Background: Pneumococcal meningitis represents one major cause of morbidity and mortality in children in France. The GPIP/ACTIV (Groupe de Pathologie Infectieuse Pédiatrique and Association Clinique et Thérapeutique Infantile du Val de Marne) set up an active surveillance network to analyze the clinical and biological features of pneumococcal meningitis and the impact of 7-valent pneumococcal conjugate vaccine (PCV7).
Methods: From 2001 to 2007, 252 French pediatric wards working with 168 microbiology laboratories enrolled all children (0-18 years old) with bacterial meningitis. Risk factors, signs and symptoms, vaccination status, cerebrospinal fluid analysis, treatments and case fatality rate were recorded.
Results: Within the 7 years study period, 832 pneumococcal meningitis were reported among 2951 bacterial meningitis. In 2001 as in 2007, excluding the neonatal period, pneumococal meningitis represented nearly 1/3 of bacterial meningitis without significant decline in the number of reported cases (less than 30% for children under 2 years old). The peak of incidence was at 5 months of age and 61.7% of cases occured in children 2 to 24 months old. PCV7 vaccinated patients represented 154 cases from 2003 to 2007. In the vaccinated population, serotypes were identified in 136 cases. Few vaccine serotypes (VT) were identified (n=18). The most important was serotype 19F (n=8) followed by 6B (n=4) and 14 (n=3). Three vaccine failures (case occurring after complete vaccination) were observed (serotypes 6B, 4 and 19F). Remaining cases (n=118) were mainly due to non vaccine serotypes (NVT): serotypes 19A, 15B/C and 7F. In 2007, the serotype 19A, more often intermediary strains to cytoxin, represented about 20% of cases. Among non vaccinated children, VT decreased between 2001 and 2007 (59/92 in 2001 vs 15/39 in 2007). Case fatality rate was stable around 11.4%.
Conclusion: In France, probably because of the insufficient vaccination coverage and the slow implementation of the PCV7, the expected decline in the number of cases of pneumococcal meningitis has not been observed. The impact of PCV7 appeared clearly since only few cases of VT pneumococcal meningitis were reported in vaccinated children.