COVID-19: Persistent viral shedding of SARS-CoV-2 in faeces

Persistent viral shedding of SARS-CoV-2 in faeces.  Jefferson T,  Heneghan C.

Published on June 30, 2020

Reference Gupta S, Parker J, Smits S, Underwood J, Dolwani S. Persistent viral shedding of SARS-CoV-2 in faeces - a rapid review. Colorectal Dis. 2020;22(6):611-620. doi:10.1111/codi.15138 2020
Study type
Country Global (Mainly China)
Setting NR
Funding Details NIHR/Academia
Transmission mode Orofecal

Bottom Line

There is a high rate of PCR positive persistence of SARS-CoV-2 in faecal samples of patients with COVID-19.

Evidence Summary

There were 26 articles included in the final analysis with 824 patients included across the studies and 540 tested for faecal viral RNA: 291 (54%) had positive faecal RT-PCR tests. 

Of the 199 patients who tested positive for faecal viral  RNA and who were followed up with stool testing, 125 (63%) had persistent shedding of virus in the stool samples after a negative nasopharyngeal swab. 

The duration for faecal shedding of viral RNA after clearance of respiratory samples ranged from 1 to 33 days and in one patient up to 47 days from symptom onset. Only one study tested the viability of fecally excreted viruses. Of 153 stool specimens tested in this study, four were tested for viability and two (50%)  were viable.

See: Overview of patient demographics from studies included in the review

What did they do?

The primary aim of the review was to assess the incidence and timing of positive faecal samples for SARS-CoV-2 in relation to the clinical course of patients with COVID-19.

The secondary aims are to establish the incidence of patients with positive faecal samples after negative respiratory swabs and any evidence to suggest faecal virus transmitted infection. 

To achieve the aims a search of a single database plus pre-print and hand searches was carried out as at 3 April 2020. Twenty-six articles (20 from China) and two from the USA and one each from Italy, Korea, Vietnam and France were included. 

Study reliability

The reporting of excretion of virus in relation to the course of the infection was variable across studies which prevented confirmation of the true prevalence of faecal samples.

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

What else should I consider?

The review needs updating and the evidence base needs developing further and the findings replicating.

The additional data file. Form studies included in the review.

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.