If You 'Deeply' Insert It in Your Nose, There's a Risk of Bacterial Infection... What Is the Correct Way to Use a Self-Test Kit?

The Ministry of Food and Drug Safety (MFDS) has provided guidance on the proper use and behavioral guidelines for COVID-19 self-test kits.
[Photo by Ministry of Food and Drug Safety YouTube capture]

[Asia Economy Reporter Hwang Sumi] Since the COVID-19 Omicron variant became the dominant strain in South Korea, the quarantine system has changed, increasing the need to learn the correct way to use self-test kits.

On the 19th, the number of new COVID-19 cases recorded the 100,000 range for two consecutive days. As the Omicron variant spread rapidly, the diagnostic testing system for COVID-19 also changed significantly for more efficient response.

PCR tests are now conducted only for high-risk groups such as those aged 60 and above or epidemiologically linked individuals. Other general suspected cases can receive PCR tests only if they test positive through rapid antigen tests at medical institutions or self-test kits.

According to the Ministry of Food and Drug Safety (MFDS), when performing a self-test, the swab should be inserted so that it touches the nasal wall at a depth of 1.5 to 2 cm inside both nostrils, and then rubbed in a circular motion 10 times each to the left and right.

There are cases where people forcefully insert the swab deep into the nose to increase the accuracy of the test, but this method is not recommended.

In fact, forcing the swab too deep into the nose can increase the risk of bacterial infection, so caution is necessary. An MFDS official explained, "Self-tests collect viruses from the nasal mucosal cells using a swab, so it is sufficient for the swab to just touch the surface of the mucosa."

The accuracy of rapid antigen tests used in self-testing is significantly lower than that of PCR tests. According to the Korean Society for Laboratory Medicine, rapid antigen tests can detect the virus only when viral shedding is 1,000 to 10,000 times higher than what PCR tests require.

Accuracy is especially low in the early stages of infection. To obtain more accurate results with a self-test kit, it is best to test within one week after symptoms appear, as this is when the virus is shed the most.

Even if the self-test kit shows a negative result, if infection is suspected, it is advisable to strictly follow quarantine guidelines and retest after a day or two. This is because viral shedding concentration may increase during this period if infected.

Experts recommend visiting medical institutions such as respiratory clinics to receive rapid antigen tests. Although self-test kits and medical institution rapid antigen tests use the same method, accuracy differs depending on which part of the body and who collects the specimen.

Professor Lee Hyuk-min of the Department of Laboratory Medicine at Severance Hospital explained, "Even though rapid antigen tests use the same method, tests where healthcare professionals collect specimens from deep inside the nasal cavity (nasopharynx) are about 10-20% more accurate than self-test kits."

This content was produced with the assistance of AI translation services.