Systematic Review With Meta-analysis

SARS-CoV-2 Stool Testing and the Potential for Faecal-oral Transmission

Amarylle S. van Doorn; Berrie Meijer; Chris M. A. Frampton; Murray L. Barclay; Nanne K. H. de Boer


Aliment Pharmacol Ther. 2020;52(8):1276-1288. 

In This Article

Abstract and Introduction


Background: Since the start of the COVID-19 pandemic, there have been many scientific reports regarding gastrointestinal manifestations. Several reports indicate the possibility of viral shedding via faeces and the possibility of faecal-oral transmission.

Aims: To critically assess the clinical relevance of testing stool samples and anal swabs and provide an overview of the potential faecal-oral transmission of SARS-CoV-2.

Methods: A systematic literature search with MeSH terms was performed, scrutinising the Embase database, Google scholar, MEDLINE database through PubMed and The Cochrane Library, including articles from December 2019 until July 7 2020. Data were subsequently analysed with descriptive statistics.

Results: Ninety-five studies were included in the qualitative analysis. 934/2149 (43%) patients tested positive for SARS-CoV-2 in stool samples or anal swabs, with positive test results up to 70 days after symptom onset. A meta-analysis executed with studies of at least 10 patients revealed a pooled positive proportion of 51.8% (95% CI 43.8 - 59.7%). Positive faecal samples of 282/443 patients (64%) remained positive for SARS-CoV-2 for a mean of 12.5 days, up to 33 days maximum, after respiratory samples became negative for SARS-CoV-2. Viable SARS-CoV-2 was found in 6/17 (35%) patients in whom this was specifically investigated.

Conclusions: Viral shedding of SARS-CoV-2 in stool samples occurs in a substantial proportion of patients, making faecal-oral transmission plausible. Furthermore, detection in stool samples or anal swabs can persist long after negative respiratory testing. Therefore, stool sample or anal swab testing should be (re)considered in relation to decisions for isolating or discharging a patient.


Since December 2019, the world has been dealing with the outbreak of the novel Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) leading to Corona Virus Disease 2019 (COVID-19) that emerged in Wuhan, China. The outbreak in this city led to a major world crisis, the COVID-19 Pandemic.[1,2]

SARS-CoV-2 is a non-segmented positive-sense RNA virus causing the third betacoronavirus outbreak of this century, which appears to have a higher transmission rate but is less deadly than the previous two; SARS-CoV 2003 and Middle East Respiratory Syndrome (MERS) 2012.[3,4] Prior studies demonstrated that the genome sequence of SARS-CoV-2 is 79.5% identical to SARS-CoV, whereas it shares 96.2% of its identity to the Coronavirus RaTG13 found in bats, but the intermediate reservoir has yet to be identified.[5]

While patients infected with SARS-CoV-2 typically present with fever and respiratory symptoms, a rapidly increasing number of studies report patients presenting with a variety of gastrointestinal symptoms such as diarrhoea, vomiting and abdominal pain.[6]

The established transmission route of SARS-CoV-2 is through respiratory droplets (aerosols), mainly during close person-to-person contact,[7] whereas numerous reports also mention the transmission by infected surfaces. Based on the spread through aerosols, the diagnosis of active COVID-19 infection primarily relies on the detection of SARS-CoV-2 viral RNA in specimens from the upper respiratory tract (URT; nasopharyngeal and oropharyngeal cavity) and/or lower respiratory specimens (LRT; sputum and/or bronchoalveolar lavage).[8,9]

Knowledge about SARS-CoV-2's other potential routes of transmission and the significance of different methods of testing is relatively sparse,[10] partly as a result of the novelty of this virus. However, there is a growing body of studies in which SARS-CoV-2 RNA was detected in stool samples (including anal swabs) from COVID-19 patients.[11] These findings support the possibility of a faecal-oral route of transmission. Interestingly, stool tests seem to remain positive when respiratory tests are, or have become, negative.[12–14]

A few articles have briefly reviewed the rapidly increasing body of knowledge on the potential for faecal-oral transmission.[11,15,16]

This study aims to (1) critically assess the clinical relevance of testing stool samples and anal swabs and (2) provide a critical overview of the available literature regarding the faecal-oral transmission of SARS-CoV-2.