Dynamics of Viral Shedding and Symptoms in Patients with Asymptomatic or Mild COVID-19.

Seongman Bae,Ji-Soo Kwon,Ho Young Lee,Mi Hyun Suh,Jiwon Jung,Hye Hee Cha,Sohyun Lee,Hyun Jung Lee,Min Jae Kim,Heedo Park,So Yun Lim,Ji Yeun Kim,Joon Seo Lim,Yong Pil Chong,Sung-Han Kim,Yang Soo Kim,Sang-Oh Lee,Man-Seong Park,Sang-Ho Choi

doi:10.3390/v13112133

Seongman Bae, Ji-Soo Kwon + Show 17 more

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https://doi.org/10.3390/v13112133

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Abstract

We conducted a prospective cohort study at a community facility designated for the isolation of individuals with asymptomatic or mild COVID-19 between 10 January and 22 February 2021 to investigate the relationship of viral shedding with symptom changes of COVID-19. In total, 89 COVID-19 adult patients (12 asymptomatic, 16 presymptomatic, 61 symptomatic) were enrolled. Symptom scores, the genomic RNA and subgenomic RNA of SARS-CoV-2 from saliva samples with a cell culture were measured. Asymptomatic COVID-19 patients had a similar viral load to symptomatic patients during the early course of the disease, but exhibited a rapid decrease in viral load with the loss of infectivity. Subgenomic RNA and viable virus by cell culture in asymptomatic patients were detected only until 3 days after diagnosis, and the positivity of the subgenomic RNA and cell culture in symptomatic patients gradually decreased in both from 40% in the early disease course to 13% at 10 days and 4% at 8 days after the symptom onset, respectively. In conclusion, symptomatic patients have a high infectivity with high symptom scores during the early disease course and gradually lose infectivity depending on the symptom. Conversely, asymptomatic patients exhibit a rapid decrease in viral load with the loss of infectivity, despite a similar viral load during the early disease course.

Highlights

While while the the persistently persistently onset asymptomatic patients had a comparable degree of viral shedding in the early period after after asymptomatic patients had a comparable degree of viral shedding in the early period the PCR-based diagnosis, negative conversion occurred more rapidly than symptomatic or the PCR-based diagnosis, negative conversion occurred more rapidly than symptomatic presymptomatic patients
By analyzing subgenomic RNA and viral culture, we observed observed that that the the duration duration of of viable viable virus virus shedding of asymptomatic patients was was we shedding of asymptomatic patients shorter than that of symptomatic or presymptomatic patients
COVID-19 patients who experienced a presymptomatic period exhibited significantly lower symptom scores than those without a presymptomatic period, while the viral loads were comparable between the two groups

Summary

Introduction

Asymptomatic or presymptomatic transmission is an important characteristic of SARS-CoV-2 infection [1], which provides a scientific basis for the recommendation of the general public to use face masks regardless of the presence of symptoms and the testing of asymptomatic individuals for SARS-CoV-2 in high-risk settings such as nursing homes or healthcare facilities [2]. A recent study reported that about three-quarters of individuals with SARS-CoV-2 infection, who were asymptomatic at the time of diagnosis, remained persistently asymptomatic, and the remaining one-quarter of those individuals developed symptoms during the disease course [3]. Asymptomatic individuals with SARS-CoV-2 infection should be divided into those who are persistently asymptomatic and those who undergo a presymptomatic period followed by a symptomatic period. An epidemiologic study suggested that persistently asymptomatic cases were associated with about an 80% lower infectivity than symptomatic cases and presymptomatic cases [4]

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