A comparison of bacteremic pneumococcal pneumonia with nonbacteremic community-acquired pneumonia of any etiology--results from a Canadian multicentre study.

BACKGROUND: Bacteremic pneumococcal pneumonia has not been the subject of a multicentre Canadian Study.
OBJECTIVES: To compare bacteremic community-acquired Streptococcus pneumoniae pneumonia with nonbacteremic community-acquired pneumonia of any etiology.
METHODS: A prospective cohort study was conducted at 15 centres in eight Canadian provinces from January 1996 to January 1998.
RESULTS: Fifty-six of the 450 patients (12.4%) had one or more blood cultures positive for S pneumoniae. Compared with the 394 blood culture-negative patients, the bacteremic patients were younger (55.6 years versus 63.4 years; P=0.002). At presentation, bacteremic patients had a higher mean oral temperature (38.1+/-1.2 degrees C versus 37.7+/-1.2 degrees C; P=0.026), a higher pulse rate (108.4+/-22.1 beats/min versus 102.1+/-20.6 beats/min; P=0.033), a lower diastolic blood pressure reading (66.8+/-12.7 mmHg versus 73.8+/-15.8 mmHg; P=0.001) and a higher percentage of white blood cells that were band forms (22.1% versus 14.2%; P=0.0007). The time from onset of symptoms until admission to hospital was shorter among the bacteremic patients (4.6+/-3.7 days versus 7.0+/-13.9 days; P=0.005). Three capsular polysaccharide types accounted for 53.4% of the isolates: type 14, 29.2%; type 4, 12.1%; and type 22 F, 12.1%. Two of 44 isolates were resistant to penicillin.
CONCLUSIONS: While some differences in patient characteristics and presentation occur when patients with bacteremic pneumococcal pneumonia are compared with nonbacteremic patients with community-acquired pneumonia, there is considerable overlap, and clinical presentation does not allow one to distinguish the bacteremic patients from the nonbacteremic patients.