title: Epidemiologic features of the first MERS outbreak in Korea: focus on Pyeongtaek St. Mary's Hospital.
abstract: OBJECTIVE
  This study investigated the epidemiologic features of the confirmed cases of Middle East Respiratory Syndrome (MERS) in Pyeongtaek St. Mary's Hospital, where the outbreak first began, in order to identify lessons relevant for the prevention and control of future outbreaks.
  
  
  METHODS
  The patients' clinical symptoms and test results were collected from their medical records. The caregivers of patients were identified by phone calls.
  
  
  RESULTS
  After patient zero (case #1) was admitted to Pyeongtaek St. Mary's Hospital (May 15-May 17), an outbreak occurred, with 36 cases between May 18 and June 4, 2015. Six patients died (fatality rate, 16.7%). Twenty-six cases occurred in the first-generation, and 10 in the second-generation. The median incubation period was five days, while the median period from symptom onset to death was 12.5 days. While the total attack rate was 3.9%, the attack rate among inpatients was 7.6%, and the inpatients on the eighth floor, where patient zero was hospitalized, had an 18.6% attack rate. In contrast, caregivers and medical staff showed attack rates of 3.3% and 1.1%, respectively.
  
  
  CONCLUSIONS
  The attack rates were higher than those of the previous outbreaks in other countries. The outbreak spread beyond Pyeongtaek St. Mary's Hospital when four of the patients were moved to other hospitals without appropriate quarantine. The best method of preventing future outbreaks is to overcome the vulnerabilities observed in this outbreak, such as ward crowding, patient migration without appropriate data sharing, and the lack of an initial broad quarantine.
authors.affiliation: Division of Epidemic Intelligence Service, Korea Centers for Disease Control and Prevention, Cheongju, Korea.
authors.forename: Kyung Min
authors.initials: KM
authors.lastname: Kim
authors.affiliation: Department of Cancer Control and Policy, Graduate School of Cancer Science and Policy, National Cancer Center, Goyang, Korea.
authors.forename: Moran
authors.initials: M
authors.lastname: Ki
authors.affiliation: Graduate School of Public Health and Institute of Health and Environment, Seoul National University, Seoul, Korea.
authors.forename: Sung-Il
authors.initials: SI
authors.lastname: Cho
authors.affiliation: Department of Architectural Engineering, Sejong University, Seoul, Korea.
authors.forename: Minki
authors.initials: M
authors.lastname: Sung
authors.affiliation: Department of HVAC & Firefighting Engineering, Gachon University College of Engineering, Seongnam, Korea.
authors.forename: Jin Kwan
authors.initials: JK
authors.lastname: Hong
authors.affiliation: Department of Social and Preventive Medicine, Sungkyunkwan University School of Medicine, Suwon, Korea.
authors.forename: Hae-Kwan
authors.initials: HK
authors.lastname: Cheong
authors.affiliation: Department of Social and Preventive Medicine, Sungkyunkwan University School of Medicine, Suwon, Korea.
authors.forename: Jong-Hun
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Division of Malaria and Parasitic Diseases, Korea Centers for Disease Control and Prevention, Cheongju, Korea.
authors.forename: Sang-Eun
authors.initials: SE
authors.lastname: Lee
authors.affiliation: Division of Epidemic Intelligence Service, Korea Centers for Disease Control and Prevention, Cheongju, Korea.
authors.forename: Changhwan
authors.initials: C
authors.lastname: Lee
authors.affiliation: Division of Epidemic Intelligence Service, Korea Centers for Disease Control and Prevention, Cheongju, Korea.
authors.forename: Keon-Joo
authors.initials: KJ
authors.lastname: Lee
authors.affiliation: Division of Epidemic Intelligence Service, Korea Centers for Disease Control and Prevention, Cheongju, Korea.
authors.forename: Yong-Shik
authors.initials: YS
authors.lastname: Park
authors.affiliation: Division of Epidemic Intelligence Service, Korea Centers for Disease Control and Prevention, Cheongju, Korea.
authors.forename: Seung Woo
authors.initials: SW
authors.lastname: Kim
authors.affiliation: Department of Preventive Medicine, Hanyang University College of Medicine, Seoul, Korea.
authors.forename: Bo Youl
authors.initials: BY
authors.lastname: Choi
keywords: Epidemiology; Korea; Middle East Respiratory Syndrome coronavirus; Nosocomial infection; Outbreak; Quarantine