Better to be safe than sorry about Cyclospora, says Emory epidemiologist

At their most recent count, the U.S. Centers for Disease Control and Prevention counts as many as 30 patients in Georgia are infected with Cyclospora. Emory epidemiologist Dr. Jodie Guest suspects there are far more cases than have been counted nationwide. (CDC/Zach Inglis/I Baihaqi/Emory University)

It’s awful. And while the clinical term is gastrointestinal distress, reporting on the recent cyclosporiasis outbreak has repeatedly used the descriptor “explosive diarrhea.” According to the Centers for Disease Control and Prevention, cyclosporiasis is an intestinal illness caused by the microscopic parasite Cyclospora cayetanensis.

Dr. Jodie Guest notes that the parasite itself is not new, but the current surge in cases is. 

“This is not about a mutation of a parasite. This is a known illness that we typically see most often in the summer,” said Guest. “But in the United States, we usually don’t see more than about 2,000 cases in an entire year. Right now, we suspect at least 5,100 cases, and that is probably a significant undercount. We are at the outbreak level for sure.”



Guest is a professor and senior vice chair in the Department of Epidemiology at Emory University’s Rollins School of Public Health. She answered questions about the latest cyclosporiasis outbreak, which has now been identified in more than half of the U.S., on “Closer Look with Rose Scott.” 

Food and Drug Administration officials said Monday they are continuing to focus on lettuce from Taylor Farms as the source of a multistate outbreak, despite inaccurate test results that the government briefly publicized over the weekend.

Guest stated, “This is one of our harder-to-find food outbreaks.” 

Also, because of the fact that this parasite is hard to test for, and it’s about 10 to 14 days after you’ve eaten something with it that you feel ill, it is a harder-to-track parasite from a public health perspective working with people who are sick.”

Guest also addressed criticism directed at the Trump administration. Last July, the Foodborne Diseases Active Surveillance Network, known as FoodNet, reduced a program that tracked food‑poisoning infections. 

“Until 2025, it monitored 10 different foodborne illnesses, and eight of them were cut from the funding. Cyclospora was one of those eight,” said Guest. “So now we don’t have routine surveillance data showing where cases are occurring.”