SIOUX FALLS, S.D. — Federal health officials are warning of a new emerging health threat, a relatively unknown, mosquito-carried virus that causes an illness for which there's no known cure.
The brain-attacking illness, Eastern equine encephalitis or EEE, has existed for centuries. But it took a particularly deadly toll in 2019 and should be considered an "emergent" threat, said officials from the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, in a commentary published in The New England Journal of Medicine.
The illness has sickened 37 in nine U.S. states this year, killing 15, as of Dec. 3, according to the Centers for Disease Control and Prevention. The states include Montana, Wisconsin and Missouri. While the illness otherwise struck mostly in states in the eastern and southern U.S., National Institute of Allergy and Infectious Diseases, or NIAID, officials cautioned that such infection sites could seed the illness elsewhere.
"Although EEE is not yet a disease of major national importance, this year’s spike in cases exposed our inadequate preparation for emergent disease threats," the officials wrote. "Though the best way to respond to these threats is not entirely clear, to ignore them completely and do nothing would be irresponsible."
How could I catch EEE?
Eastern equine encephalitis is spread between the Culiseta melanura mosquito and birds found in forested wetlands, although it can also circulate among small mammals, reptiles or amphibians, the NIAID officials said.
The illness can be highly fatal. While 96% of people infected with the illness won't show symptoms, about a third of those who show symptoms die or suffer permanent, often severe brain damage. Those inflicted with the illness can't pass it on to others.
The illness is one of several transported by mosquitos and ticks, known as arboviruses. Several arboviruses, including dengue, Zika, yellow fever and chikungunya, have evolved to be carried by the Aedes aegypti mosquito, an insect that feeds almost exclusively on humans. If the EEE could evolve to be carried by the A. aegypti mosquito, it could cause disastrous consequences.
"Any virus that can efficiently infect A. aegypti also has potential access to billions of humans, which explains why the four viruses that have done so have spread pandemically," the NIAID officials said.
There is no vaccine for EEE, although several are in development, and there are other potential treatment methods under development.
The NIAID officials recommended state and local health officials keep an eye on horses, birds and mosquitoes for the appearance of EEE, although they acknowledge insufficient funding could prove an issue.
But illnesses such as EEE are a "clear and present danger" and highlight the need for a national defense strategy against them, the officials said.