What is anal nucleic acid test
For nucleic acid detection, pharyngeal swab is the most common sampling method at present. Why should anal swab be added?
Oropharyngeal swab is convenient and fast, suitable for large-scale screening
The nucleic acid positive time of anal swab was longer
In the novel coronavirus pneumonia screening for the epidemic related population, the oropharyngeal swab nucleic acid test is mainly used, because the reason is convenient and quick, suitable for large-scale screening. Nasopharynx swab is more accurate than oropharynx swab, but the human body feels uncomfortable.
For some asymptomatic infection or mild infection, the disease recovers quickly after infection, and the pharyngeal nucleic acid may not be detected in 3 to 5 days. It was found that the duration of nucleic acid positive in feces or anal swabs of some infected patients was longer than that in upper respiratory tract. Therefore, increasing anal swab nucleic acid detection can improve the detection rate of infection and reduce missed diagnosis.
At present, anal swab collection is only for the key population
If necessary, serum antibody can be detected
Considering that anal swab collection is not as convenient as pharyngeal swab, only pharyngeal swab and anal swab are collected at isolation points and other key groups at the same time. Novel coronavirus pneumonia patients have longer serum antibodies, most of which can last more than half a year. When necessary, serum antibodies are also added to key groups. The purpose is to improve the detection rate and reduce the probability of false negative.