Matt Arteaga, 51, is one of about 500 people who got sick this summer in an outbreak linked to McDonald’s salads. The cause was a parasite, cyclospora.
Arteaga fell ill on a Thursday afternoon in June. He was in his office in Danville, Ill., when he says the symptoms came on quickly. “The chills, and body aches, severe cramping, sharp pain in my stomach,” Arteaga recalls.
After a test revealed he was infected with cyclospora, his case was reported to the Illinois Department of Public Health. At about the same time, there was “an uptick in reports of cyclospora that were being submitted to us,” the director of the department, Dr. Nirav Shah, told us.
To figure out what the source of the cyclospora might be, health department investigators asked Arteaga — and others who’d gotten sick — to make a list of every food they’d eaten before they fell ill. Arteaga says he used bank records to jog his memory.
“I pay with my debit card all the time. [I] just went through every restaurant [transaction] in the two weeks prior to getting sick,” he recalls. “I had a salad at McDonald’s three times.”
When many of the others sickened by cyclospora also reported they’d eaten salads at the chain, Shah says his department took action. They notified the Food and Drug Administration, the Centers for Disease Control and Prevention, and other public health agencies in nearby states.
“We got on the phone with McDonald’s and advised them of what we recommended, and made sure we notified the public immediately,” Shah says.
McDonald’s halted sales of salads at about 3,000 locations until it could switch to a different lettuce supplier. An FDA analysis confirmed the presence of cyclospora in an unused package of lettuce that had been distributed to to the chain.
So, is this a success story? An example of quick coordination and detective work by public health agencies to identify and halt an outbreak before it grew bigger? Or, is it evidence of the risks that exist in the food supply?
Twenty years ago, this outbreak may have been hidden. “It’s unlikely we would have detected this outbreak, because the test that doctors use to diagnose cyclospora wasn’t even approved by the FDA until May of 2014,” Shah told us.
Back then, Arteaga and others may have chalked up their sicknesses to a stomach bug and moved on. Earlier tests for cyclospora were more complicated and less reliable. And testing for cyclospora wasn’t automatic — a clinician had to suspect the parasite and specifically request testing for it. What’s more, older testing methods required visual inspection of a stool sample, and sometimes multiple stool specimens, to find the parasite.
Today, the tests yield quick results — within an hour or two — and can detect many common pathogens at once.
“Technology has been a game changer for foodborne outbreaks,” Shah says.
So, perhaps not surprisingly, diagnoses of cyclospora are up. In Illinois, there were 47 cases in 2017, compared with just two cases in 2012.
“We’re now in a situation where people know, if I go to my doctor I can get tested, I can get a diagnosis,” Shah says. And when these foodborne illnesses are reported to health authorities, “we can actually link up what’s going on.”
In addition to better testing for pathogens, detection of outbreaks has improved, too. “We’ve seen a great advance in the methodologies that we use for detecting foodborne outbreaks,” says Edward Dudley, an associate professor of food science at Penn State.
He points to the use of a technique known as whole genome sequencing to help detect a listeria outbreak linked to Blue Bell brand ice cream.
“There were only 10 individuals that were ever linked to the outbreak. The first one became ill in 2010 and the last one [became ill] in 2015,” explains Dudley.
So, how did scientists figure out these 10 cases were all connected to Blue Bell’s ice cream products? After all, there were hundreds of other cases of listeria sicknesses from other foods during that time period.
Whole genome sequencing allows scientists to produce high-resolution DNA fingerprints of the organisms under investigation.
“The advantage of whole genome sequencing is that it gives us a lot more information when we’re trying to tell whether an organism we isolate from a food is the same exact [organism] that we isolate from the individuals who became ill,” says Dudley. In outbreaks, scientists are looking for a direct match.
Older technology gives only a few dozen data points, Dudley says. “Whereas whole genome sequencing is giving us 4 to 5 million pieces of data” to make the match.
With Improved Detection Comes Perception of More Risk
So, this takes us back to a key question. Since we tend to hear more about foodborne illness outbreaks, there’s a perception that the risk has gone up. But, is our food supply any more or less safe than it used to be? All the experts I spoke with had similar answers.
“There’s really no evidence that our food supply is more unsafe than it has been in the past,” Dudley told us.
This view is echoed by Nirav Shah. “Our food system today is probably the safest it’s even been in history of the United States,” he told us.
FDA Commissioner Scott Gottlieb has weighed in as well. In a statement last June he wrote, “We believe food is safer than perhaps ever before.” He went on: “What’s happening is that our ability to identify outbreaks has dramatically improved due to new information technologies and laboratory techniques.”
So, though it may seem like a paradox, even as the CDC investigates lots of multi-state outbreaks, by many accounts our food supply is no less safe.
Another thing that adds to the perception of risk: We hear about recalls — even when they’re not linked to illness. Take for example, the recent Goldfish cracker recall. In this case there were no sicknesses linked to the cracker. However, the manufacturer of an ingredient used in some varieties of Goldfish found salmonella in its facility. So, Pepperidge Farm, out of an abundance of caution, voluntarily recalled four varieties of Goldfish crackers.
Another example: Kraft Heinz recalled its Taco Bell brand of queso from stores because of a risk of botulism. No illnesses were linked to the product, but jars showed signs of separation, which could create the conditions for the bacteria that causes botulism to grow.
When you look at the overall number of people getting sick from foodborne illness in the U.S., it’s relatively stable. From year to year, the numbers vary some, but “the overall picture is that we’re not seeing a large increase in the number of people getting sick,” says Matt Wise of the CDC’s outbreak response and prevention branch.
At the same time, there seems to be an increase in outbreaks this year.
“You can’t question that this year’s been a, sort of, bumper year. We’ve had a lot of outbreaks that have been detected and investigated,” says Wise. “So, we’ll have to wait and see whether this becomes a new normal, or whether this just happened to be a blip on the radar.”
And, of course, there’s still plenty of room for improvement when it comes to food safety. The CDC estimates that about 1 in 6 people get a foodborne illnesses each year. That equates to millions of sicknesses.
In the meantime, Matt Arteaga says the cyclospora infection took its toll. His GI distress lasted for weeks. He has hired a lawyer who is considering legal action.