Genome Stability of Pandemic Influenza A (H1N1) 2009 Based on Analysis of Hemagglutinin and Neuraminidase Genes

Emilio E Espínola*
Departamento de Biología Molecular y Genética, Instituto de Investigaciones en Ciencias de la Salud, Universidad Nacional de Asunción, Paraguay

© Emilio E. Espínola; Licensee Bentham Open.

open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.

* Address correspondence to this author at the Rio de la Plata y Lagerenza, CP 1120 Asunción, Paraguay; Tel: +595 21 424 520; Fax: +595 21 480 185; E-mail:


Influenza A virus (H1N1), which arose in 2009, constituted the fourth pandemic after the cases of 1918, 1957, and 1968. This new variant was formed by a triple reassortment, with genomic segments from swine, avian, and human influenza origins. The objective of this study was to analyze sequences of hemagglutinin (n=2038) and neuraminidase (n=1273) genes, in order to assess the extent of diversity among circulating 2009-2010 strains, estimate if these genes evolved through positive, negative, or neutral selection models of evolution during the pandemic phase, and analyze the worldwide percentage of detection of important amino acid mutations that could enhance the viral performance, such as transmissibility or resistance to drugs. A continuous surveillance by public health authorities will be critical to monitor the appearance of new influenza variants, especially in animal reservoirs such as swine and birds, in order to prevent the potential animal-human transmission of viruses with pandemic potential.

Keywords: Genome Stability, Hemagglutinin, Neuraminidase, Pandemic Influenza H1N1 2009, Respiratory Disease, Swine Flu..