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Cryptosporidium enteritis is an infection of the small intestine that causes diarrhea. The parasite Cryptosporidium causes this infection.
Cryptosporidium has recently been recognized as a cause of diarrhea worldwide in all age groups. It has a greater effect on people with a weakened immune system, including:
In these groups, this infection is not just bothersome, it also can lead to severe and life-threatening loss of muscle and body mass (wasting) and malnutrition.
The major risk factor is drinking water that is contaminated with feces. People at higher risk include:
Some outbreaks have been very large.
Outbreaks have been linked to:
Drinking from contaminated public water supplies
Drinking unpasteurized cider
Swimming in contaminated pools and lakes
- Abdominal cramping
- Diarrhea, which is usually watery, large-volume, and occurs many times a day
General sick feeling (malaise)
- Malnutrition and weight loss (in severe cases)
Exams and Tests
- Antibody test to see if Cryptosporidium is in the stool
- Intestinal biopsy (rare)
- Stool exam with special techniques (called AFB staining)
- Stool exam using a microscope to look for the parasites and their ova (eggs)
There are several treatments for cryptosporidium enteritis.
Drugs such as nitazoxanide have been used in children and adults. Other drugs that are sometimes used include:
These drugs often help only for a little while. It is common for the infection to return.
The best approach is to improve immune function in people who have a weakened immune system. In people with AIDS, this can be done by using highly active antiviral therapy. It can lead to a complete remission of cryptosporidium enteritis.
In healthy people, the infection will clear up, but it can last up to a month. In people with a weakened immune system, long-term diarrhea may cause weight loss and malnutrition.
- Inflammation of a bile duct
- Inflammation of the gallbladder
- Inflammation of the liver (hepatitis)
- Malabsorption (not enough nutrients being absorbed from the intestinal tract)
- Wasting syndrome (loss of body mass that causes extreme thinness and weakness)
When to Contact a Medical Professional
Contact your health care provider if you develop watery diarrhea that does not go away within a few days, especially if you have a weakened immune system.
Proper sanitation and hygiene, including handwashing, are important measures for preventing this illness.
Certain water filters can also reduce risk by filtering out the Cryptosporidium eggs. However, the pores of the filter must be smaller than 1 micron to be effective. If you have a weakened immune system, ask your doctor if you need to boil your water.
Lima AAM, Guerrant RL. Cryptosporidiosis. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 358.
White AC Jr. Cryptosporidium species. In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2009:chap 283.
Wright SG. Protozoan infections of the gastrointestinal tract. Infect Dis Clin N Am. Jun 2012;26(2):323-339.
- Last reviewed on 5/12/2014
- Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.
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This page was last updated: May 4, 2015