Figure 4.

Virus lung replication and development of acute respiratory distress syndrome (ARDS) in oseltamivir-treated mice infected with lethal dose of A/Anhui/1/2013 (H7N9) influenza virus. Virus titers (A, C, and E) were determined 3, 6, and 9 days postinfection (p.i.) in the lungs of BALB/c mice (3 mice per group) by 50% tissue culture infectious dose (TCID₅₀) assay on Madin-Darby canine kidney cells. Levels of hypoxemia (B, D, and F) were determined on day 9 p.i. by arterial blood gas analysis as described in the Figure 1 legend. Ratios ≤300 indicate ARDS [18].