Eastern Equine Encephalitis virus 2024: symptoms, map, update on rare mosquito bite disease

Earlier this month, the Massachusetts Department of Public Health issued a warning that the first case of Eastern Equine Encephalitis (EEE) has been documented in a person in the state this year. Here’s what you need to know about the disease and steps you can take to protect yourself.

What is Eastern Equine Encephalitis?

Eastern Equine Encephalitis, or EEE for short, is a virus that humans and animals can catch from mosquitoes, according to the Centers For Disease Control and Prevention (CDC). The virus can further cause meningitis (inflammation around the spinal cord and brain) or encephalitis (inflammation of the brain).

Infection with the virus is rare but can have devastating consequences for those infected. The CDC says that about a third of all people infected with Eastern Equine Encephalitis will die.

This disease has also been found in horses.

Where is Eastern Equine Encephalitis now?

In the United States, the CDC says there has been one confirmed human case in each of the three states by 2024 so far. Those regions are:

• Massachusetts
• New Jersey
• Vermont

However, the disease has been found in animals in other states, which suggests that mosquitoes carry it in those states, and thus people can be infected. Countries where Eastern Equine Encephalitis has been found in animals include:

• Arkansas
• Connecticut
• In Florida
• George
• in Louisiana
• Massachusetts
• In Michigan
• New Hampshire
• New Jersey
• Rhode Island
• South Carolina
• Vermont
• Virginia

How is Eastern Equine Encephalitis spread?

Eastern Equine Encephalitis is spread by mosquitoes. When a mosquito carries the virus and feeds on an animal or person, the virus can be transmitted to them.

The good news is that EEE cannot be spread from horses to humans or from human to human. However, the CDC says there has been an incident where EEE spread from one person to three others after those three people received a donor organ transplant.

What are the symptoms of Eastern Equine Encephalitis?

The CDC says that most people who contract Eastern Equine Encephalitis do not have symptoms. However, when symptoms do appear, they usually fall into two camps:

• Symptoms of febrile illness: This includes joint pain, fever, body aches, and chills.
• Neurological symptoms: These include seizures, drowsiness, behavioral changes, diarrhea, fever, headache, vomiting, and coma. These symptoms are caused by an infected person developing meningitis or encephalitis.

Symptoms usually begin to appear 4 to 10 days after infection. If the symptoms are only of a sick nature, those infected usually make a full recovery in one or two weeks, as long as there are no neurological problems.

People with neurological symptoms have a worse prognosis. About 33% of those people die within two to 10 days of the onset of symptoms, although death may occur even later. Survivors are often left with long-term psychological and physical problems.

Is there a vaccine for Eastern Equine Encephalitis?

Unfortunately, no. There is no vaccine for Eastern Equine Encephalitis at this time. Treatment options are also limited.

Can Eastern Equine Encephalitis be prevented?

The best protection is to try not to get bitten by an infected mosquito. The CDC says preventative measures include:

• Use insect repellent
• Wear long-sleeved shirts and pants
• Carry clothes and supplies
• Take measures to control mosquitoes indoors and outdoors

Other tips for preventing mosquito bites can be found on the CDC website here.