Bacteraemic pneumococcal disease in a teaching hospital in Finland

Obesity and smoking are factors associated with poor prognosis in patients with bacteraemia

Background

Bacteraemia is still a major cause of case fatality in all age groups. Our aim was to identify the major underlying conditions constituting risk factors for case fatality in bacteraemia patients.

Methods

The study involved 149 patients (79 male and 70 female) with bacteraemia caused by Staphylococcus aureus (S. aureus) (41 patients), Streptococcus pneumoniae (Str. pneumoniae) (42 patients), β-hemolytic streptococcae (β-hml str.) (23 patients) and Eschericia coli (E. coli) (43 patients). Underlying diseases, alcohol and tobacco consumption and body mass index (BMI) were registered. Laboratory findings and clinical data were registered on admission and 6 consecutive days and on day 10–14. Case fatality was studied within 30 days after positive blood culture. Associations between underlying conditions and case fatality were studied in univariate analysis and in a multivariate model.

Results

Nineteen patients (12.8%) died of bacteraemia. We found obesity (p = 0.002, RR 9.8; 95% CI 2.3 to 41.3), smoking (p < 0.001, RR 16.9; 95% CI 2.1 to 133.5), alcohol abuse (p = 0.008, RR 3.9; 95% CI 1.3 to 11.28), COPD (p = 0.01, RR 8.4; 95% CI 1.9 to 37.1) and rheumatoid arthritis (p = 0.045, RR 5.9; 95% CI 1.2 to 28.8) to be significantly associated with case fatality in bacteraemia in univariate model. The median BMI was significantly higher among those who died compared to survivors (33 vs. 26, p = 0.003). Obesity and smoking also remained independent risk factors for case fatality when their effect was studied together in a multivariate model adjusted with the effect of alcohol abuse, age (continuos variable), sex and causative organism.

Conclusion

Our results indicate that obesity and smoking are prominent risk factors for case fatality in bacteraemic patients. Identification of risk factors underlying fatal outcome in bacteraemia may allow targeting of preventive efforts to individuals likely to derive greatest potential benefit.

Bacteraemic pneumococcal infections in Southern Sweden 1981-96: trends in incidence, mortality, age-distribution, serogroups and penicillin-resistance

In a survey of pneumococcal blood isolates from patients in Southern Sweden, 560 isolates were found between 1981 and 1996. Between these years, the incidence of pneumococcal bacteraemia increased from 5.2 to 15.2/100,000/y. The eight most common serogroups/types (14, 7, 9, 6, 23, 3, 4 and 19) accounted for > 75% of the isolates, and 96.4% of the isolates were of serogroups/types represented in the present vaccine. A male preponderance (1.17:1) was noted, and the men were younger than the women (mean 57 vs 63 y of age; p < 0.05). The overall case-fatality rate during the period was 19%. Seven isolates with reduced susceptibility to penicillin were noted, all from 1991 to 1996. The increasing incidence of pneumococcal bacteraemia could not be explained by any of the following factors; age or sex of the patients, changes in prevailing serogroups/types, variations in vaccine use, emergence of penicillin-resistance, more liberal indications for blood cultures or improved culture methods.