Nationwide Results of COVID-19 Contact Tracing in South Korea: Individual Participant Data From an Epidemiological Survey

Seung Won Lee; Woon Tak Yuh; Jee Myung Yang; Yoon-Sik Cho; In Kyung Yoo; Hyun Yong Koh; Dominic Marshall; Donghwan Oh; Eun Kyo Ha; Man Yong Han; Dong Keon Yon

doi:10.2196/20992

Nationwide Results of COVID-19 Contact Tracing in South Korea: Individual Participant Data From an Epidemiological Survey

JMIR Med Inform. 2020 Aug 25;8(8):e20992. doi: 10.2196/20992.

Authors

Seung Won Lee^#¹, Woon Tak Yuh^#², Jee Myung Yang^#³, Yoon-Sik Cho¹, In Kyung Yoo⁴, Hyun Yong Koh⁵, Dominic Marshall⁶, Donghwan Oh⁷, Eun Kyo Ha⁸, Man Yong Han⁹, Dong Keon Yon^{9

10}

Affiliations

¹ Department of Data Science, Sejong University College of Software Convergence, Seoul, Republic of Korea.
² Department of Neurosurgery, Seoul National University Hospital, Seoul, Republic of Korea.
³ Department of Ophthalmology, Asan Medical Center, Seoul, Republic of Korea.
⁴ Department of Gastroenterology, CHA Bundang Medical Center, Seongnam, Republic of Korea.
⁵ FM Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States.
⁶ Critical Care Research Group, Nuffield Department of Clinical Neurosciences, Oxford, United Kingdom.
⁷ Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
⁸ Department of Pediatrics, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Republic of Korea.
⁹ Department of Pediatrics, CHA Bundang Medical Center, CHA University School of Medicine, Seongnam, Republic of Korea.
¹⁰ Armed Force Medical Command, Republic of Korea Armed Forces, Seongnam, Republic of Korea.

^# Contributed equally.

PMID: 32784189
PMCID: PMC7470235
DOI: 10.2196/20992

Abstract

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.

Keywords: COVID-19; South Korea; contact tracing; coronavirus; epidemiology; health data; survey; transmission.

©Seung Won Lee, Woon Tak Yuh, Jee Myung Yang, Yoon-Sik Cho, In Kyung Yoo, Hyun Yong Koh, Dominic Marshall, Donghwan Oh, Eun Kyo Ha, Man Yong Han, Dong Keon Yon. Originally published in JMIR Medical Informatics (http://medinform.jmir.org), 25.08.2020.