What happened after the initial global spread of pandemic human influenza virus A (H1N1)? A population genetics approach.
Viral population evolution dynamics of influenza A is crucial for surveillance and control. In this paper we analyzed viral genetic features during the recent pandemic caused by the new influenza human virus A H1N1, using a conventional population genetics approach based on 4689 hemagglutinin (HA) and neuraminidase (NA) sequences available in GenBank submitted between March and December of 2009. This analysis showed several relevant aspects: a) a scarce initial genetic variability within the viral isolates from some countries that increased along 2009 when influenza was dispersed around the world; b) a worldwide virus polarized behavior identified when comparing paired countries, low differentiation and high gene flow were found in some pairs and high differentiation and moderate or scarce gene flow in others, independently of their geographical closeness, c) lack of positive selection in HA and NA due to increase of the population size of virus variants, d) HA and NA variants spread in a few months all over the world being identified in the same countries in different months along 2009, and e) containment of viral variants in Mexico at the beginning of the outbreak, probably due to the control measures applied by the government.
Martinez-Hernandez
Fernando
F
Departamento de Ecología de Agentes Patogenos, Hospital General Dr, Manuel Gea Gonzalez, Calzada de Tlalpan 4800, DF 14080, Mexico.
Jimenez-Gonzalez
Diego Emiliano
DE
Martinez-Flores
Arony
A
Villalobos-Castillejos
Guiehdani
G
Vaughan
Gilberto
G
Kawa-Karasik
Simon
S
Flisser
Ana
A
Maravilla
Pablo
P
Romero-Valdovinos
Mirza
M
D003140:Communicable Disease Control / Q000379:methods; D019295:Computational Biology / Q000379:methods; D030561:Databases, Nucleic Acid; D019143:Evolution, Molecular; D006389:Hemagglutinins, Viral / Q000235:genetics; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology*; D017720:Molecular Epidemiology; D009439:Neuraminidase / Q000235:genetics; D058873:Pandemics; D014764:Viral Proteins / Q000235:genetics
D006389:Hemagglutinins, Viral; D014764:Viral Proteins; C458881:hemagglutinin fusogenic peptide, influenza virus; C487630:NA protein, influenza A virus; D009439:Neuraminidase