Cryptosporidiosis
Proper sanitation and hygiene, including handwashing, are important measures in the prevention of this illness.
Certain water filters can also reduce risk by filtering out the eggs of the cryptosporidium organism. However, the pores of the filter must be smaller than 1 micron to be effective. If you are immunosuppressed, ask your doctor if you need to boil your water.
Montes M, DuPont HL. Enteritis, Enterocolitis and Infectious Diarrhea Syndromes. In: Cohen J, Powderly WG, Berkley SF, et al, eds. Infectious Diseases. 2nd ed. Philadelphia, PA: Mosby Elsevier; 2004: chap 43.
Kirkpatrick BD, Sears CL. Cryptosporidiosis. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, PA: Saunders Elsevier; 2007: chap 371.