Researchers Discover the 2009 Swine Flu Pandemic Originated in Mexico MedicalXpress
go to original June 29, 2016

The swine flu outbreak in Mexico in 2009 caused widespread alarm (Getty Images)

The 2009 swine H1N1 flu pandemic - responsible for more than 17,000 deaths worldwide - originated in pigs from a very small region in central Mexico, a research team headed by investigators at the Icahn School of Medicine at Mount Sinai is reporting.

The scientists say their findings, published in the journal eLife, represent the first time that the origin of an influenza pandemic virus has been determined in such detail.

Researchers used state-of-the-art genetic analysis to identify the precise location and the main molecular transformations that allowed a pig influenza virus to jump into humans. They found that the virus responsible was a mix of one North American swine virus that had jumped between birds, humans, and pigs, and a second Eurasian swine virus, that circulated for more than 10 years in pigs in Mexico before jumping into humans.

Previously, the most closely related ancestor viruses to the 2009 H1N1 virus were identified in Asian swine, but they were not as close genetically to the human 2009 pandemic H1N1 virus as the swine Mexican isolates found in this study.



The only other H1N1 pandemic flu known to date was the "Spanish" flu of 1918 that killed between 50 and 100 million people - 3 to 5 percent of the world's population. Influenza viruses infect up to 500 million people annually.

... Determining the original location of the 2009 swine flu, known as an A/H1N1 pathogen, lends a note of caution to evolving efforts to track problematic animal and bird viruses, Dr. Garcia-Sastre says. "This virus came from, and was confined to, a very small geographic area and had been there 10 years before one emergent strain gained the capacity to infect humans," he says. "The virus was completely under the radar."

Read the rest at MedicalXpress

We invite you to add your charity or supporting organizations' news stories and coming events to PVAngels so we can share them with the world. Do it now!