Mutation of pandemic influenza A/H1N1 in Norway

Norwegian health authorities say they have discovered a potentially significant mutation of the A/H1N1 strain of influenza. They say it could be responsible for causing the severest symptoms among those infected. But the World Health Organization says the mutation does not appear to be widespread in the country.

The mutation has been found in the bodies of two people killed by the virus and in one seriously ill person. The two who died were among Norway's first fatalities from the A/H1N1 pandemic.

It is unclear whether the mutated virus is transmitted between humans. It doesn't seem the virus is circulating widely in the population.