Epidemiology

Epidemiology is the study of disease in a population. In terms of food safety, epidemiology is used by industry, academia and government agencies to study the patterns of outbreaks among the populace and identify risk factors (e.g. the emergence of antibiotic-resistance, the prevalence of particularly virulent strains, certain regions or products that are repeat offenders etc).

In addition to pooling information about human cases, epidemiology can also be applied to the bacteria itself. Advanced testing allows us to characterize bacteria on a variety of levels, from the general species (E. coli) to the specific strain (E. coli O157:H7). In addition, each strain of E. coli O157 can be further characterized, to distinguish one strain from another and determine whether multiple strains implicated in illness are from a common source. These details create a picture of risk – epidemiology seeks to map this risk as well as track sources and patterns of outbreaks.

In the reactive sense, epidemiology is used to trace the source of the pathogen after a problem has been identified and a recall issued, by tracking its movements throughout the food supply (the vehicles), and working backwards to determine a source. Ultimately the goal is to determine the fateful errors that resulted in contamination one by one, eventually pinpointing the root-cause.