In a recent Science paper, Olsen et al. (2006) state that ‘it is clear that the H5N1 problem originated from outbreaks in poultry, and that their geographical spread probably cannot be stopped without implementation of proper control measures in the global poultry industry’. It is also clear that many cases of wild bird infections seem to have occurred when the wild birds were in close proximity to captive birds (Hong Kong Agriculture, Fisheries and Conservation Department in Melville and Shortridge 2004, Chen et al. 2006). In fact, genetic sequencing of virus isolated from infected wild birds.
