tailieunhanh - Báo cáo y học: " What happened after the initial global spread of pandemic human influenza virus A (H1N1)? A population genetics approach"

What happened after the initial global spread of pandemic human influenza virus A (H1N1)? A population genetics approach | Martinez-Hernandez et al. Virology Journal 2010 7 196 http content 7 1 196 VIROLOGY JOURNAL SHORT REPORT Open Access What happened after the initial global spread of pandemic human influenza virus A H1N1 A population genetics approach Fernando Martinez-Hernandez1 Diego Emiliano Jimenez-Gonzalez1 Arony Martinez-Flores1 AC I 11 Lv I n I ỉ I I I k r I I I I r 2 í I I L I I z i Lv 2 I l M A r IX r r-ìl 1 A r cl I r r r4 D L I h ill 1 Guiehdani viiiaiooos-castiiiejos Gilberto Vaughan Simon Kawa-KarasiK Ana Flisser Pablo Maravilla Mirza Romero-Valdovinos1 Abstract 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. Findings In April 2009 the Mexican Secretariat of Health reported an outbreak of respiratory disease. A new human influenza virus A H1N1 with molecular features of North American and .