A mystery stomach bug has been reported in eight states now.

The Center for Disease Control and Prevention said more than 275 people have been sickened with the unidentified illness since mid-June.

The Food and Drug Administration is investigating the cyclospora infections which, on July 24 USA Today reported, have in the past been linked to imported fresh produce and are usually discovered in tropical or subtropical countries. The infection causes diarrhea and other flu-like symptoms.

The Centers for Disease Control and Prevention said as of July 23 the infection has been reported in Iowa, Nebraska, Texas, Wisconsin, Georgia, Connecticut and New Jersey. They also said most of the illnesses occurred from mid-June to early July, but that they aren't sure yet whether or not all the cases are linked.

The stomach bug has been hard to track because none of the patients with the illness have any social ties.

The illness is spread when people ingest food or water contaminated with feces. The CDC said no food items have been linked yet, but public health authorities are pursing all leads.

On July 24 Webpronews reports Dr. Henry Anderson, Wisconsin State Health Officer said, "Because Cyclospora can cause a prolonged illness and the disease is treatable with sulfa drugs, we want people to know that they should contact their doctor if they experience a gastrointestinal illness with watery diarrhea that lasts more than two or three days."

Tags: stomach bug mystery bug mystery illness cyclospora