After kicking up initial fears of a mutated and more virulent virus in the Ukraine
earlier in November, Norwegian scientists have confirmed that the H1N1 swine flu pandemic appears to have mutated.
The scientists identified the samples as a more deadly version of the swine flu virus
in two patients who died, finding that the mutation "could possibly make the virus more prone to infect deeper in the airways and thus cause more severe disease."
There is cause for cautious optimism, as the Norwegian scientists do not believe that the virus exists in broad circulation.
"Based on what we know so far, it seems that the mutated virus does not circulate in the population, but might be a result of spontaneous changes which have occurred in these three patients," the Norwegian Institute of Public Health said in a statement.
According to the CDC
, the H1N1 swine flu virus is responsible for more than 4,000 deaths in the U.S. alone. However, the Ukraine has reported 354 flu deaths
since late October.
"Influenza is a mutable virus, and changes are to be expected," Arnold S. Monto of the University of Michigan told Washington Post
in an e-mail. "This is typical early in the spread of a pandemic virus."