SARS-CoV-2 Nowcasting and R Estimation

The nowcasting provides an estimate of the course of the number of SARS-CoV-2 cases in Germany that have already occurred, taking into account the delay in diagnosis, reporting and transmission. Based on the nowcasting, an estimation of the time-dependent reproductive number R can be performed. The reproductive number describes how many people an infected person infects on average. It cannot be used alone as a measure of effectiveness/need for action. Also important are, among other things, the absolute number of daily new infections and the severity of the diseases. The absolute number of new infections must be small enough to allow effective contact tracing and not to overload the capacities of intensive care beds.现时预测（nowcasting）可综合考量诊断、报告及传播环节的延迟情况，对德国境内已实际发生的新型冠状病毒（SARS-CoV-2）感染病例数的当前态势进行估算。基于该现时预测结果，可估算随时间动态变化的再生数（reproductive number）R。该再生数指单名感染者平均可传染的人数，不可单独将其作为防控措施有效性或防控必要性的评估依据。除此之外，每日新增感染绝对数以及疾病严重程度同样属于关键参考要素。新增感染绝对数需维持在较低水平，以确保能够开展高效的接触者追踪工作，且不会超出重症监护床位的承载极限。