Gastrointestinal symptoms, which had not been considered primary clinical features of novel coronavirus, were observed in the first U.S. case of the illness, researchers found.

Coronavirus RNA was detected in the patient's stool sample on day 7 after illness, and the patient's clinical symptoms included a 2-day history of nausea and vomiting prior to admission, according to Michelle Holshue, MPH, of the CDC in Atlanta, and colleagues.

The patient, age 35, presented with these gastrointestinal (GI) symptoms and dry cough, but no shortness of breath or chest pain. On the second day of hospitalization, the patient passed a loose bowel movement and reported abdominal discomfort, they stated in a brief report in the New England Journal of Medicine.

Similarly, another NEJM report found that the adult son, age 27, of the family cluster of cases in Vietnam also reported GI symptoms prior to admission, including fever, vomiting, and loose stools.

Susan Kline, MD, spokesperson for the Infectious Diseases Society of America, told MedPage Today that other coronaviruses could be shed in stool, although there is not much known about this virus at this point.

But GI symptoms can be a clinical feature of coronaviruses, and were "not unusual" during the SARS outbreak, she added.

Specifically, Kline noted prior research that SARS may have been transmitted through the sewage system in a Hong Kong apartment building, where the index patient had diarrhea and used the toilet there, the virus spreading through both person-to-person contact and environmental contamination, researchers noted.

And it's not just coronaviruses. Kline said that while not thought of as the predominant presentation, several illnesses have featured vomiting and diarrhea, such as influenza and even 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," she said.

Kline added that in the case of SARS, it was helpful to have information about nausea, vomiting, and diarrhea, because up until that point, those symptoms hadn't been emphasized in the "patients under investigation" definition.

The same might be true for novel coronavirus.

"I think it would be helpful to have some additional comments there that patients may have gastrointestinal symptoms," she said. "That would be helpful for clinicians to have, so they could at least consider that a patient with novel coronavirus might have vomiting or diarrhea."

However, in terms of novel coronavirus, Kline said that it's important not to assume that all patients are having these symptoms, as illnesses never have uniform symptoms, and there can be "quite a spectrum of disease."

Holshue and colleagues wrote that detection of novel coronavirus RNA on days 4 and 7 in the upper respiratory tract is "suggestive of high viral loads and potential for transmissibility." They also found that while the patient's serum tested negative for novel coronavirus, "viral RNA has been detected in severely ill patients in China," but that the clinical significance of detecting viral RNA outside the respiratory tract is "unknown" at this time.

They detailed the progress of the patient's illness, starting with mild symptoms, eventually ending up with pneumonia on day 9, with onset of dyspnea, or shortness of breath, on day 8. Researchers noted the patient was treated with remdesivir for compassionate use, though randomized trials are needed to determine its safety and effectiveness in patients with novel coronavirus, they added.

As of January 30, the patient is described as afebrile, with all symptoms resolving with the exception of his cough. He remains hospitalized.

A 'Spectrum of Illness'

On a conference call with the media, a reporter asked CDC officials about the clinical condition of U.S. patients with novel coronavirus. Nancy Messonnier, MD, director of the CDC's National Center for Immunization and Respiratory Diseases, deferred to state health departments for specific information about each patient's condition, but acknowledged there has been a "spectrum of illness" among U.S. cases.

"Some seem pretty mild, at least some have been been more severely ill [and] there have been some ups and downs," she said, adding that so far, there have been no deaths from novel coronavirus in the U.S.

Currently, there are 167 patients under investigation in the U.S., with test results pending on 82 patients.

CDC officials also provided an update on their diagnostic test for the virus, which they plan to submit to the FDA under Emergency Use Authorization. Once approved, public health laboratories can use the CDC-developed diagnostic assay, they said.