title: Identification of severe acute respiratory syndrome in Canada.
abstract: BACKGROUND
  Severe acute respiratory syndrome (SARS) is a condition of unknown cause that has recently been recognized in patients in Asia, North America, and Europe. This report summarizes the initial epidemiologic findings, clinical description, and diagnostic findings that followed the identification of SARS in Canada.
  
  
  METHODS
  SARS was first identified in Canada in early March 2003. We collected epidemiologic, clinical, and diagnostic data from each of the first 10 cases prospectively as they were identified. Specimens from all cases were sent to local, provincial, national, and international laboratories for studies to identify an etiologic agent.
  
  
  RESULTS
  The patients ranged from 24 to 78 years old; 60 percent were men. Transmission occurred only after close contact. The most common presenting symptoms were fever (in 100 percent of cases) and malaise (in 70 percent), followed by nonproductive cough (in 100 percent) and dyspnea (in 80 percent) associated with infiltrates on chest radiography (in 100 percent). Lymphopenia (in 89 percent of those for whom data were available), elevated lactate dehydrogenase levels (in 80 percent), elevated aspartate aminotransferase levels (in 78 percent), and elevated creatinine kinase levels (in 56 percent) were common. Empirical therapy most commonly included antibiotics, oseltamivir, and intravenous ribavirin. Mechanical ventilation was required in five patients. Three patients died, and five have had clinical improvement. The results of laboratory investigations were negative or not clinically significant except for the amplification of human metapneumovirus from respiratory specimens from five of nine patients and the isolation and amplification of a novel coronavirus from five of nine patients. In four cases both pathogens were isolated.
  
  
  CONCLUSIONS
  SARS is a condition associated with substantial morbidity and mortality. It appears to be of viral origin, with patterns suggesting droplet or contact transmission. The role of human metapneumovirus, a novel coronavirus, or both requires further investigation.
authors.affiliation: Toronto Medical Laboratories and Mount Sinai Hospital Department of Microbiology, Toronto, Canada.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Poutanen
authors.forename: Donald E
authors.initials: DE
authors.lastname: Low
authors.forename: Bonnie
authors.initials: B
authors.lastname: Henry
authors.forename: Sandy
authors.initials: S
authors.lastname: Finkelstein
authors.forename: David
authors.initials: D
authors.lastname: Rose
authors.forename: Karen
authors.initials: K
authors.lastname: Green
authors.forename: Raymond
authors.initials: R
authors.lastname: Tellier
authors.forename: Ryan
authors.initials: R
authors.lastname: Draker
authors.forename: Dena
authors.initials: D
authors.lastname: Adachi
authors.forename: Melissa
authors.initials: M
authors.lastname: Ayers
authors.forename: Adrienne K
authors.initials: AK
authors.lastname: Chan
authors.forename: Danuta M
authors.initials: DM
authors.lastname: Skowronski
authors.forename: Irving
authors.initials: I
authors.lastname: Salit
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Simor
authors.forename: Arthur S
authors.initials: AS
authors.lastname: Slutsky
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Doyle
authors.forename: Mel
authors.initials: M
authors.lastname: Krajden
authors.forename: Martin
authors.initials: M
authors.lastname: Petric
authors.forename: Robert C
authors.initials: RC
authors.lastname: Brunham
authors.forename: Allison J
authors.initials: AJ
authors.lastname: McGeer
mesh_terms: D000328:Adult; D000368:Aged; D002170:Canada / Q000453:epidemiology; D002910:Chronology as Topic; D016358:Contact Tracing; D003371:Cough / Q000209:etiology; D004196:Disease Outbreaks; D018450:Disease Progression; D004417:Dyspnea / Q000209:etiology; D005192:Family Health; D005260:Female; D005334:Fever / Q000209:etiology; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D011859:Radiography; D045169:Severe Acute Respiratory Syndrome / Q000150:complications / Q000453:epidemiology* / Q000635:transmission