Ai Jingwen, Zhou Jiaxin, Li Yang, Sun Feng, Ge Shijia, Zhang Haocheng, Wu Yanpeng, Wang Yan, Zhang Yilin, Wang Hongyu, Cai Jianpeng, Zhou Xian, Wang Sen, Li Rong, Feng Zhen, Xu Xiangyanyu, Yan Xuemei, Zhao Yuchen, Zhang Juanjuan, Yu Hongjie, Zhang Wenhong
Department of Infectious Diseases, Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, National Medical Center for Infectious Diseases, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai 200433, China.
School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai 200433, China.
Virol Sin. 2024 Dec;39(6):851-859. doi: 10.1016/j.virs.2024.10.001. Epub 2024 Oct 11.
The SARS-CoV-2 virus, particularly the Omicron BA.2 variant, led to a significant surge in Shanghai, 2022. However, the viral load dynamic in Omicron infections with varying clinical severities remain unclear. This prospective cohort included 48,830 hospitalized coronavirus disease 2019 (COVID-19) patients across three hospitals in Shanghai, China, between 23 March and 15 May, 2022. Systematic nucleic acid testing was performed using RT-PCR Cycle threshold (Ct) value as a proxy of viral load. We analyzed the kinetic characteristics of viral shedding by clinical severity and identified associated risk factors. The study comprised 31.06% asymptomatic cases, 67.66% mild-moderate cases, 1.00% severe cases, 0.29% critical and fatal cases. Upon admission, 57% of patients tested positive, with peak viral load observed at 4 days (median Ct value 27.5), followed by a decrease and an average viral shedding time (VST) of 6.1 days (Interquartile range, 4.0-8.8 days). Although viral load exhibited variation by age and clinical severity, peak Ct values occurred at similar times. Unvaccinated status, age exceeding 60, and comorbidities including hypertension, renal issues kidney dialysis and kidney transplantation, neurological disorders, rheumatism, and psychotic conditions were found to correlate with elevated peak viral load and extended VST. Asymptomatic cases demonstrated a 40% likelihood of contagiousness within 6 days of detection, while mild-moderate and severe cases exhibited post-symptom resolution infectious probabilities of 27% and over 50%, respectively. These findings revealed that the initial Ct values serve as a predictive indicator of severe outcomes. Unvaccinated elderly individuals with particular comorbidities are at high-risk for elevated viral load and prolonged VST.
严重急性呼吸综合征冠状病毒2（SARS-CoV-2）病毒，尤其是奥密克戎BA.2变体，在2022年导致上海疫情大幅激增。然而，不同临床严重程度的奥密克戎感染中的病毒载量动态仍不清楚。这项前瞻性队列研究纳入了2022年3月23日至5月15日期间中国上海三家医院的48830例住院的2019冠状病毒病（COVID-19）患者。使用逆转录聚合酶链反应（RT-PCR）循环阈值（Ct）值作为病毒载量的指标进行系统核酸检测。我们分析了不同临床严重程度下病毒脱落的动力学特征，并确定了相关风险因素。该研究包括31.06%的无症状病例、67.66%的轻中度病例、1.00%的重度病例、0.29%的危重症和死亡病例。入院时，57%的患者检测呈阳性，病毒载量在4天达到峰值（中位数Ct值为27.5），随后下降，平均病毒脱落时间（VST）为6.1天（四分位间距，4.0 - 8.8天）。尽管病毒载量因年龄和临床严重程度而有所不同，但峰值Ct值出现在相似的时间。未接种疫苗状态、年龄超过60岁以及包括高血压、肾脏问题（肾透析和肾移植）、神经系统疾病、风湿病和精神疾病在内的合并症与峰值病毒载量升高和VST延长相关。无症状病例在检测后6天内具有40%的传染可能性，而轻中度和重度病例在症状缓解后的感染概率分别为27%和超过50%。这些发现表明，初始Ct值可作为严重结局的预测指标。患有特定合并症的未接种疫苗的老年人病毒载量升高和VST延长的风险很高。
