The Wake County Health Department is conducting interviews with people who test positive for cyclosporiasis to determine what products are making people sick in North Carolina.
Health Director Rebecca Kaufman said no direct source had been found, but the culprit was believed to be a vegetable or herb.
“We do an interview with a communicable disease nurse that lasts about an hour and a half, because we ask them to come back about two weeks ago and review everything they ate with us,” Kaufman said, detailing the county’s investigation.
Kaufman said the interview responses are then analyzed to try to determine if there are any commonalities among patients who tested positive for Cyclospora.
The Wake County Health Department explained that cases of cyclosporiasis in North Carolina must be reported by physicians within 24 hours of a positive test. The department added that the state requires all reportable disease investigations to be completed within 30 days of the initial report date.
Ben Chapman, a food safety specialist at North Carolina State, said the hardest part about cyclosporia is how long it takes for a person to get sick after consuming the infected product.
“Investigating an outbreak of something like Cyclospora is very similar to investigating other foodborne pathogens. You’re really looking at what are the common elements among these individuals? Did they eat the same foods? Did they eat the same dishes? Did they eat at the same restaurants?” Chapman said.
He further explained: “The difference with pathogens like salmonella or listeria is that cyclosporiasis can affect anyone. It’s not one of the pathogens that we look at and say, ‘Hey, this is probably someone who’s young, old, pregnant, or immunocompromised,’ which is really what we’re focusing on when it comes to listeria.”
Cyclosporiasis can take anywhere from a few days to a few weeks to make a person sick. Symptoms of bacteria like salmonella usually appear within 72 hours.
James Rogers, director of food safety research and testing at Consumer Reports, noted how time-consuming traceback investigations like these can be.
“If they’re lucky, they can test and trace the outbreak back to the distributor, the producer or even the farm or the country where that food was produced so they have a complete picture from farm to patient of what’s causing the problem,” he said.
Both Rogers and Chapman emphasized the use of modern technology to facilitate difficult pathogen investigations.
“It’s true that the outbreak could continue until they get it under control,” Rogers said. “But they could also take your credit card receipt, which will show where you’ve been eating, your grocery store membership card, which you scan to get discounts. They can use that to trace it back.”
“Being able to ask people if we can go back to their history and see what they ordered if they don’t remember, that’s not something we had at our fingertips 10 years ago at this rate,” Chapman added. “Public health investigators don’t always do it because not every outbreak requires it, but we’ve certainly seen cases where it’s been done successfully nationally and here in North Carolina.”
The Wake County Health Department has yet to identify restaurants linked to any of the confirmed cases in Wake County.
Kaufman previously told WRAL News that part of the reason was that only 22 of the 135 cases were linked to three restaurants, none of which were located in the same town in the county.
She also said investigations into the restaurants found no wrongdoing by the companies.
Rogers told WRAL that investigations like this can take time, but added that Consumer Reports advocates for the information to be shared with consumers.
“They didn’t name the actual source, the restaurant or the grocery store, which is unfortunate. At Consumer Reports, we advocate for providing actionable information to consumers so they can make a difference for their own health and reduce the risk of exposure,” Rogers said.
Chapman said it was rare in an investigation to have “smoking gun” quickly.
“In this particular case, there seems to be very little information: no identified food source, no identified supplier,” he said. “In a case like this, I wouldn’t say that someone made a mistake or did anything wrong. I think that’s just the way things go when you have little information.”
In addition to Wake, Durham and Orange counties also tell WRAL News they have seen one confirmed case in each county, reported in July.
Chatham and Johnston counties have not reported any cyclosporia outbreaks in recent months.
People who suspect they have cyclosporiasis infection should consult their doctor and request that the parasite be specifically tested using a stool sample.
