Michigan health officials reported 10,077 cases of cyclosporiasis on Wednesday, an increase of 397 cases since their last update a day earlier.

An investigation by the U.S. Food and Drug Administration has linked the outbreak to iceberg lettuce served at Taco Bell restaurants sourced from privately held Taylor Farms operations in central Mexico, but authorities are still looking for other potential sources given the size of the outbreak.

Consumers in the U.S. have been steering clear of some restaurant chains and buying less lettuce in grocery stores as a multistate outbreak of a parasitic disease has fueled confusion over what is safe to eat.

Michigan’s health department has reported 160 hospitalizations as of July 23, but no deaths.

The Centers for Disease Control and Prevention has received reports of 6,707 laboratory-confirmed domestic cases of cyclosporiasis, and said it was aware of more than 11,500 additional cases that are not laboratory confirmed or require further investigation across 45 states.

Health officials have said they are investigating additional potential sources of infection. In North Carolina, parsley and cilantro were commonly identified ingredients among people who fell ill, though there could be multiple sources of exposure, according to the state’s health department.

Cyclosporiasis, caused by the cyclospora parasite, can be contracted by consuming food — typically raw fruits and vegetables — or water contaminated with feces.

(Reporting by Sriparna Roy in Bengaluru; Editing by Shinjini Ganguli)