# 5848
I know Crof already posted excerpts last night, but the interview and bird flu backgrounder with Dr. Robert G. Webster that appeared yesterday in The Guardian is certainly worthy of further mention.
Webster, as most of you know, is one of the world’s most acclaimed virologists, and is the head of the virology department of St Jude Children's Research Hospital in Memphis.
Robert Webster: 'We ignore bird flu at our peril'
With the UN issuing renewed warnings and a Hollywood disaster movie stoking our fears, bird flu is back in the news. We meet the man who first warned of a pandemic 50 years ago – and who is worried again now
Like many flu observers, Webster finds the evolution of the H5N1 virus in Egypt of particular concern.
Egypt has reported the greatest number of human infections over the past couple of years, and the virus has shown signs it may be slowly adapting more towards human physiology (see PLoS: Human-Type H5N1 Receptor Binding In Egypt).
While Webster’s greatest concern is with the H5N1 bird flu virus – mostly due to its high lethality - he acknowledges that other pandemic flu threats exist, and mentions the H9N2 avian virus which is widespread across much of Asia.
Earlier this summer (see PNAS: Reassortment Potential Of Avian H9N2) we looked at some of the ways that this avian virus could reassort into a more easily transmitted pathogen.
Last week, another virologist with impeccable credentials – Professor John Oxford, Scientific Director of Retroscreen Virology Ltd. and a Professor of Virology at St Bartholomew’s and the Royal London Hospital – expressed his own pandemic concerns in a online webinar (see Webinar: John Oxford On Pandemic Preparedness).
And 3 weeks ago, in Professor Peter Doherty On Bird Flu, we looked at his worries on the possibility that the H5N1 virus might one day swap genes (reassort) with the H1N1 virus and produce an easily transmitted, highly virulent flu strain.
And indeed, just last Friday we saw research (see Study: Reassorted H1N1-H5N1 Produced Virulent Strain) where a laboratory-created reassortant virus with genes taken from the H5N1 and H1N1 virus produced a highly transmissible and virulent strain.
Of course, while the world was waiting for bird flu, in 2009 a Swine flu virus unexpectedly sparked a global pandemic. We were fortunate that it wasn’t any more severe than it was, but it illustrates that there are many ways a pandemic can evolve.
Detections of trH3N2 swine flu viruses in Pennsylvania and Indiana over the past month are a fresh reminder of the need for establishing better global surveillance of humans, and of farm animals, in order to detect the next emerging influenza virus before it can spread widely.
There is a chance, albeit it small, that a limited outbreak could be stopped if detected early enough.
That was done successfully in Hong Kong in 1997 when the H5N1 virus first emerged.
While it is always possible that the next pandemic will spring directly from the wild, the odds favor that it will come from a farm – where large numbers of animals intermingle, swap viruses, and come in daily contact with humans.
For more on the reassortment potential of avian, swine, and human flu viruses, you can’t do better than Helen Branswell’s excellent Scientific American article from last December called Flu Factories, or her SciAm Podcast interview.
And for good measure, a sampling of a few of my earlier blogs on reassortment:
Review: Evolution & Adaptation Of The 2009 pdmH1N1 Virus
You Say You Want An Evolution?
EID Journal: Co-Infection By Influenza Strains
Although we could get lucky and go years - or even decades - before the next pandemic emerges, another one could just as easily start tomorrow.
As Dr. Webster points out, we ignore these risks at our own peril.
