Abstract

The epidemiology of Middle East respiratory syndrome coronavirus (MERS-CoV) since 2012 has been largely characterized by recurrent zoonotic spillover from dromedary camels followed by limited human-to-human transmission, predominantly in health-care settings. The full extent of infection of MERS-CoV is not clear, nor is the extent and/or role of asymptomatic infections in transmission. We conducted a review of molecular and serological investigations through PubMed and EMBASE from September 2012 to November 15, 2018, to measure subclinical or asymptomatic MERS-CoV infection within and outside of health-care settings. We performed retrospective analysis of laboratory-confirmed MERS-CoV infections reported to the World Health Organization to November 27, 2018, to summarize what is known about asymptomatic infections identified through national surveillance systems. We identified 23 studies reporting evidence of MERS-CoV infection outside of health-care settings, mainly of camel workers, with seroprevalence ranges of 0%–67% depending on the study location. We identified 20 studies in health-care settings of health-care worker (HCW) and family contacts, of which 11 documented molecular evidence of MERS-CoV infection among asymptomatic contacts. Since 2012, 298 laboratory-confirmed cases were reported as asymptomatic to the World Health Organization, 164 of whom were HCWs. The potential to transmit MERS-CoV to others has been demonstrated in viral-shedding studies of asymptomatic MERS infections. Our results highlight the possibility for onward transmission of MERS-CoV from asymptomatic individuals. Screening of HCW contacts of patients with confirmed MERS-CoV is currently recommended, but systematic screening of non-HCW contacts outside of health-care facilities should be encouraged.

中文翻译：

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无症状和亚临床的中东呼吸综合征冠状病毒感染综述。

抽象的

自2012年以来，中东呼吸综合征冠状病毒（MERS-CoV）的流行病学主要特征是单峰骆驼反复发生人畜共患病，随后在人与人之间传播有限，主要是在医疗机构中。MERS-CoV的全部感染程度尚不清楚，无症状感染在传播中的程度和/或作用也不清楚。我们从2012年9月至2018年11月15日通过PubMed和EMBASE对分子和血清学研究进行了回顾，以测量医疗机构内外的亚临床或无症状MERS-CoV感染情况。我们对截至2018年11月27日向世界卫生组织报告的实验室确诊的MERS-CoV感染进行了回顾性分析，总结关于通过国家监视系统识别出的无症状感染的知识。我们鉴定了23项报告，报告了在医疗机构以外（主要是骆驼工作者）MERS冠状病毒感染的证据，其血清阳性率范围为0％至67％（视研究地点而定）。我们在卫生保健工作者（HCW）和家庭接触者的卫生保健环境中确定了20项研究，其中11篇文献记录了无症状接触者中MERS-CoV感染的分子证据。自2012年以来，世界卫生组织报告了298例实验室确认的无症状病例，其中164例是HCW。在无症状MERS感染的病毒脱落研究中已经证明了将MERS-CoV传播给其他人的潜力。我们的结果突显了无症状个体继续传播MERS-CoV的可能性。