A screening clinic in Yangcheon-gu, Seoul. The front of the inspection station is noisy. A six-year-old boy was crying all over. The child was not tested until the reporter went to the front of the inspection station from 20 meters behind. At first glance, hearing the story between the public health center staff and the child's parents, it seemed that the PCR test swab started crying as soon as it touched the nostril and screamed just by looking at the swab. About 10 minutes passed, and there was no sign of a solution. The child struggled, "I want to go home. I want to go home," trying to get out of the mother's arms. said a health care worker. "He's having a hard time, so I'll test it with his mouth."

In the past two years, I have been tested for Corona PCR more than 10 times. Almost every time I go to the screening clinic, I see this scene. A child who does not know what a PCR test is and follows her mother and then starts to cry and gets stabbed. (It is bittersweet, but there are quite a few children who are accustomed to receiving it among high school children and middle school students.) As the number of children and adolescents increases, the age of people visiting the screening clinic has also decreased. On portals and social media, articles such as 'testing stations that sting less painfully', 'places that do PCR by mouth', and 'how to get children to get PCR tests without getting sick' are also common. It would be nice not to be tested for the corona virus, but it may be unavoidable. (I've tried several ways to get a PCR test that is less painful on the market, and those that worked are added at the end of the article. Those who have to take it unavoidably, refer to it.)

The government predicts that the omicron mutation will spread rapidly and become the dominant species in Korea by the 21st.

It was predicted that the number of confirmed cases in a day could again exceed 7,000, and it was judged that the number of corona tests would greatly increase accordingly.

He also proposed a plan to reduce the self-quarantine period from the current 10 days to 7 days and to use rapid antigen testing widely instead of PCR testing.

There are growing calls to discuss the method of testing for corona again.

Any other test other than 'nose sting'?

PCR (Polymerase chain reaction), which has become a daily term familiar to all people during the Corona pandemic over the past two years, is 'polymerase chain reaction test' in Korean.

In the past, to determine whether a person was infected with a virus, the virus was isolated from a sample, cultured, and then confirmed using a diagnostic antibody.

Since this process takes a long time, there are many cases where an infectious disease has already been swept away by the results.

PCR is a technique that calls a small amount of specific DNA into a huge amount.

The lengthy inspection period has been reduced to just one day, enabling immediate quarantine and quarantine measures.

Usually, if you insert a cotton swab into your nose to collect a sample and analyze it, it usually comes out within 24 hours, or at the latest within 48 hours.

The PCR test has the highest accuracy and is mainly used in domestic diagnostic tests.

The next is 'saliva PCR' test using saliva.

It is a method in which the patient directly receives saliva from the mouth, collects it, and obtains the result through PCR test.

Finally, there is a 'rapid antigen test' that allows you to know the results within 30 minutes.

The method of pricking the nose with a cotton swab is the same as the nasopharyngeal examination, but instead of using the PCR method, the infection is checked immediately with a test kit.

The accuracy is lower than the nasal PCR test, and if the result is positive, the existing PCR test must be additionally performed.

In addition, self-test kits can be used to check for infection.

"I wish I could do it with my child's mouth..." The standard has become more strict

Corona infection can be confirmed by several methods mentioned above.

However, the only official confirmation of infection is a nasal PCR test.

Saliva test with saliva and rapid antigen test are not officially recognized by the government.

Vaccine pass is also not applicable.

In the nasal PCR test, the examiner inserts a sterile cotton swab deep inside the nose to the nasopharynx to collect the sample.

The mucous membrane inside the nose is soft and sensitive, so it is usually painful.

There are quite a few people who have suffered trauma after undergoing a PCR test.

So, more and more people are looking for a less painful way to collect mouth samples.

In particular, as the number of children and adolescents who are being tested for corona has recently increased, the number of parents who are looking for places where they can be tested by mouth has also increased.

PCR test, can I do it by mouth?

The answer is 'become'.

But it's not easy.

Let's take a look at the <Coronavirus Infectious Disease-19 Response Guidelines (for local governments) 10-3 Edition>, which was revised on November 26, last year.

It is indicated that both nasopharyngeal smear (nose) and oral smear (mouth) are possible as the type of sample odor.

However, if you look at the revised contents on January 3 this year, the item 'oral examination' disappeared.

Also, the contents of 'If it is difficult to test with the nose, such as for infants, do it with the mouth' was also deleted.

Instead, it has been modified to conduct oral examinations only in exceptional circumstances.

Exceptions are 'when it is difficult to insert a swab through the nose for surgical reasons', 'when it is difficult to perform a nasal examination due to communication difficulties', and 'when the nasal examination is not possible according to the judgment of the medical staff'.

[Click] Why do you insert the cotton swab so deep?

The nasopharyngeal space is damp, making it a good place for viruses to reside.

The nasopharyngeal test literally checks the virus through the nasopharyngeal mucosa.

What if the swab was taken from the nostril instead of deep?

Since the nasal hairs in the nostrils block bacteria from the outside, the probability of viruses resident is relatively low.

In other words, the accuracy of the results decreases.

For accurate test results, it is necessary to pierce deep into the nostrils.

"Maintain the PCR test as much as possible even if the response stage is switched"

The government has come up with a variety of response strategies, such as expanding rapid antigen testing and supporting the development of self-diagnosis kits with guaranteed accuracy whenever corona mutations appear.

Again, in response to the rapidly spreading omicron mutation, the company plans to increase the amount of PCR tests per day from the current 750,000 to 850,000.

It also announced a plan to expand the rapid antigen test in preparation for the test demand.

However, even if Omicron's 'response stage' is reached, with more than 7,000 new confirmed cases per day, the principle of allowing the existing PCR test to be carried out as much as possible has been adhered to.

The reason the government insists on nasal PCR testing is 'accuracy'.

An official from the Korea Centers for Disease Control and Prevention (KCDC) said, "Although other test methods can be used as ancillary depending on the situation, the existing PCR test with high accuracy is the official method of confirming the presence of infection."

According to the Korea Centers for Disease Control and Prevention (KCDC), the nasopharyngeal smear PCR test, which collects a sample by inserting a cotton swab deep into the nose, has a sensitivity (probability of determining positive as positive) of 98% or more and specificity (probability of determining negative as negative) of 100%. .

Although the salivary PCR test has 100% specificity, it has a sensitivity of 92%, which is inferior to that of nasopharyngeal smear PCR.

The rapid antigen test using the nasopharyngeal smear has a sensitivity of 90% and a specificity of 96%.

However, in the case of the rapid antigen test, the sensitivity may be further lowered depending on the test method such as nasal or saliva method, not nasopharyngeal smear.

Self-diagnosis kits differ from manufacturer to manufacturer, but there were cases where the sensitivity was actually lower than the sensitivity disclosed by the manufacturer.

In the results of a research team at Seoul National University Hospital published in the Journal of Korean Medicine, it was also reported that the sensitivity of a diagnostic kit from a domestic company was only 17.5%.

What happens because it's so accurate...

Even dead cells are 'positive'

It is true that nasal tests catch viruses well.

Viruses that enter the nose travel the most to cells inside the nose.

The virus travels through the nose and into the mouth, throat and lungs, where the amount decreases as it descends.

Therefore, it is most accurate to test the cells inside the nose with a cotton swab.

For oral examinations, cells inside the mouth are taken out or saliva or sputum is used.

The virus is also detected in saliva, but not as much as in the nose.

It goes without saying that the 'accuracy' of a test is important, but there are cases where it is accurate.

On the 8th, SBS medical reporter Cho Dong-chan said on the 8th news, "As the vaccination rate has increased, more people have immunity to the coronavirus. So, there are cases where the virus enters the nose and then dies. can pay,” he reported.

In fact, there are research results showing that many viruses from the nose are dead when cultured, and many viruses from saliva are live.

The 'saliva test' attracting attention...

Reduce medical overload

The salivary test is a method in which the examiner spits into the specimen container, and the test proceeds with that saliva.

Andrew Brooks, a professor of genetics at Rutgers University, and a research team led by the U.S. Food and Drug Administration (FDA) for the first time received emergency use approval in April last year.

Saliva testing can reduce medical overload by eliminating the need for medical staff to collect samples.

The nasal PCR test requires medical staff, but the saliva test requires only spitting and anyone can collect a sample.

Another advantage is that there is no need for separate facilities and quarantine measures.

The existing PCR test had a problem in that it could cause an aerosol that is easy to spread the virus by causing a patient to sneeze or cough during the test process.

In addition, there is a risk that the examiner may become infected through contact between the patient and the examiner during the sample collection process.

For this reason, medical personnel collect samples in a separate space and discard all medical tools such as protective clothing, gloves, and masks used during the collection process.

Since the salivary test does not have direct contact, the cost of this procedure can be saved.

One of the reasons for the European approval of the saliva test method is that the number of tests is rapidly increasing due to the recent corona virus resurgence in Europe.

A 'saliva test' is advantageous for asymptomatic or mild patients

Recently, research results are coming out one after another that a needle test, which was thought to be less accurate, may be better. A research team from Nagasaki University, Japan, published a study showing that saliva testing is better for asymptomatic or mildly confirmed patients.

In April 2020, a large-scale cruise ship 'Costa Atlantica', which was moored in Nagasaki Port, was infected with the coronavirus. At that time, asymptomatic or mild patients were isolated on board and treated. Medical staff compared and analyzed the test results of nasopharyngeal and saliva samples from asymptomatic or mild patients receiving isolation treatment. After testing positive, samples were collected on 25.5 days in the nasopharynx and 28.9 days in saliva. (The research team revealed that the samples could not be collected at the exact same time in a chaotic environment.) As a result of analysis of samples from 123 confirmed patients, the positive rate of the PCR test performed through the nose was 19.5% (24 people), and the saliva test was 38.2% (47 people) ) was. The saliva test was more sensitive to positive rates and viral load.

The research team emphasized that saliva testing is more advantageous to monitor the amount of virus detected in asymptomatic patients or mildly confirmed patients in the late stages of treatment. There are people who are at high risk of transmission because the virus is actively multiplying even if there are no symptoms. In this case, it can be interpreted to mean that the acupuncture test is more accurate.

There are similar studies in Korea.

Researchers at Daegu Medical Center recently published the results of a large-scale study on the usefulness of sputum and saliva testing.

For the first time in Korea, Daegu Medical Center compared the results of a sputum test and a conventional PCR test for patients visiting a screening clinic.

From February 12 to March 31, 2020, 3,390 patients were investigated, and when comparing the sensitivity of positive to positive, the existing PCR test was 94.4% and sputum was 91.6%, although there was no significant difference. did.

An increasing number of countries are also officially recognizing tests using acupuncture.

The United Kingdom and the United States allow children to be tested with acupuncture, and the United States, England, and Japan have optional acupuncture for adults.

Currently, Canada is also considering whether to allow saliva testing.

[Hot Tip] How to get PCR test less painful

The mucous membrane inside the nose is soft and sensitive, so it reacts sensitively to even small stimuli. However, if you insert it deep into the nostrils with a long cotton swab, it will inevitably hurt. If you search the Internet, there are quite a few articles and videos related to 'how to get PCR less painful'. (Based on the nasopharynx (nose)) There is even an article saying, 'If you go to a test center, it hurts less.' However, since the inspector is different each time, it is a realm of luck. There are individual differences, but the advice that the reporter has experienced is that 'don't move, hold your breath, and don't frown'. I can't forget the pain when I first got PCR. I was very nervous and took a step backwards, but I thought my nostrils were on fire. There was also a sting of blood from the mucous membrane of the nose. However, it was a lot less painful because I didn't move, hold my breath (or exhale), and grimaced.

According to the advice of the otolaryngologist, it hurts less if you poke it towards the nostrils with more space. The test swab goes along the bottom of the nose, between the nasal septum that divides the nostrils into two sides and the large mucous membrane called the inferior turbinate inside the nose. The reason why it is said that it is less painful to hold your breath if possible without moving ahead, not grimacing, is because this narrow space becomes narrower as you move, which causes pain. Since the direction of the nostrils is downward, if it goes in the direction of the nostrils, it may not enter the desired nasopharynx, but may prick the wrong place to collect an inaccurate sample or cause severe pain. So you have to tilt your head about 15 degrees.

[Composition: Senior Correspondent Lee Hyun-sik (D Content Production Committee member), Reporter Seon-i Jang / Designer: Ha-eun Myung, Jung-ha Park]