Impact of 13-valent pneumococcal conjugate vaccine on pneumococcal meningitis in children.

OBJECTIVES

To evaluate the impact of 13-valent pneumococcal conjugate vaccine on pneumococcal meningitis in children.

METHODS

Children younger than 15years of age attending 27 hospitals in the Region of Madrid with confirmed pneumococcal meningitis were identified in a prospective surveillance study, from 2007 to 2015. Clinical data, neurological sequelae, pneumococcal vaccination status, serotyping and antibiotic susceptibility were recorded.

RESULTS

One hundred and four cases of pneumococcal meningitis were identified, 63 during the period of routine 7-valent pneumococcal conjugate vaccine immunisation (May 2007-April 2010) and 41 during the period of 13-valent pneumococcal conjugate vaccine immunisation (May 2010-April 2015). When both periods were compared, a 62% (95% CI: 45-75%) decrease in the incidence of pneumococcal meningitis was observed, from 2.19 cases per 100,000 inhabitants in the PCV7 period to 0.81 per 100,000 inhabitants in the PCV13 period (p=0.0001), mainly due to an 83% (95% CI: 30-96%) reduction in cases caused by serotype 19A. Isolates not susceptible to cefotaxime (MIC>0.5μg/L) decreased from 27% to 8%, (p=0.02). Mean patient ages rose from 28.7months to 38.5months (p<0.05). Case fatality rate across both periods was 5%. An unfavourable outcome (death or neurological sequelae) occurred in 27% of patients, while the rate was similar in both periods. There was no increase in meningitis caused by pneumococcal serotypes not included in 13-valent pneumococcal conjugate vaccine throughout the years of the study.

CONCLUSIONS

Immunisation with 13-valent pneumococcal conjugate vaccine has reduced the rate of pneumococcal meningitis in children less than 15years, with a near-elimination of cefotaxime-resistant isolates, but morbidity has remained unchanged. A shift of pneumococcal meningitis towards slightly higher age groups was also observed.