What is cryptosporidiosis?

Definition

Cryptosporidiosis is an infection of the intestine
that can cause severe diarrhea. Most healthy adults recover from this infection
within a few weeks, but it can be life-threatening for young children, the
elderly, and very sick people.

Causes

Cryptosporidiosis is caused by the parasite
Cryptosporidium parvum. These protozoa live
in the intestines of infected people and animals. They can also contaminate
objects and surfaces that people touch. They may also be in soil where food is
grown. The parasite can also be found in recreational waters where people
swim.

The infection is caused by swallowing the parasite. When the parasite enters the intestine, it comes out of its shell. It will multiply and may cause an infection. Eventually, it is passed from the body through a bowel movement.

Sources of cryptosporidiosis include contact with diapers or clothing that are contaminated with the infection; contact with animal feces by touching animals, cleaning cages, or visiting barns; and sexual activity that involves contact with feces. Another source of crypto is eating food grown in, or contaminated by, infected soil; drinking unpasteurized milk or other dairy products; drinking apple juice; and eating food that was handled by an infected person or a person who has washed his or her hands in contaminated water.

Another source of infection is water. One can be infected by accidentally swallowing water from contaminated recreational sites, such as lakes, oceans, bays, streams, rivers, hot tubs, swimming pools, and water parks; and by drinking water or using ice that is contaminated.

Risk Factors

People who are at increased risk for cryptosporidiosis include young children,
especially if they are in day care; day-care staff or those who work in other
group settings; people whose immune system is weakened by cancer, human immunodeficiency virus
(HIV) infection, acquired immunodeficiency syndrome
(AIDS), or an organ transplant; people who engage in
oral-anal sex; and international travelers, backpackers, hikers, and campers.

Symptoms

Symptoms usually begin about one week after infection, but some people will not have any symptoms. Symptoms consist mainly of watery diarrhea; stomach cramps; upset stomach, vomiting; slight fever; weakness; weight loss; and dehydration. The symptoms may come and go before the infected person feels better.

Screening and Diagnosis

A doctor will take one or more stool samples, which will be sent to a laboratory to be examined.

Treatment and Therapy

People with healthy immune systems usually recover without needing treatment. Recovery can take several weeks. The infected person with severe diarrhea may be given IV fluids and antidiarrheal drugs. Nitazoxanide is approved to treat the diarrhea associated with cryptosporidiosis in healthy people.

People with a weakened immune system (such as those living with AIDS) have a greater risk of getting this infection. They are also likely to have a more severe and longer infection. Also, they might become permanently infected.

Prevention and Outcomes

There are several important measures one can take to lower the risk of getting cryptosporidiosis. These measures include good hygiene, such as washing one’s hands after using the toilet, after changing a diaper, before handling or eating food, after contact with animals or soil, and after contact with infected people. Other measures are boiling water and avoiding swallowing water when swimming, washing vegetables that will be eaten raw, drinking only pasteurized milk and juice, and using precautions during sexual activity.

If infected with cryptosporidiosis, one should take measures to avoid spreading the parasite to others; these measures include frequent handwashing, avoiding swimming in recreational waters, and taking precautions during sexual activity.

Bibliography

Centers for Disease Control and Prevention. “Cryptosporidiosis.” Available at http://www.cdc.gov/parasites/crypto.

Despommier, Dickson D., et al. Parasitic Diseases. 5th ed. New York: Apple Tree, 2006.

Kapadia, Cyrus R., James M. Crawford, and Caroline Taylor. An Atlas of Gastroenterology: A Guide to Diagnosis and Differential Diagnosis. Boca Raton, Fla.: Pantheon, 2003.

Porter, Robert S., et al., eds. The Merck Manual Home Health Handbook. 3d ed. Whitehouse Station, N.J.: Merck Research Laboratories, 2009.

Roberts, Larry S., and John Janovy, Jr. Gerald D. Schmidt and Larry S. Roberts’ Foundations of Parasitology. 8th ed. Boston: McGraw-Hill, 2009.