Close to 400 people have now gotten sick from tainted McDonald's salads.
The tally has grown to 395 cases of people who fell ill from salad mix contaminated with the Cyclospora parasite, which is spread through fecal matter. Sixteen individuals have been hospitalized, according to the Centers for Disease Control and Prevention.
Fifteen states have confirmed cases, primarily in the Midwest. Illinois, where McDonald's is headquartered, has the most: 202.
More from USA Today:
Watery diarrhea is the most common symptom of Cyclosporiasis, according to the CDC. Symptoms may also include loss of appetite, weight loss, stomach cramps and pain, bloating, increased gas, nausea, fatigue, vomiting, body aches, headache and fever. It usually takes about a week to get sick after getting infected.
Shortly after people began getting sick last month, McDonald's voluntarily stopped selling salads at impacted restaurants and switched salad suppliers.
On July 26, a U.S. Food and Drug Administration analysis confirmed that McDonald's supplier Fresh Express was the source of the problem. The analysis found Cyclospora in a sample from an unused package of salad mix with romaine lettuce and carrots. The package's expiration date had already passed.
"Fresh Express committed to using recall procedures to inform those companies that received this romaine about the sample result," the FDA said. "Fresh Express also reported that carrots used in the mix were only sent to McDonald's locations."
Fresh Express said in a statement on its website
Thursday that none of the packages were for retail sale to consumers and that the company continues to work with food safety experts, and federal and state government officials on their investigations.
"At Fresh Express, our top priority is providing consumers with the highest quality and safest fresh lettuce and leafy greens products available," the company said. "As of now, there is no clear understanding about the contamination pathway or the definitive source of infection."
There are problems with Cyclospora elsewhere. On Monday, the U.S. Department of Agriculture's Food Safety and Inspection Service issued a public health alert on Caito Foods beef, pork and poultry salad and wraps, due to concern that they'd been contaminated with Cyclospora, too. Fresh Express supplies the chopped romaine lettuce the Indianapolis-based distributor uses for its foods sold at Kroger, Trader Joe's and Walgreen's.
Here's the current breakdown of where the McDonald's cases are:
The victims in Connecticut, Tennessee, and Virginia bought salads while traveling in Illinois. And the Floridian was visiting Kentucky, the CDC said.
"We addressed it very quickly. Customers always appreciate (that)," CEO Steve Easterbrook told USA Today on July 26.
He said that as of three days earlier, all the McDonald's locations affected had been completely restocked with a fresh lettuce-mix supply.