ABSTRACT
I. BACKGROUND Mycobacterium avium subsp. paratuberculosis (also known as Mycobacterium paratuberculosis) causes Johne's disease in ruminant animals. This agent may or may not belong in a book on food safety. Although mounting evidence suggests that this organism may be a human pathogen, medical science has not classified this bacterium as a zoonotic agent. Unless M. paratuberculosis infects and causes disease in humans, it is not a microbial risk in foods. Critical analysis of the zoonotic potential of M. paratuberculosis is outside the scope of this chapter, but interested readers are referred to several authoritative reviews on the subject (1-8). It should be noted, however, that the Food Standards Agency of the U.K., in its draft plan, has elected to exercise the precautionary principle by invoking controls on M. paratuberculosis at multiple levels of the food chain (https:// w w w .foodstandards. gov .uk/consultations/map .htm).
