Hostname: page-component-cd9895bd7-lnqnp Total loading time: 0 Render date: 2024-12-27T03:17:11.588Z Has data issue: false hasContentIssue false

Risk assessment for recrudescence of avian influenza in caged layer houses following depopulation: the effect of cleansing, disinfection and dismantling of equipment

Published online by Cambridge University Press:  13 February 2020

P. Gale*
Affiliation:
Department of Epidemiological Sciences, Animal and Plant Health Agency, Weybridge, New Haw, Addlestone, SurreyKT15 3NB, UK
S. Sechi
Affiliation:
Department of Mathematics and Statistics, University of Strathclyde, Livingstone Tower, 26 Richmond Street, GlasgowG1 1XH, Scotland
V. Horigan
Affiliation:
Department of Epidemiological Sciences, Animal and Plant Health Agency, Weybridge, New Haw, Addlestone, SurreyKT15 3NB, UK
R. Taylor
Affiliation:
Department of Epidemiological Sciences, Animal and Plant Health Agency, Weybridge, New Haw, Addlestone, SurreyKT15 3NB, UK
I. Brown
Affiliation:
World Organisation for Animal Health (OIE)/Food and Agriculture Organisation (FAO) International Reference Laboratory for Avian Influenza, Newcastle Disease and Swine Influenza, Animal and Plant Health Agency, Weybridge, New Haw, Addlestone, SurreyKT15 3NB, UK
L. Kelly
Affiliation:
Department of Epidemiological Sciences, Animal and Plant Health Agency, Weybridge, New Haw, Addlestone, SurreyKT15 3NB, UK Department of Mathematics and Statistics, University of Strathclyde, Livingstone Tower, 26 Richmond Street, GlasgowG1 1XH, Scotland
*
Get access

Abstract

Following an outbreak of highly pathogenic avian influenza virus (HPAIV) in a poultry house, control measures are put in place to prevent further spread. An essential part of the control measures based on the European Commission Avian Influenza Directive 2005/94/EC is the cleansing and disinfection (C&D) of infected premises. Cleansing and disinfection includes both preliminary and secondary C&D, and the dismantling of complex equipment during secondary C&D is also required, which is costly to the owner and also delays the secondary cleansing process, hence increasing the risk for onward spread. In this study, a quantitative risk assessment is presented to assess the risk of re-infection (recrudescence) occurring in an enriched colony-caged layer poultry house on restocking with chickens after different C&D scenarios. The risk is expressed as the number of restocked poultry houses expected before recrudescence occurs. Three C&D scenarios were considered, namely (i) preliminary C&D alone, (ii) preliminary C&D plus secondary C&D without dismantling and (iii) preliminary C&D plus secondary C&D with dismantling. The source-pathway-receptor framework was used to construct the model, and parameterisation was based on the three C&D scenarios. Two key operational variables in the model are (i) the time between depopulation of infected birds and restocking with new birds (TbDR) and (ii) the proportion of infected material that bypasses C&D, enabling virus to survive the process. Probability distributions were used to describe these two parameters for which there was recognised variability between premises in TbDR or uncertainty due to lack of information in the fraction of bypass. The risk assessment estimates that the median (95% credible intervals) number of repopulated poultry houses before recrudescence are 1.2 × 104 (50 to 2.8 × 106), 1.9 × 105 (780 to 5.7 × 107) and 1.1 × 106 (4.2 × 103 to 2.9 × 108) under C&D scenarios (i), (ii) and (iii), respectively. Thus for HPAIV in caged layers, undertaking secondary C&D without dismantling reduces the risk by 16-fold compared to preliminary C&D alone. Dismantling has an additional, although smaller, impact, reducing the risk by a further 6-fold and thus around 90-fold compared to preliminary C&D alone. On the basis of the 95% credible intervals, the model demonstrates the importance of secondary C&D (with or without dismantling) over preliminary C&D alone. However, the extra protection afforded by dismantling may not be cost beneficial in the context of reduced risk of onward spread.

Type
Research Article
Copyright
© The Animal Consortium 2020

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Alarcon, P, Brouwer, A, Venkatesh, D, Duncan, D, Dovas, CI, Georgiades, G, Monne, I, Fusaro, A, Dan, A, Smietanka, K, Ragias, V, Breed, AC, Chassalevris, T, Goujgoulova, G, Hjulsager, CK, Ryan, E, Sanchez, A, Niqueux, E, Tammiranta, N, Zohari, S, Stroud, D, Savic, V, Lewis, NS and Brown, IH 2018. Comparison of 2016–17 and previous epizootics of highly pathogenic avian influenza H5 Guangdong lineage in Europe. Emerging Infectious Diseases 24, 22702283.CrossRefGoogle ScholarPubMed
Aldous, EW, Seekings, JM, McNally, A, Nili, H, Fuller, CM, Irvine, RM, Alexander, DJ and Brown, IH 2010. Infection dynamics of highly pathogenic avian influenza and virulent avian paramyxovirus type 1 viruses in chickens, turkeys and ducks. Avian Pathology 39, 265273.CrossRefGoogle ScholarPubMed
EU 2005. EU Council Directive 2005/94/EC of 20 December 2005 on Community measures for the control of avian influenza and repealing Directive 92/40/EEC Article 49. Retrieved on 20 January 2017 from http://eur-lex.europa.eu/legal-content/EN/ALL/?uri=CELEX:32005L0094.Google Scholar
Gale, P 2004. Risk to farm animals from pathogens in composted catering waste containing meat. Veterinary Record 155, 7782.CrossRefGoogle ScholarPubMed
Gale, P 2005. Land application of treated sewage sludge: quantifying pathogen risks from consumption of crops. Journal of Applied Microbiology 98, 380396.CrossRefGoogle ScholarPubMed
Gale, P 2018. Using thermodynamic parameters to calibrate a mechanistic dose-response for infection of a host by a virus. Microbial Risk Analysis 8, 113.CrossRefGoogle ScholarPubMed
Gale, P, Kelly, L and Snary, EL 2015. Qualitative assessment of the entry of capripoxviruses into Great Britain from the European Union through importation of ruminant hides, skins and wool. Microbial Risk Analysis 1, 1318.CrossRefGoogle Scholar
Gale, P, Sechi, S, Horigan, V and Kelly, L 2018. Quantitative assessment for the risk of recrudescence of avian influenza in caged layer houses following depopulation: the effect of cleansing, disinfection and dismantling of complex equipment. British Poultry Abstracts 14, 9.Google Scholar
Goddard, AD, Donaldson, NM, Horton, DL, Kosmider, RD, Kelly, LA, Sayers, AR, Breed, AC, Freuling, CM, Muller, T, Shaw, SE, Hallgren, G, Fooks, AR and Snary, EL 2012. A quantitative release assessment for the noncommercial movement of companion animals: risk of rabies reintroduction to the United Kingdom. Risk Analysis 32, 17691783.CrossRefGoogle ScholarPubMed
Guan, J, Chan, M and VanderZaag, A 2017. Inactivation of avian influenza viruses on porous and non-porous surfaces is enhanced by elevating absolute humidity. Transboundary and Emerging Diseases 64, 12541261.CrossRefGoogle ScholarPubMed
Hansen, R, Brown, I, Brookes, S, Welchman, D and Cromie, R 2018. Current status of avian influenza in Europe and the UK. Veterinary Record 182, 5455.CrossRefGoogle ScholarPubMed
Horigan, V, Gale, P, Adkin, A, Brown, I, Clark, J and Kelly, L 2019. A qualitative risk assessment of cleansing and disinfection requirements after an avian influenza outbreak in commercial poultry. British Poultry Science 60, 691699.CrossRefGoogle ScholarPubMed
Kelly, L, Kosmider, R, Gale, P and Snary, E 2018. Qualitative import risk assessment: a proposed method for estimating the aggregated probability of entry of infection. Microbial Risk Analysis 9, 3337.CrossRefGoogle Scholar
Lucyckx, KY, Weyenberg, SV, Dewulf, J, Herman, L, Zoons, J, Vervaet, E, Heyndrickx, M and De Reu, K 2015. On-farm comparisons of different cleaning protocols in broiler houses. Poultry Science 94, 19861993.CrossRefGoogle Scholar
Marois, I, Cloutier, A, Garneau, E and Richter, MV 2012. Initial infectious dose dictates the innate, adaptive, and memory responses to influenza in the respiratory tract. Journal of Leukocyte Biology 92, 112.CrossRefGoogle ScholarPubMed
OIE 2018. OIE situation report for highly pathogenic avian influenza. Last updated 31 August 2018. Retrieved on 30 May 2019 from http://www.oie.int/fileadmin/Home/eng/Animal_Health_in_the_World/docs/pdf/OIE_AI_situation_report/OIE_SituationReport_AI_August2018.pdf.Google Scholar
OIE 2019. Terrestrial animal health code. Section 2. Risk analysis. Last updated 28 June 2019. Retrieved on 29 November 2019 from https://www.oie.int/fileadmin/Home/eng/Health_standards/tahc/current/chapitre_import_risk_analysis.pdf.Google Scholar
Pujol, JM, Eisenberg, JE, Haas, CN and Koopman, JS 2009. The effect of ongoing exposure dynamics in dose response relationships. PLOS Computational Biology 5, e1000399.CrossRefGoogle ScholarPubMed
Roberts, H, Gale, P and Brown, I 2018. Findings of H5N6 HPAI in wild birds in UK/Ireland and LPAI in poultry in France. Retrieved on 30 May 2019 from https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/682151/avian-flu-wild-birds-H5N6-180213.pdf.Google Scholar
Sargent, RG 2011. Verification and validation of simulation models. In Proceedings of the 2011 Winter Simulation Conference, pp. 183198. Retrieved on 3 December 2019 from https://www.informs-sim.org/wsc11papers/016.pdf.Google Scholar
Scottish Government 2016. Calculating the amount of poultry manure produced. Retrieved on 20 January 2017 from www.gov.scot/Resource/Doc/278281/0096546.doc.Google Scholar
Spekreijse, D, Bouma, A, Koch, G and Stegeman, JA 2011. Airborne transmission of a highly pathogenic avian influenza virus strain H5N1 between groups of chickens quantified in an experimental setting. Veterinary Microbiology 152, 8895.CrossRefGoogle Scholar
Yamamoto, Y, Nakamura, K, Okamatsu, M, Miyazaki, A, Yamada, M and Mase, M 2008. Detecting avian influenza virus (H5N1) in domestic duck feathers. Emerging Infectious Diseases 14, 16711672.CrossRefGoogle ScholarPubMed
Supplementary material: File

Gale et al. supplementary material

Gale et al. supplementary material

Download Gale et al. supplementary material(File)
File 34.7 KB