How to collect anal swab for nucleic acid detection?

In order to ensure the accuracy of nucleic acid detection, anal swab detection has been recently added to throat swab and nose swab in nucleic acid detection. Many citizens are very concerned about this. What does anal swab test mean? Why should I add anal swab? How is it tested? Let's get to know each other.

Why do you want to increase anal swab

Oropharyngeal swab is convenient and quick, suitable for large-scale screening, and the positive duration of anal swab nucleic acid is longer.

Dong Li, deputy chief physician of the Department of Respiratory and Infectious Diseases, Beijing You 'an Hospital, said in an interview that when screening people related to the COVID-19 epidemic, oropharyngeal swab nucleic acid detection is mainly used, because it is convenient and quick, which is suitable for large-scale screening. The accuracy of nasopharyngeal swab in detecting COVID-19 nucleic acid is higher than that of oropharyngeal swab, but human body feels uncomfortable.

For some asymptomatic or mild infected people, the condition recovers quickly after infection, and the nucleic acid in the pharynx may not be detected for 3~5 days. It is found that the duration of nucleic acid positive in feces or anal swab of some infected people is longer than that in upper respiratory tract. Therefore, increasing the detection of nucleic acid in anal swab can improve the detection rate of infected people and reduce missed diagnosis.

: If necessary, we can join the current anal swab to collect serum antibodies only for key populations

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Dong Li once said that, considering that anal swab collection is not as convenient as throat swab, at present, only throat swab and anal swab are collected at the same time for key populations such as isolation points. The serum antibody of COVID-19 infected people lasts for a long time, most of which can exceed half a year. If necessary, additional serum antibody tests will be conducted for key populations. The purpose of this is to improve the detection rate and reduce the probability of false negative.

there are several ways to detect nucleic acid

nucleic acid is detected by throat swab, including oropharyngeal swab sampling and nasopharyngeal swab sampling. And serum antibody testing.

throat swab sampling refers to wiping the throat with a cotton swab and taking the epithelial cells of the throat for detection. The general detection method is that the examinee opens his mouth to make an "Ah" sound, and the detector uses a cotton swab to sample. There is no risk of trauma during the test, so it is a very safe test.

and the collection of nasopharyngeal swab. Generally, a fine cotton swab is used to penetrate into the nostril, reach the posterior wall of nasopharynx from the inferior nasal passage, and then twist the cotton swab for sampling. Generally, you may feel vomiting and need to wait patiently.

Now there is another anal swab sampling method.

Anal swab detection method

The so-called anal swab inspection is to insert a sampling cotton swab into the anus 2 to 3 cm for sampling, or wipe the folds around the anus for sampling. Anal swab tests have been used to screen for parasitic infections. If you eat unsanitary food at ordinary times, parasites in the intestines will lay eggs and be discharged with the stool. At this time, it is possible to find parasites through stool examination or anal swab.

Source: CCTV News, Xi 'an Ankepu