New York state reported its first case of eastern equine encephalitis in nearly a decade on Friday.
The rare mosquito-borne virus was detected in Ulster County, the New York State Department of Health said. The individual is hospitalized, it said.
MORE: 10 Massachusetts communities at high risk of mosquito-spread virus 'Triple E'The Ulster County Department of Health is currently investigating the case, which marks the first case of EEE confirmed in New York state since 2015, health officials said.
"Eastern equine encephalitis is a serious and fatal mosquito-borne disease with no vaccine," New York State Health Commissioner Dr. James McDonald said in a statement. "Even though temperatures are getting cooler, mosquito-borne illnesses are still a risk and New Yorkers must be cautious."
The human case comes after a case of EEE was confirmed in a horse in Ulster County in August, the state health department said. Earlier this month, two emus in New York's Rensselaer County also tested positive for the virus, which does not spread directly from birds to humans, the department said.
The latest human EEE case in New York brings the national tally to at least 11 so far this year, according to an ABC News tally. The national yearly average is 11, with most cases occurring in eastern or Gulf Coast states.
Beyond New York, cases have been reported in at least six other states so far this year: Massachusetts, with four; New Hampshire, with two; and, with one each, New Jersey, Rhode Island, Vermont and Wisconsin.
Between 2003 and 2023, there have been at least 196 EEE cases reported in the U.S., including 176 hospitalizations and 79 deaths.
MORE: As mosquito-borne illnesses spread, here's how to tell West Nile, dengue and EEE apartThe best way to prevent infection from the disease is to protect yourself from mosquito bites, including by using insect repellant, wearing long-sleeved shirts and pants, treating clothing and gear and taking steps to control mosquitoes indoors and outdoors.
"With the first confirmed human case of eastern equine encephalitis in Ulster County, I urge residents to take the recommended precautions to prevent mosquito bites and the risk of infection," Ulster County Executive Jen Metzger said in a statement.
Most people infected with EEE do not develop symptoms. For those who do, symptoms can include fever, headache, vomiting, diarrhea, seizures, behavioral changes and drowsiness, according to the U.S. Centers for Disease Control and Prevention.
Approximately a third of all people who develop severe cases die, according to the CDC.