[Changes in bacterial meningitis in French children resulting from vaccination]

For the past 20 years, three vaccines against the three main bacterial species implicated in meningitis in children have been included in the French vaccine calendar: Haemophilus influenzae b in 1993, 7-valent pneumococcal conjugate vaccine (PCV7) in 2003 (replaced by 13-valent in 2010) and Neisseria meningitidis C in 2009. The French active surveillance network from the GPIP/ACTIV monitors the change in the epidemiological, clinical, and biological features of bacterial meningitis due to vaccine use.

Over a 12-year period, 233 pediatric wards working with 168 microbiology departments throughout France were asked to report all cases of bacterial meningitis.

From January 2001 to December 2012, 4808 bacterial meningitis cases were reported. Between 2001 and 2012, the number of pneumococcal meningitis (PM) cases decreased by 23.4%, and by 32.2% for children less than 2 years old. During this period, the proportion of cases attributable to PCV7 and six additional PCV13 types decreased from 63.3% to 8.1% and 83.7% to 32.4%, respectively. In 2012, the main vaccine types (accounting for 25.8% of cases) were 7F (12.2%), 19A (6.8%), and 19F (6.8%), and the most frequent non-vaccine types were 12F (14.9%), 24F (14.9%), 15B/C (6.8%), 22F (6.8%), and 10A (5.4%). In 2012, the rate of strains with decreased susceptibility to cefotaxime/ceftriaxone (MIC>0.5 μg/mL) represented less than 3% of cases, with no identified resistant strain since 2010 (MIC>2 μg/mL). Between 2001 (n=67) and 2012 (n=9), the number of NmC meningitis cases decreased by 87%.

With more than 4800 bacterial meningitis cases reported in 12 years, this nationwide survey provides essential information on the microbiological and clinical characteristics of bacterial meningitis (epidemiology or resistance data). These results could lead to changing antibiotic treatment of pneumococcal meningitis before the results of antibiotic susceptibility tests.