[Q&A] "74 Cases of COVID-19 Re-Positivity... Plans to Establish Post-Quarantine Management Measures"

On the morning of the 8th, medical staff assigned to treat COVID-19 patients are heading to the negative pressure ward at Daegu Dongsan Hospital.

[Asia Economy Reporter Choi Dae-yeol] As of the 9th, a total of 74 COVID-19 patients who had been released from isolation have been found to have the virus reactivated. The quarantine authorities have decided to establish separate management policies and testing criteria, including additional isolation for a certain period after release from isolation.

On the 9th, Jung Eun-kyung, head of the Central Disease Control Headquarters, stated in a briefing, "There have been 65 confirmed cases of re-positivity after release from isolation until the previous day, and 74 cases as of midnight today." Currently, COVID-19 confirmed patients can be released from isolation only after symptoms improve and two PCR tests conducted 24 hours apart both return negative results. Asymptomatic patients must receive two PCR tests on the 7th day after confirmation and test negative.

Recently, the number of people testing positive again after release from isolation has been increasing, drawing attention from quarantine authorities. Similar cases have been reported overseas, including in China. Since there is no concern about virus transmission, isolation is lifted, but the virus reactivates afterward, raising concerns about infecting others nearby. Head Jung said, "We are conducting epidemiological and clinical information collection, virus testing, and serological testing on re-positive cases, and gathering expert opinions. We will promptly supplement management guidelines regarding isolation policies, testing criteria, and management measures after release from isolation."

The following is a Q&A with Head Jung at the briefing.

- The number of daily tests has dropped below 10,000. Is there a reason?

▲ The currently announced number of tests only counts those reported by medical institutions or public health centers for suspected patients. The actual number of tests conducted by contracted testing agencies or public health and environment research institutes is much higher. Cases related to overseas entrants or group outbreaks are partially excluded. We believe the decrease is due to the recent resolution of large-scale group outbreak cases.

- When will guidelines related to plasma therapy be released?

▲ With advice from the Korean Society of Transfusion Medicine and the Korean Society of Infectious Diseases, guidelines for plasma collection from COVID-19 recovered patients have been nearly finalized. Clinical treatment guidelines on how to apply plasma collection to which patients are still under expert review.

- How is the cost burden for pooled testing methods?

▲ Pooled testing will be used mainly by medical institutions and public health and environment research institutes for community group screening. The public health and environment research institutes do not bear per-test costs; kit usage costs are covered by national or local government budgets, so it does not affect actual test fees. Tests for suspected patients at medical institutions proceed under the existing fee system.

- How do you assess cases of re-positivity after release from isolation?

▲ (Professor Lee Hyuk-min, Yonsei University College of Medicine) Cases where patients test positive again after recovery and release from isolation can be considered reactivation. The virus decreases below measurable levels and then proliferates again for various reasons. If the illness was mild, immunity may not be fully developed, allowing reactivation after some time. The virus itself appears to have characteristics that cause some reactivation. In China, after release from isolation, a two-week self-quarantine is recommended, and patients are advised to visit medical institutions again at two and four weeks post-release for re-examination.

- How is the cause of death being determined for an 80-year-old patient in Gyeongbuk who died after recovery?

▲ The patient was confirmed positive on March 2 and received treatment, then was released from isolation on the 30th. The patient was transferred to another nursing hospital for treatment and later died. Rather than saying the patient died after recovery, it is more accurate to say the patient tested negative and was released from isolation, with no infectivity, and then transferred. The attending medical institution estimates the cause of death as related to COVID-19 and cerebrovascular disease. The exact cause will be reviewed by the Central Clinical Committee after receiving medical records and death certificates.

- How do you evaluate molecular diagnostic methods using existing tuberculosis diagnostic equipment and imported kits?

▲ (Professor Lee Hyuk-min) Rapid testing equipment like Expert or BioFire cannot perform mass testing and cannot currently replace molecular diagnostic methods. However, since samples can be processed immediately and results obtained within 45 minutes, they are very useful in emergency surgery cases. Domestic introduction is being considered for limited use.

- There are calls to investigate antibody positivity rates. Is this feasible at present?

▲ Since COVID-19 is a novel infectious disease, detailed information on how antibodies form after infection, how long they last, and whether they prevent reinfection is not yet confirmed. Research is ongoing. Preparations for antibody testing methods are also underway. We are examining ways to establish testing systems by studying antibody formation after infection and the significance of antibody presence more closely.

- Is the introduction of antigen and antibody testing methods instead of PCR testing being considered?

▲ (Professor Lee Hyuk-min) Accurate testing is necessary for emergency treatment of COVID-19 patients. Antigen and antibody tests, which show low sensitivity and specificity, are considered inappropriate as screening methods. Typically, antigen and antibody tests show about 50-70% sensitivity and specificity compared to molecular diagnostic methods. Especially, antibody tests can only diagnose from 7 to 14 days after symptom onset, so their performance is insufficient for accurate screening.

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