High viral load suggests increased COVID-19 severity in a longitudinal cohort

Background: An outbreak caused by the 2019 novel coronavirus (2019-nCoV) has spread globally. However, the viral dynamics, co-infection and their associations with clinical severity, have not been well explored. Methods: We longitudinally enrolled 23 (Five severe-type, ten common-type and eight asymptomatic-type patients) hospitalized 2019-nCov-infected patients in Jiangsu between January 21 and February 11, 2020. Medical records and pharyngeal swab specimens, were collected to analyze the association between viral dynamic and disease severity. Results: Five severe-type, ten common-type and eight asymptomatic-type patients were enrolled. Linear mixed effects models revealed that the common and severe-type patients had a higher level of viral load (3.08 points, 95% CI, 0.51-5.65, P = 0.019; 6.07 points, 95% CI, 2.79-9.35, P < 0.001) and maintained a higher peak viral load ( P = 0.066 and 0.022, respectively), when compared with the asymptomatic group. Viral load shedding among older patients (aged ≥ 60) processed slower than that among younger patients ( P = 0.047). RNA virome sequencing identified two co-infected RNA viruses, Human endogenous retrovirus H (HERV) and Human picobirnavirus (HPBV). Of note, HPBV was detected in one severe-type and two common-type patients, while was not detected in all the asymptomatic cases. Conclusion: Higher viral load was positively associated with disease severity. This finding highlights the importance of monitoring the viral kinetics to identify patients at greater risk of progressing to severe pneumonia.