key: cord-310507-5h6egve4 authors: van Doorn, Amarylle S.; Meijer, Berrie; Frampton, Chris M. A.; Barclay, Murray L.; de Boer, Nanne K. H. title: Systematic review with meta‐analysis: SARS‐CoV‐2 stool testing and the potential for faecal‐oral transmission date: 2020-08-27 journal: Aliment Pharmacol Ther DOI: 10.1111/apt.16036 sha: doc_id: 310507 cord_uid: 5h6egve4 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 portion of patients, making faecal‐oral transmission plausible. Furthermore, detection in stool sample or anal swab 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] [13] [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. This systematic literature search was performed following the PRISMA guidelines and conducted using the Embase database, Google scholar, The MEDLINE database through PubMed and The Cochrane Library from the outbreak in December 2019 until the 17 June 2020. The search strategy can be found in Online Supplement 1. All articles were imported to Mendeley (version 1.17.6), and duplicates were removed. Extensive cross-checking of reference lists of the included articles and other reviews was performed. As a result of the rapidly evolving research field concerning COVID −19, we also included journal pre-proof articles. All articles were screened based on title and abstract. Studies were included when the following inclusion criteria were met: We excluded articles written before December 2019, when the article or abstract/outcomes were not available in English, Dutch or German and when the results or quality of data were ambiguous. Papers written in Chinese, of which the abstract contained sufficient data to provide answers to our research questions, were included for analysis and data extraction. We excluded articles in which follow-up data were insufficient (ie when results of stool testing were not mentioned). Review articles were not included, however, reference lists were scrutinised for additional articles. We collected the following data from the eligible original articles: study design, geographic location, study period, number of patients, age, types of tested specimens, number of tested specimens, methods of the performed tests, duration and prevalence of positive test results in different specimens, disease severity, gastrointestinal symptoms, endoscopic results, specific evidence supporting faecal-oral transmission and remarkable patient/population characteristics. Data were subsequently analysed with descriptive statistics. Relevant data were tabulated with a subdivision by study population size. All studies with population of at least 10 patients were included in the meta-analysis. A weighted pooled estimate of the proportion testing positive from the stool samples was calculated using the Freeman-Tukey arcsine square root transformation under a random effects model. This analysis was undertaken using MedCalc® v19.4.0. The heterogeneity in the estimates between studies was statistically tested using Cochran's Q statistic and summarised as I 2 . The search strategy resulted in 300 articles suitable for title and abstract screening. After the exclusion of articles which met the exclusion criteria, we included a total of 95 articles for final analysis. Figure 1 shows details of the selection procedure. The majority of the included studies were performed in China (74 (77%)), other studies were conducted in Korea (6), Singapore (2), the United States of America (5), Italy (4), France (1), Germany (1), Thailand (1) and Austria (1). All included studies had a case report/ case series design. In most study populations, the subpopulation on which stool and/or anal testing were conducted was considerably lower. In total, stool samples or anal swabs (from now on collectively named as GI specimens) from 2175 patients were tested for SARS-CoV-2 RNA. Four studies were included for qualitative analysis, but due to the lack of necessary (follow-up) information, these studies were excluded before final quantitative analysis. [17] [18] [19] [20] Therefore, 2149 patients were included for final analysis. Seventeen (18%) studies tested SARS-CoV-2 presence in anal swabs and 81 (85%) in stool samples. In three studies, both specimens were tested. In all studies but one, real-time reverse transcription polymerase chain reaction (RT-PCR) was used to detect SARS-CoV-2. One study performed inoculation of stool suspension into Vero cells followed by virus detection through electron microscopy. 21 In 91/95 (96%) of the included studies, SARS-CoV-2 RNA was identified in GI specimens from at least one of the included patients (Tables 1 & 2 Twelve studies discussed the association between positive GI specimens and GI symptoms. 13, 14, 19, [38] [39] [40] [41] [42] [43] [44] [45] [46] In all studies, the majority of patients with GI symptoms tested positive in GI specimens, but the association was not statistically significant in most studies. In the study by Han et al, it was observed that patients with GI symptoms were significantly more likely to test positive for SARS-CoV-2 in a stool test (P = 0.033). 44 Furthermore, Cheung et al found that the proportion of positive stool tests and the stool viral load was higher in patients with diarrhoea than without (P = 0.019 and 0.06 respectively). 46 In addition to the clinical symptoms and the positive GI specimens testing, two studies detected SARS-CoV-2 RNA in endoscopic specimens of the oesophagus, stomach, duodenum and rectum in 1/1 and 2/6 patients. 41, 45 Viability of SARS-CoV-2 was investigated and detected in five studies, in which six patients (6/17 (35%)) had live active virus in their GI specimens using Vero cell testing. 19, 21, [47] [48] [49] In this study, we performed a systematic review of the rapidly expanding body of literature to assess the performance and accuracy The results of this study may have various consequences for the diagnosis, prognosis and spread of COVID-19. First and foremost, worldwide the decision to isolate or discharge a patient is primarily based on relevant clinical symptoms, focusing on the respiratory tract, and (sequential) negative test results on respiratory specimens collected more than 24 hours apart. 57 We observed that in 64% of patients who tested positive for SARS-CoV-2 in GI specimens, their GI specimens remained positive for a mean of 12.5 days after respiratory samples became negative. As a result, a number of patients were discharged up to a month before the absence of SARS-CoV-2 in GI specimens could be guaranteed. The (additional) use of GI specimen testing may provide a more appropriate rationale for isolation and discharge. A major concern could be continuing person-to-person transmission by the faecal-oral route, which argues for closer attention to hand and sanitation hygiene. This should be considered when determining diagnosis and isolation policies. In general the risk to health care professionals from patient exposure is well known, specifically in high aerosol-generating procedures. Currently, medical management protocols include measures to mitigate the aerosol transmission risks from procedures related to respiratory tract. 8 As a result, our analyses were based on relatively small patient groups (median 9; range 1-401 patients) and inconsistent methods, parameters, sample timing, sample frequencies and study endpoints differing widely between the included studies, impeding comparisons and robust conclusions. In the early response to the emerging COVID-19 outbreak, only respiratory specimens were required for the detection of SARS-CoV-2 according to initial clinical guidelines. A lot of studies, therefore, refrained from obtaining GI specimens from the patients during their first few days of hospitalisation or observation and could not determine whether respiratory and GI specimens were positive on RT-PCR analysis simultaneously. Furthermore, the phenomenon that viral RNA of SARS-CoV-2 can remain positive in GI specimens after respiratory samples became negative was not identified in all studies. This resulted in inadequate (follow-up) information, potentially causing a (outcome) measurement bias. The sole four studies that reported no positive tests in GI specimens were all based on small sample size (1-4 patients) and the testing was performed at an early stage of the disease course. Our review demonstrated that there seems a tendency for SARS-CoV-2 to be more detectable in the respiratory tract at an early stage of the disease and later on, more likely to be detected in GI specimens, which could explain the early negative testing. Our review confirms that SARS-Cov-2 is commonly present in stool samples or anal swabs in which the virus can persist long after respiratory testing has become negative and that the virus may be viable. This suggests the possibility of faecal-oral transmission and that stool sample or anal swab testing should be (re)considered in relation to decisions for isolating or discharging a patient. Guarantor of the article: NdB. A novel coronavirus from patients with pneumonia in China World Health Organization. WHO Director-General's opening remarks at the mission briefing on COVID-19 The species Severe acute respiratory syndrome-related coronavirus: classifying 2019-nCoV and naming it SARS-CoV-2 Evolutionary trajectory for the emergence of novel coronavirus SARS-CoV-2 The origin, transmission and clinical therapies on coronavirus disease 2019 (COVID-19) outbreak-A n update on the status Clinical Characteristics of COVID-19 Patients With Digestive Symptoms in Hubei, China World Health Organization W. Modes of transmission of virus causing COVID-19: implications for IPC precaution recommendations World Health Organization. WHO Clinical management of severe acute respiratory infection (SARI) when COVID-19 disease is suspected World Health Organization W. Laboratory testing for coronavirus disease 2019 (COVID-19) in suspected human cases 2019 novel coronavirus infection and gastrointestinal tract Potential Fecal Transmission of SARS-CoV-2: Current Evidence and Implications for Public Health Persistence and clearance of viral RNA in 2019 novel coronavirus disease rehabilitation patients Prolonged presence of SARS-CoV-2 viral RNA in faecal samples The presence of SARS-CoV-2 RNA in the feces of COVID-19 patients CHILDREN: IS IT TIME TO CHANGE OUR APPROACH? Pediatr Infect Dis J Review article: gastrointestinal features in COVID-19 and the possibility of faecal transmission Three cases of novel coronavirus pneumonia with viral nucleic acids still positive in stool after throat swab detection turned negative Clinical features of children with SARS-CoV-2 infection: an analysis of 13 cases from Changsha, China Detection of SARS-CoV-2 in Different Types of Clinical Specimens Detection and analysis of nucleic acid in various biological samples of COVID-19 patients Isolation of 2019-nCoV from a Stool Specimen of a Laboratory-Confirmed Case of the Coronavirus Disease 2019 (COVID-19) Virus shedding patterns in nasopharyngeal and fecal specimens of COVID-19 patients. medRxiv Epidemiological features and viral shedding in children with SARS-CoV-2 infection Detection of Novel Coronavirus by RT-PCR in Stool Specimen from Asymptomatic Child, China. Emerging Infectious Diseases Asymptomatic SARS-CoV-2 infected case with viral detection positive in stool but negative in nasopharyngeal samples lasts for 42 days COVID-19 Disease With Positive Fecal and Negative Pharyngeal and Sputum Viral Tests Epidemiological and clinical features of asymptomatic patients with SARS-CoV-2 infection Viral loads in throat and anal swabs in children infected with SARS-CoV-2 A Case Series of children with 2019 novel coronavirus infection: clinical and epidemiological features A Well Infant with Coronavirus Disease 2019 (COVID-19) with High Viral Load Positive rectal swabs in young patients recovered from coronavirus disease 2019 (COVID-19) First pediatric case of coronavirus disease 2019 in Korea An infant with a mild SARS-CoV-2 infection detected only by anal swabs: a case report Clinical and virological data of the first cases of COVID-19 in Europe: a case series Molecular and serological investigation of 2019-nCoV infected patients: implication of multiple shedding routes SARS-CoV-2-Positive Sputum and Feces After Conversion of Pharyngeal Samples in Patients With COVID-19 Do children need a longer time to shed SARS-CoV-2 in stool than adults? First case of 2019 novel coronavirus in the United States COVID-19 pneumonia in lung transplant recipients: report of two cases Fecal specimen diagnosis 2019 novel coronavirus-infected pneumonia Evidence for gastrointestinal infection of SARS-CoV-2 First 12 patients with coronavirus disease 2019 (COVID-19) in the United States Characteristics of pediatric SARS-CoV-2 infection and potential evidence for persistent fecal viral shedding Digestive Symptoms in COVID-19 Patients With Mild Disease Severity: Clinical Presentation, Stool Viral RNA Testing, and Outcomes Gastrointestinal symptoms of 95 cases with SARS-CoV-2 infection Gastrointestinal Manifestations of SARS-CoV-2 Infection and Virus Load in Fecal Samples from the Hong Kong Cohort and Systematic Review and Meta-analysis Infection of bat and human intestinal organoids by SARS-CoV-2 Virological assessment of hospitalized patients with COVID-2019 Infectious SARS-CoV-2 in Feces of Patient with Severe COVID-19 COVID-19: Gastrointestinal Manifestations and Potential Fecal-Oral Transmission Understanding Viral Transmission Behavior via Protein Intrinsic Disorder Prediction: Coronaviruses Evidence of Airborne Transmission of the Severe Acute Respiratory Syndrome Virus Enteric involvement of severe acute respiratory syndrome -Associated coronavirus infection SARS-CoV-2 RNA in wastewater anticipated COVID-19 occurrence in a low prevalence area Alterations in Gut Microbiota of Patients With COVID-19 During Time of Hospitalization Shell disorder analysis predicts greater resilience of the SARS-CoV-2 (COVID-19) outside the body and in body fluids Epidemiologic Features and Clinical Course of Patients Infected with SARS-CoV-2 in Singapore A familial cluster of pneumonia associated with the 2019 novel coronavirus indicating person-to-person transmission: a study of a family cluster SARS-CoV-2 turned positive in a discharged patient with COVID-19 arouses concern regarding the present standard for discharge First case of neonate infected with novel coronavirus pneumonia in China. Zhonghua er ke za zhi = Chinese Detectable SARS-CoV-2 viral RNA in feces of three children during recovery period of COVID-19 pneumonia Viral Shedding of COVID-19 in Pregnant Women A cross-sectional comparison of epidemiological and clinical features of patients with coronavirus disease (COVID-19) in Wuhan and outside Wuhan Prolonged viral shedding in feces of pediatric patients with coronavirus disease 2019 Anal swab findings in an infant with COVID-19 Brief report of the first cured 2019-nCoV pneumonia patient in West China Hospital Coronavirus disease (COVID-19) in a paucisymptomatic patient: Epidemiological and clinical challenge in settings with limited community transmission Novel Coronavirus can be detected in urine, blood, anal swabs and oropharyngeal swabs samples. medRxiv A case of SARS-CoV-2 carrier for 32 days with several times false negative nucleic acid tests. medRxiv Duration of viral detection in throat and rectum of a patient with COVID-19. medRxiv Comparison of different samples for 2019 novel coronavirus detection by nucleic acid amplification tests A Case of Successful Treatment of Severe COVID-19 Pneumonia with Favipiravir and Tocilizumab in Post-kidney Transplant Recipient Are They Just Two Children COVID-19 Cases Confused With Flu? Front Pediatr Epidemiology and clinical course of COVID-19 in Shanghai The positive of stool test for SARS-CoV-2: a report of 9 cases in Changsha, outside Wuhan. China Serial computed tomographic findings and specific clinical features of pediatric COVID-19 pneumonia: A case report Viral load kinetics of SARS-CoV-2 infection in first two patients in Korea Dynamic surveillance of SARS-CoV-2 shedding and neutralizing antibody in children with COVID-19. Emerging Microbes and Infections No infectious risk of COVID-19 patients with long-term fecal 2019-nCoV nucleic acid positive A family cluster of COVID-19 involving an asymptomatic case with persistently positive SARS-CoV-2 in anal swabs The implications of preliminary screening and diagnosis: Clinical characteristics of 33 mild patients with SARS-CoV-2 infection in Hunan A child with household transmitted COVID-19 Persistence of intestinal SARS-CoV-2 infection in patients with COVID-19 leads to re-admission after pneumonia resolved A report of three COVID-19 cases with prolonged viral RNA detection in anal swabs Epidemiologic and clinical characteristics of 10 children with coronavirus disease 2019 in Changsha Sequential analysis of viral load in a neonate and her mother infected with SARS-CoV-2 Dynamics of faecal SARS-CoV-2 in infected children during the convalescent phase Clinical Characteristics of Pneumonia Patients of Long Courses Infected with SARS-CoV-2 Detectable 2019-nCoV viral RNA in blood is a strong indicator for the further clinical severity. Emerging Microbes and Infections Viral load of SARS-CoV-2 in clinical samples Evaluation of SARS-CoV-2 RNA shedding in clinical specimens and clinical characteristics of 10 patients with COVID-19 in Macau Detection of SARS-CoV-2 in Fecal Samples from Patients with Asymptomatic and Mild COVID-19 in Korea Arbidol combined with LPV/r versus LPV/r alone against Corona Virus Disease 2019: A retrospective cohort study Nucleic acid detection of fecal samples from confirmed cases of COVID-19 Clinical characteristics of 2019 novel coronavirus infection in China Utility of Stool PCR for the Diagnosis of COVID-19: Comparison of Two Commercial Platforms Clinical characteristics and factors associated with long-term viral excretion in patients with SARS-CoV-2 infection: a single center 28-day study Evaluation of SARS-CoV-2 viral RNA in fecal samples Childhood COVID-19: a multicentre retrospective study Absence of SARS-CoV-2 in Semen of a COVID-19 Patient Cohort Positive results for patients with COVID-19 discharged form hospital in Chongqing. China Persistence of SARS-CoV-2 virus RNA in feces: A case series of children Viral RNA Load in Mildly Symptomatic and Asymptomatic Children with COVID-19 Dynamic Viral Severe Acute Respiratory Syndrome Coronavirus 2 RNA Shedding in Children: Preliminary Data and Clinical Consideration from a Italian Regional Center The Time Sequences of Oral and Fecal Viral Shedding of Coronavirus Disease Validation of SARS-CoV-2 detection across multiple specimen types US CDC Real-Time Reverse Transcription PCR Panel for Detection of Severe Acute Respiratory Syndrome Coronavirus 2 Coinfection and Other Clinical Characteristics of COVID-19 in Children Retrospective cohort study Laboratory data analysis of novel coronavirus (COVID-19) screening in 2510 patients Faecal calprotectin indicates intestinal inflammation in COVID-19 Positive result of Sars-Cov-2 in faeces and sputum from discharged patient with COVID-19 in Yiwu Long period dynamics of viral load and antibodies for SARS-CoV-2 infection: an observational cohort study. medRxiv Different longitudinal patterns of nucleic acid and serology testing results based on disease severity of COVID-19 patients Additional supporting information will be found online in the Supporting Information section. How to cite this article: van Doorn AS