Abstract.  This article outlines a conceptual framework for examining recent outbreaks of E. coli O157:H7 infection associated with the consumption of beef in the United States. We argue that beef produced in this country is generally safer from bacteriological contamination than in the past. Paradoxically, increasing intensification and concentration in the meat subsector since the early 1980s has (a) altered agro-food ecology, including characteristics of foodborne bacteria and human physiology; (b) created conditions favorable for the rapid amplification of low concentrations of pathogens; and (c) reduced the beef industry's flexibility to introduce changes necessary to preclude and/or control the rapid spread of pathogens in meat and meat products. As a result, beef industry currently is capable of producing large quantities of bacteriologically safe meat while simultaneously becoming more vulnerable to food contaminations that can be fatal in some cases. The limitations and effectiveness of a new regulatory regime, the HACCP (Hazard Analysis and Critical Control Points) system as well as other efforts to decontaminate the beef supply are discussed.