If the antigen test result is positive, a user must report it to the community immediately and wait for the community team to come to his or her door to conduct a nucleic acid test, a medical expert told Shenzhen Special Zone Daily on Wednesday, when a local drugstore started to sell COVID-19 antigen test kits.
If the nucleic acid test result is also positive, the user will be confirmed as a positive case, said Hao Jianhua, who is in charge of the clinical laboratory of South China Hospital Affiliated to Shenzhen University. The antigen test kit initially used should be put in a sealed bag and disposed as medical waste, Hao was quoted as saying.
Guangdong GuoDa Drugstore was authorized to sell COVID-19 antigen test kits in Shenzhen starting Wednesday.
Hao said that the antigen test is faster and is more convenient than a nucleic acid test, but it is far less sensitive than the latter. Positive antigen results should not be taken as the sole basis to diagnose a COVID infection.
Hao noted that after citizens get their test kits, they should pay attention to its validity period and then, the next step is to take sample. “The sampling process is somewhat different from the nucleic acid test we usually do,” he said.
First, citizens should wash their hands and wipe off any snot they have. Then, take out the sampling cotton swab, insert it into one nostril, rotate it three to four times and take it out. Repeat the process in the other nostril. Each rotation should take about 15 seconds.
After taking out the swab, insert it into a test tube and wait 15-20 minutes for the result.
Hao said that since an antigen test is far less sensitive than a nucleic acid test, people may find a “false negative” result. Antigen detection cannot replace a nucleic acid test and cannot be used as the gold standard to diagnose an infection.
The sampling process is very important. Users should follow instructions carefully and collect specimens from their nasopharyngeal mucosa, he emphasized.
Hao suggested that the user wrap the kit in a sealed bag after the test and treat it as ordinary garbage if he or she gets a negative result.
China has temporarily included antigen tests in its medical insurance program as an interim measure against COVID-19, the National Healthcare Security Administration said Monday.