In 2009, a new H1N1 influenza virus emerged, causing the first global flu pandemic in 40 years. Below is a timeline of major events that took place during the 2009 H1N1 pandemic. 2009 April 15 First human infection with new influenza A H1N1 virus detected in California. April 17 Second human infection with the new influenza A H1N1 virus detected in California about 130 miles away from first infection, with no known connection to previous patient. April 18 First novel 2009 H1N1 flu infections were reported by CDC to the World Health Organization (WHO) through the U.S. International Health Regulations...