"14 Days Passed vs Not Passed"…28th Patient, 'Incubation Period' Mystery (Update)

Medical staff are talking in the screening clinic at the National Medical Center. Photo by Hyunmin Kim kimhyun81@

[Asia Economy Reporter Kim Heung-soon] The 28th confirmed case of the novel coronavirus infection (Wuhan pneumonia) in South Korea (born in 1989, female of Chinese nationality) was confirmed positive after a total of three tests, as symptoms were not clearly manifested during the self-quarantine period. This patient was identified as an acquaintance of the 3rd confirmed case (54-year-old male, Korean) diagnosed on the 26th of last month. There is a possibility that the confirmation was made well beyond the previously known 14-day incubation period of the novel coronavirus, raising the incubation period as a point of contention. The quarantine authorities acknowledged this unusual situation but expressed a cautious stance, stating that further investigation is necessary.

According to the epidemiological investigation results of the 28th patient announced by the Korea Centers for Disease Control and Prevention (KCDC) Central Disease Control Headquarters on the 11th, this patient entered the country from Wuhan, China on the 20th of last month and was classified as a close contact of the 3rd confirmed case, thus placed under self-quarantine from the 26th of last month. The two visited a plastic surgery clinic together in Gangnam, Seoul on the 22nd of last month and again on the 24th. At that time, the 3rd patient had already shown symptoms such as fever and chills.

Jung Eun-kyung, Director of the KCDC, stated, "The 28th patient is an acquaintance who had close contact with the 3rd patient in Korea, and their movements almost coincide, so we judge that it is more likely that the infection was transmitted from the 3rd patient." Assuming infection from the 3rd patient, calculating from their last contact on the 25th of last month to the day before the confirmation on the 10th results in an incubation period of 17 days. This exceeds the generally known maximum incubation period of 14 days for the novel coronavirus. In China, research results have indicated that the incubation period can be as long as 24 days.

The quarantine authorities consider the start of the incubation period for the 28th patient as the beginning of self-quarantine on the 26th of last month. Therefore, the first diagnostic test was conducted on the 8th, after 14 days had passed, which yielded borderline positive and negative results, leading to a decision for retesting. Subsequently, while maintaining self-quarantine, two retests were conducted at 24-hour intervals on the 9th and 10th, which resulted in a positive diagnosis, and the patient was isolated at Myongji Hospital.

According to the quarantine authorities, the 28th patient reportedly did not have a fever during the self-quarantine period. Director Jung explained, "(The 28th patient) was receiving medical treatment unrelated to the novel coronavirus and was taking analgesic anti-inflammatory drugs and antibiotics," adding, "Being young and continuously taking analgesic anti-inflammatory drugs, the patient may not have felt symptoms such as fever, muscle pain, or sore throat."

Director Jung emphasized, "(The 28th patient) is a case that requires expert comparison and more detailed investigation to determine whether it is an asymptomatic infection or a mild onset within the incubation period that went unnoticed." She added, "Analyzing the epidemiological characteristics of domestic patients shows that the most common incubation period is about 3 to 4 days, and even the longest is analyzed to be within about 7 to 8 days. It is not appropriate to immediately change the incubation period standard to more than 14 days based on a single research result."

Meanwhile, the quarantine authorities revealed that there was one contact who lived with the 28th patient during the self-quarantine period, and this contact was confirmed negative after testing.

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