Sequence analysis of the 2009 pandemic influenza A H1N1 virus haemagglutinin gene from 2009-2010 Brazilian clinical samples

ABSTRACT

In this paper, we analysed the haemagglutinin (HA) gene identified by polymerase chain reaction from 90 influenza A H1N1 virus strains that circulated in Brazil from April 2009-June 2010. A World Health Organization sequencing protocol allowed us to identify amino acid mutations in the HA protein at positions S220T (71 percent), D239G/N/S (20 percent), Y247H (4.5 percent), E252K (3.3 percent), M274V (2.2 percent), Q310H (26.7 percent) and E391K (12 percent). A fatal outcome was associated with the D239G mutation (p < 0.0001). Brazilian HA genetic diversity, in comparison to a reference strain from California, highlights the role of influenza virus surveillance for study of viral evolution, in addition to monitoring the spread of the virus worldwide.