Cryptosporidium parvum (C. parvum)

This is a parasitic protozoa that causes the disease known as Cryptosporidiosis. It occurs in all mammals, and for humans, most commonly in ages 1 through 12. It is found in anything that can be ingested, such as food, drinks, or public water sources (i.e. pool). C. parvum grows best on warm days and while there is food and water around.

Time of Onset and Duration

Illness follows incubation period of 7-10 days, so after 7-10 days of contracting the disease, symptoms will start to show. Usually, the disease lasts 2-14 days, but excretion of oocysts can last for months afterward.

Contraction, Prevention, and Symptoms

C. parvum is contracted when a person swallows anything that is contaminated, such as food/drinks or pool water. Some symptoms are, nausea, vomiting, cramping, fevers, and large amounts of diarrhea. C. parvum can be prevented through the use of good hygien, boiling water before use, and washing fruits and vegetables before eating.


There is no cure for C. parvum, a person can only treat the symptoms. Nitazoxanide is the current treatment for the C. parvum diarrhea symptoms. Only use if if you are immunocompromised.