The landmark Study on the Efficacy of Nosocomial Infection Control definitively demonstrated that infection surveillance and control programs prevent hospital-acquired infections. The rise of public reporting, benchmarking, and pay for performance movements, however, has considerably changed the infection surveillance landscape in the 27 years since this study was published. Clinically nuanced surveillance definitions that served the profession well for many years have fallen into disfavor because their complexity and subjectivity allow for conscious and subconscious gaming. These limitations make it very difficult to determine whether changes in surveillance rates represent true changes in disease incidence or artifacts of definition subjectivity, external reporting pressures, and internal biases. Surveillance definitions need to be revised to enhance objectivity and to ensure that they detect clinically meaningful events associated with compromised outcomes. The US Centers for Disease Control and Prevention recently released modified definitions for ventilator-associated events that have the potential to make safety surveillance for ventilated patients more credible and useful once again.