Pneumococcal meningitis in Western Australian children: Epidemiology, microbiology and outcome

Objectives: Pneumococcal meningitis is now vaccine-preventable but continues to cause high rates of neurological sequelae internationally. Population-based epidemiology, outcome and microbiology data are necessary to target vaccination strategies. This study outlines these key areas for Western Australian children diagnosed 1990-2000. Methods: The charts of all rural and metropolitan children with International Classification of Disease 9 and 10 discharge codes of pneumococcal or streptococcal meningitis from the Health Department's Hospital Morbidity Data System were reviewed. Results: Over 10.5 years, 94 episodes were confirmed. The average annual incidence for children under 2 years was 13.45 per 100 000 and 0.66 per 100 000 for children 2 years or older. Indigenous children had an almost seven-fold increased risk compared to non-Indigenous (with 78.55 per 100 000 in the under two-year Indigenous group). Eight children died and 24 of the survivors had neurological sequelae. Penicillin resistance occurred in four of 87 isolates. One quarter of the cohort qualify under the current Australian policy of vaccination of high-risk children with seven-valent conjugate (7vPCV) vaccine. Most isolates (49/58) were 7vPCV serotypes, however, Indigenous populations were less well-covered (58.3% covered vs 91.3% of isolates from non-Indigenous children). Indigenous coverage would be improved to 75% with 11-valent conjugate vaccine. Conclusions: Indigenous children and those under 2 years are most affected by pneumococcal meningitis and remain primary vaccination targets. Three quarters of these children would not be protected by a policy of vaccination of only high-risk children with 7vPCV - improved protection requires higher valencies for Indigenous populations and universal infant vaccination.