Epidemiological Characteristics of COVID-19 Outbreak at Fitness
Total Page:16
File Type:pdf, Size:1020Kb
J Korean Med Sci. 2020 Aug 10;35(31):e288 https://doi.org/10.3346/jkms.2020.35.e288 eISSN 1598-6357·pISSN 1011-8934 Original Article Epidemiological Characteristics of Infectious Diseases, Microbiology & Parasitology COVID-19 Outbreak at Fitness Centers in Cheonan, Korea Sanghyuk Bae ,1 Hwami Kim ,2 Tae-Young Jung ,3 Ji-Ae Lim ,3 Da-Hye Jo ,3 Gi-Seok Kang ,3 Seung-Hee Jeong ,3 Dong-Kwon Choi ,3 Hye-Jin Kim ,3 Young Hee Cheon ,3 Min-kyo Chun ,4 Miyoung Kim ,2 Siwon Choi ,2 Chaemin Chun ,2 Seung Hwan Shin ,2 Hee Kyoung Kim ,2 Young Joon Park ,2 Ok Park ,2 and Ho-Jang Kwon 3,5 1Department of Preventive Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea 2Epidemiology & Case Management Team, COVID-19 National Emergency Response Center, Korea Centers for Disease Control and Prevention, Cheongju, Korea 3 Received: Jun 25, 2020 Chungnam Center for Infectious Diseases Control and Prevention, Hongseong, Korea 4 Accepted: Jul 31, 2020 Seosan Public Health Center, Seosan, Korea 5Department of Preventive Medicine, College of Medicine, Dankook University, Cheonan, Korea Address for Correspondence: Ho-Jang Kwon, MD, PhD Department of Preventive Medicine, College of ABSTRACT Medicine, Dankook University, 119 Dandae-ro, Cheonan 31116, Republic of Korea. E-mail: [email protected] Background: In February 2020, a coronavirus disease 2019 (COVID-19) outbreak was reported in fitness centers in Cheonan, Korea. Ok Park, MD, PhD, MPH Methods: From February 24 to March 13, an epidemiological investigation was conducted on Epidemiology & Case Management Team, the fitness center outbreak. All those who were screened were tested for severe acute respiratory COVID-19 National Emergency Response syndrome coronavirus-2 (SARS CoV-2) using real-time reverse transcriptase polymerase chain Center, Korea Centers for Disease Control and Prevention, 187 Osongsaengmyeong 2-ro, reaction. Contacts were traced and self-isolated for 14 days. We determined the epidemiological Osong-eup, Heungdeok-gu, Cheongju 28159, characteristics of confirmed cases of SARS-CoV-2 infection, and estimated the time-dependent Republic of Korea. reproduction number to assess the transmission dynamics of the infection. E-mail: [email protected] Results: A total of 116 cases were confirmed, and 1,687 contacts were traced. The source © 2020 The Korean Academy of Medical cases were 8 Zumba instructors who led aerobics classes in 10 fitness centers, and had Sciences. the largest average number of contacts. A total of 57 Zumba class participants, 37 of their This is an Open Access article distributed family members, and 14 other contacts were confirmed as cases. The attack rate was 7.3%. under the terms of the Creative Commons The contacts at Zumba classes and homes had a higher attack rate than other contacts. The Attribution Non-Commercial License (https:// mean serial interval (± standard deviation) were estimated to be 5.2 (± 3.8) days. The time- creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial dependent reproduction number was estimated to be 6.1 at the beginning of the outbreak, use, distribution, and reproduction in any but it dropped to less than 1, 2 days after the epidemiological investigation was launched. medium, provided the original work is properly Conclusion: The results suggest that the COVID-19 outbreak was effectively contained with cited. rigorous contact tracing, isolating, and testing in combination with social distancing without a lock-down. ORCID iDs Sanghyuk Bae Keywords: Coronavirus; Disease Outbreak; Epidemiology; Basic Reproduction Number; https://orcid.org/0000-0002-4995-6543 Hwami Kim Fitness Centers https://orcid.org/0000-0003-1224-5745 Tae-Young Jung https://orcid.org/0000-0001-8444-8002 Ji-Ae Lim INTRODUCTION https://orcid.org/0000-0003-0623-2446 Da-Hye Jo Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome https://orcid.org/0000-0002-4975-8627 coronavirus 2 (SARS-CoV-2), and often presents with cough, fever, and shortness of breath. https://jkms.org 1/9 COVID-19 Outbreak at Fitness Centers in Cheonan, Korea Gi-Seok Kang The severity varies from mild discomfort to fatal, and according to the Korea Centers for https://orcid.org/0000-0002-4263-0487 Disease Control and Prevention (KCDC), the crude case fatality rate in Korea is reported to Seung-Hee Jeong be 3.02% among males and 1.91% among females as of May 2020.1 The first case in Korea, https://orcid.org/0000-0002-8306-6667 Dong-Kwon Choi identified on January 19, 2020, was a Chinese woman traveling from Wuhan, China. She 2 https://orcid.org/0000-0002-8827-1483 had fever of 38.3°C when she arrived at Incheon Airport, Korea. The 29th case reported in Hye-Jin Kim Korea was the first person who had not traveled to China, and the confirmation of this case https://orcid.org/0000-0001-9584-9784 was taken as a sign of imminent community spread. Soon, an outbreak at a church in Daegu Young Hee Cheon which involved the 31st reported case, and another outbreak at a local hospital in Cheongdo https://orcid.org/0000-0002-4394-0153 dramatically increased the number of cases diagnosed in Korea. On February 23, within a Min-kyo Chun https://orcid.org/0000-0001-8154-4701 week of the first outbreak, the Korean government raised its infectious disease alert level Miyoung Kim from Alert (Orange) to Serious (Red), and more people with respiratory symptoms were https://orcid.org/0000-0003-0441-3948 tested for SARS-CoV-2.3 Siwon Choi https://orcid.org/0000-0003-1279-3661 On February 24, the first cases were confirmed in Cheonan, Chunchungnam-do (province), Chaemin Chun https://orcid.org/0000-0002-0179-2420 a city with population of 650,000. An official epidemiological investigation was launched Seung Hwan Shin jointly by the Chungnam Center for Infectious Disease Control & Prevention and the KCDC, in https://orcid.org/0000-0003-3411-4455 cooperation with local governments. The number of cases in Cheonan increased rapidly, and Hee Kyoung Kim on February 27, 35 new cases were confirmed as having COVID-19. Among the newly confirmed https://orcid.org/0000-0002-6404-6687 cases, three with similar date of onset had reported attending the same fitness center. This was Young Joon Park the first clue, and an outbreak associated with Zumba classes in fitness centers was identified https://orcid.org/0000-0001-9697-4173 Ok Park in subsequent epidemiological investigations. As of March 11, a total of 116 cases of among https://orcid.org/0000-0002-9477-9523 instructors, students, their family members, and co-workers had been confirmed.4 Ho-Jang Kwon https://orcid.org/0000-0003-3029-5674 Zumba is an exercise fitness program which combines aerobic exercise with music, and 5 Disclosure Oriental and Latin dance moves. In the fitness centers where the Zumba classes were held, a The authors have no potential conflicts of large number of students had taken classes in a relatively crowded space, although ventilation interest to disclosure. systems were working properly. Zumba is one of the most popular high-impact physical activities,6 and it provides benefits regarding cardiovascular, respiratory and proprioceptive Author Contributions 7-9 10 Conceptualization: Bae S, Kwon HJ. Data functions. However, considering that COVID-19 is transmitted by droplet and fomites, curation: Kim H, Jung TY, Lim JA, Jo DH, Kang high-impact group exercise in a confined indoor space, such as a Zumba class, could provide GS, Jeong SH, Choi DK, Kim HJ, Cheon YH, an environment prone to easy transmission of SARS-CoV-2 infection, as the droplets Chun MK, Kim M, Choi S, Chun C, Shin SH, Kim produced by exhalation or cough of a patient during the exercise have higher chance of HK, Park YJ, Park O. Formal analysis: Bae S. reaching the nose, mouth or eye of other class participants directly, as well as remaining on Investigation: Kim H, Jung TY, Lim JA, Jo DH, the surface of the exercise equipment and later transmitted by contact. Kang GS, Jeong SH, Choi DK, Kim HJ, Cheon YH, Chun MK, Kim M, Choi S, Chun C, Shin SH, Kim HK, Park YJ, Park O. Methodology: Bae S, The staff of a hospital where some of the cases were treated have reported on the clinical Park O, Kwon HJ. Project administration: Park characteristics of 54 cases who were treated in their hospital.11 We included these cases in O, Kwon HJ. Supervision: Park O, Kwon HJ. our investigation. However, the previous report was not based on the results of the official Validation: Kim H, Park YJ, Park O, Kwon HJ. epidemiological investigation conducted by the KCDC, and it did not cover the all aspects Visualization: Bae S. Writing - original draft: Bae S, Kim H, Chun MK. Writing - review & of the outbreak, but described only a portion of the cases and contacts. In this report, we editing: Park YJ, Park O, Kwon HJ. describe the epidemiological characteristics of the COVID-19 outbreak at fitness centers in Cheonan, Korea, based on the official epidemiological investigation, and document the effectiveness of contact tracing and isolation at containing the outbreaks. https://jkms.org https://doi.org/10.3346/jkms.2020.35.e288 2/9 COVID-19 Outbreak at Fitness Centers in Cheonan, Korea METHODS Diagnostic sampling and testing From February 24 to March 13, 2020, all specimens of contacts were collected at designated screening centers/stations, based on the residential address of the contact. A total of 16 screening centers in 5 metropolitan cities/provinces, Cheonan and Asan in Chunchungnam- do, Sejong, Seoul, Daegu, and Gyeonggi-do, were visited by the contacts. In Sejong, Cheonan, and Asan, where most of the cases related to Zumba classes occurred, drive- through screening sites were opened on February 26 and 28, and March 3, respectively, and most contacts used this method.