key: cord-013212-lx614fy4
authors: Nobel, Yael R.; Freedberg, Daniel E.
title: Reply to GASTRO-D-20-01179
date: 2020-10-14
journal: Gastroenterology
DOI: 10.1053/j.gastro.2020.10.014
sha: 
doc_id: 13212
cord_uid: lx614fy4

nan

We thank Drs. Liu, Xiang, and Deng for their correspondence regarding our recent manuscript "Gastrointestinal Symptoms and COVID-19: Case-Control Study from the United States". 1 In their letter titled "Focusing on gastrointestinal symptoms in COVID-19 is far from enough", the authors suggest that in patients with COVID-19, stool-based testing for leukocytes and erythrocytes/occult blood, rather than patient-reported gastrointestinal symptoms, should be considered. We reviewed their data with interest but remain unconvinced that stool-based testing adds value to the clinical diagnosis of diarrhea among patients with known or suspected COVID-19.

In our study, conducted among outpatients with respiratory symptoms being evaluated for COVID-19 during the height of the pandemic, the presence of gastrointestinal symptoms (diarrhea or nausea/vomiting) was associated with a 70% increased risk of testing positive for SARS-CoV-2. The authors note that control subjects in our study -subjects who tested negative for COVID-19 -were not limited to a specific disease state. This is correct. The primary value of our study is that it demonstrates that the clinical presence of gastrointestinal symptoms can substantially alter the pre-test probability of COVID-19 among patients who have not yet been tested and therefore not yet diagnosed with COVID-19 or with other conditions. Multiple other studies have confirmed that gastrointestinal symptoms, either in combination with respiratory disease or alone, are a hallmark of presentation for many patients with COVID-19, 2-4 and widespread awareness of these symptoms now informs decisions regarding whom to test.

We see major barriers to implementing stool-based testing among patients with suspected COVID-19. First, handling these otherwise unnecessary biospecimens might increase risk for spreading of SARS-CoV-2. Second, the stool-based testing described by Liu et al. -fecal leukocytes, erythrocytes, and occult blood -is notoriously inaccurate. [5] [6] [7] Even within their own data, it is unclear whether such stool markers indicate critical illness from any cause or COVID-19 specifically. Although it seems possible that fecal leukocytes and/or occult blood might help to classify disease severity once COVID-19 is diagnosed, there are already well-established clinical prediction scores that identify critically ill patients at the greatest risk for death, such as the Acute Physiologic Assessment and Chronic Health Evaluation (APACHE) or the Simplified Acute Physiology Score (SAPS). These scores are based on readily available clinical data and do not require stool samples.

In sum, our study found that the presence of gastrointestinal symptoms (diarrhea with or without nausea/vomiting) predicted a positive test for SARS-CoV-2 among patients with respiratory symptoms at the height of the COVID-19 pandemic. At this time, we do not believe that there is a diagnostic or prognostic role for stool-based testing among patients with known or suspected COVID-19.

Sincerely,

Gastrointestinal Symptoms and Coronavirus Disease 2019: A Case-Control Study From the United States

AGA Institute Rapid Review of the Gastrointestinal and Liver Manifestations of COVID-19, Meta-Analysis of International Data, and Recommendations for the Consultative Management of Patients with COVID-19

COVID-19 and gastrointestinal symptoms

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

Performance assessment of the fecal leukocyte test for inpatients

Devolution and Devaluation of Fecal Leukocyte Testing: A 100-Year History

Evaluation of faecal occult blood test and lactoferrin latex agglutination test in screening hospitalized patients for diagnosing inflammatory and non-inflammatory diarrhoea in Dhaka