Many places have required anal swab testing for some immigrants. Which areas are there?

In order to strengthen the control of imported cases, many cities, including Beijing and Shanghai, have begun to conduct anal swab tests on some immigrants to improve the accuracy of new coronavirus test results. ?Some Japanese people reported to the Japanese Embassy in China that they had received anal swab tests. This caused a lot of mental anguish. Katsunobu Kato said that the Japanese government has made a request to China through the Japanese Embassy in China, hoping that China will not use anal swab testing for Japanese immigrants entering China. Regarding Kato Katsunobu's statement, Chinese Foreign Ministry spokesperson Wang Wenbin responded that China has scientifically and dynamically adjusted relevant epidemic prevention measures in accordance with changes in the epidemic situation and in accordance with relevant laws and regulations. ?

Shanghai is already conducting anal swab tests for inbound travelers, but it is not for all inbound travelers. Instead, it is based on a comprehensive judgment based on the specific situation, including their health status and nucleic acid tests for people on the same flight. circumstances and whether they are coming from or passing through countries with severe epidemics. For example, the above-mentioned person said that after inbound personnel undergo nucleic acid testing at the airport, if there are more than or equal to 5 positive test results on the same flight, those who test negative for the first time will need to collect nasopharyngeal swabs and anal swabs again 24 hours after the first sampling. A full set of swabs, blood and sputum samples are sent for testing.

The first time the anal swab testing method became known to the public was from an epidemic prevention and control conference held in Beijing on January 20, 2020. At that time, there was one new case of no infection in Daxing District, Beijing. The symptomatic infected person was a 9-year-old boy. Subsequently, relevant institutions conducted nasopharyngeal swabs, oropharyngeal swabs, anal swabs and serum tests on all students, faculty and staff of the school where the case was located. During the epidemic in Shijiazhuang at the beginning of this year, Wang Haibin, a member of the Shijiazhuang COVID-19 treatment expert group, also mentioned that anal swab specimens were only collected from hospitalized COVID-19 patients with diarrhea, and there was no obvious discomfort after the anal swab collection. Healthy China, the official account of the National Health Commission, previously published an article saying that anal swab testing can increase the detection rate of people infected with the new coronavirus to a certain extent, and the positive time of anal swab testing can even precede nasopharyngeal swab testing. Moreover, there are a small number of cases where the clinical symptoms improve later in the course of the disease, and after the nucleic acid test of the nasopharyngeal swab turns negative, the anal swab test continues to be positive. Therefore, adding anal swab testing can increase the detection rate, effectively reduce the probability of false negatives, and reduce missed diagnoses.

Lu Hongzhou, a professor at the Shanghai Public Health Clinical Center, said that stool testing through anal swabs is more sensitive and accurate than testing through upper respiratory tract samples, and anal swabs are performed during the quarantine period of incoming personnel. Testing can detect positive infections as soon as possible and prevent imported cases from causing local infections. Lu Hongzhou also added that in actual operations, the sampling of nasal swabs and throat swabs may cause uncomfortable reactions, resulting in unqualified samples and false negative results. He also mentioned that anal swabs can also be replaced by stool sampling to reduce the discomfort of sampling for immigrants.