[Related story: Reported Cutaneous Manifestations Associated with COVID-19]

By Guy M. Lindberg, MD, staff GI pathologist at Inform Diagnostics

It is well established that patients with COVID-19 typically present with fever along with respiratory symptoms, such as cough and dyspnea. However, patients often have extra-pulmonary symptoms, including involvement of the gastrointestinal tract. Recent publications from Wuhan, China and the U.S. sought to characterize the gastrointestinal involvement in patients with COVID-19.

In these studies, COVID-19 patients reported gastrointestinal symptoms ranging from 10–50%, the most common symptom was diarrhea (which was relatively mild), followed by nausea/loss of appetite, and abdominal pain (2%). Occasional patients presented with digestive symptoms without any respiratory symptoms. As the severity of the COVID infection increased, digestive symptoms became more pronounced. However, the presence of gastrointestinal symptoms did not result in longer hospital stays, days in ICU, or mortality.

The virus attacks the lungs through angiotensin-converting enzyme II (ACE2) which is expressed on the alveolar cells. ACE2 is also expressed in the gastrointestinal tract cells, especially in the enterocytes of the ileum and colon, and suggests that GI symptoms result from invasion of these cells. In some studies, viral RNA has been detected in up to 50% of fecal samples in COVID patients. Interestingly, fecal samples remained positive for SARS-CoV2 RNA for an average of 11 days after clearance of respiratory tract samples, suggesting that fecal-oral transmission can last even after respiratory symptoms have resolved.

All these findings are preliminary and need to be corroborated with further studies.

References

1. Pan L, Mu M, Yang P, et al. Clinical characteristics of COVID-19 patients with digestive symptoms in Hubei, China: a descriptive, cross-sectional, multicenter study. Am J Gastro: March 2020
2. Xiao F, Tang M,et al. Evidence of Gastrointestinal Infection of SARS-CoV-2. Gastroenterology: 2020 In press
3. Gu J, Han B, Wang J. COVID-19: Gastrointestinal Manifestations and Potential Fecal-Oral Transmission. Gastroenterology: March 3, 2020
4. Cholankeril G, Podboy A, et al. High Prevalence of Concurrent Gastrointestinal Manifestations in Patients with SARS-CoV-2: Early Experience from California. Gastroenterology: April 2020. In press.
5. Nobel Y, Phipps M, et al. Gastrointestinal Symptoms and COVID-19: Case-Control Study from the United States. Gastroenterology: April 2020. In press.