Eastern Equine Encephalitis (EEE) is a rare but serious mosquito-borne disease caused by a virus transmitted through the bite of an infected mosquito. Since the virus was first identified in Massachusetts in 1938, over 115 cases have been reported in the state. The most recent significant outbreak began in 2019, with 12 human cases resulting in six deaths. This outbreak continued into 2020, with five additional cases and one death. On August 16, 2024, officials announced the first human case of EEE in Massachusetts since 2020. It is important to take proper precautions to prevent mosquito bites and reduce the risk of EEE infection. 

What is Eastern Equine Encephalitis (EEE)?

EEE or Triple E is a rare mosquito-borne disease caused by a virus spread through the bite of infected mosquitoes. The EEE virus (EEEV) can lead to encephalitis, which is inflammation of the brain and is often fatal. EEE virus can also infect a variety of animals, including mammals, amphibians, reptiles, and birds. In Massachusettes, the virus is often identified in mosquitos found in and around freshwater.

How is the EEE Virus Spread?

EEE virus is spread through the bite of an infected mosquito. Mosquitoes typically become infected with the EEE virus after feeding on birds that carry the virus. The primary bird species that transmit the virus are infected by a mosquito called Culiseta melanura, which feeds almost exclusively on birds and does not pose a risk to humans.  However other mosquito species such as Aedes, Coquillettidia, and Culex, which bite both birds and humans, can pick up the virus from infected birds and transmit it to humans. This process creates a "bridge" that allows the virus to spread to humans.

EEE is not contagious and cannot be transmitted from person to person. Horses can also become infected with the EEE virus, and the infection can be fatal to them. However, horses do not pose a significant threat to humans because they are considered "dead-end" hosts, similar to humans, meaning the virus does not continue to spread from them.

What are the symptoms of EEE?

Severe cases of Eastern Equine Encephalitis result in encephalitis or inflammation of the brain. EEE symptoms typically start suddenly with a headache, high fever, chills, and vomiting. As the illness progresses, it can lead to disorientation, seizures, and even coma. EEE symptoms usually appear three to ten days after being bitten by an infected mosquito.

According to the CDC, approximately one-third of individuals who develop EEE die from the infection, and many survivors experience mild to severe brain damage. In Massachusetts, about half of the people diagnosed with EEE die from the infection.

How can you protect yourself from EEE? 

As of now, there is no treatment for EEE. However, you can take measures to reduce the likelihood of mosquito bites, which can help lower your risk of contracting EEE:

• Apply insect repellent when outdoors: We recommend using all-natural repellents and carefully following the guidelines on the labels, especially for children. 
• Limit outdoor activities from dusk to dawn: Mosquitoes are most active during these hours, so reducing your time outside during this period can lower your risk of getting bitten.
• Cover exposed skin: Wear long sleeves, long pants, and socks when outdoors to minimize exposed skin. 
• Remove standing water around the home: Mosquitoes only need a few inches of water to breed. Be mindful about eliminating potential breeding sites like birdbaths, children's toys, and roof gutters.
• Check and repair window and door screens: Ensure screens are free of holes and fit tightly to prevent mosquitoes from entering your home. 
• Treat your property with a natural mosquito control solution: Use an effective, natural mosquito control treatment to help reduce mosquito populations around your home.

At Pure Solutions, we offer all-natural mosquito control services that kill mosquitoes on contact and provide a residual barrier of protection. Our products are safe for children, pets, and the environment. With over 15 years of experience in effective mosquito control throughout Massachusetts, our mosquito repellent property sprays are proven and reliable.

By using Pure Solutions’ services and products and following the additional prevention measures outlined above, you can be confident that you are taking proactive steps to reduce your risk of exposure to the EEE virus.

To learn more about the Pure Solutions mosquito control solution please click below.

Sources: 

About Eastern equine encephalitis. Centers for Disease Control and Prevention. (n.d.). https://www.cdc.gov/eastern-equine-encephalitis/about/index.html

Burton, P. (2024, August 16). Massachusetts man diagnosed with first human case of EEE in state since 2020. CBS News. https://www.cbsnews.com/boston/news/massachusetts-first-human-case-triple-e/

EEE (Eastern equine encephalitis). Mass.gov. (n.d.). https://www.mass.gov/info-details/eee-eastern-equine-encephalitis