Coronavirus: Human feces could be new source of spreading the disease, say scientists
Experts detected the virus in human stool from the first case identified in the US
The novel coronavirus (2019-nCoV) has been detected in the loose stool of the first patient identified in the US, a finding not reported previously among cases emerging from China.
Doctors have so far focused on respiratory samples of patients to identify coronavirus. In the case of the severe acute respiratory syndrome (SARS) outbreak, 10% to 20% of patients had diarrhea.
"The stool and both respiratory specimens later tested positive for 2019-nCoV, whereas the serum remained negative," say researchers in their findings published in The New England Journal of Medicine.
The team includes experts from the Washington State Department of Public Health Laboratories and the US Centers for Disease Control and Prevention (CDC), among others.
"This report highlights the need to determine the full spectrum and natural history of clinical disease, pathogenesis, and duration of viral shedding associated with 2019-nCoV infection to inform clinical management and public health decision-making," conclude researchers after investigating the first case of 2019 novel coronavirus in the US.
They add, "The case report highlights the importance of clinicians eliciting a recent history of travel or exposure to sick contacts in any patient presenting for medical care with acute illness symptoms, in order to ensure appropriate identification and prompt isolation of patients who may be at risk for 2019-nCoV infection and to help reduce further transmission."
In a separate study on the initial cases of 2019-nCoV in Wuhan, also published in The New England Journal of Medicine, researchers emphasize that while the initial focus of case detection was on patients with pneumonia, "but we now understand that some patients can present with gastrointestinal symptoms, and an asymptomatic infection in a child has also been reported."
The US case study
On January 19, 2020, a 35-year-old man came to an urgent care clinic in Snohomish County, Washington, with a four-day history of cough and subjective fever.
On checking into the clinic, the patient put on a mask in the waiting room. After waiting for approximately 20 minutes, he was taken into an examination room and underwent evaluation.
He disclosed that he had returned to Washington State on January 15 after traveling to visit family in Wuhan, China. The patient said that he had seen a health alert from the CDC about the novel coronavirus outbreak in China and because of his symptoms and recent travel he decided to see a healthcare provider.
"Although the patient reported that he had not spent time at the Huanan seafood market and reported no known contact with ill people during his travel to China, CDC staff concurred with the need to test the patient for 2019-nCoV on the basis of current CDC 'persons under investigation' case definitions," say researchers.
On the afternoon of hospital day 2, the patient passed a loose bowel movement and reported abdominal discomfort. A second episode of loose stool was reported overnight. A sample of this stool was collected for testing, along with additional respiratory specimens (nasopharyngeal and oropharyngeal) and serum. The stool and both respiratory specimens were later found positive for coronavirus.
"On January 20, 2020, the CDC confirmed that the patient’s nasopharyngeal and oropharyngeal swabs tested positive for 2019-nCoV by real-time reverse-transcriptase–polymerase-chain-reaction (rRT-PCR) assay," says the study.
Both upper respiratory specimens obtained on the seventh day of illness remained positive for 2019-nCoV. Stool obtained on the seventh day of illness day was also positive for 2019-nCoV, analysis shows.
According to the CDC, human coronaviruses most commonly spread from an infected person to others through the air by coughing and sneezing and via close personal contact, such as touching or shaking hands. It can also transmit by touching an object or surface with the virus on it, then touching your mouth, nose or eyes before washing your hands, but rarely, by fecal contamination.
However, much is unknown about how 2019-nCoV spreads. "Current knowledge is largely based on what is known about similar coronaviruses," says the CDC.
The current study also describes how the man progressed from initially non-specific symptoms to pneumonia on the ninth day of his illness.
"Our case patient initially presented with a mild cough and low-grade intermittent fevers, without evidence of pneumonia on chest radiography on day 4 of his illness, before having progression to pneumonia by illness day 9," says the team.
According to China's National Health Commission, as of 12 o'clock midnight on February 2, there have been 17,205 reports of confirmed cases and 361 deaths in 31 provincial-level regions on the Chinese mainland.
In all, 475 patients had been cured and discharged from hospitals. There still remains 21,558 suspected cases and 2,296 patients in serious condition. So far, 189,583 people have been identified as having had close contact with infected patients and 152,700 are now under medical observation, said the Commission.