Evolution of Panzootic H5N1 Influenza Viruses

publication Evidence: high

Author Information

Author(s): Vijaykrishna Dhanasekaran, Justin Bahl, Steven Riley, Lian Duan, Jin Xia Zhang, Honglin Chen, J. S. Malik Peiris, Gavin J. D. Smith, Yi Guan

Primary Institution: State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong

Hypothesis

The study aims to understand the early evolutionary dynamics of H5N1 virus in the population from which it emerged.

Conclusion

The H5N1 virus was likely introduced from wild birds into poultry as a non-reassortant virus and has undergone local reassortment in poultry.

Supporting Evidence

The H5N1 virus lineage has undergone extensive genetic reassortment.
The virus has spread to over 60 countries.
Genetic diversity of H5N1 viruses increased rapidly from mid-1999 to early 2000.
The prototype virus was likely introduced into poultry as a non-reassortant virus.
Reassortment events occurred locally in domestic ducks after the introduction of the prototype virus.

Takeaway

Scientists studied how the H5N1 bird flu virus changed over time and found it likely came from wild birds to chickens without mixing with other viruses at first.