Cyclospora

Cyclospora is an uncommon but important cause of prolonged watery diarrhea in children, particularly during the summer months and during foodborne outbreaks. This episode reviews the epidemiology, clinical presentation, diagnostic pitfalls, treatment, and practical emergency department approach to recognizing and managing pediatric cyclosporiasis.

 

Learning Objectives

1. Recognize the clinical features and epidemiology of Cyclospora cayetanensis infection in children, including when to suspect the diagnosis in patients with prolonged watery diarrhea.
2. Select appropriate diagnostic testing for cyclosporiasis and identify the limitations of routine stool cultures, ova and parasite examinations, and gastrointestinal pathogen panels.
3. Apply evidence-based treatment and supportive care for pediatric cyclospora infection, including appropriate antimicrobial therapy, hydration, and follow-up considerations.

References

1. Stobbe M. Outbreak of diarrhea-causing parasite grows to more than 1,000 cases. ABC News. Published July 8, 2026. Accessed July 10, 2026.
2. Bilung LM, Tahar AS, Yunos NE, et al. Detection of Cryptosporidium and Cyclospora oocysts from environmental water for drinking and recreational activities in Sarawak, Malaysia. Biomed Res Int. 2017;2017:4636420. doi:10.1155/2017/4636420.
3. Giangaspero A, Gasser RB. Human cyclosporiasis. Lancet Infect Dis. 2019;19(7):e226-e236. doi:10.1016/S1473-3099(18)30789-8.
4. Pyzocha N, Cuda A. Common intestinal parasites. Am Fam Physician. 2023;108(5):487-493.
5. Centers for Disease Control and Prevention. Clinical care of cyclosporiasis. Updated March 8, 2024. Accessed July 10, 2026. 

Transcript

This transcript was generated using Descript and subsequently reviewed and lightly edited for spelling, grammar, and clarity. Minor inaccuracies may remain, and the audio recording should be considered the definitive version of this content.

 

Welcome to PEM Currents: The Pediatric Emergency Medicine Podcast. As always, I’m your host, Brad Sobolewski. It’s July and a seven-year-old comes into your emergency department with 10 days of watery diarrhea. They were seen earlier in the week and told it was probably viral gastroenteritis. Maybe they got a prescription for ondansetron, maybe they didn’t.

Stool cultures have already come back negative. Mom tells you, “Every time I think he’s finally getting better, the explosive diarrhea comes right back.” So what’s going on? Today we’re talking about Cyclospora. Honestly, it’s one of those organisms that most of us forget about until summer rolls around, or since medical school.

We don’t diagnose it every week, and depending on where you practice, you may go years without seeing a case. But then an outbreak happens, and maybe just a handful of sporadic cases show up, and suddenly you’re reminded that not every child with prolonged diarrhea has viral gastroenteritis. Cyclospora cayetanensis is a coccidian protozoan that’s transmitted through contaminated food or water.

In the United States, it’s most commonly associated with imported fresh produce, things like cilantro, basil, lettuce, salad mixes, and berries. Unlike bacterial food poisoning, everyone at the picnic usually isn’t sick, so it often presents as an isolated illness because the exposure happened days earlier and may have involved only one particular food item.

Families are often trying to remember the one thing that they ate that made everybody sick. Honestly, sometimes it’s simply the salad they bought at the grocery store a week ago. One thing that’s helped me remember these organisms over the years is that they each sort of develop their own personality.

You know, it’s often confused with Giardia and Cryptosporidium. So if the diarrhea is greasy, think Giardia. If it’s profuse, watery diarrhea after swimming, think Cryptosporidium. If it’s prolonged, watery diarrhea during the summer, think Cyclospora. Now, obviously there are exceptions, b