Travelers to some Chinese cities are required to undergo anal swab tests for COVID-19, a move that has sparked protests in other countries, according to press reports.
This week, Japanese officials complained that some Japanese nationals arriving in China had been subjected to the tests, which “caused them great psychological pain.” according to the BBC.
And in February, some American diplomats said they had to undergo the tests, prompting a complaint from the US State Department. Vice reported.
“The State Department never agreed to this type of evidence and protested directly to the Foreign Ministry when we learned that some staff members were subject to it,” a State Department spokesman told Vice. (Chinese officials denied that US diplomats were asked to undergo anal tests, Vice reported.)
It’s unclear how many international travelers have been forced to take anal tests, but Beijing and Shanghai have reportedly required the tests for some arrivals, according to The New York Times.
Some Chinese doctors say that the tests are done to detect the silent carriers of the virus, those who may not show symptoms or develop mild symptoms but recover quickly, because the new coronavirus can be detected in the stool for longer than in the nose. and throat.
“Some asymptomatic patients or those with minor symptoms recover quickly [from COVID-19], and throat tests may not be effective for these people, “Li Tongzeng, infectious disease physician in China, told CNN.
“Researchers have shown that for some infected people, the duration of nucleic positive results was longer in their stool and in the anal smear test. [samples] than those of the upper respiratory tract. Therefore, adding anal smear tests can improve the rate of positive detection of those infected, “he said, referring to so-called PCR diagnostic tests for the virus.
Some Chinese nationals have also been asked to take COIVD-19 anal tests. In January, more than 1,000 students and teachers in a school district in Beijing received anal swab tests, as well as nasal swab tests, for COVID-19 after a 9-year-old student in the district tested positive. according to Vice. Other people staying in quarantined hotels have been asked to take the tests. One person told Vice that he was asked to have an anal test in September 2020 while in a quarantine hotel after returning from Australia. He said the test was administered by nurses and that he “felt like he had diarrhea,” Vice reported.
The tests have been controversial among experts, including in China. Yang Zhanqiu, deputy director of the department of pathogen biology at Wuhan University, told the state-controlled Chinese newspaper: Global times in January, nasal and throat tests were even more effective than anal tests, because the virus is known to spread through respiratory droplets rather than feces. If the goal of testing is to prevent an infected person from spreading the virus, the argument continues, then nasal / throat testing would work better.
“There have been cases related to the positive result of the coronavirus in the stool of a patient, but no evidence has suggested that it was transmitted through the digestive system,” Yang said.
Experts outside of China also question the practice, as those who test positive for COVID-19 on an anal test but not a nasal or throat test are likely not very contagious, according to The New York Times.
“The value of detecting people with the virus is stopping transmission,” Benjamin Cowling, a professor of public health at the University of Hong Kong, told the Times. “If someone has an infection but it is not contagious to anyone else, we do not need to detect that person.”
Originally posted on Live Science.