Factors associated with a prolonged negative conversion of viral RNA in patients with COVID-19

Abstract

Objectives: The aim of this study was to identify the factors influencing the delay in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA negative conversion.

Methods: A cohort study was conducted that included patients with coronavirus disease 2019 (COVID-19) admitted to the Tunisian national containment center. Follow-up consisted of a weekly RT-PCR test. Multivariate Cox regression analysis was performed to determine independent predictors associated with negative RNA conversion.

Results: Among the 264 patients included, the median duration of viral clearance was 20 days (interquartile range (IQR) 17-32 days). The shortest duration was 9 days and the longest was 58 days. Factors associated with negative conversion of viral RNA were symptoms such as fatigue, fever, and shortness of breath (hazard ratio (HR) 0.600, 95% confidence interval (CI) 0.401-0.897) and face mask use when exposed to COVID-19 cases (HR 2.006, 95% CI 1.247-3.228). The median time to RNA viral conversion was 18 days (IQR 16-21 days) when using masks versus 23 days (IQR 17-36 days) without wearing masks, and 24 days (IQR 18-36 days) for symptomatic patients versus 20 days (IQR 16-30 days) for asymptomatic patients.

Conclusions: The results of this study revealed that during SARS-CoV-2 infection, having symptoms delayed viral clearance, while wearing masks accelerated this conversion. These factors should be taken into consideration for the strategy of isolating infected patients.

Keywords: COVID-19; Coronavirus disease 2019; Negative conversion; SARS-CoV-2; Tunisia; Viral shedding.