Community-acquired bacterial meningitis in Loire-Atlantique: evolving pneumococcal and meningococcal susceptibility

OBJECTIVES: An epidemiological study of community-acquired bacterial meningitis was conducted in Loire-Atlantique in subjects aged over 1 month. Risk factors and changes in pneumococcal and meningococcal susceptibilty to betalactams were analyzed. PATIENTS AND METHODS: All cases of proven or presumed bacterial meningitis registered by Loire-Atlantic bacteriology laboratories between May 1995 and April 1998 were analyzed. RESULTS: One hundred two cases were registered (annual incidence: 3.12 cases per 100,000 inhabitants). In children (33 cases) the main germs were meningococci (51%), pneumococci (24%) and Haemophilus influenzae (6%). In adults (69 cases), pneumococci (49%), meningococci (14%) and Listeria (4%) predominated. An underlying disease was noted 44% of the cases. Mortality was 17.6%. Sequellae were observed in 9.5%. Some degree of penicillin resistance was observed in 45% of the pneumococcal strains and in 50% of the meningococcal strains. Half of the pneumococcal strains were also resistant to third generation cephalosporins (C3G). No risk factor was significantly related to resistant strains. Susceptibility to antibiotics was not correlated with mortality for either pneumococcal or meningococcal strains, but sequellae were more frequent after meningitis caused by resistant pneumococci. CONCLUSION: For cases of community-acquired meningococcal meningitis diagnosed in 1999, it would be advisable to prescribe a combination C3G-vancomycin regimen as the first line empirical treatment while waiting for results of susceptibility tests. Certain guidelines proposed by the February 1996 consensus conference on community-acquired purulent meningitis would thus need to be amended.