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Cryptosporidiosis is a diarrheal disease caused by microscopic parasites of the genus Cryptosporidium. Once an animal or person is infected, the parasite lives in the intestine and passes in the stool. The parasite is protected by an outer shell that allows it to survive outside the body for long periods of time and makes it very resistant to chlorine- based disinfectants. Both the disease and the parasite are commonly known as "crypto."
During the past two decades, crypto has become recognized as one of the most common causes of waterborne disease within humans in the United States. The parasite may be found in drinking water and recreational water in every region of the United States and throughout the world.
The most common symptom of cryptosporidiosis is watery diarrhea. Other symptoms include:
Some people with crypto will have no symptoms at all. While the small intestine is the site most commonly affected, Cryptosporidium infections could possibly affect other areas of the digestive or the respiratory tract.
Symptoms of cryptosporidiosis generally begin 2 to 10 days (average 7 days) after becoming infected with the parasite. In persons with healthy immune systems, symptoms usually last about 1 to 2 weeks. The symptoms may go in cycles in which you may seem to get better for a few days, then feel worse again before the illness ends.
Diagnosis of cryptosporidiosis is made by examination of stool samples. Because detection of Cryptosporidium can be difficult, patients may be asked to submit several stool samples over several days. Most often, stool specimens are examined microscopically using different techniques (e.g., acid-fast staining, direct fluorescent antibody [DFA] , and/or enzyme immunoassays for detection of Cryptosporidium sp. antigens).
Molecular methods (e.g., polymerase chain reaction – PCR) are increasingly used in reference diagnostic labs, since they can be used to identify Cryptosporidium spp. at the species level. Tests for Cryptosporidium are not routinely done in most laboratories; therefore, health care providers should specifically request testing for this parasite.
Cryptosporidium lives in the intestine of infected humans or animals. Millions of crypto germs can be released in a bowel movement from an infected human or animal. Consequently, Cryptosporidium is found in soil, food, water, or surfaces that have been contaminated with infected human or animal feces. If a person swallows the parasite they become infected. You cannot become infected through contact with blood. The parasite can be spread by
Most people who have healthy immune systems will recover without treatment. Diarrhea can be managed by drinking plenty of fluids to prevent dehydration. People who are in poor health or who have weakened immune systems are at higher risk for more severe and prolonged illness. Young children and pregnant women may be more susceptible to dehydration resulting from diarrhea and should drink plenty of fluids while ill. Rapid loss of fluids from diarrhea may be especially life threatening to babies. Therefore, parents should talk to their health care providers about fluid replacement therapy options for infants.
Anti-diarrheal medicine may help slow down diarrhea, but a health care provider should be consulted before such medicine is taken. Nitazoxanide has been FDA-approved for treatment of diarrhea caused by Cryptosporidium in people with healthy immune systems and is available by prescription. However, the effectiveness of nitazoxanide in immunosuppressed individuals is unclear.
HIV-positive individuals who suspect they have cryptosporidiosis should contact their health care provider. For those persons with AIDS, anti-retroviral therapy that improves the immune status will also decrease or eliminate symptoms of cryptosporidiosis. However, even if symptoms disappear, cryptosporidiosis is often not curable and the symptoms may return if the immune status worsens.