title: Clinical Presentation and Outcomes of Middle East Respiratory Syndrome in the Republic of Korea.
abstract: BACKGROUND
  From May to July 2015, the Republic of Korea experienced the largest outbreak of Middle East respiratory syndrome (MERS) outside the Arabian Peninsula. A total of 186 patients, including 36 deaths, had been diagnosed with MERS-coronavirus (MERS-CoV) infection as of September 30th, 2015.
  
  
  METHODS
  We obtained information of patients who were confirmed to have MERS-CoV infection. MERS-CoV infection was diagnosed using real-time reverse-transcriptase polymerase chain reaction assay.
  
  
  RESULTS
  The median age of the patients was 55 years (range, 16 to 86). A total of 55.4% of the patients had one or more coexisting medical conditions. The most common symptom was fever (95.2%). At admission, leukopenia (42.6%), thrombocytopenia (46.6%), and elevation of aspartate aminotransferase (42.7%) were observed. Pneumonia was detected in 68.3% of patients at admission and developed in 80.8% during the disease course. Antiviral agents were used for 74.7% of patients. Mechanical ventilation, extracorporeal membrane oxygenation, and convalescent serum were employed for 24.5%, 7.1%, and 3.8% of patients, respectively. Older age, presence of coexisting medical conditions including diabetes or chronic lung disease, presence of dyspnea, hypotension, and leukocytosis at admission, and the use of mechanical ventilation were revealed to be independent predictors of death.
  
  
  CONCLUSIONS
  The clinical features of MERS-CoV infection in the Republic of Korea were similar to those of previous outbreaks in the Middle East. However, the overall mortality rate (20.4%) was lower than that in previous reports. Enhanced surveillance and active management of patients during the outbreak may have resulted in improved outcomes.
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Won Suk
authors.initials: WS
authors.lastname: Choi
authors.affiliation: Division of Infectious Diseases, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Cheol-In
authors.initials: CI
authors.lastname: Kang
authors.affiliation: Center for Infectious Disease, National Medical Center, Seoul, Korea.
authors.forename: Yonjae
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul Medical Center, Seoul, Korea.
authors.forename: Jae-Phil
authors.identifier: 0000-0003-4805-7930
authors.initials: JP
authors.lastname: Choi
authors.affiliation: Respiratory Center, National Medical Center, Seoul, Korea.
authors.forename: Joon Sung
authors.initials: JS
authors.lastname: Joh
authors.affiliation: Center for Infectious Disease, National Medical Center, Seoul, Korea.
authors.forename: Hyoung-Shik
authors.initials: HS
authors.lastname: Shin
authors.affiliation: Center for Infectious Disease, National Medical Center, Seoul, Korea.
authors.forename: Gayeon
authors.initials: G
authors.lastname: Kim
authors.affiliation: Division of Infectious Diseases, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Kyong Ran
authors.initials: KR
authors.lastname: Peck
authors.affiliation: Division of Infectious Diseases, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Doo Ryeon
authors.initials: DR
authors.lastname: Chung
authors.affiliation: Department of Internal Medicine, Seoul Medical Center, Seoul, Korea.
authors.forename: Hye Ok
authors.initials: HO
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul Medical Center, Seoul, Korea.
authors.forename: Sook Hee
authors.initials: SH
authors.lastname: Song
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, Uijeongbu St. Mary's Hospital, The Catholic University of Korea, Uijeongbu, Korea.
authors.forename: Yang Ree
authors.initials: YR
authors.lastname: Kim
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, Chungnam National University School of Medicine, Daejon, Korea.
authors.forename: Kyung Mok
authors.initials: KM
authors.lastname: Sohn
authors.affiliation: Department of Internal Medicine, Hallym University Sacred Heart Hospital, Anyang, Korea.
authors.forename: Younghee
authors.initials: Y
authors.lastname: Jung
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Ji Hwan
authors.initials: JH
authors.lastname: Bang
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Nam Joong
authors.initials: NJ
authors.lastname: Kim
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, Seonam University Myongji Hospital, Goyang, Korea.
authors.forename: Kkot Sil
authors.initials: KS
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Chungbuk National University College of Medicine, Cheongju, Korea.
authors.forename: Hye Won
authors.initials: HW
authors.lastname: Jeong
authors.affiliation: Department of Internal Medicine, Dankook University College of Medicine, Cheonan, Korea.
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Rhee
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Eu Suk
authors.initials: ES
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Hallym University College of Medicine, Chuncheon, Korea.
authors.forename: Heungjeong
authors.initials: H
authors.lastname: Woo
authors.affiliation: Department of Internal Medicine, Kangwon National University School of Medicine, Chuncheon, Korea.
authors.forename: Won Sup
authors.initials: WS
authors.lastname: Oh
authors.affiliation: Division of Infectious Diseases and Office of Infection Control, Armed Forces Capital Hospital, Seongnam, Korea.
authors.forename: Kyungmin
authors.initials: K
authors.lastname: Huh
authors.affiliation: Department of Internal Medicine, Dongguk University College of Medicine, Gyeongju, Korea.
authors.forename: Young Hyun
authors.initials: YH
authors.lastname: Lee
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Joon Young
authors.initials: JY
authors.lastname: Song
authors.affiliation: Department of Internal Medicine, Hallym University College of Medicine, Chuncheon, Korea.
authors.forename: Jacob
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Chonbuk National University Medical School and Research Institute of Clinical Medicine of Chonbuk National University Hospital, Korea.
authors.forename: Chang-Seop
authors.initials: CS
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Inje University Sanggye-Paik Hospital, Seoul, Korea.
authors.forename: Baek-Nam
authors.initials: BN
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Young Hwa
authors.initials: YH
authors.lastname: Choi
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Gangnam Severance Hospital, Seoul, Korea.
authors.forename: Su Jin
authors.initials: SJ
authors.lastname: Jeong
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, Inha University College of Medicine, Incheon, Korea.
authors.forename: Jin-Soo
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Eulji University School of Medicine, Daejeon, Korea.
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Yoon
authors.affiliation: Department of Internal Medicine, Samsung Changwon Hospital, Changwon, Korea.
authors.forename: Yu Mi
authors.initials: YM
authors.lastname: Wi
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, Busan Medical Centre, Busan, Korea.
authors.forename: Mi Kyong
authors.initials: MK
authors.lastname: Joung
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, Dongguk University Ilsan Hospital, Goyang, Korea.
authors.forename: Seong Yeon
authors.initials: SY
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea.
authors.forename: Sun Hee
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Infectious Diseases, Chonnom National University Medical School, Gwangju, Korea.
authors.forename: Sook-In
authors.initials: SI
authors.lastname: Jung
authors.affiliation: Department of Internal Medicine, Kyungpook National University, School of Medicine, Daegu, Korea.
authors.forename: Shin-Woo
authors.initials: SW
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Wonkwang University College of Medicine, Iksan, Korea.
authors.forename: Jae Hoon
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Dong-A University College of Medicine, Busan, Korea.
authors.forename: Hyuck
authors.initials: H
authors.lastname: Lee
authors.affiliation: Division of Infectious Diseases, Konkuk University Hospital, Seoul, Korea.
authors.forename: Hyun Kyun
authors.initials: HK
authors.lastname: Ki
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, Chungnam National University School of Medicine, Daejon, Korea.
authors.forename: Yeon-Sook
authors.identifier: 0000-0003-1142-5488
authors.initials: YS
authors.lastname: Kim
keywords: Middle East respiratory syndrome; Republic of Korea