Effect of antibiotic streamlining on patient outcome in pneumococcal bacteraemia.

OBJECTIVES: In blood culture-proven pneumococcal infections, streamlining empirical therapy to monotherapy with a penicillin is preferred in order to reduce the use of broad-spectrum antibiotics. However, adherence to this international recommendation is poor, and curiously it is unclear whether antibiotic streamlining may be harmful to individual patients. We investigated whether streamlining in bacteraemic pneumococcal infections is associated with mortality. METHODS: Adults admitted to two Dutch hospitals between 2001 and 2011 with bacteraemic pneumococcal infections were retrospectively included. Detailed clinical data on patient characteristics, comorbidities and severity and outcome of disease were obtained in addition to data on antibiotic treatment. Those eligible for streamlining were selected for further analyses. RESULTS: In the 45.8% of cases (126 of 275) where antibiotic treatment was streamlined, a lower mortality rate was observed (6.3% versus 15.4%, P = 0.021). The decision to streamline was only marginally explained by the 38 determinants accounted for. After correction for potential confounders, the OR for death while streamlining was 0.45 (95% CI: 0.18-1.11, P = 0.082) in all cases and 0.35 (95% CI: 0.12-0.99, P = 0.048) specifically in pneumonia cases. CONCLUSIONS: Our results suggest that streamlining in eligible pneumococcal bacteraemia cases is safe, irrespective of patient characteristics, severity of disease or empirical treatment regimen.

Effects of 7-valent pneumococcal conjugate 1 vaccine on the severity of adult 2 bacteremic pneumococcal pneumonia.

PURPOSE: The introduction of a 7-valent conjugate pneumococcal vaccine (PCV7) in children largely affected the prevalence of adult pneumococcal pneumonia. In this study we investigated whether the clinical severity of adult bacteremic pneumococcal pneumonia has also altered following the introduction of pediatric PCV7 vaccination. METHODS: Adults hospitalized with bacteremic pneumococcal pneumonia between 2001 and June 2011 at two Dutch hospitals were included retrospectively. Clinical data on patient characteristics, comorbidities and severity of disease were obtained and pneumococcal serotypes were determined. RESULTS: Among 343 patients investigated, those infected with PCV7 serotypes had a higher PSI score (p=0.0072) and mortality rate (p=0.0083) compared with the remainder of the cohort. Since the introduction of PCV7 the proportion of pneumococcal pneumonias caused by serotypes 1 and 7F (p-values 0.037 and 0.025) increased, as well as the rate of pleural effusion and empyema (p-values 0.011 and 0.049). Whilst de proportion of adults infected with PCV7 serotypes decreased after the introduction of PCV7 (p=0.015), PSI scores in these patients remained higher (p=0.030), although mortality rates between PCV7 and non PCV7 types equalized. After the introduction of PCV7 a marked shortening in hospital stay was observed only among patients infected with non PCV7 serotypes (p=0.019). CONCLUSIONS: The introduction of pediatric PCV7 vaccination was accompanied by subtle changes in clinical severity of adult bacteremic pneumococcal pneumonia. Expansion of serotypes covered by pneumococcal vaccination may again influence the clinical presentation of disease.