The 1918-19 influenza pandemic revisited.

The worldwide influenza outbreak of 1918-19 was a medical catastrophe, causing the deaths of around 50 million people. There is evidence however that the major wave, in November 1918, was not part of the pandemic that started in the summer of 1918. The virus responsible for the major wave has been isolated but the structural features responsible for its severity remain incompletely understood. In 1918-19 influenza was an infection so little understood that the government was unsure of what action to take. In contrast, during the pandemic starting in 2009, international and national bodies used many means of communication to keep the public fully informed, with beneficial results. In addition, antiviral agents, a vaccine and antibiotics to treat secondary infection were available. Such a response is possible only with appropriate funding and a comprehensive medical infrastructure, making the potential outbreak of severe influenza in a poor part of the world a matter of grave concern.