H1N1 is a type A influenza virus.  In 2009, the world feared that a large outbreak was about to occur.  While the outbreak was maintained with relative success, H1N1 was the most common cause of the human flu in 2009.  In fact, the WHO (World Health Organization) declared a new strain of H1N1 officially as a pandemic.

The new strain of H1N1 was called the “swine flu” in the mainstream media.  Swine flu actually refers to the type of influenza that are endemic in pigs.  In the end, H1N1 spread across the world and caused the deaths of approximately 17,000 people by the end of 2009.  However, in August 2010, the WHO officially confirmed that the H1N1 pandemic was over and that the seasonal flu pattern had been returned to normal.

There have been several major incidents involving flu (caused by the H1N1 virus) throughout worldwide history.  The first main outbreak was the Spanish Flu, which occurred in 1918 and 1919.  This was caused by a strain of the avian (bird) flue and it killed between 50 and 100 million people during this time period.  The vast majority of these deaths were caused by a cytokine storm within the lungs.  This is where cytokines are released into the lung tissue, which eventually causes the destruction of lung tissue and allows liquid to secrete into the lungs.

Next, there was a much smaller outbreak at Fort Dix, New Jersey in the United States.  This swine flu version caused severe respiratory illness in just over a dozen soldiers, but only caused one death.  However, testing after the fact revealed that close to 230 soldiers had been inflected with the virus.  The most surprising detail is that no one has ever been able to determine what caused the outbreak and it is even more shocking because the soldiers were never shown to have had direct contact with pigs.

The 2009 outbreak in the United States has been linked to a combination of both swine and avian flu viruses.   The outbreak began in the US and Mexico in April of 2009.  The disease spread quite quickly.  The WHO actually moved the alert level to phase 6, marking the first time since 1968 that the alert had been raised this high.

In March 2010 the World Health Organization released preliminary figures about how many countries were affected and how many people fell victims to this virus.  In total, the 2009 H1N1 pandemic reached 214 countries and killed over 18,000 people.