The potential spread of highly pathogenic avian influenza virus via dynamic contacts between poultry premises in Great Britain

Abstract

BackgroundHighly pathogenic avian influenza (HPAI) viruses have had devastating effects on poultry industries worldwide, and there is concern about the potential for HPAI outbreaks in the poultry industry in Great Britain (GB). Critical to the potential for HPAI to spread between poultry premises are the connections made between farms by movements related to human activity. Movement records of catching teams and slaughterhouse vehicles were obtained from a large catching company, and these data were used in a simulation model of HPAI spread between farms serviced by the catching company, and surrounding (geographic) areas. The spread of HPAI through real-time movements was modelled, with the addition of spread via company personnel and local transmission.ResultsThe model predicted that although large outbreaks are rare, they may occur, with long distances between infected premises. Final outbreak size was most sensitive to the probability of spread via slaughterhouse-linked movements whereas the probability of onward spread beyond an index premises was most sensitive to the frequency of company personnel movements.ConclusionsResults obtained from this study show that, whilst there is the possibility that HPAI virus will jump from one cluster of farms to another, movements made by catching teams connected fewer poultry premises in an outbreak situation than slaughterhouses and company personnel. The potential connection of a large number of infected farms, however, highlights the importance of retaining up-to-date data on poultry premises so that control measures can be effectively prioritised in an outbreak situation.

Analysis of poultry transit, notification systems and legislation in the state of Sergipe, 2008-2012

“…So, preventive, combat, and control measures can be effectively prioritized in an outbreak situation, preventing the diseases spread (Dent et al, 2011;Van Steenwinkel et al, 2011).…”

Implications of within-farm transmission for network dynamics: Consequences for the spread of avian influenza

“…Empirical data was obtained from a major catching company in England which provided the daily schedules of catching-teams recorded on an hourly basis. This Catching Company Database represented 68 catching teams visiting a total of 415 farms over a total period of 950 days (see Dent et al, 2011 and Supplementary Material Section 2). Each farms’ recorded catching-team visit days were given a value determined by the total number of slaughterhouse vehicle loads ( φ ) associated.…”

“…Using temporally explicit data describing the daily on-farm visit schedules for a major poultry catching company located in England (Dent et al, 2011), we explored the interaction between the within-flock transmission dynamics of HPAI, measured in continuous time, and temporally explicit catching-team visits, measured in discrete time. These on-farm visits made by catching teams represent the risk of fomites (i.e.…”

Regional transmission and reassortment of 2.3.4.4b highly pathogenic avian influenza (HPAI) viruses in Bulgarian poultry 2017/18

“…Ducks often do not show clinical signs 422 of disease, which makes identification of infection challenging. In addition, short 423 production cycles, high movement of personnel and ducks between farms, and 424 challenges in cleaning and disinfection of transport vehicles also contribute to potential 425 maintenance of IAV without detection (Dent et al, 2011;Lowe et al, 2014;Marinova-426 Petkova et al, 2016;Guinat et al, 2019). Serological and swab testing of ducks as 427 sentinel species might be useful in predicting future outbreaks in poultry.…”