The relationship between SARS-COV-2 RNA positive duration and the risk of recurrent positive

Zhao, Hong; Zhang, Chi; Chen, Xian-Xiang; Zhu, Qi; Huang, Wen-Xiang; Zeng, Yi-Lan; Liu, Ying-Xia; Li, Guo-Jun; Du, Wei-Jun; Yao, Jing; Li, Jia-Wen; Peng, Peng; Wang, Gui-Qiang

BACKGROUND: The management of discharge COVID-19 patients with recurrent positive SARS-CoV-2 RNA is challenging. However, there are fewer scientific dissertations about the risk of recurrent positive. The aim of this study was to explore the relationship between SARS-COV-2 RNA positive duration (SPD) and the risk of recurrent positive. METHODS: This case–control multi-center study enrolled participants from 8 Chinese hospital including 411 participants (recurrent positive 241). Using unadjusted and multivariate-adjusted logistic regression analyses, generalized additive model with a smooth curve fitting, we evaluated the associations between SPD and risk of recurrent positive. Besides, subgroup analyses were performed to explore the potential interactions. RESULTS: Among recurrent positive patients, there were 121 females (50.2%), median age was 50 years old [interquartile range (IQR): 38–63]. In non-adjusted model and adjusted model, SPD was associated with an increased risk of recurrent positive (fully-adjusted model: OR = 1.05, 95% CI: 1.02–1.08, P = 0.001); the curve fitting was not significant (P = 0.286). Comparing with SPD < 14 days, the risk of recurrent positive in SPD > 28 days was risen substantially (OR = 3.09, 95% CI: 1.44–6.63, P = 0.004). Interaction and stratified analyses showed greater effect estimates of SPD and risk of recurrent positive in the hypertension, low monocyte count and percentage patients (P for interaction = 0.008, 0.002, 0.036, respectively). CONCLUSION: SPD was associated with a higher risk of recurrent positive and especially SPD > 28 day had a two-fold increase in the relative risk of re-positive as compared with SPD < 14 day. What’s more, the risk may be higher among those with hypertension and lower monocyte count or percentage. [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40249-021-00831-6.