Application of Testing-Tracing-Treatment Strategy in Response to the COVID-19 Outbreak in Seoul, Korea

Abstract

Background Following the coronavirus disease 2019 (COVID-19) outbreak in Wuhan, China, a total of 637 patients had been diagnosed with the disease in Seoul as of May 2, 2020. Our study aimed to describe the impact of the 3T strategies (preemptive testing, prompt tracing and proper treatment) on the epidemiological characteristics of COVID-19 in Seoul. Methods The descriptive and explanatory analysis was carried out on critical indicators such as epidemiological characteristics and key duration of patient status change from January 24 to May 2 in Seoul before and after preemptive testing for patients under investigation associated with COVID-19 clusters. Results Preemptive testing increased the positive test rate (3.9% to 4.2%), an asymptomatic case at diagnosis (16.9% to 30.6%), and reduced the time from symptom onset to quarantine (4.0 to 3.0 days). Prompt tracing decreased unknown sources of infection (6.9% to 2.8%), the mean number of contacts (32.2 to 23.6), and the time-varying reproduction number R(t) (1.3 to 0.6). With proper treatment, only 2 cases of mortality occurred, resulting in a fatality rate of just 0.3%. Conclusion In the first wave of the COVID-19 pandemic lasting 100 days, the effect of the 3T strategies flattened the curve and decreased the time during which infected individuals were contagious, thereby lowering the R(t) below 1 in Seoul.

Clinical Characteristics of COVID-19: Risk Factors for Early Oxygen Requirement after Hospitalization

“…The strategy of rapid tracking and mass diagnostic approaches not only prevents subsequent infections but also enables COVID-19 patients to be admitted quickly for standard care. 15 The patients with a definite exposure history tended to be diagnosed earlier, and their oxygen requirements were delayed. On the other hand, the early group tended to have an uncertain exposure history and was therefore not included in the active scope of tracking and diagnosis, which resulted in delayed diagnosis.…”

Preparing for the Coronavirus Disease (COVID-19) Vaccination: Evidence, Plans, and Implications

“…In response to COVID-19, Korea is actively using non-pharmaceutical interventions, such as stepwise social distancing. 2 73 In the first half of 2021, since vaccinations would not be available to the general population, social distancing should be followed until sufficient vaccination is achieved for the general population. However, social distancing entails enormous economic damage.…”

“… 1 In response to the pandemic, countries around the world have applied non-pharmaceutical interventions, such as quarantine, diagnostic testing, contact tracing, social distancing, and wearing masks. 2 Some countries have successfully blocked outbreaks, but most countries have just delayed the outbreak. When most pandemic infectious diseases spread in the community, the outbreak continues until herd immunity is established and several waves of the outbreak have occurred.…”

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

“… 4 A report that focused on the test, tracing and treatment of COVID-19 patients in Seoul was also published. 5 However, whole picture of Daegu COVID-19 outbreak, which is the first outbreak crisis in Korea, was not reported until now. Therefore, the aim of this study is to evaluate and describe the clinical characteristics, risk factors for the case fatality rate, and duration of isolation in patients with COVID-19 in Daegu Metropolitan City (February to June 2020) after making and clearing of Daegu COVID-19 cohort data.…”