Cyclospora
Cyclospora cayetanensis is a parasite that can infect people and cause gastrointestinal illness. Everyone is susceptible to Cyclospora, and it is generally a self-limiting disease.
Information about active outbreaks can be found on the CDC website.
Health alerts
July 14, 2026: The CDC issued a HAN on Domestically Acquired Cyclosporiasis Cases in Multiple U.S. States, 2026.
Transmission
Cyclospora is a type of parasite that is spread through fecal-oral transmission. Typically, an infected person sheds oocysts in their stool. These oocysts have to mature (sporulate) out in the environment for 1-2 weeks. Only then are the sporulated oocytes infectious to another person. As such, direct person-to-person transmission is rare. Once ingested, the sporulated oocyte will infect the intestinal lining and go through asexual and then sexual reproduction, creating more oocysts. These are shed in the stool and the life cycle repeats.
Epidemiology
According to CDC data, there were 55 outbreaks of Cyclospora in 2019, leading to over 1,000 cases of illness. Since then, the number of outbreaks has been around 11-15, causing between 200 and 1,000 illnesses each year. May-July are the months with the most diagnoses; it’s unclear why there is seasonal variation. Everyone is susceptible to infection with Cyclospora, and you can get it more than once.
Signs & symptoms
Enteritis caused by Cyclospora is marked by anorexia, weight loss, diarrhea, abdominal cramping, flatus and occasionally nausea, fevers and myalgias. It is typically self-limited, but symptom duration ranges from a few days to several weeks. It can also cause a relapsing syndrome, with symptoms resolving and then recurring.
Diagnosis
Diagnosis of Cyclospora can be difficult, as some general stool tests will not identify this parasite. Physicians will need to check with their lab to see if PCR or special staining is available for stool samples. In addition, patients may not shed large numbers of oocytes, so repeated testing with samples on different days might help improve diagnostic accuracy. Talking with the laboratory technician will help clarify the clinical concerns and help them employ the proper techniques.
Treatment
Most people will have a self-limited illness, but it can last for days-to-weeks. Treatment for Cyclospora is trimethoprim-sulfamethoxazole, which seems to be the only effective option.
Prevention strategies
There is no vaccine to prevent cyclosporiasis. Hand hygiene, especially after toileting, changing diapers or caring for someone who is ill, can prevent the spread of Cyclospora and other gastrointestinal pathogens. Wash food thoroughly and avoid recalled products. Cut away all bruised areas on produce and refrigerate produce within 2 hours of cutting.
Infection prevention and control
Cyclospora is not typically spread person-to-person, so standard precautions should be used when caring for incontinent patients. There is no specific EPA-registered disinfectant for Cyclospora. The FDA recommends cleaning household products with one tablespoon of chlorine bleach in one gallon of hot water. Healthcare facilities should clean initially with a detergent to remove visible soil and scrub surfaces thoroughly. Then, an EPA-registered hospital disinfectant should be used. After cleaning, healthcare professionals should wash their hands thoroughly.
Reporting
Cyclospora is a nationally notifiable condition in 47 states, the District of Columbia and New York City. Health care personnel should report all cases to their state, local or territorial health department.
Additional resources
JAMA Network™: Cyclosporiasis Action Plan Aims to Reduce Food Contamination
