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Influenza A virus transmission: contributing factors and clinical implications

Published online by Cambridge University Press:  09 December 2010

Jessica A. Belser
Affiliation:
Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA.
Taronna R. Maines
Affiliation:
Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA.
Terrence M. Tumpey
Affiliation:
Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA.
Jacqueline M. Katz*
Affiliation:
Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA.
*
*Corresponding author: Jacqueline M. Katz, Influenza Division MS G-16, 1600 Clifton Road NE, Atlanta, GA 30333, USA. E-mail: [email protected]

Abstract

Efficient human-to-human transmission is a necessary property for the generation of a pandemic influenza virus. To date, only influenza A viruses within the H1–H3 subtypes have achieved this capacity. However, sporadic cases of severe disease in individuals following infection with avian influenza A viruses over the past decade, and the emergence of a pandemic H1N1 swine-origin virus in 2009, underscore the need to better understand how influenza viruses acquire the ability to transmit efficiently. In this review, we discuss the biological constraints and molecular features known to affect virus transmissibility to and among humans. Factors influencing the behaviour of aerosols in the environment are described, and the mammalian models used to study virus transmission are presented. Recent progress in understanding the molecular determinants that confer efficient transmission has identified crucial roles for the haemagglutinin and polymerase proteins; nevertheless, influenza virus transmission remains a polygenic trait that is not completely understood. The clinical implications of this research, including methods currently under investigation to mitigate influenza virus human-to-human transmission, are discussed. A better understanding of the viral determinants necessary for efficient transmission will allow us to identify avian influenza viruses with pandemic potential.

Type
Review Article
Copyright
Copyright © Cambridge University Press 2010. This is a work of the US Government and is not subject to copyright protection in the USA.

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References

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Further reading, resources and contacts

Tellier, R. (2009) Aerosol transmission of influenza A virus: a review of new studies. Journal of the Royal Society, Interface 6 (Suppl. 6), S783S790CrossRefGoogle ScholarPubMed
Perdue, M.L. and Swayne, D.E. (2005). Public health risk from avian influenza viruses. Avian Diseases 49, 317327CrossRefGoogle ScholarPubMed
Brankston, G. et al. (2007). Transmission of influenza A in human beings. Lancet Infectious Diseases 7, 257265CrossRefGoogle ScholarPubMed
Belser, J.A. et al. (2009). Use of animal models to understand the pandemic potential of highly pathogenic avian influenza viruses. Advances in Virus Research 73, 5597CrossRefGoogle ScholarPubMed