THURSDAY, Nov. 14, 2024 (HealthDay News) -- The number of Americans sickened in an E. coli outbreak tied to slivered onions used on McDonald's Quarter Pounders has now risen to 104, U.S. health officials reported Wednesday.

In an update posted on its website, the U.S. Food and Drug Administration said that 34 people have now been hospitalized, four have developed serious kidney problems and one has died.

Fourteen states have been affected by the outbreak, according to the FDA: Colorado has reported the most cases (30), followed by Montana (19) and Nebraska (13).

In assigning blame for the outbreak, both the FDA and McDonald's have pointed to slivered onions provided by Taylor Farms, a California-based food producer. The company recalled its yellow onions on Oct. 22.

Tests are still pending on the recalled onions, but "at this time, there does not appear to be a continued food safety concern related to this outbreak at McDonald’s restaurants," the FDA said in its update.

Meanwhile, McDonald’s said Wednesday that it has resumed selling Quarter Pounders with slivered onions at affected locations.

"McDonald’s identified an alternate supplier for the approximately 900 restaurants that had temporarily stopped serving Quarter Pounder burgers with slivered onions," the company said in a statement. "Over the past week, these restaurants resumed the sale of Quarter Pounder burgers with slivered onions."

In its statement, McDonald’s added that “food safety is something we will never compromise on, and we remain committed to doing the right thing.”

Still, several lawsuits have been filed against McDonald’s since the outbreak was first announced, including a proposed class action lawsuit, NBC News reported.

Most people infected with the E. coli strain recover without treatment. Milder symptoms often include stomach cramps, bloody diarrhea and vomiting. In more severe cases, people can develop high blood pressure, kidney disease, neurological problems or hemolytic uremic syndrome -- a condition that can trigger kidney failure, according to the CDC.

More information

The CDC has more on E. coli.

SOURCES: U.S. Food and Drug Administration, health update, Nov. 13, 2024; McDonald's statement, Nov. 13, 2024; U.S. Foods, recall notice, Oct. 24, 2024; NBC News