Institute of Public Health, Guangzhou Medical University & Guangzhou Center for Disease Control and Prevention, Guangzhou, Guangdong, China.
National Center for Respiratory Medicine, State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
Front Public Health. 2022 Dec 21;10:979063. doi: 10.3389/fpubh.2022.979063. eCollection 2022.
SARS-CoV-2 has ravaged the world and undergone multiple mutations during the course of the COVID-19 pandemic. On 7 April 2022, an epidemic caused by SARS-CoV-2 Omicron (BA.2) variant broke out in Guangzhou, China, one of the largest transportation and logistical hubs of the country.
To fast curtained the Omicron epidemic, based on the routine surveillance on the risk population of SARS-CoV-2 infection, we identify key places of the epidemic and implement enhanced control measures against Omicron.
Transmission characteristics of the Omicron variant were analyzed for 273 confirmed cases, and key places involved in this epidemic were fully presented. The median incubation time and the generation time were 3 days, and the reproduction number Rt was sharply increased with a peak of 4.20 within 2 days. We tried an all-out effort to tackle the epidemic in key places, and the proportion of confirmed cases increased from 61.17% at Stage 2 to 88.89% at Stage 4. Through delimited risk area management, 99 cases were found, and the cases were isolated in advance for 2.61 ± 2.76 days in a lockdown zone, 0.44 ± 1.08 days in a controlled zone, and 0.27 ± 0.62 days in a precautionary zone. People assigned with yellow code accounted for 30.32% (84/277) of confirmed COVID-19 cases, and 83.33% of them were detected positive over 3 days since code assignment. For the districts outside the epicenter, the implementation duration of NPIs was much shorter compared with the Delta epidemic last year.
By blocking out transmission risks and adjusting measures to local epidemic conditions through the all-out effort to tackle the epidemic in key places, by delimiting risk area management, and by conducting health code management of the at-risk population, the Omicron epidemic could be contained quickly.
SARS-CoV-2 在 COVID-19 大流行期间经历了多次突变，肆虐全球。2022 年 4 月 7 日，中国最大的交通和物流枢纽之一广州爆发了由 SARS-CoV-2 奥密克戎（BA.2）变体引起的疫情。
为了迅速控制奥密克戎疫情，我们根据对 SARS-CoV-2 感染高危人群的常规监测，确定疫情关键地点，并实施针对奥密克戎的强化控制措施。
对 273 例确诊病例的奥密克戎变异传播特征进行了分析，并充分展示了此次疫情涉及的关键地点。中位潜伏期和世代时间为 3 天，Rt 繁殖数在 2 天内急剧增加，峰值达到 4.20。我们全力以赴处理关键地点的疫情，确诊病例比例从第 2 阶段的 61.17%上升到第 4 阶段的 88.89%。通过划定风险区域管理，共发现 99 例病例，封控区病例提前隔离 2.61±2.76 天，管控区 0.44±1.08 天，防范区 0.27±0.62 天。健康码赋黄码人员占 277 例确诊 COVID-19 病例的 30.32%（84/277），自赋码起 3 天内检测阳性的比例为 83.33%。对于非疫情中心区，与去年德尔塔疫情相比，实施非药物干预措施的持续时间要短得多。
通过在关键地点全力以赴处理疫情、通过划定风险区域管理、通过对高危人群进行健康码管理，阻断传播风险，根据疫情形势调整措施，可以迅速控制奥密克戎疫情。
