Cyclosporiasis is an intestinal infection caused by the parasite Cyclospora cayetanensis. It is usually linked to contaminated food or water and can affect people in many countries, particularly in regions where sanitation systems are limited. Travelers, restaurant customers, and people who eat fresh produce have occasionally become ill when food has been contaminated during growing, harvesting, washing, or preparation.
The illness often begins with watery diarrhea, which may be frequent and persistent. Other symptoms can include abdominal cramping, bloating, nausea, loss of appetite, fatigue, weight loss, and increased gas. Some people experience vomiting or a mild fever, while others have only a few symptoms. Without treatment, symptoms may improve and then return, making the infection feel unusually prolonged compared with a typical stomach virus.
Cyclospora is not usually spread directly from one person to another. The parasite leaves the body in stool in a form that is not immediately infectious. It needs time in the environment to become capable of causing infection, which is why transmission is more commonly associated with contaminated produce or water than with ordinary household contact. Eating raw or lightly cooked foods can carry a higher risk when they have not been handled safely.
Diagnosis can be difficult because the parasite may not appear in every stool sample, and routine testing does not always include Cyclospora. A healthcare professional may request several stool specimens or order a specific laboratory test. Anyone with diarrhea lasting more than a few days should mention recent travel, restaurant meals, and consumption of fresh herbs, leafy greens, berries, or other uncooked produce. This information can help guide testing.
The standard treatment is usually a combination of trimethoprim and sulfamethoxazole, commonly known as TMP-SMX. The appropriate medicine and duration depend on a person’s health history, allergies, age, pregnancy status, and other medications. People who cannot take this treatment should speak with a clinician about alternatives, since commonly used medications for some other intestinal parasites may not work against Cyclospora.
Fluids are an important part of recovery. Water, oral rehydration solutions, broth, and other suitable drinks can help replace losses caused by diarrhea. People with severe weakness, dizziness, very little urination, blood in the stool, persistent vomiting, or signs of dehydration should seek medical care promptly. Young children, older adults, pregnant people, and those with weakened immune systems may need closer monitoring.
Prevention depends heavily on food and water safety. Wash produce under running water before eating it, even when it will be peeled, and keep raw foods separate from uncooked meat and poultry. Washing can reduce contamination, although it may not remove every parasite. Clean hands, utensils, cutting boards, and kitchen surfaces also matter. When traveling, choose treated or bottled water and be cautious with raw foods whose preparation cannot be observed.
A lingering case of diarrhea is not something to simply endure. Cyclosporiasis is treatable, but identifying it often requires telling a clinician the details of recent meals, travel, and symptom patterns.