Scientists had wondered how a mosquito-spread virus that causes the deadly brain-swelling disease Eastern equine encephalitis (EEE) — the one responsible for two deaths in Vermont this month — survives in eastern North America during the winter. Now, they think they know the virus's keeper: snakes.
Previous work has implicated these reptiles, and the most recent study has found not only antibodies against the virus, but also genetic material from the virus itself in two species of venomous snakes living in Alabama.
"This paper is the final nail in the coffin that indicates that snakes are involved in this whole process," said Thomas Unnasch, a professor and chair of the University of Southern Florida's global health department.
Snakes appear to be the wintertime counterpart to birds, which catch the virus from mosquitoes and host it through the summer.
Mosquitoes can also spread the virus to humans with rare, but potentially devastating consequences. About six human cases of the disease the virus causes are reported in the United States every year. EEE causes a brain inflammation and can kill its victims or leave them with severe brain damage, according to the U.S. Centers for Disease Control and Prevention. The disease also affects other animals, particularly horses.