Diffusion of influenza viruses among migratory birds with a focus on the Southwest UnitedStatesInfection, Genetics and Evolution (2014)
The Southwest United States, including Arizona and New Mexico, has a diverse climate and is home to many different avian species. We sequenced the hemagglutinin (HA) gene of twenty inﬂuenza specimens for the years 2007–2009. This included four from Arizona, and sixteen from New Mexico. We analyzed the sequences and determined the following HA subtypes: H3, H4, H6, H8, and H11. For each subtype, we combined our virus sequences with those from a public database, and inferred phylogeographic models of inﬂuenza diffusion.
Statistical phylogeography indicated that overall evolutionary diffusion of avian inﬂuenza viruses is geographically structured (p < 0.05). In addition, we found that diffusion to the Southwest was often from nearby states including California.
For H3, H4 and H6, the intra-ﬂyway gene ﬂow rates were signiﬁcantly (p < 0.001) higher than those of inter-ﬂyway. Such rate difference was also observed in H8 and H11, yet, without statistical signiﬁcance (p = 0.132, p = 0.190, respectively). Excluding any one ﬂyway from the calculation generated similar results, suggesting that such barrier effect on gene ﬂow rates is not exclusively produced by any single ﬂyway.
We also calculated the Bayes factor test for the signiﬁcant non-zero rates between states and identiﬁed signiﬁcant routes both within and across ﬂyways. Such inter-ﬂyway spread of inﬂuenza was probably the result of birds from four ﬂyways co-mingling on breeding grounds in northern regions or marshaling on staging areas post breeding in Canada or Alaska, before moving south each fall.
This study provides an initial analysis of evolutionary diffusion of avian inﬂuenza virus to and from the Southwest United States. However, more sequences from this region need to be generated to determine the role of host migration and other factors on inﬂuenza diffusion.
- Influenza in birds,
- Southwestern United States
Publication DateSummer August 29, 2014
Citation InformationMatthew Scotch, Kristy Pabilonia, Theodore D. Anderson, John A Baroch, et al.. "Diffusion of influenza viruses among migratory birds with a focus on the Southwest UnitedStates" Infection, Genetics and Evolution Vol. 26 (2014) p. 185 - 193
Available at: http://works.bepress.com/john_baroch/16/