The emergence of a more dangerous strain of flu remains a theoretical risk. Different strains of virus can mix together in a process called genetic reassortment or recombination. So far there have been no cases of H5N1 bird flu in flocks in Chile. However, Dr Lubroth said: “In Southeast Asia there is a lot of the (H5N1) virus circulating in poultry. “The introduction of H1N1 in these populations would be of greater concern.”
Colin Butter from the UK’s Institute of Animal Health agrees. “We hope it is a rare event and we must monitor closely what happens next,” he told BBC News. “However, it is not just about the H5N1 strain. Any further spread of the H1N1 virus between birds, or from birds to humans would not be good. “It might make the virus harder to control, because it would be more likely to change.”
via BBC NEWS | Science & Environment | UN warns over swine flu in birds.