RESEARCHERS at the Shenzhen No.3 People’s Hospital have found that COVID-19 patients can shed the coronavirus through the intestinal tract for as long as seven weeks, Shenzhen Economic Daily reported Thursday.

The study, titled “The Time Sequences of Oral and Fecal Viral Shedding of Coronavirus Disease 2019 (COVID-19) Patients,” was published online on Gastroenterology, the most prominent journal in the field of gastrointestinal disease, May 16.

Previously, researchers at the hospital had detected SARS-CoV-2, the formal name of the novel coronavirus that caused COVID-19, in the fecal samples from patients, and successfully isolated live virus from the samples.

In this study, the researchers tested for viral RNAs in both respiratory and rectal specimens from 401 COVID-19 patients, and tracked for more than seven weeks to figure out the oral and fecal viral shedding profile, such as the duration, viral load, and relationship to patient symptoms.

It was found that SARS-CoV-2 RNA in fecal samples remained for an unexpectedly long period, with the highest positive rate and a higher viral load than the paired respiratory samples. The longest duration observed was 43 days.

The results suggest that SARS-CoV-2 test of rectal swabs is crucial to minimize false negatives for the laboratory diagnosis of COVID-19, and to reduce the potential fecal-oral transmission from asymptomatic COVID-19 patients.

The study also found that the positive rate of fecal SARS-CoV-2 RNA in children was significantly higher than adults.

Meanwhile, COVID-19 patients, whether positive or negative for fecal viral RNA, showed no difference in gastrointestinal symptoms, suggesting that SARS-CoV-2 may use the intestine as a reservoir without altering the intestine functions.

The researcher also observed that early antiviral treatment might reduce SARS-CoV-2 persistence within the intestinal tract.  

(Zhang Yu)