COVID-19: Evidence for gastrointestinal infection by SARS-CoV-2

COVID-19: Evidence for gastrointestinal infection by SARS-CoV-2. Spencer EA, Heneghan C.

https://www.cebm.net/study/covid-19-evidence-for-gastrointestinal-infection-by-sars-cov-2-2/

Published on July 1, 2020

Reference Xiao F, Tang M, Zheng X, Liu Y, Li X, Shan H. Evidence for gastrointestinal infection of SARS‐CoV‐2. Gastroenterology. 2020. 2020
Study type
Country China
Setting Hospital
Funding Details This work was funded by the National Natural Science Foundation of China (grant 81870411)
Transmission mode Orofecal
Exposures

Bottom Line

SARS-CoV-2 may both infect the gastrointestinal system and transmit via a faecal-oral route. 

Evidence Summary

RNA was detected in gastric, duodenal, and rectal epithelia. Viral nucleocapsid protein was found intracellularly in gastric, duodenal, and rectal epithelia 

Viral RNA was also detected in oesophageal mucous tissue, but with the absence of viral nucleocapsid protein staining in oesophageal mucosa, indicating low viral infection in esophageal mucosa.

What did they do?

From 1st to 14th February 2020, clinical specimens, including serum, nasopharyngeal, and oropharyngeal swabs; urine; stool; and tissues from 73 hospitalized patients infected with SARS-CoV-2 were obtained and tested for SARS-CoV-2 RNA.

The authors examined the viral RNA in faeces from 71 patients with SARS-CoV-2 infection during their hospitalizations. 

The viral RNA and viral nucleocapsid protein were examined in gastrointestinal tissues from one of the patients.

Study reliability

This is a laboratory study and does not establish for certain that faecal-oral transmission can occur.

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

What else should I consider?

In this study, immunofluorescent data showed that ACE2 protein, shown to be a cell receptor for SARS-CoV-2, is abundantly expressed in the glandular cells of gastric, duodenal, and rectal epithelia, supporting the entry of SARS-CoV-2 into the host cells. 

ACE2 staining is rarely seen in oesophageal mucosa, probably because the oesophageal epithelium is mainly composed of squamous epithelial cells, which express less ACE2 than glandular epithelial cells. Continuous positive detection of viral RNA from feces suggests that the infectious virions are secreted from the virus-infected gastrointestinal cells.

About the authors

Carl Heneghan

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

Elizabeth Spencer

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