The complex link between influenza and severe sepsis

Severe sepsis is traditionally associated with bacterial diseases. While fungi and parasites can also cause sepsis, they are significantly less common than bacterial causes. However, viruses are becoming a growing cause of severe sepsis worldwide. Among these viruses, influenza is crossing all geographic boundaries and is causing larger epidemics and pandemics. As a consequence, more critically ill patients with severe sepsis caused directly by influenza viruses, or indirectly by influenza-induced secondary bacterial infections are being admitted to hospitals worldwide. This manuscript aims to provide a pathophysiological and clinical update on the link between influenza and severe sepsis.