Original Research—Clinical
Severe Acute Respiratory Syndrome Coronavirus 2 Is Detected in the Gastrointestinal Tract of Asymptomatic Endoscopy Patients but Is Unlikely to Pose a Significant Risk to Healthcare Personnel

https://doi.org/10.1016/j.gastha.2022.06.002Get rights and content
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Background and Aims

Recent evidence suggests that the gut is an additional target for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, whether SARS-CoV-2 spreads via gastrointestinal secretions remains unclear. To determine the prevalence of gastrointestinal SARS-CoV-2 infection in asymptomatic subjects, we analyzed gastrointestinal biopsy and liquid samples from endoscopy patients for the presence of SARS-CoV-2.

Methods

We enrolled 100 endoscopic patients without known SARS-CoV-2 infection (cohort A) and 12 patients with a previous COVID-19 diagnosis (cohort B) in a cohort study performed at a regional hospital. Gastrointestinal biopsies and fluids were screened for SARS-CoV-2 by polymerase chain reaction (PCR), immunohistochemistry, and virus isolation assay, and the stability of SARS-CoV-2 in gastrointestinal liquids in vitro was analyzed.

Results

SARS-CoV-2 ribonucleic acid was detected by PCR in the colonic tissue of 1/100 patients in cohort A. In cohort B, 3 colonic liquid samples tested positive for SARS-CoV-2 by PCR and viral nucleocapsid protein was detected in the epithelium of the respective biopsy samples. However, no infectious virions were recovered from any samples. In vitro exposure of SARS-CoV-2 to colonic liquid led to a 4-log–fold reduction of infectious SARS-CoV-2 within 1 hour (P ≤ .05).

Conclusion

Overall, the persistent detection of SARS-CoV-2 in endoscopy samples after resolution of COVID-19 points to the gut as a long-term reservoir for SARS-CoV-2. Since no infectious virions were recovered and SARS-CoV-2 was rapidly inactivated in the presence of colon liquids, it is unlikely that performing endoscopic procedures is associated with a significant infection risk due to undiagnosed asymptomatic or persistent gastrointestinal SARS-CoV-2 infections.

Keywords

Endoscopy
SARS-CoV-2
Transmission Risk
Colonic Liquid

Abbreviations used in this paper

COVID-19
coronavirus disease 2019
E gene
envelope gene
GI
gastrointestinal
N gene
nucleocapsid gene
NP
nucleocapsid protein
PFU
plaque-forming units
qRT-PCR
quantitative reverse transcription polymerase chain reaction
SARS-CoV-2
severe acute respiratory syndrome coronavirus 2

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Conflicts of Interest: The authors disclose no conflicts.

Funding: Funding from the National Institutes of Health (U01EB029242-02S1; to D.B. and M.J.), the Montana Agricultural Experiment Station (to D.B., B.W., and M.J.), USDA/Hatch Multi-State project W519 (to M.J.), and the Montana State University Office of Research, Economic Development and Graduate Education (to D.B.) is gratefully acknowledged. R.K.P. and W.M. were funded by the DARPA PREEMPT program Cooperative Agreement #D18AC00031. B.W. was supported by the National Institutes of Health (R35GM134867), the M.J. Murdock Charitable Trust, a young investigator award from Amgen, and a generous gift from the Rosolowsky family.

Ethical Statement: The corresponding author, on behalf of all authors, jointly and severally, certifies that their institution has approved the protocol for any investigation involving humans or animals and that all experimentation was conducted in conformity with ethical and humane principles of research.

Data Availability Statement: The data that support the findings of this study are available from the corresponding author, D.B., upon reasonable request.

Authors contributed equally.