The severe acute respiratory syndrome COVID-19 has been in the center of the ongoing global health crisis in 2020. The high prevalence of mild cases facilitates sub-notification outside hospital environments and the number of those who are or have been infected remains largely unknown, leading to poor estimates of the crude mortality rate of the disease. Here we use a simple model to describe the number of accumulated deaths caused by COVID-19. The close connection between the proposed model and an approximate solution of the SIR model provides estimates of epidemiological parameters. We find values for the crude mortality between ${10}^{-4}$ and ${10}^{-3}$ which are lower than estimated numbers obtained from laboratory-confirmed patients. We also calculate quantities of practical interest such as the basic reproduction number and subsequent increment after relaxation of lockdown and other control measures.

严重急性呼吸系统综合症 COVID-19 一直是 2020 年持续的全球健康危机的中心。轻度病例的高患病率有助于在医院环境外进行次级通知，而感染或已经感染的人数在很大程度上仍然未知，导致对该疾病的粗死亡率估计不准确。在这里，我们使用一个简单的模型来描述由 COVID-19 造成的累计死亡人数。所提出的模型与 SIR 模型的近似解之间的密切联系提供了流行病学参数的估计。我们发现粗死亡率介于${10}^{-\mathrm{4个}}$和${10}^{-\mathrm{3个}}$这低于从实验室确诊患者获得的估计数字。我们还计算实际感兴趣的数量，例如基本再生数和放松锁定和其他控制措施后的后续增量。