INT J TUBERC LUNG DIS 9(7):803–808 © 2005 The Union Incidence of tuberculous meningitis in France, 2000: a capture-recapture analysis J. Cailhol,* † D. Che,* V. Jarlier, † B. Decludt,* J. Robert † * Institut de Veille Sanitaire, Saint Maurice, † Centre National de Référence de la Résistance des Mycobactéries aux SUMMARY Antituberculeux and Laboratoire de Bactériologie-Hygiène, Faculté de Médecine Pitié-Salpêtrière, Paris, France OBJECTIVE: To estimate the incidence of culture- positive and culture-negative tuberculous meningitis (TBM) in France in 2000. METHODS: Capture-recapture method using two unre- lated sources of data: the tuberculosis (TB) mandatory notification system (MNTB), recording patients treated by anti-tuberculosis drugs, and a survey by the National Reference Centre (NRC) for mycobacterial drug resis- tance, recording culture-positive TBM. RESULTS: Of 112 cases of TBM reported to the MNTB, 28 culture-positive and 34 culture-negative meningitis cases were validated (17 duplicates, 3 cases from outside France, 21 false notifications, and 9 lost records were excluded). The NRC recorded 31 culture-positive cases, including 21 known by the MNTB. When the capture- recapture method was applied to the reported culture- positive meningitis cases, the estimated number of men- ingitis cases was 41 and the incidence was 0.7 cases per million. Sensitivity was 75.6% for the NRC, 68.3% for the MNTB, and 92.7% for both systems together. When sensitivity of the MNTB for culture-positive cases was applied to culture-negative meningitis, the total esti- mated number of culture-negative meningitis cases was 50 and the incidence was 0.85 cases per million. CONCLUSION: TBM is underestimated in France. Capture-recapture analysis using different sources to better estimate its incidence is of great interest. KEY WORDS: tuberculosis; meningitis; surveillance TUBERCULOSIS (TB) remains a worldwide health issue, with an estimate of 10 million new cases each year and 2 million deaths globally. 1 In France, the in- cidence of TB is stable at around 11 cases per 100 000 population since 1997. 2 The proportion of tubercu- lous meningitis (TBM), the most severe form of TB, reported through the French mandatory notification system is very low, at around 1.5% of all TB cases. The diagnosis of TBM is difficult, because of the low diagnostic yield of Ziehl-Neelsen staining and Mycobacterium tuberculosis culture in cerebrospinal fluid (CSF). The proportion of TBM with culture- negative CSF has been estimated to be at least 50%. 3,4 Because of these characteristics and the lack of a stan- dardised definition for culture-negative cases, the sur- veillance of TBM and comparison of its incidence across countries is difficult. This issue is of special in- terest because incidence of TBM is a key parameter for the evaluation of bacille Calmette-Guérin (BCG) vaccination and its discontinuation. 5 The purpose of the present study was to estimate the incidence of TBM in France in 2000 using the capture-recapture method with two unrelated sources, and to delineate criteria leading to TB diagnosis for culture-negative meningitis in France. MATERIAL AND METHODS In 2000, the surveillance of TBM in metropolitan France was performed using two unrelated systems. The first system, set up in 1964, is based on manda- tory notification of TB (MNTB) by physicians in charge of the patients. Information regarding each case of TB is reported to county health authorities in charge of TB control (Direction Départementale de l’Action Sanitaire et Sociale [DDASS]). The DDASS transmits anonymous information to the National In- stitute of Health (Institut de Veille Sanitaire [InVS]). Any patient treated with three or more anti-tuberculosis drugs for more than 1 month is considered as having TB, regardless of the microbiological result. Informa- tion recorded through MNTB includes demographic data, human immunodeficiency virus (HIV) status, country of birth and nationality, site of disease and microbiological findings. Patients with culture-negative TBM were categorised using four sub-groups of criteria derived from previous studies, 6–8 as follows: A. clinical meningitis or fever with neurological symptoms: acute focal deficit, confusion, disturbed consciousness; B. biological: CSF with pleocytosis (20 cells), predominantly lymphocytes (50%), Correspondence to: Jérôme Robert, Laboratoire de Bactériologie, Faculté de Médecine Pitié-Salpêtrière, 91 Bd de l’hôpital, 75634 Paris Cedex, France. Tel: (+33) 1 40 77 97 46. Fax: (+33) 1 45 82 75 77. e-mail: jrobert@chups.jussieu.fr Article submitted 7 June 2004. Final version accepted 24 November 2004.