Source of outbreak narrowing:

Investigators may have narrowed the hunt for the source of infections caused by Cyclospora, a rare parasite that causes lingering diarrhea and other symptoms, said Dr. Patricia Quinlisk, the Iowa state medical epidemiologist.

“We got it down to five potential vegetables,” Quinlisk told NBC News on Monday.

But neither she nor officials with the Centers for Disease Control and the Food and Drug Administration would say which vegetables could be part of the outbreak that has led to at least 21 hospitalizations nationwide since mid-June.

NBC News

CDC reports as of July 26, 2013 (5pm EDT), CDC has been notified of 353 cases of Cyclospora infection from the following 15 health departments: Iowa, Texas, Nebraska, Florida, Wisconsin, Illinois, New York City, Georgia, Missouri, Arkansas, Connecticut, Kansas, Minnesota, New Jersey, and Ohio.

Most of the illness onset dates have ranged from mid-June through early July.

At least 21 persons reportedly have been hospitalized in three states.

No food items have been implicated to date, but public health authorities are pursuing all leads. Previous outbreak investigations have implicated various types of fresh produce.