Currently well-known nucleic acid detection sampling methods
There are mainly two kinds of
nasopharyngeal swab, oropharyngeal swab
Recently, Beijing Daxing District
is conducting nucleic acid tests on people in the area where the infected case is located When testing
In addition to nasopharyngeal, oropharyngeal swabs and serum testing
also added a sampling
anal swab
January 18, Beijing added 1 new case of asymptomatic infection A 9-year-old boy. The boy later developed fever and other symptoms and was diagnosed as a confirmed case.
On January 20, at a press conference on the prevention and control of the new crown pneumonia epidemic in Beijing, it was introduced that nasopharyngeal swabs, oropharyngeal swabs, anal swabs and serum tests had been performed on all students, faculty and staff of the school where the case was located.
For nucleic acid detection
At present, the most common sampling method is throat swab
Why add anal swabs?
Let's take a look first
How is the anal swab test sampled?
1. Soak the cotton swab in saline, insert it into the anus of 2-3 cm, wipe it from the folds around the anus, or rotate it gently inside the anus, and then insert it into a test tube containing saline.
2. For fecal swab culture, all the above operations need to use sterile equipment and put the swab in a sterile test tube.
*The picture shows anal examination, the source network
For anal swab detection
Many netizens say that the picture is too strong
is a bit unacceptable
This is to reduce missed diagnosis
part of the infected stool or anal swab
nucleic acid positive lasts longer
Beijing You'an Hospital Respiratory and Infectious Diseases Deputy Chief physician Li Tong once introduced in an interview,When screening for new coronary pneumonia in people related to the epidemic, oropharyngeal swab nucleic acid testing is mainly used, because it is convenient and quick and suitable for large-scale screening.
The accuracy of nasopharyngeal swabs for COVID-19 detection is higher than that of oropharyngeal swabs, but the human body feels less comfortable.
For some asymptomatic or mildly infected people, the condition recovers quickly after infection, and the pharyngeal nucleic acid may not be detected in 3 to 5 days.
Through research, it is found that the duration of positive nucleic acid in stool or anal swabs of some infected persons with is longer than the duration of the upper respiratory tract. Therefore, increasing the detection of anal swab nucleic acid can increase the detection rate of infected persons and reduce missed diagnosis.
At present, the collection of anal swabs is only for key populations.
Considering that the collection of anal swabs is not as convenient as throat swabs, currently only throat swabs and anal swabs are collected for key populations such as isolation points.
The duration of serum antibodies in patients with new coronary pneumonia infection is longer, most of which can exceed half a year, and if necessary, serum antibodies will be added to key populations. The purpose of this is to increase the detection rate and reduce the probability of false negatives.
Although medical staff will sample
very rigorously, netizens have also expressed their concerns
