Direct evidence of active SARS-CoV-2 replication in the intestine

Direct evidence of active SARS-CoV-2 replication in the intestine. Jefferson T, Heneghan C.

Published on July 27, 2020

Reference Qian Q, Fan L, Liu W, et al. Direct evidence of active SARS-CoV-2 replication in the intestine. Clin Infect Dis. 2020;ciaa925.
Study type
Country China
Setting Hospital
Funding Details National Science and Technology Major Projects
Transmission mode Orofecal

Bottom Line

SARS-CoV-2 was detected in the rectum of a COVID-19 patient during the incubation period. There was direct evidence of replication of SARS-CoV-2 in the intestine.

Evidence Summary

Typical coronavirus virions in rectal tissue were observed under electron microscopy with abundant lymphocytes and macrophages (some SARS-CoV-2 positive) infiltrating the lamina propria. Virions were found in the cytoplasm of intestinal epithelial cells and at electron microscopy, the virions showed typical morphology of coronavirus. Immunohistochemistry and immunofluorescence using the rabbit anti-SARS-CoV-2 NP antibody studies were also conducted to confirm viral replication. SARS-CoV-2 antigens were confirmed to be expressed on intestinal epithelial cells, lymphocytes and macrophages in the lamina propria.

What did they do?

The study is a case report of a patient admitted to Zhongnan Hospital of Wuhan University for treatment of a rectal adenocarcinoma. He became symptomatic for COVID-19, 3 days post ileostomy which had been carried out on 16th January 2020 with pneumonia diagnosed 7 days post-operatively. Samples were taken from enteric sections, mucosa of rectum and ileum. He was discharged on day 41 and 37 days later his rectal specimens were negative.

Study reliability

This is the first known evidence of viral replication in the gut mucosa and the study needs replication. As post-op pneumonia is a common occurrence, nasal swabs were not taken so we do not know whether these would have been positive as well as rectal specimens.

Clearly defined setting Demographic characteristics described Follow-up length was sufficient Transmission outcomes assessed Main biases are taken into consideration
Yes Yes Yes Yes Yes

What else should I consider?

This study needs replication. Further studies to understand the persistence of fecal excretion of SARS-CoV-2 and their role need to be undertaken.

The authors also speculate that the SARS-CoV-2 virus may use the same strategy as the influenza virus to spread from the lung to distant organs. 

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

Tom Jefferson

Tom Jefferson, epidemiologist.