Cryptosporidium enteritis is an infection of the small intestine with the parasite Cryptosporidium that causes diarrhea.

Cryptosporidiosis

Cryptosporidium has recently been recognized as a worldwide cause of diarrhea in all age groups. Its major impact has been among those with a weakened immune system, including:

• People who take medications to suppress their immune system
• People with HIV or AIDS
• Transplant recipients

In these groups, this infection is not just bothersome, but it also can lead to severe and life-threatening loss of muscle and body mass (wasting) and malnutrition.

The major risk factor is swallowing water contaminated with feces. Those at higher risk include:

• Animal handlers
• Men who have sex with men
• People who are in close contact with infected people
• Young children

Some outbreaks have been very large.

Outbreaks are 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 many times a day
• Malaise
• Malnutrition and weight loss (in severe cases)
• Nausea

• Antibody test to see if Cryptosporidium are in the stool
• Intestinal biopsy (rare)
• Stool examination with special techniques (called AFB staining)
• Stool ova and parasites exam using a microscope

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:

• Atovaquone
• Paromomycin

However, these drugs often only help 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. This can be done by using highly active antiviral therapy in people with AIDS. 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 who are immunosuppressed, long-term diarrhea may cause weight loss and malnutrition.

• Cholangitis (inflammation of a bile duct)
• Cholecystitis (inflammation of the gallbladder)
• Hepatitis
• Malabsorption (not enough nutrients being absorbed from the intestinal tract)
• Pancreatitis
• Wasting syndrome (loss of body mass where the person becomes very thin and weak)

Notify your health care provider if you develop watery diarrhea that does not go away within a few days, especially if you have a suppressed 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 are immunosuppressed, ask your doctor if you need to boil your water.

Lima AAM, Guerrant RL. Cryptosporidiosis. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 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.