According to livescience.com, this week, Japanese authorities are not satisfied when some Japanese citizens entering China have undergone this type of sampling. They think that taking samples for anal testing is very influencing on psychology.
In February, some US diplomats said they had been asked to have an anal test and immediately the State Department responded.
“The US State Department has never agreed to this type of test and has objected directly to the Ministry of Foreign Affairs of China knowing that some US staff are the subject of the test,” the ministry spokesman said.
China has denied that US diplomats are required to have this type of test.
It is not clear how many international passengers are required to be tested through the anus, but Beijing and Shanghai both require this test for some entry passengers.
Some Chinese doctors believe that this test is to detect people who carry the SARS-CoV-2 virus but have no symptoms or who already have mild symptoms and recover quickly. They believe the virus stays in the feces longer than in the nose and throat.
“Adding an anal test can increase the rate of positive detection,” said Li Tongzeng, an infectious disease doctor in China.
Some Chinese are also required to have this type of test. In January, more than 1,000 students and teachers in a district in Beijing examined the anus as well as through the nasal discharge to find a person with COVID-19 after a 9-year-old student was positive for SARS-CoV-2. . Some people in quarantine hotels also have to have this test.
Anal testing is controversial among specialists, even in China. Mr. Yang Zhanqiu, deputy director of the Department of Pathogenesis at Wuhan University, said that testing for nasal and throat fluids is still more effective than through the anus because the virus is spread through respiratory droplets rather than feces. If the test is to prevent the infected person from spreading the disease, then the nose and throat are still the best way.
Experts outside of China also question this test because those who test positive for COVID-19 after an anal test will not be able to infect others.