Modelling the impact of co-circulating low pathogenic avian influenza viruses on epidemics of highly pathogenic avian influenza in poultry

Nickbakhsh, S. , Hall, M. D., Dorigatti, I., Lycett, S. J. , Mulatti, P., Monne, I., Fusaro, A., Woolhouse, M. E.J., Rambaut, A. and Kao, R. R. (2016) Modelling the impact of co-circulating low pathogenic avian influenza viruses on epidemics of highly pathogenic avian influenza in poultry. Epidemics, 17, pp. 27-34. (doi: 10.1016/j.epidem.2016.10.005) (PMID:27788412)

Abstract

It is well known that highly pathogenic avian influenza (HPAI) viruses emerge through mutation of precursor low pathogenic avian influenza (LPAI) viruses in domestic poultry populations. The potential for immunological cross-protection between these pathogenic variants is recognised but the epidemiological impact during co-circulation is not well understood. Here we use mathematical models to investigate whether altered flock infection parameters consequent to primary LPAI infections can impact on the spread of HPAI at the population level. First we used mechanistic models reflecting the co-circulatory dynamics of LPAI and HPAI within a single commercial poultry flock. We found that primary infections with LPAI led to HPAI prevalence being maximised under a scenario of high but partial cross-protection. We then tested the population impact in spatially-explicit simulations motivated by a major avian influenza A(H7N1) epidemic that afflicted the Italian poultry industry in 1999–2001. We found that partial cross-protection can lead to a prolongation of HPAI epidemic duration. Our findings have implications for the control of HPAI in poultry particularly for settings in which LPAI and HPAI frequently co-circulate.

• Item Type: Articles
• Additional Information: This study was supported by The Scottish Government’s EPIC Centre of Expertise on Animal Disease Outbreaks (65206), VIZIONS a strategic award from the Wellcome Trust (WT/093724), the European Union Seventh Framework Programme [FP7/2007-2013] under Grant Agreement no 278433-PREDEMIC, and the Bill and Melinda Gates Foundation (grants P20064 and P46908). SJL is supported by a Chancellors Fellowship from the University of Edinburgh.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Nickbakhsh, Dr Sema and Kao, Professor Rowland and Lycett, Dr Samantha
• Authors: Nickbakhsh, S., Hall, M. D., Dorigatti, I., Lycett, S. J., Mulatti, P., Monne, I., Fusaro, A., Woolhouse, M. E.J., Rambaut, A., and Kao, R. R.
• College/School: College of Medical Veterinary and Life Sciences > School of Infection & Immunity; College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Epidemics
• Publisher: Elsevier
• ISSN: 1755-4365
• ISSN (Online): 1878-0067
• Published Online: 19 October 2016
• Copyright Holders: Copyright © 2016 The Authors
• First Published: First published in Epidemics 17: 27-34
• Publisher Policy: Reproduced under a Creative Commons License