Summary
As only few studies have analyzed viral kinetics between the incubation
and symptomatic periods of COVID-19
patients, we investigated the
viral kinetics and compared viral loads between patients with mild and
severe COVID-19.
We determined the viral kinetics of 10 patients diagnosed with COVID-19
at Chosun University Hospital. Six patients were classified into the
“mild” group and 4 into the “severe” group according to supplemental
oxygen use during admission. Samples were collected via nasopharyngeal
swabs and sputum specimens. SARS-CoV-2 was detected using real-time
reverse transcription-polymerase chain reaction (RT-PCR). Chest
radiograph scores during hospitalization were obtained.
Ct values of the upper respiratory tract specimens were low during the
early stages after symptom onset but gradually increased over time in
both groups. The severe group had lower Ct values than the mild group.
The Ct values of the RdRP and E genes on day 6 after
symptom onset were significantly lower in the severe group than in the
mild group (p < 0.05). Three of 6 patients had positive
results on RT-PCR even before symptom onset; 2 of them had the lowest Ct
values. The chest radiograph scores were higher in the severe group than
in the mild group, and the score in the severe group was the highest at
approximately 3 weeks after symptom onset.
Viral load and chest radiograph scores were significantly different
between the severe and mild groups of COVID-19 patients.