coming days," said Maine CDC Director Dr. Puthiery Va. "Maine people know that mosquito bites are a nuisance, but a mosquito bite can also have serious consequences for your health. Whether cleaning the yard, working, or walking the dog, remember to take precautions against mosquito bites whenever you go outside."

Symptoms of EEE, JCV, and WNV include flu-like symptoms, such as fever, body aches, and headache. Some people can develop severe symptoms, such as brain swelling (encephalitis) and inflammation of the spinal cord (meningitis). In some cases, mosquito-borne diseases can lead to death. If you experience any of these symptoms, call a health care provider.

When going outside, consider taking the following steps to help protect yourself from EEE, WNV, and JCV:

To avoid mosquito bites

• Apply Insect Repellent When Outdoors. Use and EPA-approved repellent on your skin that includes DEET, IR3535, picaridin, or oil of lemon eucalyptus on skin. Also consider pre-treating clothing with permethrin.
• Be Aware of Peak Mosquito Hours. The hours between dusk and dawn are peak biting times for many mosquitoes. Consider rescheduling outdoor activities that occur during evening or early morning in areas of high or severe risk.
• Wear Clothing That Can Help Reduce Mosquito Bites. Wear loose-fitting clothing such as long sleeves, long pants, and socks outdoors to help keep mosquitoes away from your skin.

To mosquito proof your home

• Drain Standing Water. Mosquitoes lay their eggs in standing water. Limit standing water around your home by draining or discarding items that hold water. Check rain gutters and drains. Empty water-collecting vessels such as unused flowerpots and wading pools. Change the water in birdbaths and pet bowls at least once per week.
• Install or Repair Screens. Keep mosquitoes outside with tightly fitting screens on all windows and doors.

Protect Your Animals

Some domestic animals are very sensitive to EEE and WNV. These can include horses, llamas, alpacas, and emus. Animal owners should reduce potential mosquito breeding areas on their property. Drain containers around the property that hold water, especially after heavy rain. This can include buckets, tires, and wading pools. Water troughs provide excellent mosquito breeding habitats. Flush troughs once per week to reduce mosquitoes near paddock areas.

Animal owners should speak with their veterinarian about mosquito repellents for animals and vaccinations to prevent EEE and WNV. The Maine CDC recommends keeping animals at high risk inside overnight to reduce their risk of exposure to mosquitoes.

For more information:

• Know your risk and steps to take to keep safe with the Maine Mosquito Meter.
• Find mosquito surveillance reports.
• Learn about repellents.