Transmission, viral kinetics and clinical characteristics of the emergent SARS-CoV-2 Delta VOC in Guangzhou, China
中国广州突发性 SARS-CoV-2 Delta VOC 的传播、病毒动力学和临床特征
中国広州における緊急SARS-CoV-2デルタVOCの伝播、ウイルス動態および臨床的特徴
중국 광저우에서 발생한 SARS-CoV-2 Delta VOC의 전파, 바이러스 동역학 및 임상 특성
Transmisión, cinética viral y características clínicas del COV del Delta del SARS-CoV-2 emergente en Guangzhou, China
Transmission, cinétique virale et caractéristiques cliniques du nouveau COV SARS-CoV-2 Delta à Guangzhou, Chine
Передача, вирусная кинетика и клинические характеристики эмерджентного SARS-CoV-2 Delta VOC в Гуанчжоу, Китай
Yaping Wang 王亚萍 ¹, Ruchong Chen 陈如冲 ² ³, Fengyu Hu 胡凤玉 ¹, Yun Lan 兰芸 ¹, Zhaowei Yang 杨朝崴 ² ³, Chen Zhan 詹晨 ² ³, Jingrong Shi ¹, Xizi Deng 邓西子 ¹, Mei Jiang 江梅 ², Shuxin Zhong ², Baolin Liao 廖宝林 ¹, Kai Deng 邓凯 ¹, Jingyan Tang ¹, Liliangzi Guo ¹, Mengling Jiang ¹, Qinghong Fan ¹, Meiyu Li 李美瑜 ¹, Jinxin Liu 刘晋新 ¹, Yaling Shi 石亚玲 ¹, Xilong Deng 邓西龙 ¹, Xincai Xiao 肖新才 ⁴, Min Kang 康敏 ⁵, Yan Li 李艳 ⁵, Weijie Guan 关伟杰 ², Yimin Li 黎毅敏 ², Shiyue Li 李时悦 ², Feng Li 李锋 ¹, Nanshan Zhong 钟南山 ² ⁶, Xiaoping Tang 唐小平 ¹ ⁶
¹ Guangzhou Eighth People’s Hospital , Guangzhou Medical University, Guangzhou, 510060, China
中国 广州 广州医科大学 广州市第八人民医院
² State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Laboratory, Bio-Island, Guangzhou Institute of
Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China
中国 广州 广州医科大学第一附属医院 广州呼吸健康研究院 生物岛实验室 呼吸系统疾病国家重点实验室
³ Department of Allergy and Clinical Immunology, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China
中国 广州 广州医科大学附属第一医院 过敏与临床免疫科
⁴ Guangzhou Chest Hospital, Guangzhou Medical University, Guangzhou 510095, China
中国 广州 广州医科大学 广州市胸科医院
⁵ Guangdong Provincial Center for Disease Control and Prevention, Guangzhou 511430, China
中国 广州 广东省疾病预防控制中心
⁶ Guangzhou Laboratory, Bio-Island, Guangzhou 510320, China
中国 广州 广州生物岛实验室
A novel variant of SARS-CoV-2, the Delta variant of concern (VOC, also known as lineage B.1.617.2), is fast becoming the dominant strain globally. We reported the epidemiological, viral, and clinical characteristics of hospitalized patients infected with the Delta VOC during the local outbreak in Guangzhou, China.
Methods
We extracted the epidemiological and clinical information pertaining to the 159 cases infected with the Delta VOC across seven transmission generations between May 21 and June 18, 2021. The whole chain of the Delta VOC transmission was described. Kinetics of viral load and clinical characteristics were compared with a cohort of wild-type infection in 2020 admitted to the Guangzhou Eighth People's Hospital.
Findings
There were four transmission generations within the first ten days. The Delta VOC yielded a significantly shorter incubation period (4.0 vs. 6.0 days), higher viral load (20.6 vs. 34.0, cycle threshold of the ORF1a/b gene), and a longer duration of viral shedding in pharyngeal swab samples (14.0 vs. 8.0 days) compared with the wild-type strain. In cases with critical illness, the proportion of patients over the age of 60 was higher in the Delta VOC group than in the wild-type strain (100.0% vs. 69.2%, p = 0.03). The Delta VOC had a higher risk than wild-type infection in deterioration to critical status (hazards ratio 2.98 [95%CI 1.29-6.86]; p = 0.01).
Interpretation
Infection with the Delta VOC is characterized by markedly increased transmissibility, viral loads and risk of disease progression compared with the wild-type strain, calling for more intensive prevention and control measures to contain future outbreaks.
Funding
National Grand Program, National Natural Science Foundation of China, Guangdong Provincial Department of Science and Technology, Guangzhou Laboratory
