Infectivity of Coronavirus Disease 2019: A Prospective Cohort Study in the Korean Metropolitan Area.

BACKGROUND: Although several characteristics of coronavirus disease 2019 (COVID-19), an ongoing pandemic disease, have been identified, data on the infectivity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are limited. METHODS: This prospective cohort study was conducted to analyze the infectivity of SARS-CoV-2 based on data of all patients diagnosed with COVID-19 confirmed using real-time polymerase chain reaction test from January to April 2020 in Gyeonggi-do, the largest province in Korea. RESULTS: Of the 502 patients, 298 consisting of 106 clusters with 5,909 contacts were included. Of these, 277 (93.0%) were symptomatic, and the most common symptoms were cough, fever, sputum, sore throat, and headache. A total of 94 patients (31.5%) had pneumonia, while 8 (2.7%) died during the follow-up period. The secondary attack rate (SAR) in the study population was 3.5% (204/5,909). In exposure settings, the SAR was higher in religious gathering (13.5% [95% confidence interval, 10.7-16.8%]), workplaces (8.49% [95% CI, 6.08-11.74%]), and schools (6.38% [95% CI, 3.39-11.69%]) than in health care facilities (1.92% [95% CI, 1.45-2.55%]). Sore throat at any period, dyspnea at diagnosis or any period, lower cycle threshold value in the lower respiratory tract samples, leukocytosis, and higher bilirubin levels were associated with higher infectivity of COVID-19. The presence of symptoms was not related to the infectivity. CONCLUSION: In establishing the infection control strategies for COVID-19, the variables associated with high infectivity may be considered.

Clinical and Laboratory Factors Associated with Symptom Development in Asymptomatic COVID-19 Patients at the Time of Diagnosis.

In preparation for the surge of coronavirus disease 2019 (COVID-19), it is crucial to allocate medical resources efficiently for distinguishing people who remain asymptomatic until the end of the disease. Between January 27, 2020, and April 21, 2020, 517 COVID-19 cases from 13 healthcare facilities in Gyeonggi province, Korea, were identified out of which the epidemiologic and clinical information of 66 asymptomatic patients at the time of diagnosis were analyzed retrospectively. An exposure-diagnosis interval within 7 days and abnormal aspartate aminotransferase levels were identified as characteristic symptom development in asymptomatic COVID-19 patients. If asymptomatic patients without these characteristics at the time of diagnosis could be differentiated early, more medical resources could be secured for mild or moderate cases in this COVID-19 surge.

The Development and Operation of a Home Management System during the COVID-19 Pandemic: Experience of the Local Government Gyeonggi-do in Korea.

During the three the coronavirus disease 2019 (COVID-19) surges in South Korea, there was a shortage of hospital beds for COVID-19 patients, and as a result, there were cases of death while waiting for hospitalization. To minimize the risk of death and to allow those confirmed with COVID-19 to safely wait for hospitalization at home, the local government of Gyeonggi-do in South Korea developed a novel home management system (HMS). The HMS team, comprised of doctors and nurses, was organized to operate HMS. HMS provided a two-way channel for the taskforce and patients to monitor the severity of patient's condition and to provide healthcare counseling as needed. In addition, the HMS team cooperated with a triage/bed assignment team to expedite the response in case of an emergency, and managed a database of severity for real-time monitoring of patients. The HMS became operational for the first time in August 2020, initially managing only 181 patients; it currently manages a total of 3,707 patients. The HMS supplemented the government's COVID-19 confirmed case management framework by managing patients waiting at home for hospitalization due to lack of hospital and residential treatment center beds. HMS also could contribute a sense of psychological stability in patients and prevented the situation from worsening by efficient management of hospital beds and reduction of workloads on public healthcare centers. To stabilize and improve the management of COVID-19 confirmed cases, governments should organically develop self-treatment and HMS, and implement a decisive division of roles within the local governments.