Public health officials know that eastern equine encephalitis, also known as EEE, is deadly. After all, it killed a 41-year-old New Hampshire man on Aug. 19. But the level of danger posed by the mosquito-borne virus still needs to be determined, Northeastern University health experts say. Eastern equine encephalitis has a mortality rate of 30%, according to the Centers for Disease Control and Prevention. However, Larry Han, an assistant professor in public health and health sciences at Northeastern, says the death rate may be higher.
“If you look at case reports in Massachusetts from the last 10 years, in some seasons it’s over 50%,” says Han, who has a background in statistical and machine learning methods and infectious diseases. “If you stratify by certain risk factors like age, the mortality rate could be even larger than 50%,” he says.
Most at risk are people over 50 and under 15, according to the CDC. The reason for the uncertainty is that EEE is so rare that it’s hard to draw statistical conclusions, Han says. The CDC calls EEE a rare but serious illness that can result in life-long health problems for those who survive. “The main issue here is encephalitis, inflammation of the brain, which is very serious,” Han says. “The population that suffers from severe conditions, permanent brain damage for instance, is quite high,” says Richard Wamai, a public health expert who is professor of cultures, societies and global studies at Northeastern.
