All influenza derives from wild species of waterfowl in which a very large number of different strains can be found. Three of these strains, called H1N1, H2N2 and H3N2 were responsible for human pandemics in the 20th century, of which the first, in 1918, killed as many as 40 million people world-wide. Influenza can also occur in farmyard chickens (it used to be called “Fowl Plague”) which is occasionally passed to humans. H5N1 influenza is a type of avian ‘flu that appeared in China in 1996 and has spread widely among domestic and wild birds. It has raised global concern about its potential to cause another pandemic because of the unusually large number of human infections and their high mortality. Wild birds, which usually are affected much less severely, have also suffered. At Quinhai Lake, a nature reserve in China, over 6000 wild geese and ducks died in 2005 and since then, dead and dying wildfowl have been recorded along migration routes in Asia and Europe, associated with H5N1 infection.
Prof Andrew Leigh Brown and his viral genomics group in the Institute of Evolutionary Biology at the University of Edinburgh are using Bayesian graphical modelling to unravel the key genetic changes responsible for determining virulence in this virus. As members of a new consortium in Scotland focused on influenza research (ICHAIR) they work with colleagues elsewhere in Edinburgh and in St Andrews to interpret the models. The large volume of data available for influenza and the computationally intensive nature of this type of statistical modelling requires access to high performance computers and the group are now using the IBM Blue Gene/L machine at the University of Edinburgh to expand the number of models that can be analyzed.
The project is funded by the BBSRC Combatting Avian Influenza Initiative.
A ribbon diagram of the H5N1 haemagglutinin molecule. Picture Credit: Rupert Russell, University of St Andrews