Avian influenza outbreaks have been occurring on smallholder poultry farms in Asia for two decades. Farmer responses to these outbreaks can slow down or accelerate virus transmission. We used a longitudinal survey of 53 small-scale chicken farms in southern Vietnam to investigate the impact of outbreaks with disease-induced mortality on harvest rate, vaccination, and disinfection behaviors. We found that in small broiler flocks (≤16 birds/flock) the estimated probability of harvest was 56% higher when an outbreak occurred, and 214% higher if an outbreak with sudden deaths occurred in the same month. Vaccination and disinfection were strongly and positively correlated with the number of birds. Small-scale farmers – the overwhelming majority of poultry producers in low-income countries – tend to rely on rapid sale of birds to mitigate losses from diseases. As depopulated birds are sent to markets or trading networks, this reactive behavior has the potential to enhance onward transmission.
The study dataset is available online at the Open Science Framework, https://osf.io/ws3vu/.
Poultry Population and Farm Management Dynamics - Ca Mau - VietnamOpen Science Framework, 10.17605/OSF.IO/WS3VU.
- Maciej F Boni
- Maciej F Boni
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Human subjects: The research collaboration was approved by the Hospital for Tropical Diseases in Ho Chi Minh City, and the study design was approved by the Ca Mau sub-Department of Livestock Production and Animal Health. The Ca Mau sub-Department of Livestock Production and Animal Health (CM-LPAH) specifically approved this study and is equivalent to an Animal Care and Use Committee that approves studies like this in Vietnam. CM-LPAH approved the publication of these results. No consenting process was required as the study involved no human biological samples, no patients, and no personal or identifiable information. The IRB that made this determination was the Hospital for Tropical Diseases Scientific and Ethical Committee (Ho Chi Minh City).
- Joshua T Schiffer, Fred Hutchinson Cancer Research Center, United States
© 2020, Delabouglise et al.
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