Influenza case definitions need to be fit for purpose

摘要

The authors concluded that the revised World Health Organization (WHO) influenza-like illness (ILI) defini- tion was an improvement on alternative definitions used by the United States Centers for Disease Control and Prevention (CDC) and the European Centre for Disease Prevention and Control (ECDC), based on its higher positive predictive value (PPV) and higher likeli- hood ratio for a positive test. However, these are not necessarily the most important measures of success for all ILI case definitions, and different definitions will be required for different purposes. Identify-ing influ- enza for surveillance, for case finding during activities to prevent spread during an epi-demic, and for case finding for participation in research studies of treat- ment or prevention of transmission will require differ- ent case definitions.