Bird Flu Infection in Teen Elevates Concern Among Scientists

Viral sequences taken from boy suggest it contained mutations that could enable it to spread from human to human

Viral genome sequences taken from a Canadian boy critically ill with a strain of the avian influenza virus H5N1 is raising fears among some scientists that the pathogen might have improved its ability to infect the human airway. If true, it could mean that the virus might be able to rapidly evolve to make the jump from birds to humans.

The strain of H5N1 currently in circulation in North America has already decimated wild birds and livestock, and even some people have tested positive for the avian flu. Yet, public health officials continue to stress that there is no evidence the that the virus can transmit from person to person, and no reason to believe that a pandemic is imminent. That position appears unchanged, even with the Canadian case.

However, the data gleaned from the genome sequences taken from the teen are worrisome. While scientists found him infected with a mixture of viruses, all of them similar to the H5N1 viruses currently circulating in poultry and waterfowl, they also found some key differences. Those differences included two possible mutations that could enhance the virus's ability to infect human cells and another that could allow it to replicate more easily in human cells, not just in the cells of the avian host.

To learn more about this Canadian case check out the entire story in Nature.