A potentially deadly mosquito-borne virus has arrived in Pennsylvania.
Eastern equine encephalitis, also known as EEE or Triple-E, has been confirmed in mosquitoes in Carbon and Monroe counties, just north of the Allentown-Bethlehem-Easton area, and in Erie County.
It's already sickened three people in New Jersey, in Atlantic, Somerset, and Union counties, and caused more than a dozen horses to be put down.
RELATED: What is Eastern Equine Encephalitis?
In early August, Delaware said EEE was detected in sentinel chickens in all three counties.
Elsewhere in the U.S., EEE's toll has been devastating, with New England hardest hit.
Massachusetts has had three human deaths and 10 cases, while Connecticut and Rhode Island have had one death each, and at least half a dozen cases
Michigan has had three deaths and seven infections in the southwestern portion of the state
RELATED: Rare, potentially deadly mosquito-borne disease found in Delaware
The virus is carried by birds. When a mosquito bites an infected bird, it can spread the virus to humans, horses, and other birds.
EEE is rare, and when most people get it, symptoms are mild, similar to the flu.
But it can cause a life-threatening swelling of the brain, with a 33% fatality rate.
The symptoms include:
-High fever (103 to 106F)
-Lack of energy
Symptoms develop three to 10 days after being bitten.
RELATED: EEE virus in Michigan: Health officials warn of mosquito-borne virus amid worst outbreak in more than 10 years
The best protection is to prevent mosquito bite by taking steps to eliminate standing water around your home.
-Remove tin cans, plastic containers, ceramic pots, discarded tires or any object that could collect standing water. Drill holes in the bottom of recycling containers left outdoors.
-Have roof gutters cleaned annually, particularly if leaves from nearby trees have a tendency to clog the drains.
-Turn over plastic wading pools and wheelbarrows when not in use.
-Do not let water stagnate in bird baths.
-Aerate ornamental pools or stock them with fish.
-Clean and chlorinate swimming pools and remove standing water from pool covers.
-Use landscaping to eliminate standing water that collects on your property.
-Treat standing water that cannot be eliminated with Bti products, which are sold at outdoor supply, home improvement, and other stores. Bti is a natural product that kills mosquito larvae, but is safe for people, pets, aquatic life and plants.