Locally Acquired Eastern Equine Encephalitis Virus Infection Identified in a Maine Resident

Public reminded to monitor for signs of mosquito-borne illness

AUGUSTA -- The Maine Center for Disease Control and Prevention (Maine CDC) announced today the detection of a locally acquired Eastern Equine Encephalitis virus (EEE) in a Maine resident. This is the first Maine resident to become infected with EEE this year, and the first since 2015.

The case is an adult from Penobscot County with no history of recent travel out of state. The individual became ill with severe symptoms in early October and remains hospitalized. The results are presumptive while awaiting confirmation by the U.S. Centers for Disease Control and Prevention.

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

"Even though the risk of mosquito bites is low right now, it can take up to several weeks for people who were bitten by an infected mosquito to develop symptoms," said Maine CDC Director Dr. Puthiery Va. "We want Maine people and visitors to be on the lookout for symptoms and get medical care if they get sick."

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.

Maine tests animals and mosquitoes for the presence of EEE, JCV, and WNV. So far this year, Maine CDC has reported:

  • Positive for EEE: 1 mosquito pool (group of up to 50 mosquitoes collected during routine surveillance), 3 wild birds, 18 domestic animals (including two recent positives in horses from Lincoln and Penobscot Counties), and 1 human
  • Positive for JCV: 4 mosquito pools
  • Positive for WNV: 1 mosquito pool, 33 wild birds, 2 domestic animals, and 2 humans (one case acquired in Maine, and one acquired out of state )

Two hard frost events across most of the state dramatically reduces the risk of mosquito-borne diseases.

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