Cryptosporidiosis (also referred to as Crypto) is a gastrointestinal illness that results from exposure to the organism Cryptosporidium parvum (C. parvum). Cryptosporidiosis rose to public attention in the United States in 1993 when more than 100 people died and more than 400,000 people were sickened by Crypto in Milwaukee, Wisconsin.

Cryptosporidiosis is primarily a waterborne illness. People get infected from drinking inadequately treated drinking water, or from swallowing or drinking untreated water from a lake, stream, or swallowing water from a recreational swimming pool. People can become infected with Crypto through contact with the contaminated fecal matter of humans or animals carrying the organism, usually by swallowing food or liquid that has had contact with the contaminated fecal matter. Children at day care centers, day care workers, and health care workers interacting with infected individuals must be vigilant about sanitation to reduce the spread of the organism. Unwashed fruits and vegetables...