[Q&A] New Coronavirus Can Infect Even Without Symptoms or With Mild Symptoms

Mild Symptoms in Patient No. 6, Two Family Members of Contact Confirmed Positive
"Asymptomatic Infection Cases Reported in Germany and China, Under Review"

A Korean Air charter flight carrying Korean residents from Wuhan, Hubei Province, China, where the novel coronavirus infection occurred, arrived at Gimpo International Airport in Gangseo-gu, Seoul on the 31st. Among the residents who completed departure procedures, those with fever are leaving the airport by ambulance. Photo by Kim Hyun-min kimhyun81@

[Asia Economy Reporter Choi Dae-yeol] On the 31st, the 12th day since the first confirmed case of the novel coronavirus infection (Wuhan pneumonia) in Korea, Director Jeong Eun-kyung of the Korea Centers for Disease Control and Prevention (KCDC) announced in a briefing that five additional confirmed cases were identified. After the secondary infection (patient No. 6), who contracted the virus without having traveled to China, was first confirmed the previous day, two family members among the contacts of this patient tested positive. Director Jeong stated that this is presumed to be tertiary infection. Below is the Q&A.

▲ Are the two family members of the sixth confirmed patient tertiary infections?

- Among the contacts of patient No. 6, two family members tested positive. Since these family members have no travel history, it is currently judged that they were infected by patient No. 6. At this point, it is considered a positive case among contacts of patient No. 6 and presumed to be tertiary infection. (The KCDC believes that patient No. 6 was infected while dining with the third confirmed patient at a restaurant.)

▲ Documents that appear to contain information about confirmed patients are circulating on the internet. Is this information accurate?

- We have not confirmed the circulating information. If it is found that accurate information has been leaked, we will strictly investigate the information leak, including requesting police investigation. To prevent further information leaks, local governments and central agencies will find ways to block it and strengthen information security.

▲ You mentioned it is presumed to be tertiary infection. Could this lead to a chain of infections?

- Among the newly added patients today, two (family members of patient No. 6) are believed to have been infected by patient No. 6 after patient No. 3 initially transmitted the virus to patient No. 6. This is considered a tertiary infection. Their symptoms are mild. One acquaintance among the contacts of patient No. 5 was confirmed positive. Regarding how transmissible the virus is as transmission progresses, since much about the novel coronavirus is still unknown, we need to observe further.

▲ Patient No. 6, who was infected while having lunch with patient No. 3 for about 1 hour and 30 minutes, was classified as a casual contact. How do you distinguish between casual and close contacts?

- Initially, patient No. 3’s contact range was set after the meal, and the meal itself was classified as casual contact. However, after tracking card usage and movement, it was determined that symptoms began around 1 p.m. that day, which led to an increase in the number of contacts. During the second investigation, the contact intensity of patient No. 6 should have been reclassified, but it was mistakenly managed as casual contact. Going forward, we will classify and manage contacts more strictly. There is an opinion that risk assessment should be redone and criteria for case definitions and contact management strengthened, so detailed measures are under review.

Jung Eun-kyung, Director of the Korea Disease Control and Prevention Agency

▲ Is infection possible without symptoms?

- This remains controversial. Some cases have been reported in Germany and China where exposure occurred during an asymptomatic period just before symptom onset. We are carefully analyzing such cases to determine how to assess exposure timing in epidemiological investigations. It is difficult to conclude that asymptomatic transmission is widespread, and this is under review.

▲ Is the virus spreading widely in the community?

- So far, confirmed cases have been identified among imported cases or within known contact ranges. Currently, transmission is occurring within families and acquaintances in a limited scope, so it is not considered widespread community transmission.

▲ Patient No. 3 visited a plastic surgery clinic with an acquaintance. How is that acquaintance being managed?

- Since they spent a lot of time together, the acquaintance is classified as a close contact and is under self-quarantine management.

▲ Human-to-human transmission has been confirmed. Are there any changes in domestic quarantine measures?

- So far, cases have occurred through contact with imported cases, and secondary transmission from domestic importation is the main characteristic. Since mid-January, people arriving from Wuhan have been considered high risk, and comprehensive investigations are underway. Over 500 screening clinics have been designated and are operating to detect patients early. Rapid differentiation and testing at screening clinics are the most important measures to detect cases early and reduce additional community exposure.

▲ What is the condition of the confirmed patients?

- Patient No. 4 is undergoing oxygen therapy due to pneumonia and is reported to be somewhat improved compared to yesterday. The other patients are hospitalized without severe symptoms and are receiving X-rays, basic tests, and treatment.

On the morning of the 31st, quarantine officials at Seoul Gimpo International Airport completed the quarantine of Korean residents returning by flight from Wuhan, Hubei Province, China, where the novel coronavirus infection (Wuhan pneumonia) occurred, and were leaving the airport. Photo by Kim Hyun-min kimhyun81@

▲ Patient No. 6 is said to have mild symptoms. Can infection still occur around them in such a state?

- The attending physician is currently investigating past medical history and symptoms. On the 26th, three days before confirmation, the patient had slight flu-like symptoms but they were not severe and improved quickly. The patient said it felt like that because of exercising outdoors. There were no other special symptoms until today, when a slight fever was noted.

▲ Since when has the new testing method been applied?

- The seven patients confirmed until yesterday were tested using the existing method. The four patients confirmed afterward, including patient No. 8 and three contacts, were tested using the new method.

▲ What is the condition of the Wuhan evacuees who arrived today?

- The 18 people transferred to hospitals are currently undergoing admission procedures. After admission, they will be placed in negative pressure isolation rooms and immediately tested. No patients are showing severe symptoms. Those moving to temporary living facilities will undergo specimen collection for comprehensive testing. They waited a long time at the airport, had a flight, and could not rest, so some may have elevated temperatures or other symptoms due to tension. The 350 people entering temporary facilities will be tested individually, and results are expected in about two days.

▲ Among the Wuhan evacuees, 18 were reported symptomatic. What symptoms do they have?

- At the Chinese airport, health questionnaires were used before boarding. Twelve people reported symptoms such as abdominal pain, diarrhea, cough, or sore throat. One had a fever, but it did not exceed the criteria of China or Korea, so the doctor allowed boarding. Using a contact thermometer (tympanic thermometer), those with 37.5℃ or higher were classified as symptomatic, but none met this criterion at that time. No additional tests were done on the plane. Upon arrival at Gimpo Airport, individual temperatures were taken with a tympanic thermometer, and six more were classified as symptomatic for exceeding 37.5℃. Fourteen were transferred to the National Medical Center, and four to Chung-Ang University Hospital.

Overseas Koreans who returned from Wuhan, China by chartered flight are moving to a temporary accommodation set up at the Chungnam Asan Police Human Resources Development Institute on the 31st.
Photo by Jinhyung Kang, Asan aymsdream@