Photo: Xinhua

Recently, anal swab testing came under the spotlight again after Japan's chief cabinet secretary Katsunobu Kato said on Monday that Tokyo has requested Beijing to stop taking anal swab tests for COVID-19 on Japanese citizens because the procedure causes "great psychological pain." 

In response, Wang Wenbin, spokesperson from China's Foreign Ministry, said on a Monday conference that China has made scientific adjustment of COVID-19 prevention measures.

The Global Times learned that several Chinese cities, such as Beijing, Shanghai and Qingdao in East China's Shandong Province are requiring certain international arrivals to take anal swab tests before completing quarantine periods, as health experts believe the method is more accurate than nasal and throat swabs. 

Some experts even suggested that people under quarantine can submit stool samples instead, so as to reduce the discomfort during the sampling process.

An employee of the Shanghai CDC told the Global Times on Tuesday that Shanghai asks certain overseas travelers to undergo anal swab testing. For example, travelers on a plane where more than five people test positive for the coronavirus have to undertake a full set of tests, including anal swabs, nasal/throat swab tests, and tests of blood and phlegm. Travelers from countries or regions where the virus is rife or test positive upon arrival also have to undergo this full set of tests, said the employee.

In special circumstances, such as a traveler who has developed symptoms like diarrhea, the person will have to take an anal swab test for COVID-19, the staffer revealed. 

The Global Times learned that medical staff will collect nasal or throat swab samples of international travelers to Beijing on the third and seventh day after arrival. On the 14th and 21st days after their arrival, anal swab testing will be added. 

An employee from Beijing's Daxing district epidemic control department told the Global Times that general international travelers to Beijing are subject to anal swab testing, along with nasal swab and environment sample testing.

"If people are not familiar with the procedure for taking an anal swab test, our employees will help explain how it will be done," she said. 

Yet anal swabs are not compulsory for international arrivals in all Chinese cities. A resident from the island of Taiwan said that he was not required to do the under-the-belt test when he arrived at Xiamen, South China's Fujian Province. Also, a staffer from Tianjin's Heping district disease control center said anal swabs tests are not required for international arrivals to the city. 

Anal swab testing involves a cotton swab from three to five centimeters long being inserted in one's rectum and gently rotated for 10 seconds of sample excavation, the Beijing health commission explained on its website.  

Last week, a US Department of State spokesperson claimed that US diplomats in China were subjected to anal swab tests for COVID-19 and said that the US had lodged representations with China. 

"To my knowledge...China has never required US diplomatic staff stationed in China to conduct anal swab tests," Chinese Ministry of Foreign Affairs spokesman Zhao Lijian said in response. 

The testing method first came to public attention in January, when it was being used on a few key groups in China, including some cold-chain workers, certain people returning from overseas and close contacts of patients. Health experts suggested that although it is awkward for the patient, anal swab tests are more reliable than nasal tests because traces of the virus remain longer in fecal matter than in the respiratory tract. 

Lu Hongzhou, an expert from the Public Health Clinical Center affiliated to Fudan University, told the Global Times that he is a firm supporter of anal swab testing for international travelers to China, as nasal or throat swab testing may bring false negative results.

Anal swab testing will tell whether the person is a virus carrier immediately, and it will effectively prevent transmission, said Lu. 

He suggested that for the testing, people staying under hotel quarantine can submit stool samples instead, so as to reduce the discomfort during the sampling process.