Government officials are investigating an “onion grower of interest” in Washington state, after further cases of E. coli poisoning was linked to raw, slivered onions on McDonald’s Quarter Pounder burgers.
On Wednesday the Food and Drug Administration (FDA) said 90 people across 13 states have fallen ill in the outbreak, up from 75 at the end of last week.
The number of people hospitalized increased by five, to 27 people. One death, that of an older person in Colorado, has been tied to the outbreak, according to the FDA.
Officials have said the raw, slivered onions on McDonald’s Quarter Pounder hamburgers are the likely source of the E. coli, rather than the beef patties.
McDonald’s said the onions came from a single supplier, the California-based Taylor Farms. The company has since recalled the yellow onions it sent to McDonald’s and other restaurant chains.
“In addition, FDA has initiated inspections at a Taylor Farms processing center in Colorado and an onion grower of interest in Washington state. FDA’s investigation is ongoing,” the online release stated.
The agency did not name the grower.
“McDonald’s continues to not use slivered onions in impacted states,” it added.
More than 80 per cent of people who had contracted E. coli, interviewed by government investigators, reported eating McDonald’s items containing fresh, slivered onions, the FDA noted.
McDonald’s said last week that onions from the Colorado Springs facility were distributed to approximately 900 of its restaurants, including some in transportation hubs like airports.
The restaurant chain announced that it would resume serving Quarter Pounders at hundreds of its restaurants after testing ruled out beef patties as the source of the outbreak.
The strain of E. coli behind the outbreak can cause dangerous diarrhea and lead to kidney failure and other serious problems, according to the Centers for Disease Control and Prevention (CDC).
It causes about 74,000 infections in the U.S. annually, leading to more than 2,000 hospitalizations and 61 deaths each year.
In their release, FDA officials said the current risk of illness “is low because the onions have been recalled and should no longer be available.” They noted that all of the reported cases occurred before Taylor Farms and McDonald’s removed the onions from the market.