But at four months following diagnosis, when no more COVID remained in their lungs, nearly 13% of patients continued to shed viral RNA in their feces.
About 4% still were shedding viral RNA in their feces seven months out from their initial diagnosis, researchers found.
Bhatt was quick to note that the RNA constituted genetic remnants of the coronavirus, and not actual live virus — so it’s unlikely a person’s poop could be contagious.
“While there have been isolated reports of people being able to isolate live SARS-CoV-2 virus from stool, I think that that’s probably much less common than being able to isolate live virus from the respiratory tract,” Bhatt said. “I don’t think that our study suggests that there’s lots of fecal-oral transmission.”
But the lingering presence of COVID in the gut does suggest one potential influence for long-haul disease, she said.
“SARS-CoV-2 might be hanging out at the gut or even other tissues for a longer period of time than it sticks around in the respiratory tract, and there it can basically continue to kind of tickle our immune system and induce some of these long-term consequences,” Bhatt said.
Long COVID has become such an established problem that many major medical centers have established their own long COVID clinics to try to suss out symptoms and potential treatments, said Dr. William Schaffner, medical director of the National Foundation for Infectious Diseases.
“A very substantial proportion of individuals who recover from COVID acutely nonetheless have lingering symptoms, and they can involve an array of different organ systems,” Schaffner said.
“These data add to the notion that the cells in the intestine may themselves be involved with COVID viral infection, and they could potentially be contributors to some of the symptoms — abdominal pain, nausea, kind of just intestinal distress — that can be one aspect of long COVID,” he said.
Bhatt said the findings also have implications for public health efforts to predict emerging COVID outbreaks by testing a community’s wastewater for evidence of the virus, and Schaffner agrees.
“If, as they say, about 4% of people seven or eight months later are still excreting viral remnants in their stool, it complicates the assessment of the density of new infections in a community,” Schaffner said. “It’s another thing we have to take into consideration and start looking at going forward.”