Invasive pneumococcal infections in children following transplantation in the pneumococcal conjugate vaccine era.

BACKGROUND: Pediatric recipients of hematopoietic stem cell and solid organ transplants are at increased risk of invasive pneumococcal infections (IPI). Data on IPI in this population are scarce. To our knowledge, this is the first study describing the epidemiology of IPI among pediatric transplant recipients in the pneumococcal conjugate vaccine (PCV) era. METHODS: We identified transplant recipients with IPI at 8 children's hospitals in the U.S. from our surveillance database (2000-2014). Pneumococcal isolates were collected prospectively. Serotyping and antibiotic susceptibility were performed in a central laboratory. Categorical variables were analyzed by Fisher's exact test and continuous variables with nonparametric tests. Indirect cohort study design was used to calculate vaccine effectiveness. RESULTS: We identified 65 episodes of IPI in transplant recipients. Recurrent IPI was observed in 10% of transplant recipients. The IPI crude incidence rate in solid organ transplant recipients was higher than in the general population. Most IPI episodes occurred >6 months after transplantation. Bacteremia and pneumonia were the most common presentations. Meningitis was unusual. No case fatalities were observed. Serotype 19A was the most common serotype (n=10), followed by 6C (n=7). In 2010-2014, 37% of IPI was caused by PCV13 serotypes. Four cases of vaccine breakthrough were identified. Most isolates were susceptible to penicillin and ceftriaxone. Pneumococcal conjugate and polysaccharide immunization rates were low. CONCLUSION: Pediatric transplant recipients remain at increased risk of IPI in the vaccine era. Most cases presented as a late post-transplant infection. The interval between transplantation and IPI may allow adequate time for pneumococcal immunization.

Antibiotic resistant infections due to Streptococcus pneumoniae: impact on therapeutic options and clinical outcome.

PURPOSE OF REVIEW: Streptococcus pneumoniae is a major cause of morbidity and mortality in the pediatric population. The development of increasing resistance to multiple classes of antibiotics is making treatment of infections due to this organism much more difficult. The ultimate impact of high-level antibiotic resistance on therapeutic options and clinical outcomes of various pneumococcal infections is unclear and remains to be determined. Use of the conjugate pneumococcal vaccine has markedly decreased invasive pneumococcal disease in children under 5 years of age; however, its impact on decreasing antibiotic resistance is currently unknown. RECENT FINDINGS: Studies suggest that response to therapy and clinical outcome of infections due to pneumococcal isolates with intermediate resistance to the beta-lactam antibiotics is no different from that of infections due to susceptible isolates. However, evidence is accumulating that infections caused by highly resistant pneumococcal isolates are associated with higher rates of treatment failure and mortality than infections due to susceptible strains. SUMMARY: Use of a conjugate pneumococcal vaccine in conjunction with educational intervention programs that promote appropriate and judicious antibiotic use is a safe and effective means of decreasing the prevalence of pneumococcal disease in the pediatric population, decreasing the use of broad-spectrum antibiotic agents and potentially decreasing the amount of antibiotic resistance currently being seen.