Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 7, 3584 CL, Utrecht, The Netherlands.
Prev Vet Med. 2010 Jul 1;95(3-4):297-300. doi: 10.1016/j.prevetmed.2010.04.006. Epub 2010 May 21.
Highly pathogenic avian influenza (HPAI) viruses show different disease dynamics between virus strains and host species, and therefore epidemic field data are very valuable. This study used field data of the HPAI H7N1 epidemic which affected Northern Italy in 1999-2000. Field mortality data was back-calculated into a S-I-format to estimate the transmission rate parameter beta, indicating the number of birds infected per infectious bird per time unit. The bird-infectious period was assumed to be 2 days, and all birds were assumed to die after this infectious period. The estimated beta for HPAI H7N1 virus transmission in turkeys was 1.43 (95% CI: 1.17-1.74). Farm risk factors such as flock size and age of the turkeys did not influence the estimated transmission rate parameter.
高致病性禽流感 (HPAI) 病毒在不同病毒株和宿主种间表现出不同的疾病动态，因此流行领域的数据非常有价值。本研究使用了 1999-2000 年影响意大利北部的 HPAI H7N1 流行的现场数据。现场死亡率数据被回溯到 S-I 格式，以估计传播率参数β，该参数表示每单位时间内每只感染鸟类感染的鸟类数量。假设鸟类感染期为 2 天，并且所有鸟类在该感染期后都会死亡。估计 HPAI H7N1 病毒在火鸡中的传播β值为 1.43（95%置信区间：1.17-1.74）。农场风险因素，如禽类数量和火鸡年龄，并不影响估计的传播率参数。
