Cryptosporidiosis: A Guide for Persons with HIV/AIDS

What Is Cryptosporidiosis?

Cryptosporidiosis (krip-toe-spo-rid-e-o-sis), often called "crypto," is a disease caused by a single-cell parasite, cryptosporidium parvum, which is too small to be seen without a microscope. Although sometimes people infected with cryptosporidium don't get sick, when they do get sick they can have watery diarrhea, stomach cramps, an upset stomach, or a slight fever. The first symptoms of cryptosporidiosis may appear 2 to 10 days after a person becomes infected. Crypto causes more severe and longer illness in persons with AIDS than in other people.

How Does Cryptosporidiosis Affect Someone with a Weakened Immune System?

In persons with severely weakened immune systems, especially those with AIDS, cryptosporidiosis can be serious, long-lasting and sometimes deadly. If your CD4 cell count is below about 200, you are more likely to have diarrhea and other symptoms for a long time. If your CD4 count is above 200 and you get crypto you may feel better in about one to three weeks, but you might still have the infection and be able to pass it to others even after you feel better. If you are still infected and your CD4 count later drops below 200, the crypto may act up again.

How Is Cryptosporidiosis Spread?

You can get crypto when you put anything in your mouth that has touched the "stool" (that is, bowel movement) of a person or animal with cryptosporidiosis. Cryptosporidia are too small to be seen without a microscope by the naked eye. Cryptosporidiosis is not spread in blood. The most common ways you can get crypto are touching your mouth before washing your hands and after touching the stool of infected persons, or touching the stool of infected animals, or touching soil or objects contaminated with stool. You can also get a cryptosporidium infection by drinking water contaminated with stool or eating food contaminated with stool.

What Is the Treatment for Cryptosporidiosis?

Some drugs may reduce the symptoms of crypto, but no drug can cure it. New drugs are being tested. If you think you have crypto talk about testing and treatment with your health care provider. You can also drink an oral rehydration therapy mix, to avoid getting dehydrated. You can buy these mixes at drug stores and sports stores.

How Can I Prevent Cryptosporidiosis?

There are many things that you can do to reduce your risk of getting crypto. The more things you do, the better your chances of avoiding cryptosporidiosis. These actions will also help protect you against other diseases.

  1. Wash your hands. Washing your hands often with soap and water is probably the single most important thing you can do to avoid crypto and other illnesses. Wash your hands well after touching children in diapers; after touching clothing, bedding, or bed pans soiled by someone who has diarrhea; after gardening; any time you touch pets or other animals; and after touching anything that might have had contact with even the smallest amounts of human or animal stool. Even if you wear gloves when you do these activities you will still need to wash well when you finish. Always wash your hands before preparing food to avoid spreading any infections you might have to others. Supervise hand washing by HIV-infected children.

  2. Avoid sex that involves contact with stool. Infected persons may have cryptosporidium on their skin in the genital area, including the thighs and buttocks. However, since you cannot tell if a person has cryptosporidiosis, you may want to take these precautions with any sex partner:

    • don't kiss or lick the genitals or anus
    • wash your hands well after touching your partner's anus or rectal area

    Rimming (licking the anus) is so likely to spread infection that you should avoid it, even if you and your partner wash well before.

  3. Avoid touching farm animals. If you touch a farm animal, particularly a calf, lamb or other young animal, or visit a farm where they are raised, wash your hands well with soap and water before preparing food or putting anything into your mouth. Do not touch the stool of any animal, including any stool you find on your shoes or boots.

  4. Avoid touching the stool of pets. Most pets are safe to keep. However, you should have someone else clean the litter boxes of cats and dispose of the stool of other animals. If someone else cannot help you, use disposable gloves when handling anything that might be contaminated by the stool of pets. Wash your hands after taking off the gloves. The risk of getting crypto is greatest from pets less than six months old and animals that have diarrhea. Older animals can also have cryptosporidiosis, but they are less likely to be sick or to pass the disease to humans. If you are getting a puppy or kitten that is less than six months old, have your veterinarian test the animal for crypto before bringing it home. Do not adopt a stray animal. If your pet develops diarrhea later, have your veterinarian test it for cryptosporidiosis again. Wash your hands after touching any animal.

  5. Wash and/or cook your food. Vegetables and fruits that may have touched soil or water might be contaminated. Wash vegetables or fruit you will eat uncooked. If you choose to take extra steps to make your water safe (see below for ways to make sure that your water is safe), you should rinse your fruits and vegetables only with a stream of this safe water. You can also peel fruit that you will not cook. Do not eat or drink unpasteurized milk or dairy products. Cooking kills cryptosporidium. Cooked food and processed or packaged foods are probably safe after cooking or processing if they are not handled by an infected person.

  6. Be careful when swimming in lakes, rivers, pools, or jacuzzis. Be careful when swimming in lakes, rivers, public pools, or jacuzzis because of the risk of swallowing contaminated water. If you do go swimming, don't swallow any water.

  7. Drink safe water. Don't drink water directly from lakes, rivers, streams, or springs. You may wish to avoid drinking tap water. Because public water quality and treatment varies in the United States, you should check with your local health department and water utility to see if they have made any recommendations for HIV-infected persons about drinking local tap water. There are three extra measures you may wish to take to ensure that your drinking water is safe: boil your water, filter your water with certain home filters, or drink certain types of bottled water. Processed bubbly drinks in cans or bottles are probably safe also. If you choose to take these extra measures, take them all the time, not just at home. If your local public health office warns you to boil your water, don't drink tap water unless you make it safe. Here are some extra measures you may wish to take to make sure your water is safe:

    1. Boiling water: Boiling is the best extra measure you may wish to take to be sure that your water is free of cryptosporidium and any other germs. You yourself can see that the water was boiled and that it was stored safely. Bring your water to a rolling boil and let it boil for one (1) minute. After your boiled water cools, put it in a clean bottle or pitcher with a lid and store it in your refrigerator. Use the water as you normally would. Ice made from contaminated water can also contain cryptosporidium. To be safe, make your ice from boiled water. Water bottles and ice trays should be cleaned with soap and water before you use them. Do not touch the inside of your water bottles or ice trays. If you can, clean your water bottles and ice trays yourself.

    2. Filtering tap water: There are many different kinds of home water filters, but not all of them remove cryptosporidium. If you want to know if a particular filter will remove cryptosporidium, call NSF at 1-800-673-8010. NSF is an independent testing group. If you want a list of filters that remove cryptosporidium, call, write or fax NSF and ask for their "Standard 53 Cyst Filters" list. You can reach NSF at:

      NSF International
      3475 Plymouth Road
      P.O. Box 130140
      Ann Arbor, MI 48113-0140
      1-313-769-0109 (fax)

      If you choose to buy a filter, look for this information on the label:

      Water Filter Label Information
      What to Look for on the Filter Label

      Promises the filter removes cryptosporidiumDoes not promise the filter removes 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

      Nominal one micron size

      Effective against giardia

      Effective against parasites

      Carbon filter

      Water purifier

      EPA approved

      Activated carbon

      Removes chlorine

      Ultraviolet light

      Pentiodide resins

      Filters collect germs from your water, so you should have a friend who is not HIV positive change the filter cartridges for you or wear gloves and wash your hands if you must do it yourself. Filters may not remove cryptosporidium as well as boiling, because some filters may not seal tightly or they may have other defects.

    3. Bottled water: If you choose to drink bottled water, read the bottle label and look for this information:

      Bottled Water Label Information
      What to Look for on the Bottled Water Label

      Promises the water has no cryptosporidiumDoes not promise the water has no cryptosporidium
      Reverse osmosis treated


      Filtered through an absolute one micron or smaller filter








      Ultraviolet light treated

      Activated carbon-treated

      Carbon dioxide-treated

      Ion exchange-treated




      Well water

      Artesian well water

      Spring water

      Mineral water

    4. Store-bought bubbly drinks: Although no group tests prepared bubbly drinks like sodas and beer for cryptosporidium, the water that is used for these drinks is usually filtered or heated enough to kill cryptosporidium. Cryptosporidium is also killed when the drinks are mixed in the factory. So, sodas and other canned or bottled bubbly drinks can be assumed to be safe. Sodas not in a bottle or can or non-bubbly drinks may be made with tap water so they may not be safe. Hot tea and coffee also have no cryptosporidium.

  8. Take extra care when traveling. If you travel to developing nations you may be at a greater risk of getting cryptosporidiosis. Foods and drinks, in particular raw fruits and vegetables, tap water or ice made from tap water, unpasteurized milk or dairy products, and items purchased from street vendors may be contaminated with cryptosporidium. You should avoid these items. Steaming hot foods, fruits you peel yourself, bottled and canned processed drinks and hot coffee or tea are probably safe to drink. Avoid swallowing water when swimming and avoid swimming in water that may be contaminated with human or animal waste. Talk with your health care provider about other precautions you may want to take when you travel abroad, especially in developing countries.

For more information on cryptosporidiosis, call the CDC AIDS Hotline at 1-800-342-AIDS.