SARS-CoV-2 in serum, urine, and stool specimens of COVID-19 patients from the Republic of Korea.

SARS-CoV-2 in serum, urine, and stool specimens of COVID-19 patients from the Republic of Korea. Spencer EA, Heneghan C.

Published on July 8, 2020

Reference Kim J-M, Kim H-M, Lee E-J, et al. Detection and isolation of SARS-CoV-2 in serum, urine, and stool specimens of COVID-19 patients from the Republic of Korea. Osong Public Health Res Perspect. 2020;11(3):112-117. Published online May 8, 2020 2020
Study type
Country South Korea
Setting Hospital
Funding Details Non reported
Transmission mode Orofecal, Urine
Exposures Hospitalised patients

Bottom Line

SARS-CoV-2 RNA was detected in serum, urine or stool samples in 20% of patients hospitalised with COVID-19. However, the virus could not be isolated from these samples and therefore the risk of transmission via these media is not established. 

Evidence Summary

Serum, urine and stool samples were collected (non-periodically) from 74 hospitalised COVID-19 patients. 

SARS-CoV-2 was detected in 15 of 74 participants’ serum, urine, or stool samples. 

  • serum of six patients;
  • urine samples of two patients; and  
  • stool samples of eight patients.

The virus detection rate in the serum, urine, and stool samples were 2.8% (9/323), 0.8% (2/247), and 10% (13/129). 

The mean viral load in positive samples was:  

  • Serum 1,210 ± 1,861 copy/µL,
  • Urine 79 ± 30 copy/µL, and 
  • Stool  3,176 ± 7,208 copy/µL. 

In three cases, the virus was not detected in respiratory samples, although it was present in stool samples.

SARS-CoV-2 was not isolated by the culture method from the samples that tested positive for the SARS-CoV-2 gene. So, it is not clear how viable any virus within these samples would be.

SARS-CoV-2 was detectable in the respiratory samples of COVID-19 patients for several days after hospitalization. Its detection in the serum, urine, and stool samples was intermittent.

What did they do?

The study aimed to determine the rate and probability of SARS-CoV-2 transmission from COVID-19 cases via non-respiratory routes. Serum, urine, and stool samples were collected non-periodically from 74 hospitalized patients diagnosed with COVID-19, based on detection of SARS-CoV-2 in respiratory samples. 

The SARS-CoV-2 RNA genome was extracted from each specimen and real-time reverse transcription-polymerase chain reaction performed. CaCo-2 cells were inoculated with the specimens containing the SARS-COV-2 genome and subcultured for virus isolation. After culturing, viral replication in the cell supernatant was assessed.

Study reliability

This study was moderately small and performed over a short period of time. Replication is needed to establish the reliability of the findings.

Clearly defined setting Demographic characteristics described Follow-up length was sufficient Transmission outcomes assessed Main biases are taken into consideration
Yes No Unclear No Unclear

What else should I consider?

We are not currently aware of previous reports of SARS-CoV-2 presence in the serum.

About the authors

Carl Heneghan

Carl is Professor of EBM & Director of CEBM at the University of Oxford. He is also a GP and tweets @carlheneghan. He has an active interest in discovering the truth behind health research findings

Elizabeth Spencer

Dr Elizabeth Spencer; MMedSci, PhD. Epidemiologist, Nuffield Department for Primary Care Health Sciences, University of Oxford.