Friday, March 19, 2010

Referral: Virology Blog On D225G Mutation

 

 


# 4447

 

 

There has been a lot of speculation regarding the D225G mutation first announced in Norway last November, suggesting that it may increase the virulence of the novel H1N1 virus.

 

This mutation, sometimes called D222G (or D225G in influenza H3 numbering) had actually been detected months earlier, and in many other countries.  Norway was simply the first country to announce a possible connection between that mutation and greater virulence.

 

 

This mutation involves a single amino acid change in the HA1 gene at position 222 from aspartic acid (D) to glycine (G).

 

The World Health Organization’s take on this mutation has been pretty consistent.  It is worth following, and studying, but there is no evidence (as yet) that it poses a substantial public health hazard.

 

In January, in a blog entitled WER Review: D222G Mutation In H1N1, I quoted the latest WHO report that stated:

 

`Based on currently available virological, epidemiological and clinical information, the D222G substitution does not appear to pose a major public health issue.’

 

This view is not universally held, however.  There are some who have maintained that that the WHO is underestimating the impact of this mutation.

 

Not being a virologist (or scientist of any flavor), I don’t have a pathogen in this fight. Therefore, I’m not offering any theories of my own.

 

The best I can do is offer up the opinions of scientists and agencies that I view as credible (admittedly a subjective evaluation), along with the caveat that we are still learning about such things.

 

Nothing is writ in stone.

 

That said, today I’ll refer you to Vincent Racaniello’s excellent Virology Blog, where he takes us on a tour of some of the possibilities that surround this D225G mutation.  

 

A bit technical at times, granted.  But well worth reading, even if you don’t get every reference.   

 

The upshot here being that the interaction between pathogen and host is very complex, incompletely understood, and that simplistic models are likely to fall short of the mark.

 

Read Vincent Racaniello’s:

 

The D225G change in 2009 H1N1 influenza virus