Center for Vectorborne Diseases, School of Veterinary Medicine, University of California, Davis, California 95616, USA.
Am J Trop Med Hyg. 2010 Nov;83(5):1137-45. doi: 10.4269/ajtmh.2010.10-0078.
In Los Angeles, California, West Nile virus (WNV) has followed a pattern of emergence, amplification, subsidence, and resurgence. A time series cross-correlation analysis of human case counts and sentinel chicken seroconversions revealed temporal concordance indicating that chicken seroconversions tracked tangential transmission of WNV from the basic passeriform-Culex amplification cycle to humans rather than antecedent enzootic amplification. Sentinel seroconversions provided the location and time of transmission as opposed to human cases, which frequently were reported late and were assumed to be acquired 2-14 days before disease onset at their residence. Cox models revealed that warming degree-days were associated with the increased risk of seroconversion, whereas elevated herd immunity in peridomestic birds dampened seroconversion risk. Spatially, surveillance data collected within a 5 km radius of flock locations 15-28 days before the bleed date were most predictive of a seroconversion. In urban Los Angeles, sentinel chicken seroconversions could be used as an outcome measure in decision support for emergency intervention.
在加利福尼亚州洛杉矶，西尼罗河病毒（WNV）的出现、扩增、消退和再次出现呈现出一定的模式。对人类病例数和哨兵鸡血清转化的时间序列交叉相关分析显示，时间上的一致性表明，鸡血清转化跟踪了 WNV 从基本雀形目-库蚊扩增循环到人类的切线传播，而不是先前的地方性扩增。哨兵鸡血清转化提供了传播的地点和时间，而不是人类病例，后者经常报告得很晚，并假定是在发病前 2-14 天在其居住地获得的。Cox 模型显示，变暖度日数与血清转化率的增加风险相关，而家庭周围鸟类的群体免疫力升高则降低了血清转化率的风险。在空间上，在采血日期前 15-28 天收集的距鸡群位置 5 公里半径内的监测数据最能预测血清转化率。在城市洛杉矶，哨兵鸡血清转化率可用作紧急干预决策支持的结果指标。
