Tuberculous meningitis in France in 1990: characteristics and impact of BCG vaccination

Setting: France, 1990. Objective: To measure the incidence and describe the characteristics of bacteriologically-confirmed tuberculous meningitis (TBM) and to estimate the protective efficacy of BCG vaccination in children aged less than 5 years. Design: An active surveillance of TBM cases confirmed by positive cerebrospinal fluid (CSF) culture was conducted through a network of microbiology laboratories serving 99.8% of regional and district general hospitals and other large private hospitals. Results: A total of 70 cases were reported: 61% were adults over 44 years, 64% were males and 77% were born in France. 7 patients were known to be infected with HIV. 6 cases were observed in children aged less than 5 years, 2 of whom had been vaccinated with BCG. 3 of the 6 children died (one had been BCGvaccinated). Given the 80% coverage of BCG in this age group, the protective efficacy of BCG vaccination was estimated to be 87.5% (95% CI: 30-98), which indicates that 14 TBM cases may have been prevented by BCG vaccination in 1990. Conclusion: Results are consistent with the number of TBM cases expected on the basis of a 0.04% annual risk of infection. Current BCG vaccination policy in France still has a measurable impact on the incidence of tuberculous meningitis in children under 5 years of age. Given the probable continuous decrease of the annual risk of infection in future years, alternative policies should be considered.