检查确诊中东呼吸综合征冠状病毒 (Middle East respiratory syndrome coronaviru, MERS-CoV) 感染。
下呼吸道样本(例如痰、气管抽吸物、支气管肺泡灌洗液)是 RT-PCR 的首选样本,因为痰和气管抽吸物所含病毒载量最高,所以检出率最高。[5]Shalhoub S, Farahat F, Al-Jiffri A, et al. IFN-alpha-2a or IFN-beta-1a in combination with ribavirin to treat Middle East respiratory syndrome coronavirus pneumonia: a retrospective study. J Antimicrob Chemother. 2015;70:2129-2132.
http://www.ncbi.nlm.nih.gov/pubmed/25900158?tool=bestpractice.com
[90]Memish ZA, Al-Tawfiq JA, Makhdoom HQ, et al. Respiratory tract samples, viral load, and genome fraction yield in patients with Middle East respiratory syndrome. J Infect Dis. 2014;210:1590-1594.
https://academic.oup.com/jid/article/210/10/1590/2192931/Respiratory-Tract-Samples-Viral-Load-and-Genome
http://www.ncbi.nlm.nih.gov/pubmed/24837403?tool=bestpractice.com
然而,支气管镜检查可能会产生气溶胶,通常不推荐使用。建议使用上呼吸道样本(例如鼻咽和口咽拭子、鼻咽抽吸物/冲洗液)并采集血清,以检测病毒,尤其在无法获得下呼吸道样本,并且在症状出现后 7 天或更短时间的情况下。[86]Ministry of Health (Saudi Arabia). Middle East respiratory syndrome coronavirus; guidelines for healthcare professionals, version 5.1. May 2018 [internet publication].
https://www.moh.gov.sa/CCC/StaffRegulations/Corona/Documents/MERS-CoV%20Guidelines%20for%20Healthcare%20Professionals%20-%20April%202018%20-%20v5.pdf
[91]World Health Organization. Laboratory testing for Middle East respiratory syndrome coronavirus. Interim guidance (revised). January 2018 [internet publication].
http://www.who.int/csr/disease/coronavirus_infections/mers-laboratory-testing/en/
[92]Centers for Disease Control and Prevention. CDC laboratory testing for Middle East respiratory syndrome coronavirus (MERS-CoV). June 2018 [internet publication].
http://www.cdc.gov/coronavirus/mers/lab/lab-testing.html
也可以使用尿液和粪便样本;但与呼吸道样本相比,这些样本的病毒含量较低。
医务工作者在采集标本时,应穿戴适当的个人防护用品(例如面罩、护目镜、手套、长大衣)。[91]World Health Organization. Laboratory testing for Middle East respiratory syndrome coronavirus. Interim guidance (revised). January 2018 [internet publication].
http://www.who.int/csr/disease/coronavirus_infections/mers-laboratory-testing/en/
MERS-CoV RT-PCR (upE):针对 E 蛋白基因上游区域 (upE) 的高度敏感筛查检测。[95]Corman VM, Eckerle I, Bleicker T, et al. Detection of a novel human coronavirus by real-time reverse-transcription polymerase chain reaction. Euro Surveill. 2012;17:20285.
http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=20285
http://www.ncbi.nlm.nih.gov/pubmed/23041020?tool=bestpractice.com
MERS-CoV RT-PCR (ORF 1b):针对开放阅读框架 1b (ORF 1b) 的确认检测。比 upE 测定的敏感性低,但特异性更高。[95]Corman VM, Eckerle I, Bleicker T, et al. Detection of a novel human coronavirus by real-time reverse-transcription polymerase chain reaction. Euro Surveill. 2012;17:20285.
http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=20285
http://www.ncbi.nlm.nih.gov/pubmed/23041020?tool=bestpractice.com
MERS-CoV RT-PCR (ORF 1a):针对 ORF 1a 的确认检测。具有高度特异性,比 ORF 1b 检测的敏感性更高,但与 upE 测定的敏感性类似。[93]Corman VM, Muller MA, Costabel U, et al. Assays for laboratory confirmation of novel human coronavirus (hCoV-EMC) infections. Euro Surveill. 2012;17:20334.
http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=20334
http://www.ncbi.nlm.nih.gov/pubmed/23231891?tool=bestpractice.com
世界卫生组织 (WHO) 建议首先进行筛查试验,如果结果呈阳性,则进行确认检测。如果确认检测结果呈阳性,则确认感染。如果确认检测结果呈阴性,考虑重复检测(如果流行病学证据提示感染)或进行测序试验。[91]World Health Organization. Laboratory testing for Middle East respiratory syndrome coronavirus. Interim guidance (revised). January 2018 [internet publication].
http://www.who.int/csr/disease/coronavirus_infections/mers-laboratory-testing/en/
至少 2 个特定基因组靶的 PCR 结果呈阳性,或者对第二个基因靶标测序得到一个阳性靶标,方可确诊。[87]World Health Organization (WHO). Middle East respiratory syndrome coronavirus: case definition for reporting to WHO. July 2017 [internet publication].
http://www.who.int/csr/disease/coronavirus_infections/case_definition/en/
[88]Centers for Disease Control and Prevention. Interim patient under investigation (PUI) guidance and case definitions. September 2017 [internet publication].
http://www.cdc.gov/coronavirus/mers/case-def.html