STREAM 4: OPTIMIZING TREATMENT

Overview

The influenza A viruses continue to present challenges for the treatment of influenza disease. These challenges relate to the substantial impacts of seasonal influenza infections, uncommon but serious avian influenza A(H5N1) and other zoonotic influenza infections, and pandemic (H1N1) 2009 influenza infections. Studies of experimental infection in animal models and human infections have increased our understanding of the pathogenesis of human disease, particularly serious life-threatening disease. However, our knowledge about the viral and host factors leading to severe influenza illness is incomplete, and improved clinical management strategies are needed. Comparison of the reconstructed 1918 pandemic A(H1N1) virus, avian A(H5N1) viruses and the pandemic (H1N1) 2009 virus with seasonal viruses has identified viral factors which enhance pathogenicity and the risk of secondary bacterial infections. In addition, careful analysis of pandemic H1N1 infections in previously healthy persons as well as persons with underlying medical conditions has provided new insights. However, these analyses also have raised new questions about the treatment of serious disease, particularly for ‘at risk’ patients such as pregnant women and individuals who are obese.