Reid Scott M, Coward Vivien J, James Joe, Hansen Rowena D E, Birch Colin, Bakrania Mayur, Brookes Sharon M, Brown Ian H, Banyard Ashley C
Department of Virology, Animal and Plant Health Agency-Weybridge, Addlestone, UK.
WOAH/FAO International Reference Laboratory for Avian Influenza, Animal and Plant Health Agency-Weybridge, Addlestone, UK.
Vet Rec. 2025 Jan 18;196(2):e4842. doi: 10.1002/vetr.4842. Epub 2024 Nov 19.
The international gold standard for avian influenza virus (AIV) diagnosis is virus isolation (VI) in specific pathogen-free embryonated chicken eggs (ECEs). AIV isolation typically involves a 6-day turnaround, during which premises under suspicion for notifiable AIV infection are held under restriction regardless of molecular diagnoses, often with significant welfare implications.
A reduction in time for negation by VI was investigated following experimental inoculation of AIV from known-positive original clinical material into ECEs. VI data derived from more than 600 case investigations from epizootics of high-pathogenicity AIV (HPAIV) in Great Britain since 2016 and from low-pathogenicity AIV (LPAIV) cases in Great Britain since 2014 were examined to support a reduction in test timing using alternative regimens.
HPAIVs were isolated during the first passage, and for LPAIV VI, the second passage could be reduced to 2 days. Power analysis showed that the benefit of reducing the number of days outweighed the risk of missing a positive isolate.
Limited data were available from experimental inoculations.
This truncated methodology, which enables an earlier release of restrictions, may substantially ease the economic implications of restriction. It could also reduce bird welfare implications and improve international standards without loss of test performance.
禽流感病毒（AIV）诊断的国际金标准是在无特定病原体的鸡胚（ECE）中进行病毒分离（VI）。AIV分离通常需要6天的周转时间，在此期间，无论分子诊断结果如何，疑似发生应通报AIV感染的场所都要受到限制，这往往会对动物福利产生重大影响。
将已知阳性的原始临床材料中的AIV接种到ECE中进行实验接种后，研究缩短VI阴性判定时间的方法。对自2016年以来英国高致病性AIV（HPAIV） epizootics和自2014年以来英国低致病性AIV（LPAIV）病例的600多个病例调查的VI数据进行了检查，以支持使用替代方案缩短检测时间。
HPAIV在首次传代时被分离出来，对于LPAIV VI，第二次传代可缩短至2天。功效分析表明，缩短天数的益处大于错过阳性分离株的风险。
实验接种的数据有限。
这种能够更早解除限制的简化方法，可能会大大减轻限制措施对经济的影响。它还可以减少对鸟类福利的影响，并在不损失检测性能的情况下提高国际标准。
