- Almost half of COVID-19 patients in a recent study experienced nausea, vomiting, or diarrhea.
- Though the virus primarily causes fever or difficulty breathing, gastrointestinal symptoms sometimes appear first.
- In one case, a coronavirus patient was placed in the wrong ward because they only showed abdominal symptoms. They spread the virus to 14 other people there.
- Like SARS, the new coronavirus could spread through poop.
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The new coronavirus is giving some patients nausea, vomiting, and diarrhea – symptoms that could be early clues of infection.
A study published in The American Journal of Gastroenterology looked at 204 coronavirus patients who were hospitalized in the Hubei province in China between January 18 and February 28. More than 50% of them reported digestive symptoms like lack of appetite, diarrhea, vomiting, or abdominal pain. Six of those patients had no respiratory symptoms whatsoever.
“We’re so focused on a cough and fever, but it’s possible there are people with digestive symptoms that are not being tested,” Dr. Brennan Spiegel, the journal’s editor in chief, told Ohio news channel Spectrum News 1.
“This new study from Wuhan, China found that actually these digestive symptoms are much more common than I think we thought they were,” he added.
Another peer-reviewed study published in the Journal of the American Medical Association identified 14 coronavirus patients who had diarrhea and nausea before they showed any signs of fever or respiratory symptoms. That was 10% of the study's 138-person sample size.
One of those patients was placed in a surgical ward because they only showed abdominal symptoms, so doctors didn't suspect the new coronavirus. That patient then transmitted the virus to at least 10 healthcare workers and four other patients in the ward. (If you think you might have the coronavirus, call a doctor before leaving the house.)
Researchers found the virus in poop
The first US patient with the new coronavirus had diarrhea and reported abdominal discomfort the day after he arrived at the hospital, according to a report published in the New England Journal of Medicine. Researchers later detected the coronavirus' RNA in his poop.
Another study, shared in the pre-publication repository biorXiv, detected an enzyme signature of the virus in cells from the small intestine and colon.
"If it's coming out into the saliva, then you can swallow your saliva and naturally that can go into the stomach," Spiegel said in a video he posted to Twitter. "The fact that we're seeing so much in the stool samples means that it might be able to get past that acid layer."
Spiegel added that, once the coronavirus gets into the gastrointestinal system, it can enter GI cells using a particular receptor called ACE2. Once inside those cells, the virus can thrive.
"It can replicate in the GI system," he said.
Patients in China and Vietnam have also had diarrhea, vomited, or reported nausea.
These symptoms could be relatively rare, though: A study published in the pre-print repository medRxiv (which has not been peer-reviewed) looked at data from 1,099 patients. Less than 4% of those people experienced diarrhea and about 5% experienced vomiting.
Though the US Centers for Disease Control and Prevention (CDC) did not mention gastrointestinal symptoms in official guidelines in February, it has since added a note that some patients have experienced them before developing fever or respiratory symptoms.
Watching for nausea, vomiting, and diarrhea could help contain the outbreak
This is not the first time scientists have found a coronavirus in patients' poop. Research has indicated that SARS traveled through a Hong Kong apartment's sewage system to infect some residents after one sick person had diarrhea.
Dr. Susan Kline, a spokesperson for the Infectious Diseases Society of America, told MedPage Today that gastrointestinal symptoms were "not unusual" in SARS patients during the virus's deadly 2003 outbreak.
Within just six week, the new coronavirus reached a higher death toll than SARS had in eight months.
Kline said that many illnesses cause nausea, diarrhea, and vomiting, even if those aren't the primary symptoms. Looking for them can be crucial in the early stages of a new outbreak, as it was with SARS and Ebola.
"It was not recognized early on that [Ebola] patients had prominent diarrhea. Later, as [there were] reports of large numbers of patients, it became more obvious that it could be a predominant part of the illness," Kline said.
Kline added that it's important not to assume that all patients will have gastrointestinal problems, though. Still, looking for those symptoms could help catch more coronavirus cases early on.
"We probably need to be testing the stool more commonly, thinking about testing more in people who have sever diarrhea and fever," Spiegel said.