Why does nucleic acid testing increase anal swab sampling?

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　　On January 18, Beijing added one asymptomatic infection to a 9-year-old boy.

The boy later developed fever and other symptoms and was diagnosed as a confirmed case.

On January 20, a press conference on the prevention and control of the new crown pneumonia epidemic in Beijing introduced that

all students, faculty and staff of the school where the case was located had been tested for nasopharyngeal swabs, oropharyngeal swabs, anal swabs and serum.

　　For nucleic acid testing, currently the most common sampling method is throat swabs,

why add anal swabs?

Oropharyngeal swabs are convenient and quick for large-scale screening

Anal swab nucleic acid positive lasts longer

　　Li Tong, deputy chief physician of the Department of Respiratory and Infectious Diseases of Beijing You'an Hospital, once said in an interview that 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 fast, suitable for large-scale screening. check.

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.

Studies have found that

the duration of nucleic acid-positive stool or anal swabs of some infected people 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.

Currently anal swab collection is only for key populations

Serum antibodies can be added if necessary

　　Li Tong once said that considering that the collection of anal swabs is not as convenient as throat swabs,

currently only throat swabs and anal swabs are collected from key groups such as isolation points.

The serum antibodies of people infected with new coronary pneumonia last longer, most of which can be more than 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.

　　CCTV Reporter丨Zhang Jingyu Jingjing