Microbial Risk Assessment Scenarios, Causality, and Uncertainty

Abstract

Difficulties establishing causality in biological systems are abundant— and they affect efforts to assess risks of importance in microbiology, such as likelihoods of infectious disease or development of antibiotic resistance. Consider the case in which von Pettenkofer openly challenged Robert Koch on whether Vibrio cholerae causes cholera by drinking some of the cholera bacillus (Microbe, May 2006, p. 223). When von Pettenkofer failed to develop symptoms of cholera, he concluded that V. cholerae does not cause the disease. Of course, subsequent experimental research established that this microbe causes cholera, and von Pettenkofer merely proved that exposure to the pathogen alone is not sufficient to cause this illness.