The University of Sydney, Sydney School of Veterinary Science, Faculty of Science, Sydney, NSW, Australia.
Quantitative Sciences, Department of Agriculture and Water Resources, Canberra, ACT, Australia.
PLoS One. 2018 Mar 1;13(3):e0193730. doi: 10.1371/journal.pone.0193730. eCollection 2018.
The objective of this study was to elicit experts' opinions and gather estimates on the perceived probability of introduction and spread of avian influenza (AI) virus in the Australian broiler and layer industry. Using a modified Delphi method and a 4-step elicitation process, 11 experts were asked to give initial individual estimates for the various pathways and practices in the presented scenarios using a questionnaire. Following this, a workshop was conducted to present group averages of estimates and discussion was facilitated to obtain final individual estimates. For each question, estimates for all experts were combined using a discrete distribution, with weights allocated representing the level of expertise. Indirect contact with wild birds either via a contaminated water source or fomites was considered the most likely pathway of introduction of low pathogenic avian influenza (LPAI) on poultry farms. Presence of a water body near the poultry farm was considered a potential pathway for introduction only when the operation type was free range and the water body was within 500m distance from the shed. The probability that LPAI will mutate to highly pathogenic avian influenza (HPAI) was considered to be higher in layer farms. Shared personnel, equipment and aerosol dispersion were the most likely pathways of shed to shed spread of the virus. For LPAI and HPAI spread from farm to farm, shared pick-up trucks for broiler and shared egg trays and egg pallets for layer farms were considered the most likely pathways. Findings from this study provide an insight on most influential practices on the introduction and spread of AI virus among commercial poultry farms in Australia, as elicited from opinions of experts. These findings will be used to support parameterization of a modelling study assessing the risk of AI introduction and spread among commercial poultry farms in Australia.
本研究旨在征求专家意见并收集对澳大利亚肉鸡和蛋鸡产业中禽流感（AI）病毒传入和传播的感知概率的估计。使用改进的 Delphi 方法和四步启发式过程，11 名专家通过问卷调查被要求对所提出情景中的各种途径和做法给出初步的个体估计。在此之后，举办了一次研讨会，介绍了小组对估计数的平均值，并促进了讨论，以获取最终的个人估计数。对于每个问题，使用离散分布组合所有专家的估计数，其中分配的权重代表专业水平。通过受污染的水源或媒介物与野鸟的间接接触被认为是低致病性禽流感（LPAI）传入家禽养殖场的最可能途径。在禽舍附近存在水体仅被认为是引入的潜在途径，当操作类型是自由放养且水体距离棚舍 500 米以内时。LPAI 突变为高致病性禽流感（HPAI）的概率被认为在蛋鸡场更高。共用人员、设备和气溶胶扩散是病毒在棚舍之间传播的最可能途径。对于 LPAI 和 HPAI 从农场到农场的传播，肉鸡共用皮卡和蛋鸡共用蛋盘和蛋托盘被认为是最可能的途径。本研究的结果提供了对澳大利亚商业家禽养殖场中 AI 病毒传入和传播最有影响的实践的深入了解，这是从专家意见中得出的。这些发现将用于支持评估澳大利亚商业家禽养殖场中 AI 传入和传播风险的建模研究的参数化。
