The Centers for Disease Control and Prevention now says that lettuce from Mexico that was served at Taco Bell locations across five states was a source of the outbreak of diarrhea-causing parasite cyclospora.

The agency on Thursday warned consumers not to eat shredded lettuce from Taco Bell restaurants in Indiana, Kentucky, Michigan, Ohio and West Virginia, the Associated Press reported. The announcement was made about two months after the first cases were reported. 

Cases of the disease have been reported in more than 30 states, and experts say that the outbreak could be caused by multiple sources. A Food and Drug Administration investigation identified one lettuce supplier in Mexico, but the federal warnings haven't identified the company. 

The CDC said that the FDA is working with the supplier of the lettuce to determine if potentially contaminated shredded iceberg lettuce remains on the market. 

“Taco Bell has committed to stop using any lettuce from the supplier identified by FDA’s traceback investigation," the CDC said. 

Cyclospora is a microscopic, spherical parasite that commonly causes watery diarrhea “with frequent and sometimes explosive bowel movements,” according to the CDC. It is not life-threatening and usually treated with antibiotics.