MicrobeWorld

Last year a mutation in the HA gene of the 2009 H1N1 influenza virus was identified in isolates from patients with severe disease. At the time I concluded that the emergence of this change was not a concern. Recently the Norwegian Institute of Public Health reported that the mutation, which causes a change from the amino acid aspartic acid to glycine at position 225 of the viral HA protein (D225G), has been identified in 11 of 61 cases (18%) of severe or fatal influenza, but not in any of 205 mild cases. Have these observations changed my view of the importance of this mutation?