Clinical Characteristics and Outcomes of COVID-19 Cohort Patients in Daegu Metropolitan City Outbreak in 2020

Abstract

Background: A coronavirus disease 2019 (COVID-19) outbreak started in February 2020 and was controlled at the end of March 2020 in Daegu, the epicenter of the coronavirus outbreak in Korea. The aim of this study was to describe the clinical course and outcomes of patients with COVID-19 in Daegu. Methods: In collaboration with Daegu Metropolitan City and Korean Center for Diseases Control, we conducted a retrospective, multicenter cohort study. Demographic, clinical, treatment, and laboratory data, including viral RNA detection, were obtained from the electronic medical records and cohort database and compared between survivors and non-survivors. We used univariate and multi-variable logistic regression methods and Cox regression model and performed Kaplan-Meier analysis to determine the risk factors associated with the 28-day mortality and release from isolation among the patients. Results: In this study, 7,057 laboratory-confirmed patients with COVID-19 (total cohort) who had been diagnosed from February 18 to July 10, 2020 were included. Of the total cohort, 5,467 were asymptomatic to mild patients (77.4%) (asymptomatic 30.6% and mild 46.8%), 985 moderate (14.0%), 380 severe (5.4%), and 225 critical (3.2%). The mortality of the patients was 2.5% (179/7,057). The Cox regression hazard model for the patients with available clinical information (core cohort) (n = 2,254) showed the risk factors for 28-day mortality: age > 70 (hazard ratio [HR], 4.219, P = 0.002), need for O 2 supply at admission (HR, 2.995; P = 0.001), fever (> 37.5°C) (HR, 2.808; P = 0.001), diabetes (HR, 2.119; P = 0.008), cancer (HR, 3.043; P = 0.011), dementia (HR, 5.252; P = 0.008), neurological disease (HR, 2.084; P = 0.039), heart failure (HR, 3.234; P = 0.012), and hypertension (HR, 2.160; P = 0.017). The median duration for release from isolation was 33 days (interquartile range, 24.0-46.0) in survivors. The Cox proportional hazard model for the long duration of isolation included severity, age > 70, and dementia. Conclusion: Overall, asymptomatic to mild patients were approximately 77% of the total cohort (asymptomatic, 30.6%). The case fatality rate was 2.5%. Risk factors, including older age, need for O 2 supply, dementia, and neurological disorder at admission, could help clinicians to identify COVID-19 patients with poor prognosis at an early stage.

Precautionary Behavior Practices and Psychological Characteristics of COVID-19 Patients and Quarantined Persons

“…The participants in this study were those who finished the treatment and, hence, pre-symptomatic patients were not included. The proportion of asymptomatic patients in the study was similar to the findings in a previous study, in which the proportion of asymptomatic cases was estimated by following-up with patients [ 4 ].…”

“…COVID-19 symptoms include fever, cough, fatigue, body aches, headache, sore throat, diarrhea, loss of taste, and loss of smell [ 3 ]. It is reported that, in most persons infected with SARS-CoV-2, the symptoms are mild or moderate, and approximately 30% of cases are asymptomatic [ 4 , 5 ]. In comparison to SARS and MERS, COVID-19 has a lower mortality rate, but its basic reproduction number (R 0 ) is reported to be as high as 2.87 (95% CI, 2.39–3.44) [ 5 ].…”

Neutralizing Antibody Responses to SARS-CoV-2 in Korean Patients Who Have Recovered from COVID-19

“…Daegu city was the first area where a severe COVID-19 outbreak was identified in the Republic of Korea from February to March 2020. 10 We screened recovered COVID-19 patients using the patient data registry from the Daegu Center for Infectious Diseases Control and Prevention. To confirm the possibility of participation in the study and to arrange blood sampling hospital visits, cellular phone text messages were sent to recovered COVID-19 patients in Daegu.…”

“…SARS-CoV-2 infection was confirmed by real-time reverse transcription-PCR assay performed using nasopharyngeal swabs or other upper respiratory tract specimens. 11 COVID-19 clinical severity classification was defined on the basis of clinical information as follows 10 : 1) asymptomatic, no symptoms or discomfort throughout the disease period, with body temperature <37.5℃; 2) mild, the presence of any symptoms with or without fever (≥37.5℃), but not manifesting pneumonia; 3) moderate, pneumonia diagnosed by a clinician, but not requiring oxygenation other than room air; 4) severe, pneumonia diagnosed by a clinician and requiring oxygenation therapy (nasal prong, facial mask, or high-flow oxygen therapy); and 5) critical, pneumonia diagnosed by a clinician and requiring mechanical ventilation therapy or extracorporeal membrane oxygenation or death. High NAb titer was defined as NAb titers higher than the median value.…”

Sources of Infection Among Confirmed Cases of COVID-19 in Jeju Province, Korea

“…Among cases with a source of infection from outside Jeju Province, four confirmed cases had visited Daegu during the first wave of the nationwide outbreak (February 18, 2020 to May 5, 2020), during which there was a large-scale outbreak centered around a specific church in Daegu [6]. During the second wave of the outbreak (August 12, 2020 to November 12, 2020), 33 individual and small-group cases were reported among those who had visited other provinces and those who had been in contact with confirmed cases in other provinces between July and September.…”