SARS-CoV-2 Viral Load is Associated with Increased Disease Severity and Mortality

Fajnzylber, J. M.; Regan, J.; Coxen, K.; Corry, H.; Wong, C.; Rosenthal, A.; Worrall, D.; Giguel, F.; Piechocka-Trocha, A.; Atyeo, C.; Fischinger, S.; Chan, A.; Flaherty, K. T.; Hall, K.; Dougan, M.; Ryan, E. T.; Gillespie, E.; Chishti, R.; Li, Y.; Jilg, N.; Hanidziar, D.; Baron, R. M.; Baden, L.; Tsibris, A. M.; Armstrong, K. A.; Kuritzkes, D. R.; Alter, G.; Walker, B. D.; Yu, X.; Li, J.; Readiness, Massachusetts Consortium for Pathogen

The relationship between SARS-CoV-2 viral load and risk of disease progression remains largely undefined in coronavirus disease 2019 (COVID-19). We quantified SARS-CoV-2 viral load from participants with a diverse range of COVID-19 severity, including those requiring hospitalization, outpatients with mild disease, and individuals with resolved infection. SARS-CoV-2 plasma RNA was detected in 27% of hospitalized participants and 13% of outpatients diagnosed with COVID-19. Amongst the participants hospitalized with COVID-19, higher prevalence of detectable SARS-CoV-2 plasma viral load was associated with worse respiratory disease severity, lower absolute lymphocyte counts, and increased markers of inflammation, including C-reactive protein and IL-6. SARS-CoV-2 viral loads, especially plasma viremia, were associated with increased risk of mortality. SARS-CoV-2 viral load may aid in the risk stratification of patients with COVID-19 and its role in disease pathogenesis should be further explored.