[The Lancet] Viral dynamics in mild and severe cases of COVID-19

The Lancet, 19 March 2020 Yang Liu, Li-Meng Yan, Lagen Wan, Tian-Xin Xiang, Aiping Le, Jia-Ming Liu, Malik Peiris, Leo L M Poon, Wei Zhang  

Highlights:

• Findings from Feb, 2020, indicated that the clinical spectrum of this disease can be very heterogeneous. Here, we report the viral RNA shedding patterns observed in patients with mild and severe COVID-19.
• The mean viral load of severe cases was around 60 times higher than that of mild cases, suggesting that higher viral loads might be associated with severe clinical outcomes.
• Mild cases were found to have an early viral clearance, with 90% of these patients repeatedly testing negative on RT-PCR by day 10 post-onset. By contrast, all severe cases still tested positive at or beyond day 10 post-onset.
• Overall, our data indicate that, similar to SARS in 2002–03, patients with severe COVID-19 tend to have a high viral load and a long virus-shedding period. This finding suggests that the viral load of SARS-CoV-2 might be a useful marker for assessing disease severity and prognosis.

Full text