PRIMER: Cyclospora

Plagues with Dr. Keith

This episode of 'Plagues with Dr. Keith' explores the recent Cyclospora outbreak in the United States, detailing its transmission through co

Key takeaways

• Cyclospora is a parasite transmitted through contaminated produce, primarily due to human fecal matter entering irrigation or soil systems.
• The parasite requires one to two weeks of sporulation in warm, moist environments before becoming infectious.

Main topics

• Cyclospora parasite and its lifecycle
• Recent U.S. outbreak linked to iceberg lettuce

Notable quotes

Cyclospora is a unicellular parasite that is microscopic. It was only recently discovered in 1979.

Conclusion

Food and waterborne illnesses remain persistent threats due to systemic vulnerabilities in

Transcript preview

Speaker 1 (0:00) Welcome to episode 2 of my primer series. The purpose of this primer series is to inform you of recent outbreaks of disease and epidemics. I hope you enjoy. Speaker 1 (0:23) Cyclospora sounds like a name of an alien from a science fiction movie, but it's not. It's a parasite that lives here in our own backyard. But one could argue that Cyclospora certainly is an alien to the human gut. Cyclospora is a unicellular parasite that is microscopic. It was only recently discovered in 1979. and wasn't given a name until 1994. Humans are the primary host and the only known reservoir. So, Rover and Fluffy? are safe from this little alien. An outbreak had begun before 17 July 2026, and as of 31 August 2026, there have been over 18,000 cases of illness. 49 states reported individual illnesses, with 20 states reporting extensive outbreaks. The states most affected were Michigan and Ohio. Nationwide, there has been about 1,000 hospitalizations and two deaths. These infections have been linked to iceberg lettuce from Taylor Farms, New Mexico. This lettuce was distributed to various locations, including Taco Bell. Symptoms are consistent with many other gastrointestinal infections, watery diarrhea that sometimes is explosive, abdominal cramping, bloating, along with fatigue. And if symptoms persist, dehydration from the diarrhea can result in weight loss. If not treated, symptoms can last for weeks to months. Outbreaks occur when large volumes of produce are contaminated during harvesting or while the produce is being processed. Subsequently, the produce is shipped, often globally, resulting in outbreaks in various geographic regions, past large outbreaks of cyclosporiasis. have been tied to contaminated peas, raspberries, herbs, and romaine lettuce. As noted, this recent outbreak in the U.S. is linked to iceberg lettuce. How is this parasite transmitted to produce? It comes from human feces. Gross, I know. Cyclospora ooocysts, kind of like an egg version of this parasite, are present in the stool of humans. The produce mentioned share a characteristic. They have ridges and crevices that make them more challenging to clean, and they're eaten raw. It's not transmitted directly between people. These ooocysts linger in the environment. and are not immediately infectious as they are immature. The environment they're in is soil and water as they need to sporulate, which can take several days, two weeks, depending on environmental conditions. Warm temperatures and increased moisture are more favorable to the process of sporulation. What is sporulation? Speaker 1 (3:35) a transformation involving internal changes