Identification of severe acute respiratory syndrome in Canada.

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.

[1]  R. Sidwell,et al.  Inhibition of murine hepatitis virus infections by the immunomodulator 2,3,5,6,7,8-hexahydro-2-phenyl-8,8-dimethoxy-imidazo[1,2a]pyridine (PR-879-317A) , 1987, Antimicrobial Agents and Chemotherapy.

[2]  R. Weiss,et al.  Inhibitory effects of ribavirin alone or combined with human alpha interferon on feline infectious peritonitis virus replication in vitro☆ , 1989, Veterinary Microbiology.

[3]  D. W. Smith,et al.  A controlled trial of aerosolized ribavirin in infants receiving mechanical ventilation for severe respiratory syncytial virus infection. , 1991, The New England journal of medicine.

[4]  M. Lamy,et al.  The American-European Consensus Conference on ARDS. Definitions, mechanisms, relevant outcomes, and clinical trial coordination. , 1994, American journal of respiratory and critical care medicine.

[5]  T. Harder,et al.  There is nothing permanent except change. The emergence of new virus diseases , 1995, Veterinary Microbiology.

[6]  Michael A. Matthay,et al.  Acute respiratory distress syndrome , 1996, Nature reviews. Disease primers.

[7]  A. Falsey,et al.  The “Common Cold” in Frail Older Persons: Impact of Rhinovirus and Coronavirus in a Senior Daycare Center , 1997, Journal of the American Geriatrics Society.

[8]  J. Petitjean,et al.  [Human coronavirus infections: importance and diagnosis]. , 1998, Presse medicale.

[9]  Arthur S Slutsky,et al.  Multiple system organ failure. Is mechanical ventilation a contributing factor? , 1998, American journal of respiratory and critical care medicine.

[10]  C L Bartlett,et al.  Risk factors for community-acquired pneumonia diagnosed upon hospital admission. British Thoracic Society Pneumonia Study Group. , 2000, Respiratory medicine.

[11]  J. Arnold,et al.  The broad-spectrum antiviral ribonucleoside ribavirin is an RNA virus mutagen , 2000, Nature Medicine.

[12]  D. Schoenfeld,et al.  Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome. , 2000, The New England journal of medicine.

[13]  T. Kuiken,et al.  A newly discovered human pneumovirus isolated from young children with respiratory tract disease , 2001, Nature Medicine.

[14]  G. Rodier,et al.  Hot spots in a wired world: WHO surveillance of emerging and re-emerging infectious diseases. , 2001, The Lancet. Infectious diseases.

[15]  J. Bartlett,et al.  Once-Daily Valacyclovir to Reduce the Risk of Transmission of Genital Herpes , 2004 .

[16]  Philip K. Russell,et al.  Hemorrhagic fever viruses as biological weapons: medical and public health management. , 2002, JAMA.

[17]  L. Anderson,et al.  Characterization of Human Metapneumoviruses Isolated from Patients in North America , 2002, The Journal of infectious diseases.

[18]  L. Anderson,et al.  Virological features and clinical manifestations associated with human metapneumovirus: a new paramyxovirus responsible for acute respiratory-tract infections in all age groups. , 2002, The Journal of infectious diseases.

[19]  S. Withers,et al.  Evidence of human metapneumovirus in Australian children , 2002, The Medical journal of Australia.

[20]  S. Twu,et al.  Update: outbreak of severe acute respiratory syndrome--worldwide, 2003. , 2003, MMWR. Morbidity and mortality weekly report.

[21]  J. Gerberding,et al.  Update: Outbreak of severe acute respiratory syndrome--worldwide, 2003. , 2003, MMWR. Morbidity and mortality weekly report.

[22]  A. Hart,et al.  Human Metapneumovirus in Severe Respiratory Syncytial Virus Bronchiolitis , 2003, Emerging infectious diseases.

[23]  Arthur S Slutsky,et al.  Injurious mechanical ventilation and end-organ epithelial cell apoptosis and organ dysfunction in an experimental model of acute respiratory distress syndrome. , 2003, JAMA.