SARS-CoV-2 remains in the GI tract long after it clears the lungs

SARS-CoV-2 remains in the GI tract long after it clears the lungs

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The new data provide further evidence that SARS-CoV-2 infection can be lodged in the gastrointestinal (GI) tract and can persist long after the infection has cleared the lungs.

The study authors suggest that GI infection may feature prominently in prolonged COVID.

Led by Aravind Natarajan, PhD, with the Departments of Genetics and Medicine at Stanford University, they analyzed fecal RNA shed up to 10 months after a COVID-19 diagnosis in 673 stool samples from 113 patients with mild to moderate disease.

They found that in the week following diagnosis, COVID RNA residues were present in the stool of about half (49.2%) of patients. After seven months, about 4% of them had shed their faecal RNA.

The authors note that there was no persistent SARS-CoV-2 RNA leak in patients’ respiratory samples at the 4-month mark.

Using self-reported symptoms collected regularly by questionnaire, they also found an association between long-term fecal elimination of SARS-CoV-2 RNA with abdominal pain, nausea and vomiting.

The results have been published online at Med.

Long-term consequences of viral precipitation

Previous studies have found SARS-CoV-2 RNA in respiratory and fecal samples, and documented viral replication in lung and intestinal tissue.

But before the current study, little was known about long-term hair loss, especially in those with mild COVID. Most of the studies on viral shedding have been with severe COVID cases.

The authors note that most studies of this type are cross-sectional studies. The few other longitudinal studies focused on early time points immediately after diagnosis.



Dr. Ami Bhatt

Senior author Ami S. Bhatt, MD, associate professor of medicine and hematology at Stanford University, said, Medscape Medical News that although viral genetic material remains in the stool, based on the available evidence, it is unlikely to be infectious in most cases.

She said understanding the dynamics of fecal disposal of SARS-CoV-2 genetic material will help explain wastewater-based studies trying to determine the spread of the virus in a population.

“Although we do not know the exact clinical significance of long-term elimination of SARS-CoV-2 in individuals with COVID-19, some have speculated that those with long-term elimination of SARS-CoV-2 may have persistent infections. benefit from treatment.”

“Our data support the idea that in some people the long-term symptoms associated with the GI tract may be the result of persistent GI infection, even after the respiratory infection has cleared,” Bhatt said.

“Alternatively, the persistent presence of viral genetic material in the gut may be a trigger for the immune system to be continuously active against the virus, and the reaction of our immune system may be the cause of prolonged COVID symptoms,” she added. “This area is ripe for additional studies.”

Bhatt and colleagues will continue to study virus elimination in stool samples as part of a nationwide recovery initiative.



David Johnson

When reached for comment, David A. Johnson, MD, professor of medicine and chief of gastroenterology, Eastern Virginia Medical School in Norfolk, Virginia, Medscape Medical News Previous studies indicated that the virus could be detected in the stool for a month or more, and for an average of two weeks. Whether the virus is contagious or not.

But he said the virus is not contagious in the gastrointestinal tract and causes symptoms. Instead, there are biological changes associated with COVID, including a loss of diversity in gut bacteria, which leads to an imbalance.

“This may actually somehow predispose some patients to hinder the removal of their symptoms,” Johnson explained. “There appears to be a growing recognition that this entity called long-term COVID may be associated with certain bacterial disorders, and the faster these disorders resolve, the less likely long-term symptoms are to persist.”

And among people with mild COVID-19, the virus usually clears and gut bacteria return to normal, he said. With severe or persistent illness, he said, gut dysbacteriosis persists.

“People should realize that the GI tract is involved in a significant proportion of COVID patients,” Johnson said. “Gastrointestinal testing may reflect that the virus is present, but a persistently positive test that is detectable is unlikely to reflect the active virus.”

In this study, the authors note that they collected only six samples from participants over a 10-month period.

“Follow-up studies with more frequent sampling, especially in the first two months after diagnosis, may help build a more accurate model of the decline in fecal RNA concentration over time,” they wrote.

The study was supported by a Stanford ChemH-IMA grant, fellowships from the AACR and the National Science Foundation, and the National Institutes of Health. The authors and Johnson did not report any relevant financial relationships. Johnson is a regular contributor to Medscape.

Med. Posted online April 12, 2022. Full text

Marcia Frelick is a freelance journalist based in Chicago. She has previously written for the Chicago Tribune, Science News, and Nurse.com, and has been an editor for the Chicago Sun-Times, Cincinnati Enquirer, St. Cloud (Minnesota) Times. Follow her on Twitter at Tweet embed.

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2022-05-10 13:47:11

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