Cyclospora infection: Infection with Cyclospora cayetanensis, a single-celled parasite. The first known human cases of illness caused by Cyclospora were reported in 1979. More recently, outbreaks of cyclosporiasis have been reported in the US and Canada. Cyclospora is spread by people ingesting water or food that was contaminated with infected stool. Outbreaks of cyclosporiasis have been linked to various types of fresh produce. People of all ages are at risk for the infection. The time between becoming infected and becoming sick is usually about 1 week. Cyclospora infects the small intestine (bowel) and usually causes watery diarrhea, with frequent, sometimes explosive, bowel movements. Other symptoms can include loss of appetite, substantial loss of weight, bloating, increased gas, stomach cramps, nausea, vomiting, muscle aches, low-grade fever, and fatigue. If not treated, the illness may last from a few days to a month or longer. Symptoms may seem to go away and then return one or more times (relapse).

Identification of this parasite in stool requires special laboratory tests that are not routinely done. The recommended treatment for infection with Cyclospora is a combination of two antibiotics, trimethoprim-sulfamethoxazole, also known as Bactrim, Septra, or Cotrim. People who have diarrhea should rest and drink plenty of fluids. Avoiding water or food that may be contaminated with stool may help prevent Cyclospora infection. People who have previously been infected with Cyclospora can become infected again.