2009 swine flu pandemic timeline summary

Timeline summary of the 2009 swine flu pandemic

The 2009 swine flu pandemic was an influenza pandemic that lasted from early 2009 to late 2010, involving the H1N1 influenza virus. This article provides a timeline summary of the key events during the pandemic.

Background

The 2009 swine flu pandemic was caused by a new strain of the H1N1 influenza virus, which was first detected in Mexico in April 2009. The virus quickly spread to other countries, leading to widespread outbreaks and prompting the World Health Organization (WHO) to declare a pandemic.

Timeline

April 2009

In April 2009, the first cases of the H1N1 virus were reported in Mexico. The virus was identified as a novel strain of influenza, and cases began to appear in the United States and Canada. On April 25, the WHO declared the outbreak a "public health emergency of international concern."

May 2009

By May, the virus had spread to several countries across different continents. The WHO raised the pandemic alert level to Phase 5, indicating that a pandemic was imminent. Efforts to contain the virus included travel advisories and increased surveillance.

June 2009

Map showing confirmed community outbreaks of H1N1

On June 11, 2009, the WHO officially declared the H1N1 outbreak a pandemic, raising the alert level to Phase 6. This was the first pandemic declaration since the 1968 Hong Kong flu. The virus continued to spread globally, with confirmed cases in over 70 countries.

July 2009

In July, the number of cases continued to rise, with significant outbreaks reported in the Southern Hemisphere, particularly in Australia and Argentina. The WHO emphasized the importance of vaccination and antiviral treatments.

August 2009

By August, the focus shifted to preparing for the upcoming flu season in the Northern Hemisphere. Countries began stockpiling vaccines and antiviral drugs in anticipation of increased cases.

September 2009

Map of H1N1 cases in the USA as of June 3, 2009

In September, vaccination campaigns were launched in several countries, targeting high-risk groups such as healthcare workers, pregnant women, and individuals with chronic health conditions.

October 2009

The vaccination efforts intensified in October, with millions of doses distributed worldwide. The virus continued to circulate, but the availability of vaccines helped mitigate the impact of the pandemic.

November 2009

By November, the number of new cases began to decline in many regions, although the virus remained active. Public health officials continued to monitor the situation closely.

December 2009

In December, the WHO reported that the pandemic was showing signs of peaking in some areas, but cautioned that the virus could still cause significant illness and death.

Aftermath

The pandemic officially ended in August 2010, when the WHO declared that the H1N1 virus had transitioned into a post-pandemic period. The virus became part of the regular seasonal influenza viruses, continuing to circulate globally.

Related pages

• Influenza pandemic
• World Health Organization
• H1N1 influenza virus