The risk of waterborne cryptosporidiosis from public drinking water varies depending on the quality of the source water and the type of water treatment system. People suffering from immune system disorders, such as AIDS, should be especially aware of the risks associated with cryptosporidium, Hairston says. Filter water to remove both the cryptosporidium oocysts and cysts of another potentially dangerous parasite, Giardi lamblia, says Hairston. These filters may attach to the faucet or feature a pour-through design. Symptoms usually develop from two to 10 days after infection.
Drinking water is only one source of exposure to cryptosporidiosis.
Swallowing a small amount of water while swimming, even if the water is chlorinated, can result in infection. The parasite also may be spread in uncooked foods and beverages. Good hygiene is essential in households where cryptosporidiosis has occurred in order to prevent further spread of the disease.