Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, USA.
Laboratory of Virology, Rocky Mountain Laboratories, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA.
Vector Borne Zoonotic Dis. 2021 Feb;21(2):128-131. doi: 10.1089/vbz.2020.2669. Epub 2020 Nov 16.
Middle East respiratory syndrome coronavirus (MERS-CoV) is a zoonotic disease that was first identified in humans in 2012 in Saudi Arabia. MERS-CoV causes acute and severe respiratory disease in humans. The mortality rate of MERS in humans is ∼35% and >800 deaths have been reported globally as of August 2020. Dromedary camels are a natural host of the virus and the source of zoonotic human infection. In experimental studies, Bactrian camels are susceptible to MERS-CoV infection similar to dromedary camels; however, neither the virus, viral RNA, nor virus-specific antibodies were detected in Bactrian camel field samples so far. The aim of our study was to survey Mongolian camels for MERS-CoV-specific antibodies. A total of 180 camel sera, collected in 2016 and 2017, were involved in this survey: 17 of 180 sera were seropositive with an initial enzyme-linked immunosorbent assay (ELISA) test performed at the State Central Veterinary Laboratory in Mongolia. These 17 positive sera plus 53 additional negative sera were sent to the Rocky Mountain Laboratories, NIAID/NIH, and tested for the presence of antibodies with a similar ELISA, an indirect immunofluorescence assay (IFA), and a virus neutralization test (VNT). In these additional tests, a total of 21 of 70 sera were positive with ELISA and 10 sera were positive with IFA; however, none was positive in the VNT. Based on these results, we hypothesize that the ELISA/IFA-positive antibodies are (1) non-neutralizing antibodies or (2) directed against a MERS-CoV-like virus circulating in Bactrian camels in Mongolia.
中东呼吸综合征冠状病毒（MERS-CoV）是一种人畜共患病，于 2012 年在沙特阿拉伯首次在人类中发现。MERS-CoV 导致人类急性和严重呼吸道疾病。截至 2020 年 8 月，MERS 在人类中的死亡率约为 35%，全球报告的死亡人数超过 800 人。单峰驼是该病毒的天然宿主，也是人畜共感染的源头。在实验研究中，双峰驼与单峰驼一样易感染 MERS-CoV；然而，迄今为止，在双峰驼野外样本中既未检测到病毒、病毒 RNA ，也未检测到病毒特异性抗体。我们的研究目的是调查蒙古骆驼是否存在 MERS-CoV 特异性抗体。本研究共涉及 180 份骆驼血清样本，这些样本于 2016 年和 2017 年采集：在蒙古国家中央兽医实验室进行的初始酶联免疫吸附试验（ELISA）检测中，180 份血清中有 17 份呈血清阳性。这 17 份阳性血清加上另外 53 份阴性血清被送往美国国立卫生研究院（NIH）下属的洛基山实验室，用类似的 ELISA、间接免疫荧光测定（IFA）和病毒中和试验（VNT）检测抗体的存在。在这些额外的检测中，总共 70 份血清中有 21 份 ELISA 检测呈阳性，10 份 IFA 检测呈阳性，但 VNT 检测均为阴性。根据这些结果，我们假设 ELISA/IFA 阳性抗体是（1）非中和抗体，或（2）针对在蒙古双峰驼中循环的 MERS-CoV 样病毒。
