What is Cryptosporidium?

Cryptosporidium is a one-celled parasite that can cause a gastrointestinal illness called cryptosporidiosis.

Where does it come from?

Cryptosporidium occurs in the feces of infected animals or humans. It is environmentally resistant and may survive outside the body for long periods of time. To become infected, a person must consume contaminated food or water, including from streams or rivers.

What are the symptoms of cryptosporidiosis?

Diarrhea, abdominal cramps, headaches, nausea, vomiting and a low-grade fever. These symptoms can last for weeks and may result in weight loss and dehydration. Symptoms are more severe for people with weakened immune systems and can lead to death.

Who are people with weakened immune systems?

Those on chemotherapy, organ or bone marrow recipients, persons with HIV or AIDS, malnourished children, the very young and the very old.

When do symptoms appear?

From two to 12 days after ingestion. The average is seven days.

How is it spread?

A person can be infected by consuming contaminated water or food. Direct or hand-to-mouth transfer of the parasite from human or animal feces can also cause infection. Streams or lakes may be contaminated by animal feces and infect swimmers or hikers drinking untreated water.

What is the treatment for cryptosporidiosis?

If you think you may have cryptosporidiosis, see a health care provider, especially if you have a weakened immune system. For people with healthy immune systems, most recover without treatment; however, treatment is available that may reduce symptoms

Who is at risk?

Anyone exposed to feces is at risk. This include those drinking contaminated water while camping or traveling, child care workers, young children who attend child care centers, persons exposed to human feces by sexual contact, and caregivers who might come in contact with feces while caring for a person infected with cryptosporidiosis. Farm animals and farm products (unpasteurized apple cider) have caused exposures. Children are especially susceptible because they put so many things into their mouths.

How common is cryptosporidiosis in Washington?

Cryptosporidiosis became a reportable illness in Washington in 2001. Originally considered a parasite of animals, reptiles and birds, it first was detected as a source of illness for humans in 1976. Health officials now believe Cryptosporidium has been causing human illnesses for a long time, but it was overlooked due to difficulties in testing and diagnosis. A specific parasite test for Cryptosporidium can be done at the request of a health care provider.

How can I ensure my water is safe to drink?

Pay attention to health advisories and boil water notices. To ensure your drinking water is safe during boil water notices, always boil, filter or use bottled water:

  • Boiling water is the best way to ensure your water is free of Cryptosporidium and other microorganisms. Bring the water to a rolling boil for one minute. After it cools, put it in the refrigerator in clean bottles or pitchers with a lid. Use boiled water to brush your teeth, make ice, rinse food that will not be cooked and to make baby formula or coffee (coffee makers do not get hot enough to kill Cryptosporidium).
  • Water filters can collect Cryptosporidium and other microorganisms from the water, but may not be as effective as boiling. Read the water filter label. Only those with the following messages are effective for Cryptosporidium: "Tested and certified by NSF standard 53 for cyst removal," "Tested and certified by NSF standard 53 for cyst reduction," "Reverse osmosis," "Absolute micron size of one micron or smaller." To find out if a particular filter removes Cryptosporidium, contact NSF International (3475 Plymouth Road, PO Box 130140, Ann Arbor, MI, 48113-0140, 1-800-673-8010, fax: 1-313-769-0109), an independent testing group. Ask for a list of "Standard 53 Cyst Filters."
  • Bottled water may be a reasonable alternative to tap water, but the origin, quality and treatment of water before it is bottled varies considerably among companies and even among brands of water produced by the same company. Generally, water that is labeled as follows is free of Cryptosporidium: "Reverse osmosis treated," "Distilled," "Filtered through an absolute one micron or smaller filter." Carbonated water in cans or bottles is usually filtered or heated enough to remove Cryptosporidium. Fountain drinks made from tap water should be avoided during boil water notices.

What else can I do to avoid cryptosporidiosis?

The single, most effective way to avoid illness is to wash your hands often with soap and water. During boil water advisories, use water that has been boiled and cooled, filtered or safely bottled for washing dishes, fruits and vegetables.

  • Always wash your hands before handling food and dishes and after using the toilet, gardening, changing diapers or handling pets or farm animals, particularly young animals like calves.
  • Wash fruits and vegetables with safe water, especially if you plan to eat them raw. You can also peel fruit that you will not cook.
  • Never cook for other people if you have diarrhea.
  • Avoid unpasteurized milk or dairy products and unpasteurized juices. Cooking kills Cryptosporidium and other microorganisms.
  • Do not swim in public pools or lakes if you have diarrhea.
  • Don't swallow any water from lakes, rivers, pools or jacuzzis. Water swallowed accidentally while swimming may contain the organism.
  • Take care when traveling in developing countries. Foods and drinks, in particular raw fruits and vegetables, tap water or ice made from tap water, unpasteurized milk or dairy products, and items from street vendors may be contaminated with Cryptosporidium. Talk to your health care provider about other precautions you may want to take when traveling abroad.