Disentangling the role of poultry farms and wild birds in the spread of highly pathogenic avian influenza virus in Europe

Abstract

In winter 2016-17, Europe was severely hit by an unprecedented epidemic of highly pathogenic avian influenza virus (HPAIV), causing significant impact on animal health, wildlife conservation and livestock economic sustainability. By applying phylodynamic tools to virus sequences collected during the epidemic, we investigated when the first infections occurred, how many infections were unreported, which factors influenced the virus spread and how many spillover events occurred. HPAIV was likely introduced into poultry farms during the autumn, in line with the timing of wild birds’ migration. In Germany, Hungary and Poland, the epidemic was dominated by farm-to-farm transmission, showing that understanding of how farms are connected would greatly help control efforts. In Czech Republic, the epidemic was dominated by wild bird-to-farm transmission, meaning that more sustainable prevention strategies should be developed to reduce HPAIV exposure from wild birds. Inferred transmission parameters will be useful to parameterize predictive models of HPAIV spread. None of the predictors related to live poultry trade, poultry census and geographic proximity were identified as supportive predictors of HPAIV spread between farms across borders. These results are crucial to better understand HPAIV transmission dynamics at the domestic-wildlife interface, with the view to reduce the impact of future epidemics.

Evolution and Epidemic Spread of the Avian Infectious Bronchitis Virus (IBV) GI-23 in Brazil

“…It is also necessary to consider that fomites (feed/slaughter contacts) and human movements (company technician, veterinarian, shared farm workers) could be linked to this recent introduction of IBV GI-23. All these possibilities were already associated with the introduction of avian influenza virus (AIV) into different poultry farms and geographic regions [ 29 , 30 ]. There is a strong positive relationship between the opening of new markets and the introduction of a range of animal diseases, as well as a strong association of the growing trade volumes with the probability that poultry viral diseases will establish and spread [ 30 , 31 ].…”

“…Detailed knowledge of how poultry farms are connected to each other can help contain IBV GI-23. The disruption of the potential transmission network between poultry farms is necessary to control the continued spread of viral diseases, as previously demonstrated [ 30 ]. This is necessary for IBV as well as the highly pathogenic AIV recently detected in South America [ 32 ].…”

The perks of being an organic chicken – animal welfare science on the key features of organic poultry production

“…Although the risk of predator attacks might be difficult to completely eliminate, especially from aerial predators, proper fencing and sufficient protective cover can nevertheless help reduce this welfare issue (Van de Weerd et al, 2009;Göransson et al, 2021;Bonnefous et al, 2022). Another peril of free-ranging is that of infectious disease transmission, considering the biosecurity challenges associated with outdoor access (Gonzales et al, 2017;Guinat et al, 2022). The introduction of, for example, highly pathogenic avian influenza (HPAI) virus may lead to widespread disease outbreaks, with severe health impairments, high mortality rates and mass culling of poultry flocks.…”

Are all avian influenza outbreaks in poultry the same? The predicted impact of poultry species and virus subtype

“…Moreover, each virus strain can mutate during an outbreak, especially when infecting domestic poultry, which can alter the transmissibility parameters (Capua & Marangon, 2006;Guinat et al, 2022).…”

“…(2014) quantified the transmission of four H5 LPAI strains in Muscovy ducks and found large differences in transmission between strains. Moreover, each virus strain can mutate during an outbreak, especially when infecting domestic poultry, which can alter the transmissibility parameters (Capua & Marangon, 2006; Guinat et al., 2022).…”