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Volume 23, Number 11—November 2017

Highly Pathogenic Avian Influenza A(H7N9) Virus, Tennessee, USA, March 2017

Dong-Hun Lee, Mia K. Torchetti, Mary Lea Killian, Yohannes Berhane, and David E. SwayneComments to Author 
Author affiliations: US Department of Agriculture, Athens, Georgia, USA (D.-H. Lee, D.E. Swayne); US Department of Agriculture, Ames, Iowa, USA (M.K. Torchetti, M.L. Killian); National Centre for Foreign Animal Disease, Winnipeg, Manitoba, Canada (Y. Berhane)

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Times to most recent common ancestors of H7N9 viruses, Tennessee and Alabama, USA, March 2017*

Virus clusters (no. taxa)† tMRCA‡ BCI 95% Posterior probability
Tennessee and Alabama LPAI and HPAI viruses (22) 2016 Oct 5 2016 Aug 8–2016 Dec 10 1.00
Tennessee LPAI and HPAI viruses (15) 2016 Dec 21 2016 Nov 7–2017 Feb 3 1.00
Tennessee LPAI virus (3) 2017 Jan 23 2016 Dec 3–2017 Feb 25 0.98
Tennessee HPAI virus (12) 2017 Jan 30 2017 Jan 1–2017 Feb 25 1.00
Alabama LPAI virus from backyard guinea fowl (3) 2017 Jan 8 2016 Nov 18–2017 Feb 21 1.00
Alabama LPAI virus from commercial chicken (3) 2017 Jan 26 2016 Dec 10–2017 Mar 8 1.00

*BCI, Bayesian credible interval; HPAI, highly pathogenic avian influenza; LPAI, low pathogenicity avian influenza; tMRCA, time to most recent common ancestor.
†See online Technical Appendix Table ( for specific virus strains used in analysis.
‡Times to most recent common ancestors of hemagglutinin segment.

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Page created: October 17, 2017
Page updated: October 17, 2017
Page reviewed: October 17, 2017
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.