You may think that choosing a salad over a juicy hamburger while dining at McDonald's is the healthier option, but apparently, that decision has backfired for many Iowa residents lately.

According to NPR, McDonald's has pulled salads from 3,000 of their locations, including several in Iowa, due to an outbreak of an intestinal parasite called Cyclospora. The Iowa Department of Public Health reports that 15 Iowa residents have contracted the illness after consuming salads from McDonald's from late June to early July. Cases of the parasite have also been reported in Illinois, Minnesota, Missouri, and several other states.

Cyclospora is a particularly rough illness and can cause symptoms such as frequent, explosive diarrhea, bloating, weight loss, cramping, nausea, and fever. So far, no deaths have been reported from the outbreak, but there have been hospitalizations.

The IDPH is urging those who experience these symptoms after eating a McDonald's salad to see their healthcare provider immediately.