China’s Zero-Tolerance Covid Tactics Now Include Anal Swabs
(Bloomberg) -- China is ramping up efforts to neutralize the coronavirus as new outbreaks challenge its already stringent pandemic strategy, with another weapon added to an arsenal of border curbs, mass testing and hard lockdowns: anal swabs.
While there’s no nationwide policy on use of the technique, some residents in China’s northern regions -- where more than 1,700 cases have emerged -- have been subjected to the swabs with little warning. The method involves the insertion of a saline-soaked cotton swab about two-to-three centimeters into the anus, with the sample then tested for active traces of the virus.
More than 1,000 schoolchildren and teachers in Beijing were given anal, throat and nose swabs last week, along with a separate antibody test, after one asymptomatic virus case was detected on campus, according to local officials.
On Monday, passengers on a flight from Changchun, the capital city of Jilin province, to Beijing were told to disembark after officials discovered that someone from an area deemed as high risk for virus transmission was on board. They were then brought to a hotel where health workers took nose and anal swabs, said a passenger who asked to be identified only by his last name, Wang.
Some people arriving into Beijing are being asked to undertake anal swabs as well, with one traveler who came from Hong Kong a few weeks ago telling Bloomberg News she was told to do the swab herself while in mandatory hotel quarantine. The person, who didn’t want to be identified citing privacy concerns, also had to do three nose and throat tests, one blood test and her hotel room has been tested twice.
Use of the new detection technique is based on research that traces of the virus found in the anus can last longer than in the respiratory tract, Li Tongzeng, deputy director of the respiratory and infectious disease department of Beijing You An Hospital said in an interview with state television last week. Anal swabs could be more accurate than throat and nose tests, especially in detecting asymptomatic cases, he said, adding they were only being used on at-risk groups, including at quarantine sites.
Still, there’s no evidence that virus transmission is any more common among patients who test positive in the anus area, and anal swabbing has not been conducted in other places that have successfully achieved near-elimination of the pathogen, like New Zealand.
Since quelling its original outbreak in the central city of Wuhan last year, China has mounted a relentless drive to stamp out the coronavirus within its vast population, often deploying resources and powers that wouldn’t be viable or even countenanced in other countries.
While Western nations like the U.S. and U.K. still struggle with adequate virus testing, China is not just testing entire city populations every week, but also millions of frozen food imports and the containers that they arrive in every day for minute traces of the pathogen.
That zeal, driven in part by local government officials concerned about repercussions should their cities become the next Wuhan, has worked at keeping outbreaks in check, but the use of techniques like anal swabbing is being questioned by some experts -- even in the country’s state-run media. So far, it appears to be only being used consistently in the north, including the capital.
“I don’t understand why Beijing added anal swabs. It’s not like poking the throat. You need a certain place and the risk of such transmission routes is lower,” said Jiang Qingwu, a professor of epidemiology at the School of Public Health at Shanghai’s Fudan University. “Maybe they want to find remnants? It’s true that the virus can be detected there.”
Scientists have found that some Covid-19 patients have active and prolonged gut viral infection, even if they don’t manifest gastrointestinal symptoms. For such people, stool samples often test positive even a week after their respiratory samples have gone negative, researchers from the Chinese University of Hong Kong found.
While more research is needed to determine how effective anal swabs are, stool testing has been “grossly underutilized” in the pandemic, said Francis Chan, dean of the university’s faculty of medicine and director of its Centre for Gut Microbiota Research. The virus was still actively replicating in the feces of at least half of the study participants after they’d cleared it from their lungs, he said.
China’s capacity to endure disruption to business and everyday life in its ferocious fight against the coronavirus is a hallmark of its approach.
It’s the only country that has repeatedly detected traces of the virus on frozen food imports, with efforts that include disinfecting packaging adding to delays at ports, where containers of produce have been piling up. Local consumers are shunning foreign food for fear of infection, and China’s meat imports are projected to plunge as much as 30% this year from a record in 2020.
China’s lockdowns are also getting tougher, rivaling the severity of curbs placed on Wuhan a year ago even as case levels pale in comparison to elsewhere. China has reported just two Covid-19 deaths since April, and new infections at the height of the current flare-up number around 100 a day, compared with hundreds of thousands in the U.S.
In Tonghua, a city of 2 million people in Jilin province bordering North Korea, all residents have been banned from leaving their homes since Jan. 21 after 100 infections were detected. Some have complained on social media of insufficient food supplies after the sudden order, prompting an apology from local officials.
There are signs that the central government is trying to encourage some moderation.
An editorial from the Xinhua state news agency said Jan. 16 that local authorities should cease using the phrase “wartime measures” to describe their containment efforts. Such slogans could cause unnecessary panic, “paralyze people’s minds” and affect normal activities, the editorial said.
But with the Lunar New Year holiday approaching in mid-February, when officials expect 1.7 billion trips to be taken despite pleas for people to stay home, the wartime footing is likely to continue. The country is also doubling down on vaccination, with plans to inoculate 50 million people by the holiday with locally-developed vaccines.
“We don’t tolerate the virus circulating. Once we find it, we immediately quash it and outbreaks are not allowed,” said Lu Hongzhou, an infectious disease physician who advises both the central and Shanghai governments on Covid-19 treatment.
“Our country has always pursued this strategy and it can’t be adjusted.”
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