# 4051
Viruses mutate.
It is perhaps the one thing you can count on with influenza. If you wait awhile, the virus will change.
Those changes can be benign, or even favorable towards humanity, or they can convey additional transmissibility or virulence.
As Forrest Gump would say . . . “ you never know what you’re going to get”.
We’ve seen a number of minor changes – mutations if you will – in the H1N1 virus so far, but the virus has remained pretty stable. None of these past changes have been linked to increased virulence or transmissibility.
Today, however, Norwegian scientists are reporting a mutation found in a handful of samples that could increase the virulence of the virus – make it better adapted to deep lung tissues – which could make it more apt to cause severe viral pneumonias.
There is a lot about this story we simply don’t know yet.
Prime among those is whether this mutated virus is capable of ongoing transmission, or if it is something that occurred spontaneously in a handful of victims.
For now, officials are downplaying the idea that it might be circulating.
This will no doubt be a subject we return to with some frequency over the days and weeks ahead.
FluTrackers has an ongoing thread on this story with translations of news reports out of Norway. These machine translations are often difficult to decipher, so I’ll go with a Washington Post article by Rob Stein instead.
Norwegian scientists raise concerns about mutated form of swine flu
By Rob Stein
Washington Post Staff Writer
Friday, November 20, 2009; 10:51 AMScientists in Norway have identified a mutated form of the swine flu virus that is raising concern because it was found in two patients who died of the flu and a third who was severely ill with the disease, officials announced Friday.
In a statement, the Norwegian Institute of Public Health said the mutation "could possibly make the virus more prone to infect deeper in the airways and thus cause more severe disease."
Scientists have analyzed about 70 viruses from confirmed Norwegian swine flu cases and found the mutation in only those three patients, Geir Stene-Larsen, the institute's director general, said in the statement.
"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 statement said.
