Department of Preventive Medicine, Hanyang University Medical College, Seoul, South Korea; Department of Cancer Control and Population Health, Graduate School of Cancer Science and Policy, National Cancer Centre, Goyang, South Korea.
Department of Mathematics, Konkuk University, Seoul, South Korea.
J Hosp Infect. 2018 Jun;99(2):162-168. doi: 10.1016/j.jhin.2017.09.017. Epub 2017 Sep 25.
Effective countermeasures against emerging infectious diseases require an understanding of transmission rate and basic reproduction number (R). R for severe acute respiratory syndrome is generally considered to be >1, whereas that for Middle East respiratory syndrome (MERS) is considered to be <1. However, this does not explain the large-scale outbreaks of MERS that occurred in Kingdom of Saudi Arabia (KSA) and South Korean hospitals.
To estimate R in nosocomial outbreaks of MERS.
R was estimated using the incidence decay with an exponential adjustment model. The KSA and Korean outbreaks were compared using a line listing of MERS cases compiled using publicly available sources. Serial intervals to estimate R were assumed to be six to eight days. Study parameters [R and countermeasures (d)] were estimated by fitting a model to the cumulative incidence epidemic curves using Matlab.
The estimated R in Korea was 3.9 in the best-fit model, with a serial interval of six days. The first outbreak cluster in a hospital in Pyeongtaek had an R of 4.04, and the largest outbreak cluster in a hospital in Samsung had an R of 5.0. Assuming a six-day serial interval, the KSA outbreaks in Jeddah and Riyadh had R values of 3.9 and 1.9, respectively.
R for the nosocomial MERS outbreaks in KSA and South Korea was estimated to be in the range of 2-5, which is significantly higher than the previous estimate of <1. Therefore, more comprehensive countermeasures are needed to address these infections.
有效应对新发传染病需要了解传播率和基本繁殖数 (R)。严重急性呼吸综合征 (SARS) 的 R 一般被认为大于 1，而中东呼吸综合征 (MERS) 的 R 则被认为小于 1。然而，这并不能解释在沙特阿拉伯王国 (KSA) 和韩国医院发生的大规模 MERS 爆发。
估计 MERS 医院感染暴发的 R。
使用指数调整模型的发病率衰减来估计 R。使用从公开来源汇编的 MERS 病例清单对 KSA 和韩国的暴发进行比较。假设 R 的间隔时间为六到八天。使用 Matlab 拟合累积发病率流行曲线，估计研究参数 [R 和对策 (d)]。
在最佳拟合模型中，韩国的估计 R 为 3.9，间隔时间为六天。平泽一家医院的第一个暴发集群的 R 值为 4.04，三星一家医院的最大暴发集群的 R 值为 5.0。假设间隔时间为六天，吉达和利雅得的 KSA 暴发的 R 值分别为 3.9 和 1.9。
沙特阿拉伯和韩国医院内发生的 MERS 感染暴发的 R 值估计在 2-5 之间，明显高于先前估计的 <1。因此，需要采取更全面的对策来应对这些感染。
