# 4170
The D225G mutation, which made a splash in the headlines about a month ago with an announcement out of Norway, has actually been detected in many countries around the globe and almost from the start of the novel H1N1 outbreak.
It has, nevertheless, become known as the `Norway Mutation’
Its true significance is not yet known, despite some of the more strident reportage in recent weeks. While it has been seen in fatal cases, it has also been seen in some mild cases as well.
Hong Kong detected their 1st `Norway Mutation’ in July, months before the Norwegian announcement (see H1N1 Mutation Found In Hong Kong).
This mutation involves a single amino acid change in the HA1 gene at position 222 (225 in influenza H3 numbering) from aspartic acid (D) to glycine (G).
The assumption by some has been that this mutation must increase the virulence of the virus because it was found in several severe cases in Norway, some with fatal outcomes.
While it may indeed prove to be a factor in the virulence of H1N1, what we don’t have a good handle on is how many mild cases have occurred with this mutation?
Without knowing that, it is very difficult to assess the relative dangers of this single amino acid substitution.
There are some experts, such as Vincent Racaniello – who is a Professor of Microbiology at Columbia University Medical Center – who argues in his Virology Blog that the change impairs the `fitness’ of the virus to transmit to other hosts, and therefore isn’t as big of threat as some have suggested.
The D225G change in 2009 H1N1 influenza virus is not a concern
by Vincent Racaniello on 24 November 2009
Today the Centre for Health Protection in Hong Kong has announced the detection of 4 more instances of this D225G mutation, bringing their total to 8. Of those 3 have died, 4 have recovered, and 1 is still receiving treatment.
Since not every infection is sampled and tested for this mutation, it is highly likely that it occurs more commonly than we know.
This report is from http://www.news.gov.hk
Swine flu virus mutation detected
The Centre for Health Protection has found the same mutation in three human swine influenza virus samples as the one detected in Norway recently, bringing the total number of them in Hong Kong to eight.
Among these cases, three of the patients died and one is still receiving intensive care treatment. The other four recovered. These viruses are still sensitive to antiviral drugs, oseltamivir and zanamivir.
Scientists in the World Health Organisation network of influenza laboratories are assessing the mutation's significance.
The centre is closely monitoring flu viruses worldwide and remains vigilant for changes in the virus that may have public health significance.
