Wei Yongyue, Guan Jinxing, Ning Xiao, Li Yuelin, Wei Liangmin, Shen Sipeng, Zhang Ruyang, Zhao Yang, Shen Hongbing, Chen Feng
Department of Epidemiology and Biostatistics, School of Public Health, Nanjing Medical University, Nanjing 211166, China.
China International Cooperation Center for Environment and Human Health & Center for Global Health, Nanjing Medical University, Nanjing 211166, China.
Engineering (Beijing). 2022 Jun;13:91-98. doi: 10.1016/j.eng.2021.07.015. Epub 2021 Sep 14.
The occurrence of coronavirus disease 2019 (COVID-19) was followed by a small burst of cases around the world; afterward, due to a series of emergency non-pharmaceutical interventions (NPIs), the increasing number of confirmed cases slowed down in many countries. However, the lifting of control measures by the government and the public's loosening of precautionary behaviors led to a sudden increase in cases, arousing deep concern across the globe. arousing deep concern across the globe. This study evaluates the situation of the COVID-19 pandemic in countries and territories worldwide from January 2020 to February 2021. According to the time-varying reproduction number (()) of each country or territory, the results show that almost half of the countries and territories in the world have never controlled the epidemic. Among the countries and territories that had once contained the occurrence, nearly half failed to maintain their prevention and control, causing the COVID-19 pandemic to rebound across the world-resulting in even higher waves in half of the rebounding countries or territories. This work also proposes and uses a time-varying country-level transmission risk score (CTRS), which takes into account both () and daily new cases, to demonstrate country-level or territory-level transmission potential and trends. Time-varying hierarchical clustering of time-varying CTRS values was used to successfully reveal the countries and territories that contributed to the recent aggravation of the global pandemic in the last quarter of 2020 and the beginning of 2021, and to identify countries and territories with an increasing risk of COVID-19 transmission in the near future. Furthermore, a regression analysis indicated that the introduction and relaxation of NPIs, including workplace closure policies and stay-at-home requirements, appear to be associated with recent global transmission changes. In conclusion, a systematic evaluation of the global COVID-19 pandemic over the past year indicates that the world is now in an unexpected situation, with limited lessons learned. Summarizing the lessons learned could help in designing effective public responses for constraining future waves of COVID-19 worldwide.
2019年冠状病毒病（COVID-19）出现后，全球范围内出现了一小波病例；之后，由于一系列紧急非药物干预措施（NPIs），许多国家确诊病例的增长速度放缓。然而，政府取消管控措施以及公众放松预防行为导致病例数突然增加，引起了全球的深切关注。本研究评估了2020年1月至2021年2月全球各国和各地区的COVID-19大流行情况。根据每个国家或地区的时变繁殖数（()），结果显示，世界上几乎一半的国家和地区从未控制住疫情。在曾经控制住疫情的国家和地区中，近一半未能维持其防控措施，导致COVID-19大流行在全球反弹——在一半的反弹国家或地区中引发了更高的疫情高峰。这项工作还提出并使用了一个时变的国家层面传播风险评分（CTRS），该评分同时考虑了()和每日新增病例，以展示国家或地区层面的传播潜力和趋势。利用CTRS值的时变层次聚类成功揭示了在2020年最后一个季度和2021年初导致近期全球大流行加剧的国家和地区，并确定了在不久的将来COVID-19传播风险增加的国家和地区。此外，回归分析表明，包括工作场所关闭政策和居家要求在内的NPIs的出台和放松似乎与近期全球传播变化有关。总之，对过去一年全球COVID-19大流行的系统评估表明，世界目前处于意想不到的状况，吸取的教训有限。总结经验教训有助于设计有效的公共应对措施，以遏制未来全球范围内的COVID-19疫情浪潮。
