SARS-CoV-2 viremia and mortality
SARS-CoV-2 viral loads, especially plasma viremia, are associated with increased risk of mortality. This is the result of a study by Jonathan Li, Jesse Fajnzylber and colleagues who report SARS-CoV-2 respiratory tract, plasma, and urine viral loads of 235 participants who were either hospitalized with COVID-19 (n=88), evaluated as symptomatic outpatients (n=94), or had recovered from COVID-19 disease (n=53). The prevalence of SARS-CoV-2 plasma viremia in hospitalized individuals with severe disease was relatively high, but plasma viremia was also detected in symptomatic non-hospitalized participants. Compared to individuals who were discharged from the hospital, those who eventually died had significantly higher levels of plasma viremia at the time of initial sampling (median plasma viral load 1.0 vs 2.0 log10 RNA copies/mL). For hospitalized individuals with initial detectable viremia, 32% died vs. 8% of those without initial viremia (odds ratio (OR) 5.5).
Fajnzylber J, Regan J, Coxen K, et al. SARS-CoV-2 viral load is associated with increased disease severity and mortality. Nat Commun 11, 5493 (2020). https://doi.org/10.1038/s41467-020-19057-5