LACKAWANNA COUNTY, PA — Eastern equine encephalitis (EEE), a viral disease spread by mosquitoes, was discovered in Lackawanna County in December, according to the Pennsylvania Department of Environmental Protection (DEP).

Rocco Genovese, director of Lackawanna County’s West Nile virus mitigation program, said the EEE virus—which is distinct from the West Nile virus—killed a horse in the county, but that the state agency declined to identify the animal’s location. No human cases have been reported.

People infected with EEE may demonstrate flu-like symptoms, with advanced cases progressing to meningitis or encephalitis.  Children, seniors and adults with compromised immune systems are most susceptible. EEE is not contagious from human to human.

Genovese said EEE is relatively rare in Pennsylvania but that it is more dangerous than West Nile virus. Fewer than 1% of people infected with West Nile virus die from it, whereas EEE is fatal in 33% of human infections.

EEE is particularly lethal for horses. Genovese said about 90% of infected horses die.

Fortunately, vaccinations have proved to be highly effective in protecting horses from EEE infections. The state DEP recommends that horses be vaccinated at this time of year, by a qualified veterinarian, before mosquitoes emerge in warmer weather. The DEP also recommends bringing horses indoors in the evening, and eliminating standing water near horse enclosures.

Genovese said the county does not need to take any extraordinary measures regarding the EEE case, because the same mosquito-killing measures it employs to mitigate West Nile virus will kill mosquitoes carrying the EEE virus.