July 25, 2013 -- Cyclosporiasis, a stomach bug that's typically picked up from fresh produce, has sickened more than 285 people in 11 states, according to the CDC.
That makes it one of the largest outbreaks of cyclospora infection ever reported. "In recent years we haven't seen a big outbreak like this," says Monica Parise, MD, chief of the parasitic disease branch at the CDC.
Health officials are urgently trying to track down the source of the infection.
So far, Iowa with 138 cases, Nebraska with 70, and Texas with 66 are the hardest hit states. Georgia, Connecticut, New Jersey, Ohio, Illinois, Wisconsin, Minnesota, and Kansas each have reported between one and three cases. So far, 18 people have been hospitalized.
To find out more about this foodborne illness, WebMD reached out to Andi Shane, MD, MPH, a pediatric infectious disease specialist at Emory University in Atlanta, and Ann Garvey, DVM, MPH, deputy state epidemiologist with the Iowa Department of Public Health in Des Moines.
Here's what they told us about the current outbreak, symptoms of cyclosporiasis, and how the illness is diagnosed and treated.
What is cyclospora?
Cyclospora are single-celled parasites that mostly live in tropical environments. It has two life stages: One is an active organism, and the other is a dormant stage called an oocyst. When people swallow the oocyst, they become active in the body, causing uncomfortable gastrointestinal symptoms.
How does it get into food?
The dormant oocyst is excreted through human stool into the environment, where it can contaminate fruits, vegetables, or water, Shane says.
"Humans, as far as we know, are the only hosts for this organism. So what happens is farmworkers will get ill in the fields near fruits and vegetables, or they go to the bathroom and they don't wash their hands properly. They transfer the parasite onto the fruits or vegetables," Shane says.
What kinds of foods are usually affected?
Outbreaks in the United States are typically associated with fresh fruits and vegetables, according to the CDC. Fresh raspberries imported from Guatemala sickened more than 1,000 people in 20 states in 1996.