Timeline: Swine Flu

The following is a timeline detailing the outbreak of the H1N1-strain of the Influenza-A flu virus.

-In March and April 2009, Novel Influenza A (H1N1) is a new flu virus of swine origin that first caused illness in Mexico and the U.S.

-On March 28, 2009, first known case of swine flu in Mexico

-On April 15, 2009, the first Novel H1N1 patient in the U.S. was confirmed by laboratory testing at the Center for Disease Control.

-On April 17, 2009, the second patient in the U.S. was confirmed.

-On April 22, 2009, the CDC activated its Emergency Operations Center to better concentrate the public health response.

-On April 26, 2009, the U.S. government declared a public health emergency and has been actively and aggressively implementing the nation’s pandemic response plan.

-On April 27, 2009, the U.S. confirmed the first death from the swine flu outside of Mexico.

-On May 4, 2009, the U.S. passed the 1000-case mark.

-On May 5, 2009, in the U.S. the second death was reported.

-As of May 25, 2009, according to the World Health Organization (WHO) the virus had spread to 43 countries with 12,515 reported cases and 91 associated deaths, and it has been assessed as having pandemic potential.

-On May 27, 2009, in the U.S. 11 deaths, and 7,927 confirmed cases.

-On June 11, 2009, the WHO signaled that a global pandemic of Novel Influenza A (H1N1) was underway by raising the worldwide pandemic alert level to Phase 6. At this time, more than 70 countries had reported cases of Novel Influenza A infection and there were ongoing community level outbreaks of Novel H1N1 in multiple parts of the world.

-On June 19, 2009, all 50 states in the U.S, the District of Columbia, Puerto Rico, and the U.S. Virgin Islands have reported novel H1N1 infection.

-On July 24, 2009, official reporting of individual cases of confirmed and probable Novel H1N1 infection was discontinued.

-As of July 24, 2009, in the U.S. states reported a total of 43,771 confirmed and probable cases of Novel Influenza A infection. Of those cases reported, 5,011 people were hospitalized and 302 people died.

-On July 29, 2009, Advisory Committee on Immunization Practices (ACIP) met to consider who should receive the 2009 H1N1 vaccine when it becomes available.

-As of September 13, 2009, the WHO reported worldwide cases more than 296,471 and at least 3,486 deaths.

-On September 15, 2009, Pennsylvanians have a new online resource to help them learn about and help control the spread of Novel H1N1 virus. The new website is

-On September 15, 2009, the FDA approved four vaccines against 2009 H1N1 infection.

-Update on September 22, 2009, Flu Screening Administration latest cases confirmed in Pa was 2,389 and 57 probable cases.

*A vaccine to protect against 2009 H1N1 infection is expected to be available in the U.S. by mid-October 2009. The first batch of 2009 H1N1 influenza vaccine is to be shipped the first week of October 2009.