As the genetic origins of the novel strain of H1N1 influenza A become better understood, serious and urgent questions are emerging over the role of intensive livestock farming in the development and transmission of potentially pandemic flu viruses.
This isn’t just about the now-notorious Granjas Carroll de Mexico farm (part-owned by Smithfield, the world’s largest pork producer) in Veracruz, Mexico. Even if the virus is ultimately linked to the Granjas Carroll CAFO, it would only make it the last link in a complex process of virus mutation, reassortment and transmission that’s played out on pig farms over the last 10 (or even 90) years.
As the outbreak of novel, swine-related (A)H1N1 influenza virus (note the carefully chosen terminology) continues to provoke confused messages as to the safety of pork, ProMED reports that the three leading international food, animal and public health organisations – the FAO, OIE, WHO – have reasserted the safety of properly cooked pork.
A brief history of the swine influenza virus (SIV) from 1918 to 2009 – including 1998 H3N2 reassortment of swine, avian and human viruses; 2001 identification of reassortant H1N1 from 1998 H3N2 and classic H1N1; 2009 emergence of swine-origin H1N1 influenza A virus in humans.
@tracingpaper follows the emergence of the novel H1N1 flu virus; the impact on pigs, farming and pork; and the debate over its possible links with industrial pig production. This list will continue to be updated, with latest entries at the top.
There’s currently no scientific certainty about the source of the new Mexican strain of H1N1 flu, but circumstantial evidence is emerging that should direct epidemiological investigations.
While the mainstream media concentrated on the spread and pandemic potential of the new virus, bloggers were the first to investigate and question circumstantial suggestions that the new strain may have emerged from intensive pig production units.
There are important questions to ask about the source of the virus but it’s important to keep in mind the essential difference between circumstance and epidemiology.
The new strain of the H1N1 influenza virus that has emerged in Mexico, with particular virulence, and is now spreading to other parts of the globe is almost universally reported as swine flu. The name suggests a clear and direct link with pigs, but is it really that simple?
