But the fear of widespread outbreak failed to materialize.
"Contamination during harvest or processing can cause widespread outbreaks, such as the recent 11- state outbreak."
The extent of the reaction from the public and the economic markets may depend on how widespread the outbreak is determined to be.
New York City has been reporting widespread outbreaks for weeks.
In 1507 a second, less widespread outbreak occurred, followed in 1517 by a third and much more severe epidemic.
This widespread outbreak is the result of a slow-moving but powerful storm system.
The cases are the first reported in the United States this year, but officials said there was no reason to fear a widespread outbreak.
It took two weeks to get lab results, agriculture officials said, and will take days longer to say how widespread the outbreak could be.
Alaska and Montana reported more widespread outbreaks than the other states.
In 2012, there was a widespread outbreak with the second-highest total case numbers.