During moderate-to-severe acute SARS-CoV-2 infection, viral RNA is shed in feces. Viral RNA and antigens, and even live virus, have been demonstrated in gastrointestinal (GI) biopsies. The virus also can infect intestinal cell lines.

In a study from Stanford University, researchers followed 113 people (median age, 36) for as long as 10 months after diagnoses of mild-to-moderate COVID-19; 673 fecal samples were collected at prespecified times during follow-up. Almost half (49%) of fecal samples collected during the first week after diagnoses contained viral RNA. By 7 months after diagnoses, 4% of fecal samples contained viral RNA. GI shedding of viral RNA continued long after virus could no longer be detected in the oropharynx. Ongoing shedding of viral RNA correlated significantly with GI symptoms (e.g., nausea, abdominal pain, vomiting) and non-GI symptoms (e.g., rhinorrhea, headaches, myalgias).

COMMENT

In some people with mild-to-moderate COVID-19, a long-term infection of the gut can occur, with ongoing shedding of viral RNA that can be associated with GI and non-GI symptoms. The authors speculate that a continued reservoir of infection in the immunologically active intestinal mucosa could trigger chronic inflammation which, in turn, might be a cause of “long COVID” symptoms.