History of Pandemics

In the 20th century, the appearance of new subtypes of the influenza virus caused three pandemics, which have spread throughout the world in less than 1 year.
 
The famous 1918 Spanish flu that killed 50 million people isn't the only pandemic that caused a global health crisis in the past century. Two other pandemics, though much milder than the more well-known one, also strained national health-care systems, researchers say. The 1957 Asian flu killed at least 2 million, and about 700,000 died during the 1968 Hong Kong flu.
 
Although the origin of the 1918-19 pandemic is not clear, recent pathology analysis of 1918/19 tissue samples from US WWI soldiers place the likely beginnings in Kansas, where the virus was likely passed from birds to swine to people. It then travelled easily across the Atlantic with troop deployment and press censorship during the war prevented information from being shared among countries and scientists, except in Spain, which was a neutral country and open to sharing information on their pandemic – hence the reference to “Spanish”. We now know that the 1957-58 and the 1968-69 pandemics were both caused by viruses which contained a genetic combination of information from a human influenza virus and an avian one.
 

  • 1918-19 Spanish flu [caused by A (H1N1)], lead to a record number of deaths caused by the influenza virus: more then 500,000 people in the USA, more than 50,000 in Canada and almost 50 million people worldwide. The death came either during the first couple of days after the infection, or later due to unexpected complications. Half of the people who died were healthy and young. The H1N1 virus has been reintroduced among the human population in the 1970’s and it circulates among us, even today.
  • 1957-58 Asian flu [caused by the A (H2N2) virus], is held responsible for about 70,000 human deaths in the USA. It was first identified in February 1957 in China but it rapidly spread in the USA in a couple of months (June 1957).
  • 1968-69 Hong Kong flu [caused by the A (H3N2) virus], killed almost 34,000 people in the USA. This virus also originates from Asia: it was discovered in Hong Kong in 1968 and it arrived in the USA that same year. The H3N2 virus still circulates today throughout the world.

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