新型冠状病毒肺炎基本再生数的初步预测

Preliminary prediction of the basic reproduction number of the novel coronavirus 2019-nCoV

目的预测新型冠状病毒感染肺炎(2019-nCoV)的基本再生数,为其防控和相关政策支持提供依据。方法基于包括"易感态-潜伏态-感染态-移除态"的SEIR仓室模型,假设2020年1月25日及以前出现症状的感染者均属于无干预自由传播期间感染的人员,结合截至1月26日凌晨已确诊和疑似病例数及国际同行预测的感染人数,参考SARS的流行病学关键参数,对新型冠状病毒感染肺炎的基本再生数进行估计。结果以《人民日报》和丁香园发布的新型冠状病毒感染肺炎疫情实时动态数据为基准,估计2019-nCoV的基本再生数在2.8~3.3之间;以国外同行预测的感染人数为基准,基本再生数在3.2~3.9之间。结论 2019-nCoV早期致病传播能力与SARS接近或略高于SARS,属于中高度传染性的传播疾病。迅速切断传播途径,采用及时有效的防控措施能够较快遏制2019-nCoV的进一步蔓延。

Objectives To estimate the basic reproduction number of the novel coronavirus(2019-nCoV) and to provide support to epidemic preparedness and response. Methods Based on the susceptible–exposed–infected–removed(SEIR) compartment model and the assumption that the infection cases with symptoms occurred before January26, 2020 were resulted from free propagation without intervention, we estimated the basic reproduction number of2019-nCoV according to the reported confirmed cases and suspected cases, as well as theoretical estimated number of infected cases by other research teams, together with some epidemiological determinants learned from the severe acute respiratory syndrome. Results The basic reproduction number fall between 2.8 to 3.3 by using the real-time reports on the number of 2019-nCoV infected cases from People’s Daily in China, and fall between 3.2 and 3.9 on the basis of the predicted number of infected cases from international colleagues. Conclusions The early transmission capability of 2019-nCoV is close to or slightly higher than SARS. It is a controllable disease with moderate-high transmissibility. Timely and effective control measures are capable to quickly reduce further transmission.