Virus World

A comprehensive evaluation of the risks and 1-year burdens of gastrointestinal disorders in the post-acute phase of COVID-19 is needed but is not yet available. Here we use the US Department of Veterans Affairs national health care databases to build a cohort of 154,068 people with COVID-19, 5,638,795 contemporary controls, and 5,859,621 historical controls to estimate the risks and 1-year burdens of a set of pre-specified incident gastrointestinal outcomes. We show that beyond the first 30 days of infection, people with COVID-19 exhibited increased risks and 1-year burdens of incident gastrointestinal disorders spanning several disease categories including motility disorders, acid related disorders (dyspepsia, gastroesophageal reflux disease, peptic ulcer disease), functional intestinal disorders, acute pancreatitis, hepatic and biliary disease.

The risks were evident in people who were not hospitalized during the acute phase of COVID-19 and increased in a graded fashion across the severity spectrum of the acute phase of COVID-19 (non-hospitalized, hospitalized, and admitted to intensive care). The risks were consistent in comparisons including the COVID-19 vs the contemporary control group and COVID-19 vs the historical control group as the referent category. Altogether, our results show that people with SARS-CoV-2 infection are at increased risk of gastrointestinal disorders in the post-acute phase of COVID-19. Post-covid care should involve attention to gastrointestinal health and disease. SARS-CoV-2 infection can lead to varied post-acute symptoms in the lungs and other organs, including the gastrointestinal system. Here the authors estimate the risks and 1-year burdens of a set of pre-specified incident gastrointestinal outcomes following SARS-CoV-2 infection in an electronic health care record-based cohort study.

Published in Nature Comm. (March 7, 2023):

https://www.nature.com/articles/s41467-023-36223-7 

Gut organoids, three-dimensional cell culture models of the intestine, have been used to demonstrate that the coronavirus SARS-CoV-2 can infect cells of the intestine and multiply there. The models indicate that SARS-CoV-2 might also infect and replicate in the cells lining the human intestine. It is even possible that the human intestine is—as researchers have suspected—a significant route for SARS-CoV-2 transmission. That is, SARS-CoV-2 transmission via gastrointestinal organs, as well as that via the respiratory organs, may account for the devastating spread of COVID-19. Patients with COVID-19 show a variety of symptoms associated with respiratory organs—such as coughing, sneezing, shortness of breath, and fever—and the disease is transmitted via tiny droplets that are spread mainly through coughing and sneezing. One-third of the patients, however, also have gastrointestinal symptoms, such as nausea and diarrhea. In addition, the virus can be detected in human stool long after the respiratory symptoms have been resolved. This suggests that the virus can also spread via so-called fecal-oral transmission.

Though the respiratory and gastrointestinal organs may seem very different, there are some key similarities. A particularly interesting similarity is the presence of the ACE2 receptor, the receptor through which the COVID-19 causing SARS-CoV-2 virus can enter the cells. The inside of the intestine is loaded with ACE2 receptors. However, it has been unclear whether intestinal cells could get infected and produce virus particles. To explore the possibility of an intestinal route, scientists in the Netherlands generated human small intestinal organoids (hSIOs) derived from primary gut epithelial stem cells. The scientists—who represented—Hubrecht Institute, Erasmus University Medical Center, and Maastricht University—asserted that such hSIOs contain all the proliferative and differentiated cell types of the in vivo epithelium. When grown in four different culture conditions, the hSIOs contained cells that expressed varying amounts of ACE2 and were thus capable, in theory, of being infected with SARS-CoV-2. To see if the cells actually experienced infection, the scientists observed them closely, as described in an article (“SARS-CoV-2 productively infects human gut enterocytes”) that appeared May 1 in the journal Science. “In hSIOs, enterocytes were readily infected by SARS-CoV and SARS-CoV-2 as demonstrated by confocal and electron microscopy,” the article’s authors wrote. “Consequently, significant titers of infectious viral particles were detected. mRNA expression analysis revealed strong induction of a generic viral response program.”

Published in Science (May 1, 2020): 

https://doi.org/10.1126/science.abc1669