What are the main types of samples currently collected and what are their advantages and disadvantages in nucleic acid testing?
When diagnosing neocoronary pneumonia, a variety of samples can be collected for laboratory testing. Upper respiratory tract specimens can be collected, including nasopharyngeal swabs and pharyngeal swabs. Lower respiratory tract specimens Rapid antigen nasal swab can also be collected, including deep cough sputum, alveolar lavage, bronchial lavage, and respiratory aspirates. You can also collect fecal samples, anal swabs, blood samples, serum samples, urine samples, and more.
The different types of specimens commonly used to study nucleic acids for testing techniques are nasopharyngeal swabs, oropharyngeal swabs, and sputum, each with their own advantages and disadvantages. The pharynx, deep in the nose and mouth, is divided from the outside inward into three parts through the nasopharynx, oropharynx and laryngopharynx.
Nasopharyngeal swab collection, commonly known as "nose poking", is a sampling tool inserted into the nasal cavity to collect nasopharyngeal specimens, the detection rate and accuracy will be higher, but the procedure is more complex and difficult, some groups are not easy to adapt to, and the degree of acceptance of the people is slightly lower.
The collection of an oropharyngeal swab is often referred to as a "throat prick". Collecting an oropharyngeal sample through the mouth allows the sampler to see the location of the pharynx to be sampled, but the sample is irritating to the oropharyngeal mucosa and may cause coughing, nausea or even vomiting.
Collection of sputum specimens, especially deep cough sputum specimens, can also detect coronavirus nucleic acids with a high positive rate, but the collection of deep cough sputum specimens cannot be used to collect saliva specimens, and false-negative results may occur if qualified deep cough sputum specimens are not available.
Compared with nasopharyngeal swabs and sputum specimens, oropharyngeal swabs are fast to collect, simple and easy to perform, and the detection rate can meet the requirements. Usually, for low-risk groups, the collection of a pharyngeal swab for testing is sufficient. For some high-risk groups, such as asymptomatic infected persons, inbound persons and close contacts, nasopharyngeal swabs should be collected for nucleic acid testing at the time of isolation and observation in order to collect samples with higher viral loads and increase the positive detection rate.
Large-scale use of the population for nucleic acid screening, the collection of pharyngeal swab specimens is highly efficient, people are more likely to be acceptable, easy to achieve the organization and carry out the development of a faster screening of suspected positive people, quickly through the adoption of isolation control measures, which contributes to the rapid disposal of the enterprise aggregation of outbreaks and the effective management and control.
