Cyclosporiasis refers to infection by Cyclospora, a microscopic, single-celled parasite that infects the human intestine. This parasite is a memberof the group of protozoa known as coccidia, to which Cryptosporidia also belongs. This group of parasites infects the human intestine, and causeschronic recurrent infections in those with altered immunity or AIDS>.Even in people with normal immune function, Cyclopsora can cause prolonged bouts of diarrhea and other gastrointestinal symptoms.
Until recently, Cyclospora was considered to be a form of algae. The parasite causes a common form of waterborne infectious diarrhea throughout theworld. Just how the parasite gets into water sources is not yet clear. It isknown that ingestion of small cysts in contaminated water leads to disease.
Symptoms begin after an incubation period of about a day or so following ingestion of cysts. A brief period of flu-like illness characterized by weaknessand low-grade fever is followed by watery diarrhea, nausea, loss of appetiteand muscle aches. In some patients symptoms may wax and wane for weeks, and there are those in whom nausea and burping may predominate. It is also believed that infection can occur without any symptoms at all.
In patients with altered immune systems, such as those with AIDS and cancer,prolonged diarrhea and severe weight loss often become major problems. The bile ducts are also susceptible to infection in AIDS patients.
The disease should be suspected in anyone with a history of prolonged or recurrent diarrhea. The parasite can be identified from stool specimens. Using anendoscope to obtain tissue samples from an infected organ such as the intestine is another way to make the diagnosis.
The first aim of treatment, as with any severe diarrheal illness, is to avoiddehydration and malnutrition. Oral rehydration solution or intravenous fluids are sometimes needed. Medications used to treat diarrhea by decreasing intestinal movement, such as loperamide or diphenoxylate, are also useful but should only be used with the advice of a physician.
The use of the medication trimethoprim-sulfamethoxazole (Bactrim) for one week can be successful in treating intestinal infections and prevents relapse inthose with a normal immune system. The same medicine can be prescribed to treat infections of both the intestine or bile ducts in individuals with impaired or weakened immune systems, but maintenance or continuous treatment is often needed.
Even without treatment, symptoms usually do not last much more than a month or so except in cases with altered immunity. Fortunately, treatment is usuallysuccessful even in those patients.
Aside from a waterborne source as the origin of infection, little else is known about how the parasite is transmitted. Therefore, little can be done regarding prevention, except to maintain proper hand washing techniques and hygiene.