Health officials have raised alarms following a significant outbreak of E. coli linked to McDonald’s Quarter Pounder. As of now, at least 75 suspected cases of food poisoning have emerged across 13 states, with reports indicating that 22 individuals have been hospitalized and one has tragically died. Two other patients have developed severe kidney issues.

The FDA has been closely monitoring the situation, and although the exact source of the outbreak is still under investigation, preliminary assessments suggest that the contamination may stem from “undercooked onion slices.”

Colorado is experiencing the most severe impact, with 26 reported cases, followed by Montana with 13 and Nebraska with 11. Other states reporting cases include Utah and New Mexico (5 each), Missouri and Wyoming (4 each), Michigan (2), and Iowa, Kansas, Oregon, Wisconsin, and Washington (1 each). Some patients have noted that they had traveled to other states prior to becoming ill, with at least three of them confirming that they consumed McDonald’s burgers during their travels. Those out-of-state cases experienced symptoms between September 27 and October 11. In light of the outbreak, McDonald’s announced on the 25th that the affected restaurants will no longer serve the Quarter Pounder.

According to FDA officials, the onion supplier, Taylor Farms, only issued recalls to its direct customers and did not notify the general public. Typically, food companies are responsible for releasing recall announcements, which the FDA then communicates. However, there is no legal requirement for manufacturers to inform the public directly.

McDonald’s confirmed that the recalled onions from Taylor Farms were distributed through a certain hub to the restaurants linked to the illnesses, though they did not specify which distribution center was involved. Immediately following the official announcement of the E. coli outbreak on the 22nd, McDonald’s ceased sales of the Quarter Pounder in several states, primarily in the Midwest and those west of the Rocky Mountains.

In a proactive response, other fast-food chains including Taco Bell, Pizza Hut, KFC, and Burger King have also started banning raw onions in certain locations. Restaurant Brands International Inc., the parent company of Burger King, stated that around 5% of their restaurants use whole onions distributed from Taylor Farms’ facility in Colorado. As a precautionary measure, they have decided to discard all onions sourced from that facility.