Upper respiratory tract viral load quantification in COVID-19 patients at hospital admission and its association with disease severity

Abstract

Introduction: There are aspects of COVID-19 pathogenesis that are still unknown. Objective: To determine the relationship between severity, mortality and viral replication in patients with COVID-19. Methods: Clinical characteristics, severity and mortality of 203 patients hospitalized for COVID-19 were analyzed and correlated with viral load (VL) and threshold cycle (TC) at admission; nasopharyngeal swab was obtained. Results: Mean VLs in surviving patients with mild to moderate, moderate to severe and severe disease were the following: 6.8 x 106, 7.6 x 107 and 1.0 x 109, respectively; and in patients with critical disease who died, VL was 1.70 x 109. TCs were 26.06, 24.07, 22.66 and 21.78 for the same groups. In those who died, a higher mean VL was observed at admission in comparison with those who survived (1.7 x 109 vs. 9.84 x 106; p < 0.001). A significant correlation was observed between VL, severity and death (r = 0.254, p < 0.045 and r = 0.21, p < 0.015). High VL was associated with increased in-hospital mortality in comparison with low VL (OR = 2.926, p < 0.017). Conclusion: SARS-CoV-2 VL determined at hospital admission might classify risk simultaneously with other factors described in COVID-19.