Transmission Dynamics of the Delta Variant of SARS-CoV-2 Infections in South Korea
Transmission Dynamics of the Delta Variant of SARS-CoV-2 Infections in South Korea
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DOI：
10.1093/infdis/jiab586
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发表时间：
2021-12-31
影响因子：
6.4
通讯作者：
Ryu, Sukhyun
中科院分区：
文献类型：
--
作者：
Hwang, Hari;Lim, Jun-Sik;Ryu, Sukhyun
研究背景严重急性呼吸综合征冠状病毒2型（SARS-CoV-2）的Delta变异体是本研究时全球范围内的主要变异体。然而，其传播动力尚不清楚。方法我们分析了2021年6月22日至7月31日在韩国大田市发现的405例感染SARS-CoV-2 Delta变异体的本地病例和病毒脱落的时间模式。结果在流行病学调查时，20%的患者有症状前期。我们确定了6起聚集性暴发，均与室内设施有关。在23名家庭接触者中，二次发病率为63%。我们估计平均连续间隔为3.26天（95%可信区间，2.92-3.60），15%（95%可信区间，13%-18%）的病例播种了80%的本地传播。鼻咽拭子样本分析确定了症状前病例的病毒脱落，症状发作后2天观察到最高病毒载量。结论我们的研究结果表明Delta变异在室内环境和家庭中具有高度传播性。为了减少Delta变异病毒的社区传播，需要快速追踪接触者，隔离无症状接触者，严格遵守公共卫生措施，增加2019冠状病毒病（COVID-19）疫苗接种，包括加强剂量。Delta变异病毒在室内环境中具有高度传播性，可能会缩短连续间隔并增加家庭发病率。
Background The Delta variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was the predominant variant worldwide at the time of this study. However, its transmission dynamics were unclear. Methods We analyzed 405 local cases infected with the Delta variant of SARS-CoV-2 and temporal patterns of viral shedding identified between 22 June and 31 July 2021 in Daejeon, South Korea. Results Overall, 20% were presymptomatic at the time of epidemiological investigation. We identified 6 clustered outbreaks, and all were associated with indoor facilities. In 23 household contacts, the secondary attack rate was 63%. We estimated the mean serial interval as 3.26 days (95% credible interval, 2.92-3.60), and 15% (95% confidence interval, 13%-18%) of cases seeded 80% of all local transmission. Analysis of the nasopharyngeal swab samples identified virus shedding from the presymptomatic cases and the highest viral load was observed 2 days after symptom onset. Conclusions Our findings suggest that the Delta variant is highly transmissible in indoor settings and households. Rapid contact tracing, isolation of the asymptomatic contacts, strict adherence to public health measures, and increased uptake of coronavirus disease 2019 (COVID-19) vaccination, including booster doses, are needed to reduce community transmission of the Delta variant.Delta variant is highly transmissible in indoor settings, likely shortening the serial interval and increasing the household attack rate.