Pelletier Sky T K, Rorres Chris, Macko Peter C, Peters Sarah, Smith Gary
School of Veterinary Medicine, University of Pennsylvania, New Bolton Center, 382 West Street Road, Kennett Square, PA 19348, USA.
Trop Anim Health Prod. 2012 Oct;44(7):1681-7. doi: 10.1007/s11250-012-0124-2. Epub 2012 Apr 3.
State-scale and premises-scale gravity models for the spread of highly pathogenic avian influenza (H5N1) in Nigeria and Ghana were used to provide a basis for risk maps for future epidemics and to compare and rank plausible culling and vaccination strategies for control. Maximum likelihood methods were used to fit the models to the 2006-2007 outbreaks. The sensitivity and specificity of the state-scale model-generated probabilities that any given state would be involved in an epidemic were each 57 %. The premises-based model indicated that reactive, countrywide vaccination strategies, in which the order in which flocks are vaccinated was strictly determined by known risk factors for infection, were more effective in reducing the final size of the epidemic and the epidemic impact than vaccinating flocks at random or ring vaccination. The model suggests that an introduction of highly pathogenic avian influenza (H5N1) into Ghana had a high chance (84 %) of causing a major outbreak. That this did not happen was most probably a result of the very swift Ghanaian response to news of the first introductions.
利用国家尺度和场所尺度的重力模型来研究高致病性禽流感（H5N1）在尼日利亚和加纳的传播情况，以此为未来疫情风险地图提供依据，并对合理的扑杀和疫苗接种控制策略进行比较和排序。采用最大似然法将模型与2006 - 2007年疫情爆发情况进行拟合。国家尺度模型生成的任何给定州发生疫情的概率，其敏感性和特异性均为57%。基于场所的模型表明，在全国范围内采取反应性疫苗接种策略（即根据已知感染风险因素严格确定鸡群接种顺序），相较于随机接种鸡群或环状疫苗接种，在减少疫情最终规模和疫情影响方面更为有效。该模型表明，高致病性禽流感（H5N1）传入加纳有很大机会（84%）引发大规模疫情。而实际未发生这种情况很可能是因为加纳对首次传入消息做出了非常迅速的反应。
