The recent outbreak of a parasitic illness is being linked to McDonald’s (NYSE:MCD) salads.

News of the possible connection that the illness has to McDonald’s salads  comes after more than 100 people have reported the illness. This includes 90 residents in Illinois and another 15 people in Iowa.

While all of these people were found to have contracted the cyclospora cayetanesis parasite, only about a quarter of them had reportedly eaten a McDonald’s salad before becoming ill. The parasite is found in food and water that are contaminated with feces.

An investigation into the matter is currently underway. McDonald’s is assisting with the case and is also replacing salads at roughly 3,000 stores in the Midwest, just to be safe, reports Fox News.

Here’s what the Centers for Disease Control and Prevention (CDC) has to say about the cyclospora cayetanesis parasite.

“The time between becoming infected and becoming sick is usually about 1 week. Cyclospora infects the small intestine (bowel) and usually causes watery diarrhea, with frequent, sometimes explosive, bowel movements. Other common symptoms include loss of appetite, weight loss, stomach cramps/pain, bloating, increased gas, nausea, and fatigue. Vomiting, body aches, headache, fever, and other flu-like symptoms may be noted. Some people who are infected with Cyclospora do not have any symptoms.”

The CDC says that those contaminated by the virus may see symptoms last for just a few days, or as long as a month. This is possible due to a relapse. It also notes that those experiencing these symptoms are often tired.

As of this writing, William White did not hold a position in any of the aforementioned securities.