COLUMBIA, S.C. () — The South Carolina Department of Public Health (SCDPH) said Friday that the state has experienced its first confirmed death caused by infection with eastern equine encephalitis (EEE) virus in more than 20 years. The person was from Beaufort County.

This is the first human case of EEE virus to be reported in South Carolina since 2020 and the first fatality from the virus in the state since 2003.

EEE virus is spread to people through the bite of an infected mosquito and is not transmissible from person to person.

Dr. Edward Simmer, interim SCDPH director, said, “While cases of the virus in people are extremely rare, the effects can be very serious to those who are infected.  We encourage everyone to take action to reduce the risk of mosquito bites, including eliminating mosquito breeding sites.”

Approximately 30% of people who develop severe eastern equine encephalitis die. According to the Centers for Disease Control and Prevention (CDC). many survivors have ongoing neurologic problems.

There are no vaccines to prevent or medicines to treat infection in humans.

The best way to reduce your risk of infection with EEE virus is by preventing mosquito bites. The American Mosquito Control Association (AMCA) recommends wearing long sleeves, long pants and light-colored, loose-fitting clothing when outdoors and properly applying an EPA-registered product that contains a repellent such as catnip oil, oil of citronella, DEET, IR 3535, oil of lemon eucalyptus, picaridin, p-menthane-3,8-diol (PMD), 2-undecanone. Be sure to follow product label instructions.   

Beaufort County Mosquito Control performed multiple spraying applications for mosquitoes by truck in the general area of the human case since the reported illness onset date. Additionally, Beaufort County will spray by helicopter for more effective coverage.

The county will also set mosquito traps in the area for the purpose of EEE virus testing. No EEE-virus positive mosquitoes have been detected thus far in 2025. The county will continue to monitor the mosquito population with increased trapping in the area and will conduct more mosquito spray missions based on that surveillance data.

So far in 2025, SCDPH has detected 10 EEE-virus positive horses in Aiken County (3), Colleton County (2), Horry County (1), Jasper County (1), Orangeburg County (1), and Sumter County (2) from mid-July through August.

Mosquitoes can develop in water that stands for more than five days. SCDPH recommends following these guidelines to keep your home and yard mosquito-free:

• Tip over anything that can hold water, such as toys, plant saucers or vases. To disrupt mosquito breeding cycles, change water often, even daily, in items like dog bowls and bird baths.
• Toss or recycle any unwanted yard items that may collect water, such as old tires, junk, or trash.
• Turn over items that can hold water like children’s pools, wheelbarrows, or buckets.
• Tighten tarps over items like boats, wood piles, grills, and pools.
• Take care of your property. Clean out debris from ditches, drains, and gutters. Keep grass cut low and trim or remove overgrown plants.
• Treat items that can’t be drained or emptied with appropriate mosquito control products.
• Team up and talk with neighbors about reducing mosquitoes in and around your home and neighborhood.

Click here for additional information on mosquito prevention, bite prevention and more.