Middle East respiratory syndrome coronavirus in dromedary camels: an outbreak investigation
Middle East respiratory syndrome coronavirus in dromedary camels: an outbreak investigation
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DOI：
10.1016/s1473-3099(13)70690-x
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发表时间：
2014-02-01
影响因子：
56.3
通讯作者：
Koopmans, Marion P. G.
中科院分区：
文献类型：
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作者：
Haagmans, Bart L.;Al Dhahiry, Said H. S.;Koopmans, Marion P. G.
背景中东呼吸综合征冠状病毒(MERS-CoV)可引起人类严重的下呼吸道感染。此前的研究表明，单峰骆驼是这种病毒的宿主。2013年10月，我们从卡塔尔一个农场的单峰骆驼身上检测了MERS冠状病毒的存在，该农场与两例人感染MERS冠状病毒有关。方法我们从卡塔尔农场的所有骆驼身上采集鼻拭子、直肠拭子和血液样本。我们用RT-PCR检测拭子，并针对E基因(Upe)、nudeocapsid(N)基因和开放阅读框架(ORF)1a进行扩增。用不同的MERS-CoV特异性聚合酶链式反应对阳性标本进行检测，获得的序列与连锁的人病例和其他人病例的序列一起用于系统学分析。我们对骆驼的血清样本进行了免疫荧光分析、蛋白质芯片和病毒中和分析。结果，我们于2013年10月17日从14头骆驼身上获得了样本。我们通过三个独立的RT-PCR和测序从三个骆驼的鼻拭子中检测到MERS冠状病毒。ORF1a片段和4.2kb串联片段的核苷酸序列与来自同一农场的两例人MERS冠状病毒和来自Hafr-Al-Batin的MERS冠状病毒分离物非常相似。另外8个骆驼鼻拭子在一个或多个RT-PCR上呈阳性，但无法通过测序确认。所有骆驼都有MERS-CoV尖峰结合抗体，这与MERS-CoV中和抗体的存在有很好的相关性。解释我们的研究提供了骆驼MERS-CoV的病毒学证实，并表明最近的一次疫情影响了人和骆驼。我们不知道农场里的人是不是被骆驼感染的，或者反之亦然，或者是否有第三个来源对此负责。
Background Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe lower respiratory tract infection in people. Previous studies suggested dromedary camels were a reservoir for this virus. We tested for the presence of MERS-CoV in dromedary camels from a farm in Qatar linked to two human cases of the infection in October, 2013.Methods We took nose swabs, rectal swabs, and blood samples from all camels on the Qatari farm. We tested swabs with RT-PCR, with amplification targeting the E gene (upE), nudeocapsid (N) gene, and open reading frame (ORF) la. PCR positive samples were tested by different MERS-CoV specific PCRs and obtained sequences were used for phylogentic analysis together with sequences from the linked human cases and other human cases. We tested serum samples from the camels for IgG immunofluorescence assay, protein microarray, and virus neutralisation assay.Findings We obtained samples from 14 camels on Oct 17, 2013. We detected MERS-CoV in nose swabs from three camels by three independent RT-PCRs and sequencing. The nudeotide sequence of an ORFla fragment (940 nucleotides) and a 4.2 kb concatenated fragment were very similar to the MERS-CoV from two human cases on the same farm and a MERS-CoV isolate from Hafr-Al-Batin. Eight additional camel nose swabs were positive on one or more RT-PCRs, but could not be confirmed by sequencing. All camels had MERS-CoV spike-binding antibodies that correlated well with the presence of neutralising antibodies to MERS-CoV.Interpretation Our study provides virological confirmation of MERS-CoV in camels and suggests a recent outbreak affecting both human beings and camels. We cannot condude whether the people on the farm were infected by the camels or vice versa, or if a third source was responsible.