Oysters collected at sites along Chesapeake Bay in Maryland were found to be contaminated with Cryptosporidium parvum, a parasite that can cause serious gastrointestinal illness. Oysters in natural waters harbor infectious C. parvum oocysts (the infectious agent of Cryptosporidium) and can serve as mechanical vectors of this pathogen.. Susceptibility to Cryptosporidium infection can vary between individuals. Children, the elderly, and those with compromised immune systems (such as those with AIDS) are most at risk. Serious infection can result in debilitating, potentially life-threatening diarrhea lasting for days or weeks.

Applied and Environmental Microbiology (1998;64(3):1070-1074)

COMMENT: I find it useful to document how science continues to confirm the validity of avoiding scavenger animals if one wants to stay optimally healthy. Shellfish and pork should be avoided if one wants to limit their exposure to potentially infectious agents. In newsletter #30 I quoted the source the reference that has also identified pork as being linked with hepatitis E.