TY  - JOUR
AU  - Lee, Seung Won
AU  - Yuh, Woon Tak
AU  - Yang, Jee Myung
AU  - Cho, Yoon-Sik
AU  - Yoo, In Kyung
AU  - Koh, Hyun Yong
AU  - Marshall, Dominic
AU  - Oh, Donghwan
AU  - Ha, Eun Kyo
AU  - Han, Man Yong
AU  - Yon, Dong Keon
PY  - 2020
DA  - 2020/8/25
TI  - Nationwide Results of COVID-19 Contact Tracing in South Korea: Individual Participant Data From an Epidemiological Survey
JO  - JMIR Med Inform
SP  - e20992
VL  - 8
IS  - 8
KW  - COVID-19
KW  - contact tracing
KW  - coronavirus
KW  - South Korea
KW  - survey
KW  - health data
KW  - epidemiology
KW  - transmission
AB  - Background: Evidence regarding the effectiveness of contact tracing of COVID-19 and the related social distancing is limited and inconclusive. Objective: This study aims to investigate the epidemiological characteristics of SARS-CoV-2 transmission in South Korea and evaluate whether a social distancing campaign is effective in mitigating the spread of COVID-19. Methods: We used contract tracing data to investigate the epidemic characteristics of SARS-CoV-2 transmission in South Korea and evaluate whether a social distancing campaign was effective in mitigating the spread of COVID-19. We calculated the mortality rate for COVID-19 by infection type (cluster vs noncluster) and tested whether new confirmed COVID-19 trends changed after a social distancing campaign. Results: There were 2537 patients with confirmed COVID-19 who completed the epidemiologic survey: 1305 (51.4%) cluster cases and 1232 (48.6%) noncluster cases. The mortality rate was significantly higher in cluster cases linked to medical facilities (11/143, 7.70% vs 5/1232, 0.41%; adjusted percentage difference 7.99%; 95% CI 5.83 to 10.14) and long-term care facilities (19/221, 8.60% vs 5/1232, 0.41%; adjusted percentage difference 7.56%; 95% CI 5.66 to 9.47) than in noncluster cases. The change in trends of newly confirmed COVID-19 cases before and after the social distancing campaign was significantly negative in the entire cohort (adjusted trend difference –2.28; 95% CI –3.88 to –0.68) and the cluster infection group (adjusted trend difference –0.96; 95% CI –1.83 to –0.09). Conclusions: In a nationwide contact tracing study in South Korea, COVID-19 linked to medical and long-term care facilities significantly increased the risk of mortality compared to noncluster COVID-19. A social distancing campaign decreased the spread of COVID-19 in South Korea and differentially affected cluster infections of SARS-CoV-2. 
SN  - 2291-9694
UR  - http://medinform.jmir.org/2020/8/e20992/
UR  - https://doi.org/10.2196/20992
UR  - http://www.ncbi.nlm.nih.gov/pubmed/32784189
DO  - 10.2196/20992
ID  - info:doi/10.2196/20992
ER  -