The Illinois Department of Public Health is investigating an uptick in parasitic foodborne illnesses linked to McDonald's salads.
The IDPH has received reports of 90 cases of cyclosporiasis, a disease caused by ingesting parasites in contaminated food or drink. About one quarter of the cases have been linked to McDonald's salads.
The Iowa Department of Public Health, in its own release, said it has identified 15 cases linked to the same illness and parasite.
The cases reported in Illinois started in mid-May. The cases reported in Iowa date back to late June.
The most common symptom is watery diarrhea. Other symptoms could include appetite and weight loss, intestinal pain, nausea and fatigue. Cyclosporiasis can be treated with antibiotics.
In a statement, McDonald's said it has been in contact with public health authorities and has voluntarily stopped selling salads at impacted restaurants.
The Associated Press contributed to this report.
Foodborne illness linked to McDonald's salads in Illinois, Iowa