Another Reason to Be Wary of Snakes: They Harbor a Deadly Brain-Swelling Virus
By Bridget DeSimone, October 16, 2012
For years, scientists and public health officials couldn’t figure out how the deadly mosquito-borne Eastern Equine encephalitis virus (EEEV)—which is causing unusually severe outbreaks this year in parts of New England—survives the cold mosquito-killing winters in the Northeastern U.S. But a new study offers a missing piece to the puzzle: snakes. According to researchers who wrangled and tested snakes (mostly Cottonmouths) in the Tuskegee National Forest, the reptiles harbor the virus in their bodies throughout hibernation. This sets the stage for a new crop of mosquitoes that feed on the infected snakes in the spring to pass the virus on to other animals and humans.
“They act as the Typhoid Mary of the virus,” Thomas Unnasch, lead author of the study and an infectious disease expert at the University of South Florida, told NBC News. (Wondering how mosquitoes manage to bite through the tough-skinned snakes for their blood meal? They target the soft membrane right around a snake’s eyes.)
EEEV, which has been detected along the Atlantic and Gulf Coast states as well as in Michigan and Ohio, is rare, but lethal to horses and humans. And while there is a vaccine for horses, there isn’t one for humans. So far this year, at least four people have died from EEEV in Vermont and Massachusetts and nearly a dozen other less serious cases have been reported—up from an average of five to ten human cases of EEEV reported annually in the entire U.S. (CDC).
“This paper is the final nail in the coffin that indicates that snakes are involved in this whole process,” Unnasch told LiveScience. The study was published online this month in the journal of American Society of Tropical Medicine and Hygiene—a Burness client.
The findings could also point to a better way to combat the deadly disease, Unnasch says, including smaller, more targeted spraying earlier in the year, to keep outbreaks like this year’s at bay in the future.
