Surveillance definitions are designed to study and identify trends in a population.  The application of these standardized criteria, and only these criteria, in a consistent manner allows confidence in aggregation and analysis of data. Alternatively, clinical diagnoses are patient specific. Unlike surveillance definitions, ALL available diagnostic data are considered in a clinical diagnosis, including additional clinical, epidemiological and laboratory data not used for NHSN surveillance. Therefore, a clinical diagnosis may be made even when a surveillance definition may not be met and vice versa is also true.  Failure to meet a surveillance definition should never impede or override clinical judgment during diagnosis, management, or treatment of patents. Nor should failure to meet clinical definitions result in non-reporting to NHSN infections meeting the NHSN surveillance criteria.