Clinical characteristics of the recovered COVID-19 patients with re-detectable positive RNA test

Jianghong An; Xuejiao Liao; Tongyang Xiao; Shen Qian; Jing Yuan; Haocheng Ye; Furong Qi; Chengguang Shen; Yang Liu; Lifei Wang; Xiaoya Cheng; Na Li; Qingxian Cai; Fang Wang; Jun Chen; Yingxia Liu; Yunfang Wang; Feng Zhang; Yang Fu; Xiaohua Tan; Lei Liu; Zheng Zhang

The quantitative reverse transcription polymerase chain reaction (qRT-PCR) was assessed as described previously [14] . Nasopharyngeal and anal specimens collected during hospitalization were sent to the laboratory in viral transport case. Total nucleic acid extraction were extracted from the samples using the QIAamp RNA Viral Kit (Qiagen, Heiden, Germany), and quantitative RT-PCR was performed using a China Food and Drug Administration (CFDA) approved commercial kit specific for 2019-nCoV detection (GeneoDX Co., Ltd., Shanghai, China) or Sherlock kit gifted from Feng Zhang lab according to the manual. Each RT-PCR assay provided a Ct value, which is the number of cycles required for the fluorescent signal to cross the threshold for a positive test, a higher Ct value is correlated with a lower viral load. The specimens were considered positive if the Ct value was ≤ 37.0, and negative if the viral load were undetectable. Specimens with a cycle-threshold value higher than 37 were repeated. The specimen was considered positive if the repeat results were the same as the initial result and between 37 and 40. If the repeat Ct was All rights reserved. No reuse allowed without permission. the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.