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Cryptosporidium is a parasite that causes diarrhea
Cryptosporidium infections (cryptosporidiosis) have been reported in
humans and a wide variety of animals such as cattle, dogs, and cats.
Infected humans and animals shed the parasite in their feces (stool).
As a result, Cryptosporidium can be found in environments contaminated
by the feces of infected humans or animals. Lakes, rivers, reservoirs,
and shallow wells may be affected. The parasite is highly resistant to
chlorine, which is commonly used as a disinfectant in water treatment
plants and recreational water venues, such as swimming pools and water
Transmission can occur by coming into direct or indirect contact with feces of infected humans or animals, including:
Symptoms appear 1 to 12 days or more, after exposure, on average 7 days.
The most common symptoms are diarrhea and stomach cramps. Fever,
vomiting, and nausea may occur. Some infected people have no symptoms.
People with normal immune systems usually have symptoms for one to two
weeks and then recover fully. However, people with weakened immune
systems, such as cancer patients, organ transplant recipients, and
HIV-infected persons, may have more severe diarrhea that can persist
long enough to become life-threatening.
Replacement of fluid lost through diarrhea may be necessary.
Sometimes, treatment with medication is also necessary. Patients with
severe or long-lasting diarrhea should consult their health care
Tests are available to look for Cryptosporidium in feces and in water
The Environmental Protection Agency (EPA) requires that certain large
water companies routinely test water for Cryptosporidium. Health care
providers can do tests to help determine if a person is infected with
Cryptosporidiosis can be prevented
People with weakened immune systems may want to take extra action to reduce the risk:
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