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.