Saegerman C, Speybroeck N, Vanopdenbosch E, Wilesmith J W, Berkvens D
Secretariat of the Scientific Committee, Administration of Control Policy, Federal Agency for the Safety of the Food Chain, World Trade Center III, Avenue Simon Bolivar 30, B-1000 Brussels, Belgium.
Vet Rec. 2006 Oct 28;159(18):583-7. doi: 10.1136/vr.159.18.583.
There were 118 cases of bovine spongiform encephalopathy (BSE) in Belgium before January 1, 2004. Trends in their age at detection were analysed and attempts were made to use this parameter as a predictor of the current status of the BSE epidemic in the country. The following variables were considered: date of birth, breed, date of detection, mode of detection, and the number and age of animals slaughtered and rendered each month. Age at detection as a function of date of birth was a very poor epidemiological indicator. It was concluded that the increasing age of BSE cases when they were detected was due to the depletion of cases, as a result of there being no new infections, and that it is a reliable indicator of a decrease in the epidemic curve in Belgium. By means of a simulation it is shown how age distribution at the time of detection closely follows the epidemic curve and data from Great Britain are used to illustrate the point.
2004年1月1日前，比利时有118例牛海绵状脑病（BSE）病例。分析了这些病例的发现年龄趋势，并尝试将该参数用作该国BSE疫情当前状况的预测指标。考虑了以下变量：出生日期、品种、发现日期、发现方式以及每月屠宰和处理的动物数量及年龄。发现年龄作为出生日期的函数是一个非常差的流行病学指标。得出的结论是，发现BSE病例时其年龄增加是由于没有新感染导致病例减少，并且这是比利时疫情曲线下降的可靠指标。通过模拟展示了发现时的年龄分布如何紧密跟随疫情曲线，并使用来自英国的数据来说明这一点。
