On March 12, the State Food and Drug Administration issued a notice approving the application change of the self-test application of new crown antigen products in Nanjing Novizan, Beijing Jinwolf, Shenzhen Huada Inyuan, Guangzhou Wanfu Biology and Beijing Huaketai Biology. Since then, five new crown antigen self-test products have been officially launched.
Previously, the National Health Commission issued a notice saying that it decided to add antigen detection as a supplement to nucleic acid testing, and organized the formulation of the "Application Plan for Antigen Detection of The New Coronavirus (Trial)".
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Who can test themselves?
The "Application Plan for The Detection of New Coronavirus Antigens" makes it clear that three types of people can self-test:
(1) Persons who go to primary medical and health institutions for medical treatment, accompanied by respiratory tract, fever and other symptoms, and who have symptoms within 5 days.
(2) Personnel in isolation and observation, including personnel in home isolation observation, close and sub-close contact, entry isolation and observation, sealing and control areas, and control areas.
(3) Residents of communities with antigen self-testing needs.
Can self-test results replace nucleic acid results?
No, nucleic acid testing is still the basis for confirming the diagnosis of COVID-19 infection.
The "Basic Requirements and Procedures for Self-Testing of New Coronavirus Antigens" in the pilot plan emphasizes that antigen testing is generally used for sample testing during the acute infection period, that is, within 7 days of the onset of symptoms in suspected people. Both positive and negative antigenic results in suspected populations should be further nucleic acid testing, and positive results can be used for early triage and rapid management of suspected populations, but cannot be used as a basis for confirming the diagnosis of new coronavirus infection.
Where can I buy self-testing agents?
The plan points out that if community residents have self-testing needs, they can purchase antigen detection reagents for self-testing through retail pharmacies, online sales platforms and other channels.
The management department that organizes the isolation observation (such as the community, village, town, isolation point, etc.) is responsible for the procurement, distribution, management and other related work of antigen detection reagents.
It should be noted that in order to ensure the quality of sampling and testing, residents must carefully read the instructions and standardize the operations such as sampling, sampling, and result interpretation in accordance with the prescribed requirements and procedures.
What are the precautions for self-testing?
There are three major steps to antigen self-testing.
First, prepare before antigen self-testing.
1. Wash your hands. Wash your hands with running water or hand sanitizer.
2. Understand the inspection process. Carefully read the antigen self-test agent supporting instructions and antigen self-test related precautions.
3. Reagent preparation. Check whether the antigen self-test agent is within the shelf life, and check whether the contents of nasal swabs, sampling tubes, test cards, etc. are missing or damaged. If the reagent is expired or the reagent contents are missing or damaged, the detection reagent should be replaced in time.
4. Confirm the environmental temperature and humidity requirements for the test. Colloidal gold test strip detection is generally required to avoid excessive cold, overheating or excessive humidity caused by abnormal detection results under the condition of 14 °C ~ 30 °C normal temperature. Antigen test cards are unpacked and placed in a flat, clean place.
Second, sample collection.
1. For those over the age of 14, nasal swab sampling can be performed by themselves. The self-examiner first blows off the snot with toilet paper. Carefully unpack the nasal swab and avoid hand contact with the swab head. Then the head is slightly tilted, one hand holds the swab on one side of the nostril, slowly deepens backwards along the bottom of the lower nasal passage for 1 to 1.5 cm, and then rotates the nasal cavity for at least 4 turns (stay time of not less than 15 seconds), and then repeats the same operation on the other nasal cavity with the same swab.
2. Self-testers aged 2-14 should be sampled by other adults. For sampling, blow the nose off with toilet paper and then tilt your head slightly. The sampling personnel carefully unpack the nasal swab package, avoid contact with the swab head with the hand, gently support the head of the person being collected with one hand, hold the swab in one hand and paste the nostril on one side to enter, slowly go back 1 cm along the bottom of the lower nasal passage, and then rotate the nasal cavity for at least 4 turns (staying for not less than 15 seconds), and then repeat the same operation for the other nasal cavity using the same swab.
Schematic diagram of antigen self-test process (refer to specific kit instructions)
Third, antigen detection.
1. According to the reagent instructions, the nasal swab after the sample is collected is immediately placed in the sampling tube, and the swab head should be rotated and mixed in the preservation solution for at least 30 seconds, while squeezing the swab head at least 5 times by hand across the outer wall of the sampling tube to ensure that the sample is fully eluted in the sampling tube.
2. Squeeze the swab head liquid dry by hand across the outer wall of the sampling tube, and discard the swab. After the sampling tube is covered, drop the liquid vertically into the test card sample well.
3. According to the reagent instructions, wait for a certain amount of time to interpret the results. Positive results: Red or purple bands are shown at both "C" and "T", and the bands at "T" can be dark or light, and both are positive results. Negative results: a red or purple band appears at "C" and a band is not shown at "T". Invalid result: No red or purple band appears at "C", regardless of whether the band appears at "T". The results are invalid, and the test strip needs to be re-tested.
What to do with used self-test agents?
Isolation observer: Whether the test result is negative or positive, all sample swabs, sampling tubes, test cards, etc. after use are loaded into sealed bags by the management personnel with reference to medical waste or according to procedures.
Community residents: If the test result is negative, all nasal swabs, sampling tubes, test cards, etc. after use are loaded into a sealed bag and disposed of as general garbage; if the test result is positive, it will be handed over to the medical institution for treatment according to medical waste when the personnel are transferred.
What about the self-test results?
1. If the antigen test is positive, regardless of whether there are respiratory tract, fever and other symptoms, residents should immediately report to the community (village or town), and the community (village) shall contact the emergency center to transfer the residents to the medical institution that has set up a fever clinic for nucleic acid testing in accordance with the guidelines for the transfer of personnel related to the new crown pneumonia epidemic.
2. Antigen-negative, asymptomatic residents can be closely observed, and then carry out antigen detection or nucleic acid testing when necessary; symptomatic residents are recommended to go to the medical institution that sets up fever clinics as soon as possible for nucleic acid testing; if it is inconvenient to seek medical treatment, they should self-isolate at home, avoid outdoor activities, and conduct antigen self-testing once a day for 5 consecutive days.
What are the test results used for?
Antigen testing can be used as a supplement to screening specific populations, which is conducive to improving the ability to "detect early". It is not yet clear whether the results of the self-test of the new crown antigen can be used as travel vouchers.