Efficacy of surveillance for 2009 H1N1 pandemic within a healthcare system.

In the fall of 2009, our hospital introduced a surveillance system to monitor the increase in cases of H1N1 pandemic influenza A virus infection. The system involved tracking cases of influenza-like illness in the emergency department, the outpatient clinics, and the inpatient wards as well as specimens with positive polymerase chain reaction results reported by the microbiology laboratory. Our data correlated well with national and regional data.