When was the worst case of Swine Flu?

The 1918 flu pandemic

- The 1918 flu pandemic was the most severe pandemic in recent history. It was caused by an H1N1 influenza virus with genes of avian origin.

- The pandemic lasted from January 1918 to December 1920 and infected about 500 million people worldwide—about one-third of the planet’s population at the time.

- The death toll is estimated to have been at least 50 million worldwide with about 675,000 occurring in the United States.

- The 1918 pandemic was particularly deadly for young adults, who were more likely to develop severe complications of the flu.