EEEV is a particularly rare infection - it tends to spread in remote, swampy areas far from human civilization. But when the disease does strike, it can be grave: Gizmodo reports that a bite from an infected mosquito can cause severe, fatal brain swelling in a matter of days.
Health Department officials found EEEV in a flock of sentinel chickens, which local governments use to monitor and track infectious diseases, according to the warning, which included a list of steps people can take to prevent mosquito populations from growing.
If the sentinel chickens are getting bit, that means human infections could follow close behind, according to Gizmodo.
While EEEV is rare and human infections that lead to dangerous symptoms are even rarer, scientists have yet to figure out a vaccine or treatment for the disease, posing a problem for our warmer future.