Center for Infectious Diseases Dynamics, The Pennsylvania State University, University Park, United States.
UMR ASTRE, CIRAD, INRAE, Université de Montpellier, Montpellier, France.
Elife. 2020 Aug 25;9:e59212. doi: 10.7554/eLife.59212.
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.
禽流感疫情在亚洲的小农户家禽养殖场已经出现了二十年。农民对这些疫情的反应可以减缓或加速病毒传播。我们使用了对越南南部 53 个小规模养鸡场的纵向调查，调查了具有疾病致死率的疫情爆发对收获率、疫苗接种和消毒行为的影响。我们发现，在小肉鸡群（≤16 只/群）中，如果疫情爆发，收获的估计概率会增加 56%，如果同一月爆发有突然死亡的疫情，收获的估计概率会增加 214%。疫苗接种和消毒与禽鸟数量呈强烈正相关。小规模养殖户——绝大多数低收入国家的家禽养殖者——往往依靠快速出售禽鸟来减轻疾病造成的损失。由于被扑杀的禽鸟被送往市场或贸易网络，这种被动反应行为有可能增强病毒的进一步传播。
