West Nile Virus and EEE Lead to Illnesses and Deaths Across the U.S.

As Americans get outdoors to enjoy the last weeks of summer, public health officials are urging everyone to take precautions against insect bites as the threat of mosquito-borne illnesses rises.

Nearly 300 cases of West Nile virus have been reported in 33 states so far this year, killing at least 18 people, according to the Centers for Disease Control and Prevention.

Among those infected was Anthony Fauci, MD, the former director of the National Institute of Allergy and Infectious Diseases, who was hospitalized with severe symptoms last month.

A less widespread disease, eastern equine encephalitis virus (EEE), has infected four people in four states this year, and a 41-year-old New Hampshire man who was otherwise healthy died of EEE infection in August.

“It’s déjà vu all over again,” says Richard Pollack, PhD, a senior environmental public health officer at Harvard University in Boston, about the seasonal return of these viruses. “West Nile virus spread from coast to coast some years ago, and it is here to stay, and you can expect it to be encountered in most any community every year.”

He adds that EEE is generally restricted to some traditional hot spots, such as southeastern Massachusetts. The virus is likely to return each late summer and early fall — although it does not necessarily come back every year.

West Nile and EEE Attack the Central Nervous System

Primarily spread through mosquito bites, both the West Nile and EEE viruses infect the central nervous system and can cause a range of symptoms, including:

  • Fever
  • Headache
  • Body aches
  • Vomiting
  • Diarrhea
  • Rash

“When I had West Nile virus, I was the sickest I’ve ever been,” said Lyle Petersen, MD, the director of the CDC’s division of vector-borne disease, in an August 31 post on X. “I was a marathon runner at the time, yet couldn’t make it up the stairs. It took six months to fully recover.”