A virus never before seen in the Western Hemisphere caused at least one of the deaths in New York City attributed to St. Louis encephalitis, officials say.
Barbara Reynolds of the Centers for Disease Control and Prevention said that scientists there analyzed tissue from one of three New York City residents who have died of a mysterious, mosquito-borne virus in recent weeks.
"We were able to identify West Nile-like virus," she said. "We're using the word 'like' to indicate that we still have some more work to do to determine if it is a variation on the strain of West Nile or a new virus."
Officials said the unprecedented discovery was no cause for alarm, as pesticide spraying against St. Louis encephalitis should also fight the new virus.