Influenza virulence in obese mice

Obesity is associated with increased disease severity, elevated viral titers in exhaled breath and significantly prolonged viral shed during influenza A virus infection. Due to the mutable nature of RNA viruses, we questioned if obesity could influence influenza virus evolution. We show that viral spread and diversity is increased in obese mice at day 3 post infection. The obese-derived viral population exhibits increased viral replication and enhanced virulence upon inoculation of wild-type mice, which is shown to be sensitive to interferon levels. Treatment of obese mice with recombinant interferon reduces viral diversity and viral passage through lean, interferon-deficient mice increases viral pathogenicity.