Current epidemiological situation of Middle East respiratory syndrome coronavirus clusters and implications for public health response in South Korea
Current epidemiological situation of Middle East respiratory syndrome coronavirus clusters and implications for public health response in South Korea
复制标题
DOI：
10.5124/jkma.2015.58.6.487
复制
发表时间：
2015-06-01
影响因子：
0.3
通讯作者：
Kim, Sang Hoo
中科院分区：
文献类型：
--
作者：
Choi, Jae Wook;Kim, Kyung Hee;Kim, Sang Hoo
自2015年5月20日韩国确诊首例中东呼吸综合征（MERS）病例以来，韩国聚集性病例在一个月内已成为继沙特阿拉伯之后最大的观察病例。与在中东观察到的情况类似，确诊病例是通过院内传播感染的，聚集性人群主要限于患者、医护人员以及在有确诊病例的医疗机构中探望患者的访客。与阿拉伯半岛疫情的一个主要区别是韩国的三级传播病例数量较多，截至6月12日已达到40例。这一观察结果可能表明，尽管韩国的中东呼吸综合征冠状病毒（MERS-CoV）缺乏基因突变，但该病毒的表现可能与中东地区的病毒不同。韩国“超级传播者”的较高传染性也表明这一说法应得到进一步调查。一些组织提出了急诊室分诊不充分的建议，特别是在三星医疗中心，该中心是院内感染最多的地方，有 60 例病例，这是这种迅速传播的基础。然而，这并不能解释分诊不可能实施的事实，因为在指标患者入住医疗机构期间，韩国是否存在中东呼吸综合征冠状病毒（MERS-CoV）是未知的。本文旨在确定中东呼吸综合征冠状病毒在韩国扩大传播的关键因素。首先是在医院确诊MERS后，最初未能及时确诊并隔离指示病例，并且在隔离前缺乏追踪指示病例社区潜在暴露的详细信息。二是疾病管理本部早期对密切接触者进行分类的措施不充分。由于对密切接触的定义不一致，一些病例被忽视隔离，没有接受调查。最后，确诊或潜在的中东呼吸综合征患者被送往没有足够疾病控制措施或房间的医疗机构接受治疗和观察，例如通风单间或空气预防室。由于中东呼吸综合征冠状病毒不能通过空气传播的严格立场，感染控制措施迄今为止忽视了含有病毒的较小飞沫（气溶胶）可以与空气传播病毒类似的作用的证据，这可能是急诊室和医院病房中广泛而快速传播的原因。尽管韩国政府预计新确诊病例将在未来几周内减少，但如果不严格执行明确的指导方针来控制进一步传播，当前趋势的停止可能会持续较长一段时间。此外，由于韩国超级传播者感染率较高，应加大对潜在超级传播者的筛查力度，并对确诊的超级传播者进行彻底排查，快速查明传染源，减少二、三级传播，防止可能出现的四级传播。
Since May 20, 2015, when the first case of Middle East respiratory syndrome (MERS) in South Korea was confirmed, the cluster case in South Korea has grown to become the largest observed case following Saudi Arabia within the span of one month. Akin to what was observed in the Middle East, confirmed cases were infected through nosocomial transmission where the cluster is largely limited to patients, healthcare workers, and visitors to patients in healthcare facilities with confirmed cases. A major difference from the outbreaks in the Arabian Peninsula has been the large number of tertiary transmission cases in South Korea, which had reached forty cases by June 12. This observation may suggest that despite the lack of genetic mutation of Middle East respiratory syndrome coronavirus (MERS-CoV) in South Korea, the virus may be behaving differently from that of the Middle East. The higher infectiousness of 'super-spreaders' in South Korea also suggests that this assertion should be under further investigation. Suggestions of inadequate triage in emergency rooms, particularly at Samsung Medical Center which accounts for the most nosocomial infection with 60 cases, have been made by several organizations as the basis for this rapid spread. This, however, does not account for the fact that triage was impossible to implement, since the presence of MERS-CoV in South Korea was unknown during the index patient's stay at the healthcare facilities. This paper aims to identify the key factors in the amplified spread of MERS-CoV in South Korea. The first is the initial failure to confirm diagnosis promptly and to isolate the index case after confirmation of MERS in hospital and the lack of detail in tracking potential exposures in the community of the index case before isolation. The second is the early inadequate measures the Korea Centers for Disease Control and Prevention took in categorizing close contacts. Due to inconsistencies in defining what constitutes close contact, a number of cases were neglected from quarantine and were not subjected to investigation. Finally, confirmed or potential MERS patients were admitted for treatment and observation at medical facilities without adequate disease control measures or rooms, such as ventilated single rooms or airborne precaution rooms. Due to the rigid position that MERS-CoV cannot be transmitted via airborne means, infection control measures has so far neglected evidence that smaller droplets (aerosol) containing the virus can act similar to airborne agents, which may account for the widespread and rapid transmission in a emergency room and a patient's room in hospital. Although the South Korean government expects newly confirmed cases to abate in the coming few weeks, without stringent implementation of clearly defined guidelines to control further transmissions, the cessation of the current trend may continue for an extended period. Additionally, due to the high infection rate of super-spreaders in South Korea, efforts to screen for potential super-spreaders and a thorough investigation of those confirmed to be super-spreaders should be done to quickly identify source of infection, to potentially lower the number of secondary, tertiary transmissions and prevent possible quaternary transmissions.