Impact of the seven-valent pneumococcal conjugate vaccination (PCV7) programme on childhood hospital admissions for bacterial pneumonia and empyema in England: national time-trends study, 1997-2008.

BACKGROUND: Childhood bacterial pneumonia and empyema rates have reportedly increased in recent years in Europe. In September 2006 the seven-valent pneumococcal conjugate vaccination (PCV7) was introduced to the childhood national immunisation programme in England following a successful PCV7 campaign in the USA. The aim of this study was to report national time trends in hospital admissions for childhood bacterial pneumonia and empyema in England before and after the introduction of PCV7.
METHODS: A population-based time-trend analysis of Hospital Episode Statistics data of children aged <15 years admitted to all NHS hospitals in England, with a primary diagnosis of bacterial pneumonia and empyema from 1997 to 2008 was performed. Annual crude and age-sex standardised hospital admission rates for bacterial pneumonia and empyema were calculated.
RESULTS: Admission rates for bacterial pneumonia and empyema increased from 1997 to 2006, then declined to 2008. Bacterial pneumonia rates decreased to 1079 (95% CI 1059 to 1099) per million children and empyema rates decreased to 14 (95% CI 11 to 16) per million children. The RR for bacterial pneumonia admissions was 1.19 (95% CI 1.16 to 1.22) in 2006 compared with 2004 and 0.81 (95% CI 0.79 to 0.83) in 2008 compared with 2006. For empyema, the corresponding RRs were 1.77 (95% CI 1.38 to 2.28) in 2006 compared with 2004 and 0.78 (95% CI 0.62 to 0.98) in 2008 compared with 2006.
CONCLUSION: Childhood bacterial pneumonia and empyema admission rates were increasing prior to 2006 and decreased by 19% and 22% respectively between 2006 and 2008, following the introduction of the PCV7 pneumococcal conjugate vaccination to the national childhood immunisation programme.