Cryptosporidium

What is Cryptosporidium?

Cryptosporidium is a one-celled parasite that can cause a gastrointestinal illness called cryptosporidiosis in humans and animals.

What are the symptoms?

Symptoms can include diarrhea (sometimes watery), abdominal cramps, headaches, nausea, vomiting, and a low-grade fever starting from two to 12 days after exposure, usually around seven days. These symptoms can last for weeks and may result in weight loss and dehydration. Symptoms are more severe and can lead to death for people with weakened immune systems from chemotherapy, bone marrow transplant, HIV or AIDS, malnourishment, or who are either very young or old. 

How does a person get a Cryptosporidium infection?

People are most often infected by eating contaminated food, swallowing contaminated water, or by touching their mouth with contaminated hands after touching infected animals or humans. 

Common water exposures include:

• Drinking untreated water or using untreated ice from lakes, rivers, springs, ponds, streams, or shallow wells.
• Swallowing contaminated water from recreational water sites, such as pools, splash pads, or lakes.
• Eating contaminated food.
• Drinking contaminated food like unpasteurized (or “raw”) milk or apple cider.

Other common exposures:

• Touching your mouth with contaminated hands after you:
  • Care for someone with a cryptosporidiosis infection.
  • Change a diaper.
  • Come in contact with an infected animal’s environment, including contact with its bedding, toys, or bathroom area).
  • Touch clothing or shoes worn in a contaminated environment.
• Put a contaminated object in your mouth.
• Exposure to poop through sexual contact.

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

Who gets Cryptosporidium infection?

Infection can be severe and persistent in persons who have weakened immune systems. 

How can I prevent Cryptosporidium infection?

Wash your hands often with soap and water. During boil water advisories, use water that has been boiled and cooled, filtered, or safely bottled to wash dishes and food.

• Always wash your hands before you handle food and dishes and after you use the toilet, garden, change diapers, or handle pets or farm animals – particularly poultry and young animals like calves.
• Wash fruits and vegetables with safe water, especially if you plan to eat them raw. You can also peel fruit or vegetables that you will not cook.
• Wash utensils, cutting boards, and counters after handling raw poultry, and cook poultry until there is no pink meat.
• Avoid unpasteurized (raw) milk or dairy products and unpasteurized juices. 
• Never cook for other people if you have diarrhea.
• 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 abroad where water may not undergo the same treatment as in the United States. Foods and drinks with a higher risk for contamination include raw fruits and vegetables, tap water or ice made from tap water, unpasteurized milk or dairy products, and items from street vendors. Talk to your health care provider about precautions you might want to take when traveling abroad.

Pay attention to health advisories and boil water notices. During boil water notices, always boil, filter, or use bottled water:

• Boiling water is the best way to ensure water is safe. Bring the water to a rolling boil for several minutes. After it cools, refrigerate it in clean containers with lids. Use boiled water to brush your teeth, make ice, rinse food that will not be cooked, and make baby formula or coffee (coffee makers do not get hot enough). Check if any purchased prepared food and beverages were made with safe water.
• Water filters 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," or "absolute micron size of one micron or smaller." To check about a particular filter, contact NSF International (3475 Plymouth Road, PO Box 130140, Ann Arbor, MI, 48113-0140, 1-800-673-8010, fax: 1-313-769-0109). Ask for a list of "Standard 53 Cyst Filters."
• Bottled water may vary in origin, quality and treatment of water before it is bottled. Generally, water is free of Cryptosporidium if labelled: "Reverse osmosis treated," "distilled," or "filtered through an absolute one micron or smaller filter." Carbonated water in cans or bottles is usually safe to drink. 

What is the treatment for a Cryptosporidium infection?

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

More Resources

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