Bounding Resistance Risks for Penicillin
Chapter 8 calculated a plausible upper bound for the fraction of disease preventable by blocking a specific causal pathway in a complex, uncertain biological system, using smoking-induced lung cancer as an example. This example required considering relevant biological knowledge and biomarker data in some detail. But plausible upper bounds on preventable risks can also be developed using much less detailed knowledge, and data that are relatively easy to obtain and understand, for many other systems. This chapter develops bounding calculations for preventable fractions in a very different complex uncertain system: the highly uncertain set of pathways and mechanisms (if any) leading from the use of penicillin in food animals to resistance to penicillin drugs in human patients. Unlike the campylobacteriosis and virginiamycin case studies in Chapters 6 and 7, respectively, no individual-level exposure and response data are provided for this penicillin risk assessment.