- China uses anal swabs for COVID-19, in ‘key groups’ because it is allegedly more accurate.
- An anal swab test involves inserting a small cotton swab into the rectum.
- Anal swabs are “not nice”, but the tests makes sense, said Joanne Santini, microbiology professor.
- Visit Business Insider’s homepage for more stories.
China has introduced anal swabs as a new type of test that can detect coronavirus more accurately.
“Adding anal swab tests can increase our patients’ identification of infected patients,” Li Tongzeng, an infectious disease specialist at Beijing You’an Hospital, told state broadcaster China Central Television.
“But of course, considering that the collection of anal swabs is not as convenient as throat swabs, currently only key groups like those in quarantine receive both,” Tongzeng added.
An anal swab test means inserting a swab that is about 3-5 cm (1-2 inches) of cotton into the rectum, which is then sent to a laboratory for testing for the virus. They are analyzed in the same way as the Polymerase Chain Reaction (PCR) coronavirus tests taken from the nose or throat.
Tonzeng said a study has shown that the virus lasts longer in the anus or feces than in the airways. Thus, an anal swab or stool may be helpful in identifying diseases in mild or asymptomatic cases.
But Yang Zhanqiu, deputy director of the Department of Pathogenology at Wuhan University, told the state-run pony newspaper The Global Times that the virus has been shown to be transmitted via the upper respiratory tract rather than through the digestive system, the most effective tests. is still nose and throat swabs.
“There have been cases involving the coronavirus that were positive in a patient’s feces, but no evidence indicated that it was transmitted through the digestive system,” Yang said.
Joanne Santini, professor of microbiology at University College London, said Insider anal swabs are not a great way to test, but it makes sense. “It’s the obvious thing to do,” Santini said.
Santini explained that the virus attaches to the human body using a receptor called ACE2, and that there are many ACE2 receptors in the gut. The viral load – the amount of virus shedding – can also be higher in the stool, especially if someone suffers from gastrointestinal problems caused by coronavirus. And viral shedding can last longer in the stool than in sputum.
“Although a common way of infection is through breathing, I think there should be an infection through the intestines through the mouth,” she said. “There is evidence that SARS-CoV-2 is contagious in feces, just like other viruses, such as norovirus and other coronaviruses.”
Santini said poop samples would be preferable to anal swabs because they are less invasive and can be especially helpful in collecting samples from children.
“It’s less painful for children, and people do it all the time for other tests,” she said. “You don’t have to go anywhere, and you can do it yourself.”