Cryptosporidiosis (or “Crypto” for short) is a disease that causes watery diarrhea. It is caused by microscopic germs—parasites called Cryptosporidium. Although Crypto can affect all people, some groups are likely to develop more serious illness. For people with weakened immune systems, symptoms can be severe and could lead to severe or life-threatening illness. Examples of people with weakened immune systems include those with HIV/AIDS; those with inherited diseases that affect the immune system; and cancer and transplant patients who are taking certain immunosuppressive drugs.
Crypto lives in the gut of infected humans or animals. An infected person or animal sheds Crypto parasites in their poop. An infected person can shed 10,000,000 to 100,000,000 Crypto germs in a single bowel movement. Shedding of Crypto in poop begins when symptoms like diarrhea begin and can last for weeks after symptoms stop. Swallowing as few as 10 Crypto germs can cause infection.
Crypto can be spread by:
Crypto is not spread through contact with blood.