key: cord-0811167-eitm7k9k
authors: Zhou, Jin‐Qiu; Liu, Gong‐Xiang; Huang, Xiao‐Li; Gan, Hua‐Tian
title: The importance of fecal nucleic acid detection in patients with coronavirus disease (COVID‐19): A systematic review and meta‐analysis
date: 2022-03-21
journal: J Med Virol
DOI: 10.1002/jmv.27652
sha: 8f14bbc3c7ed801506c950bbcfe45241bcf9e5aa
doc_id: 811167
cord_uid: eitm7k9k

Pooled data from 2352 hospitalized coronavirus disease 2019 (COVID‐19) patients with viral RNA in feces across 46 studies were analyzed and the pooled prevalence of fecal RNA was 46.8% (95% confidence interval [CI]: 0.383–0.554). The pooled analysis showed that the occurrence of total gastrointestinal (GI) symptoms was 28.5% (95% CI: 0.125–0.44) in COVID‐19 patients with fecal RNA, that of both respiratory and GI symptoms was 21.9% (95% CI: 0.09–0.346), that of only GI symptoms was 19.8% (95% CI: 0.107–0.288), and that of only respiratory symptoms was 50.5%（95% CI: 0.267–0.744). The pooled data showed no significant difference in positive fecal RNA between severe and nonsevere cases (odds ratio = 2.009, p = 0.079, 95% CI: 0.922–4.378). During hospital admission, after samples from the respiratory system tested negative for viral RNA, 55.4% (95% CI: 0.418–0.669) of the patients with positive fecal RNA had persistent shedding of fecal RNA and pooled results from the other 4 studies including 848 discharged patients with nucleic acid‐negative stool samples indicated that the occurrence of repositive stool swabs was 18.1% (95% CI: 0.028–0.335), that of repositive respiratory swabs was 22.8% (95% CI: 0.003–0.452), that of both repositive stool and respiratory swabs was 19.1% (95% CI: 0.019–0.363), and that of only repositive stool swabs was 9.6% (95% CI: 0.010–0.203). The digestive tract may be an important organ involved in COVID‐19 infection and in the excretion of the virus. Because of the potential risk of fecal–oral transmission, giving emphasis on stool swab tests can help increase the detection rate of asymptomatic carriers and reduce missed diagnoses.

expressed in the upper esophagus and stratified epithelial cells, and absorptive enterocytes from the ileum and colon, which is the entry point for the virus to the epithelial cells. 6, 7 The presence of new mutations may enable an increase in the viral tropism of the digestive tract. 8 At present, the GI symptoms in different studies are quite different in patients with COVID-19 with nucleic acid-positive stool samples, [9] [10] [11] which poses an important diagnostic challenge to clinicians on initial presentation. The presence of SARS-CoV-2 in stool samples and the potential of fecal-oral transmission is critical for our understanding of COVID-19; therefore, more attention should be given to these patients.

In addition, the recurrence of SARS-CoV-2 viral RNA in patients makes the pandemic more complex and some countries are facing a resurgence of the disease. This increases healthcare costs and the financial burden to families and societies. As viral loads in stool and perianal swabs appear to decline slower than in throat swabs, 12 the concern is the infectivity of SARS-CoV-2 in feces in the late stages of This search was done in two parts and the following search terms alone or matched with the Boolean operators "AND" or "OR" were used: "diarrhea," "gastrointestinal," "digestive," "feces," "fecal," "stool," "rectal swab," "anal swab," "COVID-19," "severe acute respiratory syndrome coronavirus 2," "SARS-CoV-2," "novel coronavirus," "2019-nCoV," "recurrence," "discharge," and "recovery." No language or geographic restrictions were imposed. We focused on full-text articles, but abstracts were considered if relevant. In addition, relevant review articles and references were examined for thorough assessment for existing literature. All articles were managed with Endnote X9.2 (Thompson and Reuters)/EndNote(version X9.2) and duplicates were removed.

Two reviewers (ZJQ and LGX) independently screened the titles and abstracts according to these eligibility criteria. A third reviewer (HXL) subsequently reviewed the full-text articles and identified articles for inclusion. Disagreement was discussed and subsequently resolved via consensus. The inclusion criteria included the following: (1) study population: COVID-19 patients (including adult or pediatric patients and pregnant women) provided data on stool/anal/perianal viral RNA; (2) study design: case series, prospective/retrospective cohort study, case-control study, and randomized controlled trials. There was no language restriction. The exclusion criteria were small studies (N < 5), review articles, meta-analyses, editorials, and other forms (e.g., commentary).

A data extraction sheet was created and the study characteristics, source of data, patient characteristics, and outcome of interest were collected. Two of the authors (ZJQ and LGX) independently extracted data and potential discrepancies were resolved by the third author (GHT).

Organization interim guidance, 13 

Our analysis includes cumulative descriptive statistics expressed as counts (n) and percentages (%) with a comparative analysis for the selected studies. The quantitative variables with normal distribution are presented as the mean ± SD and those with skewed distribution as median or range. We computed the odds ratios (ORs) as our effect estimate using the Mantel-Haenszel method with random effects, with a study confidence interval (CI) of 95%. Depending on the heterogeneity between studies, a fixed-or random-effects model was used to estimate the average effect and its precision. We used the I 2 statistic and Cochran's Q test to assess statistical heterogeneity. The publication bias was evaluated by the visual inspection of funnel plot and Begger's regression tests. The publication bias was done to assess the effect of each study on the pooled effect size. A p < 0.05 was considered statistically significant. All statistical analyses were performed using the STATA software (version 15.0, Stata Corp. LP).

Trial sequential analysis (TSA) was performed for the nucleic acid-positive stool of patients with diarrhea compared with those without diarrhea, using the TSA software 0.9.5.10 Beta (Copenhagen Trial Unit; Figure 3 ). The thresholds for the Z values using O'Brien-Fleming α-spending function were adjusted to control the risk of type 1 error. The cumulative Z curve represents the trial data. The risk of type 2 error was controlled using the β-spending function and futility boundaries. Random-effects modeling were applied. A two-sided CI with 95% confidence level was used to indicate statistical significance. We estimated the information size for the analyses based on the achievement of 80% power and 10% relative risk reduction between the two groups. 

The characteristics of the included studies with data of viral RNA in stool samples at the first hospitalization are shown in Table 1 Figure 2 and Table 2 ). The median age of patients with positive fecal RNA was 41.6 ± 4.24 years and 55.4%

were male.

Fourteen studies 11, 19, [22] [23] [24] [25] 28, 30, 33, 34, 38, 39, 43 including 609 patients reported the prevalence of fecal SARS-CoV-2 RNA in patients 

In addition, 4 studies, 55 

The funnel plot of clinical parameters is shown in Figures S1−S8 and Begger's tests are shown in Table 2 . There was no publication bias in this study. In sensitivity analysis, it revealed that the study performed by Wu et al. 67 and Xu et al. 53 (Table 3 ).

The Therefore, patients who only have positive RT-PCR tests in stool samples may be clinically ignored. Pauci-symptomatic and asymptomatic individuals represent a major concern for diagnosis and viral transmission. Furthermore, false-negative results of OP/NP swabs ranged from 1% to 30% in previous studies. 62 Furthermore, even if viral nucleic acid examinations in stool were negative at discharge, there is still a possibility of repositive tests for SARS-CoV-2 RNA. It is still uncertain whether the recurrence of SARS-CoV-2 RNA among discharged COVID-19

patients could be contagious. 66 In our analysis, 9.6% of discharged patients tested positive again for SARS-CoV-2 RNA in stool samples but negative in respiratory samples; the possibility cannot be excluded that the virus may be transmitted through the digestive tract. Therefore, to prevent the spread of the pandemic, it is important to monitor patients, and respiratory

and fecal samples should be tested regularly after discharge. 66 Patients need to pay close attention to hand hygiene and try to avoid sharing toilets with family members after discharge.

Attention should be paid to standard and transmission-based precautions for patients until the negative conversion of SARS-CoV-2 RNA in feces. 39 In conclusion, the detection of fecal SARS-CoV-2 RNA in patients with COVID-19 is common, and the repositive tests of viral RNA are not unusual in discharged patients. 

The authors declare no conflicts of interest. 

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Jin-Qiu Zhou https://orcid.org/0000-0002-3858-0851

Manifestations and prognosis of gastrointestinal and liver involvement in patients with COVID-19: a systematic review and meta-analysis

Novelty in the gut: a systematic review and meta-analysis of the gastrointestinal manifestations of COVID-19

The characteristics of gastrointestinal symptoms in patients with severe COVID-19: a systematic review and meta-analysis

Evidence for gastrointestinal infection of SARS-CoV-2

Detection of SARS-CoV-2 in different types of clinical specimens

Receptor recognition by novel coronavirus from Wuhan: an analysis based on decade-long structural studies of SARS

COVID-19: gastrointestinal manifestations and potential fecal-oral transmission

COVID-19 gastrointestinal manifestations are independent predictors of PICU admission in hospitalized pediatric patients

Clinical characteristics of 138 hospitalized patients with 2019 novel coronavirus-infected pneumonia in Wuhan, China

Asymptomatic SARS-CoV-2 infected case with viral detection positive in stool but negative in nasopharyngeal samples lasts for 42 days

Characteristics of pediatric SARS-CoV-2 infection and potential evidence for persistent fecal viral shedding

Gastrointestinal symptoms of 95 cases with SARS-CoV-2 infection

Global surveillance for human infection with coronavirus disease (COVID-19)

Guidance for discharge and ending isolation in the context of widespread community transmission of COVID-19-first update

Molecular and serological investigation of 2019-nCoV infected patients: implication of multiple shedding routes

Epidemiologic features and clinical course of patients infected with SARS-CoV-2 in Singapore

A case series of children with 2019 novel coronavirus infection: clinical and epidemiological features

Persistence and clearance of viral RNA in 2019 novel coronavirus disease rehabilitation patients

Digestive symptoms in COVID-19 patients with mild disease severity: clinical presentation, stool viral RNA testing, and outcomes

A cross-sectional comparison of epidemiological and clinical features of patients with coronavirus disease (COVID-19) in Wuhan and outside Wuhan, China

Evaluation of SARS-CoV-2 RNA shedding in clinical specimens and clinical characteristics of 10 patients with COVID-19 in Macau

The implications of preliminary screening and diagnosis: clinical characteristics of 33 mild patients with SARS-CoV-2 infection in Hunan

Clinical and virologic characteristics of the first 12 patients with coronavirus disease 2019 (COVID-19) in the United States

Clinical and virological data of the first cases of COVID-19 in Europe: a case series

Comparison of different samples for 2019 novel coronavirus detection by nucleic acid amplification tests

Detectable 2019-nCoV viral RNA in blood is a strong indicator for the further clinical severity

Prolonged presence of SARS-CoV-2 viral RNA in faecal samples

SARS-CoV-2 can be detected in urine, blood, anal swabs, and oropharyngeal swabs specimens

Viral load dynamics and disease severity in patients infected with SARS-CoV-2 in Zhejiang province, China

Fecal specimen diagnosis 2019 novel coronavirus-infected pneumonia

Infectious SARS-CoV-2 in feces of patient with severe COVID-19

Different longitudinal patterns of nucleic acid and serology testing results based on disease severity of COVID-19 patients

Diarrhea is associated with prolonged symptoms and viral carriage in corona virus disease 2019

Epidemiologic and clinical characteristics of 10 children with coronavirus disease 2019 in Changsha

SARS-CoV-2-positive sputum and feces after conversion of pharyngeal samples in patients with COVID-19

Clinical features of children with SARS-CoV-2 infection: an analysis of 13 cases from Changsha

Virological assessment of hospitalized patients with COVID-2019

Caution should be exercised for the detection of SARS-CoV-2, especially in the elderly

The presence of SARS-CoV-2 RNA in the feces of COVID-19 patients

Rapid SARS-CoV-2 antigen detection assay in comparison with real-time RT-PCR assay for laboratory diagnosis of COVID-19 in Thailand

Epidemiological features and viral shedding in children with SARS-CoV-2 infection

Comparison of clinical characteristics between fecal/perianal swab nucleic acid-positive and -negative patients with COVID-19

Gastrointestinal manifestations of SARS-CoV-2 infection and virus load in fecal samples from a Hong Kong cohort: systematic review and meta-analysis

Necessity for detection of SARS-CoV-2 RNA in multiple types of specimens for the discharge of the patients with COVID-19

Detection of SARS-CoV-2 in fecal samples from patients with asymptomatic and mild COVID-19 in Korea

Association between detectable SARS-COV-2 RNA in anal swabs and disease severity in patients with coronavirus disease 2019

Fecal viral shedding in COVID-19 patients: clinical significance, viral load dynamics and survival analysis

Value of swab types and collection time on SARS-COV-2 detection using RT-PCR assay

Positive result of Sars-Cov-2 in faeces and sputum from discharged patients with COVID-19 in Yiwu

Faecal calprotectin indicates intestinal inflammation in COVID-19

Dynamic viral severe acute respiratory syndrome coronavirus 2 RNA shedding in children: preliminary data and clinical consideration from a Italian Regional Center

Temporal profiles of viral load in posterior oropharyngeal saliva samples and serum antibody responses during infection by SARS-CoV-2: an observational cohort study

Clinical features and dynamics of viral load in imported and non-imported patients with COVID-19

Alterations in gut microbiota of patients with COVID-19 during time of hospitalization

Recurrence of positive SARS-CoV-2 viral RNA in recovered COVID-19 patients during medical isolation observation

Clinical, immunological and virological characterization of COVID-19 patients that test re-positive for SARS-CoV-2 by RT-PCR

Do children need a longer time to shed SARS-CoV-2 in stool than adults?

A case series of recurrent viral RNA positivity in recovered COVID-19 Chinese patients

Functional assessment of cell entry and receptor usage for SARS-CoV-2 and other lineage B betacoronaviruses

The digestive system is a potential route of 2019-nCov infection: a bioinformatics analysis based on single-cell transcriptomes

An infant with a mild SARS-CoV-2 infection detected only by anal swabs: a case report

Occurrence and timing of subsequent SARS-CoV-2 RT-PCR positivity among initially negative patients

False-negative results of initial RT-PCR assays for COVID-19: a systematic review

SARS-CoV-2 detection in fecal sample from a patient with typical findings of COVID-19 pneumonia on CT but negative to multiple SARS-CoV-2 RT-PCR tests on oropharyngeal and nasopharyngeal swab samples

Value of anal swabs for SARS-COV-2 detection: a literature review

Recurrence of SARS-CoV-2 viral RNA in recovered COVID-19 patients: a narrative review

Detection and analysis of nucleic acid in various biological samples of COVID-19 patients

SARS-CoV-2 viral load in clinical samples from critically Ill patients

How to cite this article

The importance of fecal nucleic acid detection in patients with coronavirus disease (COVID-19): a systematic review and meta-analysis