Causes

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

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

In these groups, this diarrheal infection is not just bothersome, but it also 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 fecal matter. Those at higher risk include:

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

Outbreaks have been linked to:

• Drinking from contaminated public water supplies
• Drinking unpasteurized cider
• Swimming in contaminated pools and lakes

Symptoms

• Abdominal cramping
• Diarrhea, which is usually watery, large-volume, and many times a day
• Malaise
• Malnutrition and weight loss (in severe cases)
• Nausea

Exams and Tests

• 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

Treatment

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
• Azithromycin
• Metronidazole
• Paromomycin
• Trimethoprim-sulfamethoxazole

However, these drugs often only help for a little while. It is common for the infection to return.

The best approach is to improve the immune status 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.

Outlook (Prognosis)

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.

Possible Complications

• 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)

When to Contact a Medical Professional

Notify your health care provider if you develop watery diarrhea that does not go away within a few days, especially if you are immunosuppressed.

Prevention

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.

Alternative Names

Cryptosporidiosis

References

Kirkpatrick BD, Sears CL. Cryptosporidiosis. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, PA: Saunders Elsevier; 2007:chap 371.

Update Date: 5/25/2012

Reviewed by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; 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. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.