Severe acute respiratory syndrome (SARS) is an emerging infectious disease
that first manifested in humans in China in November 2002 and has subsequently
To describe the clinical characteristics and short-term outcomes of
SARS in the first large group of patients in North America; to describe how
these patients were treated and the variables associated with poor outcome.
Design, Setting, and Patients
Retrospective case series involving 144 adult patients admitted to 10
academic and community hospitals in the greater Toronto, Ontario, area between
March 7 and April 10, 2003, with a diagnosis of suspected or probable SARS.
Patients were included if they had fever, a known exposure to SARS, and respiratory
symptoms or infiltrates observed on chest radiograph. Patients were excluded
if an alternative diagnosis was determined.
Main Outcome Measures
Location of exposure to SARS; features of the history, physical examination,
and laboratory tests at admission to the hospital; and 21-day outcomes such
as death or intensive care unit (ICU) admission with or without mechanical
Of the 144 patients, 111 (77%) were exposed to SARS in the hospital
setting. Features of the clinical examination most commonly found in these
patients at admission were self-reported fever (99%), documented elevated
temperature (85%), nonproductive cough (69%), myalgia (49%), and dyspnea (42%).
Common laboratory features included elevated lactate dehydrogenase (87%),
hypocalcemia (60%), and lymphopenia (54%). Only 2% of patients had rhinorrhea.
A total of 126 patients (88%) were treated with ribavirin, although its use
was associated with significant toxicity, including hemolysis (in 76%) and
decrease in hemoglobin of 2 g/dL (in 49%). Twenty-nine patients (20%) were
admitted to the ICU with or without mechanical ventilation, and 8 patients
died (21-day mortality, 6.5%; 95% confidence interval [CI], 1.9%-11.8%). Multivariable
analysis showed that the presence of diabetes (relative risk [RR], 3.1; 95%
CI, 1.4-7.2; P = .01) or other comorbid conditions
(RR, 2.5; 95% CI, 1.1-5.8; P = .03) were independently
associated with poor outcome (death, ICU admission, or mechanical ventilation).
The majority of cases in the SARS outbreak in the greater Toronto area
were related to hospital exposure. In the event that contact history becomes
unreliable, several features of the clinical presentation will be useful in
raising the suspicion of SARS. Although SARS is associated with significant
morbidity and mortality, especially in patients with diabetes or other comorbid
conditions, the vast majority (93.5%) of patients in our cohort survived.
Published online May 6, 2003 (doi:10.1001/jama.289.21.JOC30885).