Rapid antigen test ‘10% false negative rate’, increasing the burden on the medical system

Results in 15 minutes … More tests, ‘choice and focus’ may be missedExperts “restricted the use of places where there is concern about group infection”

As the ‘third Corona 19 epidemic’ accelerates, concerns have been raised among experts as the government decided to set up temporary screening clinics in areas where there are many young people and introduce rapid antigen tests to significantly expand diagnostic testing. .

At the Blue House meeting on the 9th, Chung Eun-kyung, director of the Korea Centers for Disease Control and Prevention, said: “We will establish temporary screening clinics in 150 locations, including university districts and the Seoul, where young people gather to block possible sources of infection in the metropolitan area. ” In addition, it has announced that it will allow test applicants to select a saliva test method and a rapid antigen test method in addition to the existing gene amplification test (PCR).

Rapid antigen testing has the advantage that it only takes 15 minutes to confirm the result after sample collection. The problem is that the probability of inaccurate results is significantly higher than that of the PCR test. The false negative rate for this test (the rate of positive but negative values) is known to be 10%, and the false positive rate (the rate of negative but positive values) reaches 4%. For this reason, many experts believe that rapid antigen testing should be used in places where there is a high risk of group infection from high-risk groups, such as nursing homes. In the case of a full introduction to screening clinics, it can only increase the load on the medical system.

Jeong Hyeong-jun, head of the policy committee of the Federation of Health and Medical Organizations, said: “Because people infected with false negative results can roam and become another transmission channel, most of them do not use tests rapid antigens except in places that have been ‘disrupted’ like the United States and Europe. ” He said: “The core of K’s quarantine is a 3T ‘Test-Trace-Treat’ strategy, and the introduction of this test makes the ‘Test’ process complicated.”

There is also an analysis that it will not help much in speed, which is the biggest advantage of the rapid antigen test. Im Seung-gwan, director of Anseong Hospital, Gyeonggi Medical Center, said: “The rapid antigen test should be observed for 10 minutes after the color of the reagent changes on the spot by the medical personnel who took the sample.” “You can say it is fast if you only count one sample, but for each individual sample more than 10 minutes. Considering what is needed, even if it takes 6 hours, it is difficult to say that it is much faster than PCR than can be run in bulk at a time “Director Lim said:” Rapid antigen tests can be useful if used on a limited basis in settings such as emergency rooms in small local hospitals far from PCR testing facilities, but not it’s appropriate to put more manpower into screening clinics. “

Experts also raised concerns about the government’s decision to significantly expand temporary street screening clinics to find asymptomatic patients. The 3T strategy is no longer valid because the number of confirmed cases per day exceeds 1000.

“The biggest crisis at the moment is that the healthcare system may collapse due to the inability to handle patients with symptoms, especially high-risk or severe patients,” said Bae Ban-hwan, Director of the Operations Center. of the Central Hospital for Infectious Diseases. It is only a quarter of those who suffer from the disease, and if labor and money are invested to find them, it could accelerate the collapse of the health care system. Now is the time to “pick and focus” to utilize limited medical resources. Kim Tak, professor of infectious medicine at Soonchunhyang University, also told his social networking service (SNS): “Even if you do a lot of testing now, it is not a situation that can be followed up and treated. I will not be able to bear it. .

On the other hand, Professor Kimoran from the National Cancer Center said: “To keep the positive rate, which is currently 4.8%, below 1%, we must significantly increase the number of tests.” Rather than a total lockdown, which has a significant social impact, evidence should be expanded to reduce the spread of asymptomatic infections. Professor Jeong Jae-hoon from the Department of Preventive Medicine at Gachon Medical University also told SNS: “We need to complement our ability to preventively perform comprehensive tests and diagnostic tests.” “The PCR test should be expanded more than the rapid antigen test.”