Reports of Cyclospora infections across the United States are prompting public health warnings as officials continue working to determine what may be driving the spread of the intestinal parasite.
National news outlets, citing public health tracking and outbreak reporting, have described cases in at least 25 states and more than 1,700 illnesses. The cases involve cyclosporiasis, an infection caused by the microscopic parasite Cyclospora cayetanensis. It is best known for causing prolonged watery diarrhea, which can be severe and may come with cramping, bloating, nausea, fatigue, loss of appetite and weight loss.
Health officials have not identified one clear food source tied to all reported illnesses. Cyclospora outbreaks in the United States have previously been associated with fresh produce, including herbs, leafy greens and berries, but investigations can be difficult because people often eat several fresh items and symptoms may not appear until about a week after exposure.
How Cyclospora spreads
Cyclospora spreads when people ingest food or water contaminated with the parasite. Unlike some stomach viruses, it is not typically spread directly from one person to another because the parasite needs time in the environment before it becomes infectious.
That feature can make outbreaks harder to trace. A person may become sick days after eating contaminated produce, and the item may already be consumed or discarded by the time investigators begin interviewing patients. Produce also can move through complex supply chains, crossing state lines before reaching stores, restaurants and homes.
Symptoms can last for days to weeks if untreated and may seem to improve before returning. People with persistent diarrhea, signs of dehydration or underlying health conditions should contact a health care provider. Diagnosis usually requires a stool test, and the infection can be treated with prescription medication, most commonly trimethoprim-sulfamethoxazole. Patients with sulfa allergies should discuss alternatives with a clinician.
Steps to reduce risk
Consumers can lower risk by washing hands before handling food, rinsing fruits and vegetables under running water and refrigerating cut produce promptly. Scrubbing firm produce and keeping raw meats separate from ready-to-eat foods also can reduce the chance of foodborne illness.
However, washing may not remove all parasites if contamination is embedded in delicate produce or occurred before harvest. That is why investigators often focus on farms, distributors, importers and restaurants when searching for the source of a multistate outbreak.
Public health agencies generally urge people who become ill to remember what they ate in the days before symptoms began and to report suspected foodborne illness to local health departments. Those reports can help investigators identify patterns that may otherwise be missed.
The latest reports come during a season when Cyclospora cases often rise in the U.S. Health officials are expected to continue reviewing laboratory-confirmed infections, patient interviews and food distribution records as they look for a common source and assess whether additional advisories are needed.
Key questions
- What is Cyclospora?
- Cyclospora is a microscopic parasite that can cause cyclosporiasis, an intestinal infection marked by watery diarrhea, cramps, nausea, fatigue and other gastrointestinal symptoms.
- How can people reduce the risk of Cyclospora infection?
- People can reduce risk by washing hands, rinsing produce under running water, refrigerating cut fruits and vegetables, separating raw meats from ready-to-eat foods and seeking medical care for persistent diarrhea.
