Reliable and rapid diagnosis of influenza A H1N1 is essential to initiate appropriate antiviral therapy and preventive measures. We analysed the differences in clinical presentation and laboratory parameters between emergency department patients with PCR-confirmed H1N1 influenza infection (n = 199) and those with PCR-negative influenza-like illness (ILI; n = 252). Cough, wheezing, leucopenia, eosinopenia and a lower C-reactive protein remained significant predictors of H1N1 influenza. Proposed combinations of clinical symptoms with simple laboratory parameters (e.g. reported or measured fever and either cough or leucocytes <8.5 × 10(9) /L) were clearly superior to currently used official ILI case definitions that use clinical criteria alone.
Keywords: Berlin; H1N1; PCR; clinical presentation; influenza A; laboratory values.
© 2013 The Authors Clinical Microbiology and Infection © 2013 European Society of Clinical Microbiology and Infectious Diseases.