[Comparison of severe acute respiratory syndrome with community-acquired pneumonia]

To study the features of severe acute respiratory syndrome (SARS) and community acquired pneumonia (CAP).

The clinical presentation, chest radiographs, white blood cell count and outcome of 45 SARS patients from April 5 to 20 2003 were compared, with those of 80 CAP patients from October 1 2002 to April 1 2003 in our hospital, and the clinical features of SARS were summarized.

(1) Fever above 38.5 centigrade, dry cough, short of breath, headache, myalgia, diarrhea in SARS were more common in SARS patients than those in CAP (P<0.01). (2) Leucopenia was more common and leukocytosis was less common in SARS than those in CAP (P<0.01). (3) 22.2 percent of SARS patients were found abnormal chest radiographs within 24 hours after onset, 71.1 percent of SARS patients were showed progressive pulmonary infiltration via serial chest radiographs, while all CAP patients had abnormal chest radiographs when they were seen first time, and no patient showed progressive pulmonary infiltration, the difference was significant between the two groups (P<0.01). (4) Patients with SARS were lack of a response to the initial antimicrobial therapy, all patients with CAP had an adequate clinical response within three days, the difference was significant between the two groups(P<0.01 ). (5) The ratio of severe pneumonia and mortality in SARS was much higher than in CAP (both P<0.01).

The clinical presentation, chest radiographs, white blood cell count, response to initial antimicrobial therapy, and outcome in SARS is much different from CAP, differentiate them will be helpful to early recognition, prompt isolation, and prevention of its spread.