In the days before Kamberlyn Bowler became ill, she went to McDonald’s several times for her favorite meal: a Quarter Pounder with cheese and extra pickles. The previously healthy, active 15-year-old is now hospitalized and battling kidney failure — a rare and potentially life-threatening complication of E. coli poisoning.

Kamberlyn, of Grand Junction, Colorado, is one of dozens of people who say they became sick after having eaten McDonald’s Quarter Pounders. According to the Centers for Disease Control and Prevention, at least 75 people across 13 states have been infected with E. coli following meals at the fast-food chain. One person has died.

McDonald’s says the most likely source of the contamination was slivered onions served on its Quarter Pounders. The restaurant giant has removed the onions from its menu items. The distributor of the onions, California-based Taylor Farms, has said that while no specific ingredient has been confirmed as the source of the outbreak, it has “preemptively recalled” yellow onions from the Colorado facility that distributed produce to food service customers.

In her first interview about her ordeal, Kamberlyn, a high school freshman, wiped away tears as she summarized how the past few weeks have felt: “Not fun,” she said via Zoom from her hospital room Monday afternoon.

Kamberlyn’s mother, Brittany Randall, said her daughter’s symptoms started this month with a fever and stomach pain. Neither Kamberlyn nor Randall was too concerned at first.

“We both kind of thought I just had a fever, like just the flu or something — a stomach bug,” Kamberlyn said. “But then I started throwing up, having diarrhea, and it was bloody, so it scared me.”

Randall took Kamberlyn to the doctor and then to the emergency room for some scans, which didn’t show anything significant, she said. But back at home, Kamberlyn didn’t get better. 

“I think it was day six that she said: ‘Something’s not right. I don’t feel good. I need to go back to the hospital,’” Randall said. 

This time, the tests showed something alarming: Kamberlyn had an E. coli infection so severe that she was in renal failure. On Oct. 18, she was airlifted to Children’s Hospital Colorado outside Denver, where she has remained ever since.

“It’s been definitely a roller coaster from the time that we’ve gotten here until now. Every day has been new tests or new things that pop up, or it’s basically watching her body just not work,” Randall said.

Kamberlyn has been diagnosed with enterohemorrhagic Escherichia coli-associated hemolytic uremic syndrome, or HUS — which can arise if E. coli bacteria attack the kidneys. She has received multiple rounds of dialysis in the hospital.

Randall said that her daughter’s kidneys are showing “some signs” of functioning again but that it’s not clear what the extent of the lasting damage will be.

“We’re not really sure what it’s going to look like for her moving forward,” she said, adding: “She’ll probably have to do another round of dialysis. We’re hoping that that’s the last one, but we also don’t know, and we don’t know if there’s going to be future issues.”

Kamberlyn and Randall plan to sue McDonald’s and have hired an attorney who has already filed two suits on behalf of other clients. But for now, they are focused on Kamberlyn’s recovery.

Symptoms for most people infected with E. coli usually start three to four days after they consume contaminated food, and include severe stomach cramps, diarrhea and vomiting, according to the CDC. Most who are infected recover without treatment within a week. 

But a very small percentage of patients — estimates of how many vary, with some calculating it as low as 2% — go on to develop HUS.

People who are very young or very old are the most susceptible to HUS, said Dr. Nicole Iovine, chief epidemiologist at UF Health Shands Hospital in Florida, who isn’t treating Kamberlyn.

“It’s a rare complication, but it is definitely something that can occur. Unfortunately, some people end up with decreased kidney function or permanent renal failure,” she said.

Before she contracted E. coli, Kamberlyn didn’t have any underlying health conditions, and she regularly exercised and played softball — all factors that should help her as she tries to get better from HUS, Iovine said.

“It’s not predictable, and the pre-existing health of the patient is really important,” she said.

The experience has been terrifying for Randall, who said she is grateful that Kamberlyn recognized that something was very wrong.

“If she would have waited, if I would have waited longer, she could not be here right now,” Randall said. “She went from being super healthy and no issues at all to possibly kidney damage for her whole life.”

McDonald’s said in an email that hearing reports like Kamberlyn’s “is devastating to us.”

“We know that people and families have been significantly impacted, and the well-being of our customers is deeply important to us,” the email said.

In a video posted Sunday, McDonald’s USA President Joe Erlinger vowed to regain customers’ trust.

“On behalf of the McDonald’s system, I want you to hear from me: We are sorry,” he said in a video posted Sunday. “For those customers affected, you have my commitment that, led by our values, we will make this right.” 

Ron Simon, a national food poisoning attorney representing Kamberlyn and 32 other victims of the McDonald’s E. coli outbreak from 10 states, said he has received hundreds of calls from people since news of the outbreak spread.

“It’s going to be a lot more cases in this outbreak than 75,” he said, referring to the latest case tally from the CDC. “Way more, without question.”

Simon said he plans to file Kamberlyn’s suit this week. Of the people he’s representing, he said, nine have been hospitalized, and one other has contracted HUS.

“We hope that through these lawsuits and others that we can figure out exactly where the breakdown was so we can fix it and just make sure it doesn’t happen to anyone else,” he said.