Will the Outbreak Be Over Soon?
The outbreak isn’t likely to end anytime soon, says John Sellick Jr., DO, an infectious disease expert and epidemiological researcher at the State University of New York at Buffalo. “There are probably a couple of different outbreaks going around. We already know that iceberg lettuce is an issue, but it wouldn’t be surprising if other contaminated produce shows up as well.”
The iceberg lettuce implicated in the outbreak has already been recalled and pulled from the market. But reported cases of cyclosporiasis are likely to go up.
Symptoms of cyclosporiasis, the intestinal illness caused by the cyclospora parasite, can take a few weeks to surface in an infected person, Dr. Sellick says. “Cyclospora needs a couple of weeks to go through a molting phase before it becomes an infectious organism,” he says. “By the time you come in with diarrhea, it could be from something you ate two weeks ago.”
That means cases being confirmed now could be linked to foods eaten quite a while ago. “Many of the newly added cases may have become ill before the lettuce was recalled on July 17, or up to two weeks after the recall due to a period of incubation, and are only now being interviewed, confirmed, and linked to the outbreak,” says Zoe Weiss, MD, the director of clinical microbiology at Tufts Medical Center in Boston.
Dr. Weiss says it can take up to six weeks to determine whether an illness belongs in this outbreak, which can further delay the data.
Cyclospora is also not always included on routine stool tests, and many people may wait to see if they have a short-lived digestive illness before visiting a doctor, says Hannah Newman, MPH, the senior director of infection prevention at Northwell’s Lenox Hill Hospital in New York City. “That means official case counts may understate the scope of the outbreak at any given moment,” she says.
There can also be delays in case reporting, even when testing confirms cyclosporiasis. “Health departments have limited resources, and that’s compounded by the gutting of the CDC that we’ve had in the past two years,” Sellick says. “If somebody has a stool sample that’s positive, local and state health departments will be alerted. Depending on the volume of cases, they’re going to try to investigate it, but that takes time.”
