Nucleic acid testing is a scientific and effective means to implement the "four early", and plays a key role as the "outpost" for epidemic prevention and control work. Nucleic acid sampling is an important part of the nucleic acid testing process, how to ensure the standardization of nucleic acid sampling? What are the factors affecting the sampling of pharyngeal swabs? The State Department's joint prevention and control mechanism experts to provide authoritative answers.
"Nucleic acid testing is a mature and internationally accepted laboratory diagnostic method." Li Jinming, deputy director of the National Health and Wellness Commission's Clinical Laboratory Center, introduced the high sensitivity of nucleic acid testing methods, and the positive results of nucleic acid testing can be equivalent to the results of pathogen culture, becoming the "gold standard" for diagnosing new coronavirus infections.
Sampling is an important part of nucleic acid testing. The State Department's Joint Prevention and Control Mechanism Integrated Group recently issued a notice on further strengthening the quality management of nucleic acid sampling for neo-coronavirus, requiring further improvement in the standardization and accuracy of nucleic acid sampling.
The notice requires that local health administrative departments to produce training videos and organize hands-on training to make sampling personnel proficient in common collection methods such as oropharyngeal swabs and nasopharyngeal swabs, and to correctly put on and take off personal protective equipment and implement various infection control measures. Not through the video training instead of hands-on training. All places should effectively strengthen the quality control of nucleic acid sampling, in accordance with the principle of "no training, no job, no qualified training," to ensure that the sampling personnel operation and behavior of scientific standards.
Li Ang, deputy director of the Beijing Municipal Health Commission, said that the factors affecting pharyngeal swab sampling include the depth of pharyngeal swab collection, the time of contact with the mucosa, the strength of the sample, the height difference between the sampler and the sampled person and the degree of cooperation of the sampled person in the collection process, and other five aspects.
"In the process of collecting pharyngeal swabs, the sampled person needs to have his or her head slightly tilted and mouth slightly opened to reveal the pharyngeal tonsils on both sides, and the sampler needs to sample the pharyngeal tonsils and the posterior pharyngeal wall on both sides." Leon hinted that the public should actively cooperate with the sampling personnel when participating in nucleic acid testing, in accordance with the site requirements, standardize the sampling with the action to ensure the sampling effect.
"Sampling swabs belong to medical devices, the most basic standard is non-toxic and harmless." Li Jinming introduced, sampling swabs are not cotton swabs, it is made of polyester or nylon fiber. When doing sampling swabs, is millions of tiny fibers vertically and evenly covered in the swab handle end above. Sampling swab is to brush the posterior pharyngeal wall of the mouth to take cells, and then the sampling swab into the sampling tube, because the use of polyester or nylon fibers, it is easy to get off to the preservation solution, followed by the laboratory for related testing.
Li Jinming said that the sampling process will have some stimulation, individual differences. Sampling is usually open mouth, some people's soft palate on the tongue root together, the sampler to ensure the quality of sampling, it will probe inward, looking for the posterior pharyngeal wall, tonsils, resulting in irritation. Some people react strongly to stimulation, vomiting, coughing and other symptoms, but after sampling is complete, this discomfort will be relieved.
