Bacteremic pneumococcal pneumonia: a prospective study in Edmonton and neighboring municipalities

Abstract

Bacteremic pneumococcal pneumonia (BPP) is an important disease that should be frequently re-evaluated due to changes in demographics and recommended treatment. We conducted a prospective study from 2000 to 2002 in adults aged 17 years and over who presented to any of 6 hospitals and 1 freestanding emergency room in Edmonton, Alberta, with signs and symptoms compatible with pneumonia, a chest radiograph interpreted as pneumonia by the attending physician, and a positive blood culture for Streptococcus pneumoniae. We identified 129 patients with BPP, for an overall incidence of 9.7/100,000 person years. The rate was markedly higher among pregnant women, homeless persons, and those in prison. Sixteen percent were managed as outpatients, 61.2% as ward patients, and 22.5% required admission to the intensive care unit (ICU). Tobacco smoking was predictive of BPP, and antibiotic therapy before presentation was protective. According to pneumonia severity index, 47.3% were in low-risk classes I-III, 31.0% were in class IV, and 21.7% were in class V. Twelve (9.3%) patients died. Four died within 24 hours of arrival at hospital, and 2 had end-stage lung disease that resulted in a decision to discontinue therapy. Of the S. pneumoniae isolates, 12.5% were not susceptible to penicillin. The overall rate of BPP appears to be decreasing, although the rate is markedly increased in certain populations, which now should be targeted for vaccination. We identified 3 subsets of patients with BPP according to the site of care (ambulatory, ward, and ICU), with different outcomes.