Viral RNA Shedding in Stool Common in Patients with COVID19, May Persist for Weeks

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Viral shedding of RNA in the stool appears to be common in many patients with COVID-19, and may persist in the absence of positive respiratory samples.

Nearly one-fifth of patients with coronavirus disease (COVID-19) present with gastrointestinal symptoms, according to study data published in Gastroenterology. In addition, viral shedding of RNA in the stool appears to be common in many patients, and may persist in the absence of positive respiratory samples. As such, investigators emphasized caution during stool sample collection or endoscopy procedure.

Investigators conducted a cohort study of patients diagnosed with COVID-19 in the month of February, 2020 in Hong Kong. The prevalence of gastrointestinal symptoms—including nausea or vomiting, diarrhea, and abdominal pain or discomfort—was reported. Additionally, investigators conducted a systematic review of the PubMed, Embase, and Cochrane Library databases for scientific articles focused on COVID-19. Articles published between December 2019 and March 2020 were eligible for inclusion. Investigators assessed each article for reports of gastrointestinal symptoms and viral RNA load in patients with confirmed COVID-19. The Cochran Q test was used to detect heterogeneity among studies.  

The cohort study comprised 59 patients with confirmed COVID-19, of whom 27 (45.8%) were men. Median patient age was 58.5 years (interquartile range [IQR], 43.5-68.0 years). Fever was present in nearly all patients (n=56; 94.9%). Cough and dyspnea were observed in 22 (37.3%) and 4 (6.8%) patients, respectively. However, 36 (61.0%) patients did not have respiratory symptoms at first presentation of COVID-19. Gastrointestinal symptoms were present in 15 (25.4%) patients, of whom 100% also had fever. Over half (n=8; 53.5%) of patients with gastrointestinal symptoms did not have cough or dyspnea. Overall, 9 (15.3%) patients had viral RNA in stool samples. Detectable stool viral RNA was more prevalent among patients with diarrhea vs patients without (38.5% vs 8.7%; P =.019). Additionally, viral load was generally higher among patients with diarrhea compared to patients without (P =.06).

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The meta-analysis comprised 69 studies, of which 60 assessed gastrointestinal symptoms in patients. Data from 4243 patients with COVID-19 were included. The majority of selected studies were conducted in China (88.3%), though South Korea, Singapore, Vietnam, the United States, and the United Kingdom were also represented. The pooled prevalence of all gastrointestinal symptoms was 17.6% (95% confidence interval [CI], 12.3-24.5), though significant between-study heterogeneity was observed (P <.001). Gastrointestinal symptoms appeared to be more common in patients with severe disease. The pooled prevalence of gastrointestinal symptoms was lower for studies conducted in China (16.1%; 95% CI, 10.9-23.0) compared with those conducted in other countries (33.4%; 95% CI, 15.2-58.3). However, significant heterogeneity was observed among studies conducted in China (P <.001), with the prevalence of gastrointestinal symptoms ranging from 5.0% to 18.6% across studies. In addition, estimates from within the Hubei province appeared to differ significantly from estimates outside the Hubei province (P <.001). Of the 11 studies which reported viral RNA load in stool samples, 9 reported persistent positive stool RNA even in the absence of positive respiratory samples. In some cases, stool sample positivity persisted for over 33 days after illness onset.

These results underscore the prevalence of gastrointestinal symptoms in COVID-19. While the disease primarily presents with respiratory involvement, gastrointestinal symptoms should be monitored and logged. Investigators also urged health providers to exercise caution when handling the stool samples of patients with known or suspected COVID-19.


Cheung KS, Hung IF, Chan PP, et al. Gastrointestinal manifestations of SARS-CoV-2 infection and virus load in fecal samples from the Hong Kong cohort and systematic review and meta-analysis [published online April 3, 2020]. Gastroenterology. doi: 10.1053/j.gastro.2020.03.065