Cyclospora Parasite (cont.)

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The CDC has a site (see the CDC reference below) that is updated with information that answers the following questions about cyclosporiasis:

What is Cyclospora?

Cyclospora is a parasite that is composed of one cell. It is too small to be seen without a microscope. Its full name is Cyclospora cayetanensisa, and it has a life cycle that involves both sexual and asexual reproduction. The part of the cycle in man is the ingestion of sporulated oocysts that pass through the GI tract where the sporocysts break open in the small intestine and release oocysts that infect the GI cells. The organisms then reproduce and release unsporulated oocysts into the stool contents that are excreted into the environment where they develop into sporulated oocysts that can infect humans.

The first known human cases of Cyclospora infection were diagnosed in 1977. Cases began being reported more often in the mid-1980s. More frequent reports may be due to better techniques that are now being used to detect the parasite in specimens of stool (bowel movements).

How is Cyclospora transmitted?

Cyclospora is transmitted by a person putting something in his or her mouth that was contaminated with sporulated oocysts in water or on foods that have been exposed to human feces in the recent past. Cyclospora oocysts needs time (days or weeks) after being passed in a bowel movement to develop into an infectious organism (sporulated oocysts). Therefore, transmission of Cyclospora directly from an infected person to an uninfected person is unlikely.

Who is at risk for infection with Cyclospora?

People of all ages are at risk for infection. In the past, Cyclospora infection was usually found in people living or traveling in tropical countries. More and more, cases are being recognized in countries such as the United States and Canada. The risk may vary with season. Infection may be most common in spring and summer.

What are the symptoms of Cyclospora infection?

Cyclospora infects the small intestine and usually causes watery diarrhea (sometimes described as explosive diarrhea) with frequent bowel movements. Other symptoms include loss of appetite, weight loss, bloating, increased gas, stomach cramps, nausea, vomiting, tiredness, muscle aches, and low-grade fever. Other infectious organisms can cause a similar illness, and these symptoms are not specific for Cyclospora infection. Some people infected with Cyclospora do not develop any symptoms.