Haemagglutinin D222G mutation found in a fatal case of pandemic (H1N1) flu in Tunisia.

Recently, the D222G substitution was observed in the HA of pandemic (H1N1) 2009 viruses isolated from fatal cases in several countries. We made a similar observation in one fatal case in Tunisia showing a D222G substitution in a virus isolate. The man was 47 years old and had no other subjacent pathologies or any known risk factors. He died after three days, suffering from severe respiratory symptoms of flu. The causal link of the D222G substitution in Tunisia with virulence must be verified. Further study is warranted to elucidate the intriguing relationship between the D222G substitution and severe disease. Constant molecular surveillance is important to monitor the pathogenicity of circulating strains and evaluate vaccine efficacy.