Swine flu origin traced to Spanish flu

The pigs may have spread the current strain of influenza to humans, to attract the attention of the world, but the new LED-Canadian research suggests they might first swine flu in 1918 in the Spanish flu pandemic.

A group of researchers from Canada and the United States, writing in the May issue of the Journal of Virology, such attempts in the way the pigs of the Spanish flu in 1918, supported the theory that the virus is transmitted from pigs to humans in 1918, the Spanish flu pandemic.

Both the human influenza virus known as Spanish flu and swine respiratory disease occurred almost simultaneously. The first human cases of Spanish influenza appeared in the spring of 1918, while the first reports of the disease of pigs in the autumn of this year.

Some strains of swine influenza, including that which comes from Mexico, is known to belong to the same subtype - H1N1 - the Spanish flu. But the virus of classical swine flu (an H1N1 subtype of influenza virus type A) was isolated from a pig, until 1930, so that the link between the Spanish flu and swine influenza is unclear.

One reason for the two strains of virus has not been strong, dramatically because of different effects.

The Spanish flu, the first time in May 1918 in Spain, was a murderer, killing at least 21 million people worldwide. Is also known for a deadly infection in a number of other animals, including ferrets, mice, macaques, a primate in Europe and Asia.

Swine influenza, which for the first time in 1918, but do not have the same impact on pork, so that only a slight disorder of the airways, so that they are not closely related.

2009 swine flu as deadly as the Spanish flu: U.S. official
The latest version of the virus of swine influenza does not appear to the Spanish flu, according to the U.S. Centers for Disease Control and Prevention (CDC). The CDC said Friday the new virus is deadly because it lacks the genes that are lethal 1918 pandemic strain.

However, in order to examine the source of most of swine influenza, the Canadian Food Hana Weingartl researcher and his colleagues tested the resistance of pigs to the pandemic virus of 1918 and the 1930-virus and swine fever . The tests were performed on a Biosafety Level 4 enclosure and laboratory animals at the National Center for Animal Disease in Winnipeg, where Weingartl works.

They found that there was no significant difference in force between the two viruses of swine, for example by a slight disorder of the airways, the symptoms for the first time in 1918 and 1930.

"These results support the hypothesis that the 1918 human influenza virus and influenza during the pandemic of 1918 pig are the same," wrote Weingartl and his colleagues.

Weingartl suggests that the susceptibility of pigs to humans by the virus and the time of the first report of the swine flu swine attitude - in October 1918, five months after the first human case - suggest that the virus of the pig population.

"After the pigs May contribute to the dissemination of new people," he said.

Since then, the virus of swine influenza has. The charge, which recently is "quite different" from the H1N1 virus strain first time in Spain in May 1918, said Weingartl.

The CDC in the United States Friday, said the new strain is "very unusual" combination of human genes and genes of swine and avian influenza viruses in North America, Asia and Europe.

The current strain of the virus has killed at least 10 people, nine in Mexico and the United States, the World Health Organization said Friday.