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

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 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.