Swine Flu History

Swine flu history is around 90 years old. In 1918 during the virulent flu disease, Swine influenza was originally detected as an infection associated with the human influenza, actually when pigs became ill at the same time people also. The H1N1 type of swine flu is from the family of the flu that caused in the 1918 flu pandemic. The 1918 Influenza pandemic called the “Spanish virus” strain. During year 1918-1919 it is considered that third of the world population get infected and caused possibly 50 million deaths. This counting is according to the “U.S. Centre for Disease Control”. Number of deaths may be more than that because many who died during that phase were not really diagnosed, nor were samples taken for lab testing and detection. In 1918, causes of human flu and its links swine influenza were still unknown.

The first detection of a flu virus as a cause of infection in pigs identified about ten years later in 1930. Swine flu is a respiratory disorder of pigs. For the next 60 years, swine influenza infections were approximately exclusively H1N1. Then, among 1997 and 2002, new infection of three different subtypes and five different genotypes become known as causes of infection with pigs in North America. In year 1997–1998, H3N2 infection comes into view. H3N2 type of infection includes genes derived from human being, swine and avian viruses, have turn into a main cause of swine influenza in North America. In between H1N1 and H3N2 a new flu virus produced called H1N2. In Canada 1999, infection of H4N6 detected that was crossed the genus barrier from birds to pigs, but was restricted on a single farm.

However, straight transmission from pigs to humans is uncommon and only 12 cases in the United State since 2005. Swine flu has been reported several times as a zoonosis in human beings, generally with partial distribution, rarely with a widespread circulation.