Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Microbiology Research, Westmead Hospital, Sydney, Australia.
J Clin Virol. 2009 Dec;46(4):384-6. doi: 10.1016/j.jcv.2009.09.019. Epub 2009 Oct 13.
The performance of influenza laboratory diagnostics in young adults and in the setting of outbreaks during mass gatherings has not been well studied.
We compare the performance of point-of-care tests (POCTs) and immunofluorescence assays (IFAs) with nucleic acid tests (NATs) and viral culture in pilgrims attending influenza clinics established during a large influenza outbreak (World Youth Day, Sydney, Australia, 2008) to assess their performance under the real-life pressures of a mass influenza outbreak.
Patients with an influenza-like illness (ILI) underwent respiratory specimen sampling. Combined deep nares and throat swabs were collected for POCT by trained or untrained clinic staff; type-specific IFA; NAT and viral culture. Laboratory-confirmed influenza occurred if viral culture and/or NAT were positive; the performance of laboratory tests was calculated against this 'gold standard'.
A total of 230 samples were collected from 227 patients (median age, 20 years; interquartile range, 18-28 years), with 95 samples (41.3%) having laboratory-confirmed influenza infection (influenza A, 57; influenza B, 38). IFA and POCT sensitivities were 74.5% and 55%, respectively. Four of 51 (8%) culture-positive specimens were negative by NAT, and several errors in influenza virus typing occurred with IFA, POCT and NAT. A non-significant trend towards better POCT performance with increased operator training was demonstrated.
Different environments, patient populations, operator experience, laboratory access and practicalities associated with performing tests during mass influenza outbreaks may affect performance of influenza-specific laboratory tests.
流感实验室诊断在年轻成年人和大规模集会期间暴发时的表现尚未得到很好的研究。
我们比较了即时检测（POCT）和免疫荧光检测（IFA）与核酸检测（NAT）和病毒培养在参加大暴发流感期间设立的流感诊所的朝圣者中的表现，以评估其在大规模流感暴发的实际压力下的性能。
有流感样疾病（ILI）的患者接受了呼吸道标本采样。受过培训或未经培训的诊所工作人员对合并的深鼻和咽拭子进行 POCT 检测；进行针对特定类型的 IFA；进行 NAT 和病毒培养。如果病毒培养和/或 NAT 阳性，则发生实验室确诊的流感；根据此“金标准”计算实验室检测的性能。
从 227 名患者中采集了 230 份样本（中位数年龄为 20 岁；四分位距为 18-28 岁），其中 95 份样本（41.3%）具有实验室确诊的流感感染（甲型流感 57 例；乙型流感 38 例）。IFA 和 POCT 的敏感性分别为 74.5%和 55%。51 份培养阳性标本中有 4 份（8%）经 NAT 检测为阴性，IFA、POCT 和 NAT 在流感病毒分型方面存在若干错误。随着操作人员培训的增加，POCT 性能的提高呈非显著趋势。
不同的环境、患者人群、操作人员经验、实验室获取和在大规模流感暴发期间进行检测的实际情况可能会影响流感特异性实验室检测的性能。
