title: Hospital outbreak of Middle East respiratory syndrome coronavirus.
abstract: BACKGROUND
  In September 2012, the World Health Organization reported the first cases of pneumonia caused by the novel Middle East respiratory syndrome coronavirus (MERS-CoV). We describe a cluster of health care-acquired MERS-CoV infections.
  
  
  METHODS
  Medical records were reviewed for clinical and demographic information and determination of potential contacts and exposures. Case patients and contacts were interviewed. The incubation period and serial interval (the time between the successive onset of symptoms in a chain of transmission) were estimated. Viral RNA was sequenced.
  
  
  RESULTS
  Between April 1 and May 23, 2013, a total of 23 cases of MERS-CoV infection were reported in the eastern province of Saudi Arabia. Symptoms included fever in 20 patients (87%), cough in 20 (87%), shortness of breath in 11 (48%), and gastrointestinal symptoms in 8 (35%); 20 patients (87%) presented with abnormal chest radiographs. As of June 12, a total of 15 patients (65%) had died, 6 (26%) had recovered, and 2 (9%) remained hospitalized. The median incubation period was 5.2 days (95% confidence interval [CI], 1.9 to 14.7), and the serial interval was 7.6 days (95% CI, 2.5 to 23.1). A total of 21 of the 23 cases were acquired by person-to-person transmission in hemodialysis units, intensive care units, or in-patient units in three different health care facilities. Sequencing data from four isolates revealed a single monophyletic clade. Among 217 household contacts and more than 200 health care worker contacts whom we identified, MERS-CoV infection developed in 5 family members (3 with laboratory-confirmed cases) and in 2 health care workers (both with laboratory-confirmed cases).
  
  
  CONCLUSIONS
  Person-to-person transmission of MERS-CoV can occur in health care settings and may be associated with considerable morbidity. Surveillance and infection-control measures are critical to a global public health response.
authors.affiliation: Global Center for Mass Gatherings Medicine, Ministry of Health, Riyadh, Saudi Arabia.
authors.forename: Abdullah
authors.initials: A
authors.lastname: Assiri
authors.forename: Allison
authors.initials: A
authors.lastname: McGeer
authors.forename: Trish M
authors.initials: TM
authors.lastname: Perl
authors.forename: Connie S
authors.initials: CS
authors.lastname: Price
authors.forename: Abdullah A
authors.initials: AA
authors.lastname: Al Rabeeah
authors.forename: Derek A T
authors.initials: DA
authors.lastname: Cummings
authors.forename: Zaki N
authors.initials: ZN
authors.lastname: Alabdullatif
authors.forename: Maher
authors.initials: M
authors.lastname: Assad
authors.forename: Abdulmohsen
authors.initials: A
authors.lastname: Almulhim
authors.forename: Hatem
authors.initials: H
authors.lastname: Makhdoom
authors.forename: Hossam
authors.initials: H
authors.lastname: Madani
authors.forename: Rafat
authors.initials: R
authors.lastname: Alhakeem
authors.forename: Jaffar A
authors.initials: JA
authors.lastname: Al-Tawfiq
authors.forename: Matthew
authors.initials: M
authors.lastname: Cotten
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Watson
authors.forename: Paul
authors.initials: P
authors.lastname: Kellam
authors.forename: Alimuddin I
authors.initials: AI
authors.lastname: Zumla
authors.forename: Ziad A
authors.initials: ZA
authors.lastname: Memish
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001483:Base Sequence; D017934:Coronavirus / Q000235:genetics* / Q000302:isolation & purification; D018352:Coronavirus Infections / Q000453:epidemiology / Q000635:transmission* / Q000821:virology; D003428:Cross Infection / Q000453:epidemiology / Q000635:transmission* / Q000821:virology; D004279:DNA, Viral / Q000032:analysis; D004196:Disease Outbreaks; D018562:Disease Transmission, Infectious; D005260:Female; D006801:Humans; D055256:Infectious Disease Incubation Period; D017758:Infectious Disease Transmission, Patient-to-Professional; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D010802:Phylogeny; D011024:Pneumonia, Viral / Q000453:epidemiology* / Q000635:transmission / Q000821:virology; D006435:Renal Dialysis; D012529:Saudi Arabia / Q000453:epidemiology
chemical_list: D004279:DNA, Viral