Résumé
Difficulties facing bacteriological diagnosis of meningitis are frequent, specially those caused by mycobacteria. From 1983 to 1987 samples of cerebrospinal fluid (CSF) from 16,921 patients mainly from the Emílio Ribas Hospital, SP, with clinical signs of meningitis were examined at the Instituto Adolfo Lutz, SP. 2,951 of the patients were diagnosed as being cases of bacterial meningitis, 134 of which tuberculous meningitis (4.5 per cent). 40.2 per cent were individuals of age 0-4 years, 52.3 per cent over 14 years and 7.5 per cent of unknown age. Tuberculous meningitis was clinically suspected in 51.5 per cent of the cases, while in the remaining cases (48.5 per cent) it was detected mainly because of the routine investigation of mycobacteria in CSF. Considering that the laboratory does not always receive a request to analyze M. tuberculosis in CSF and that, in terms of public health, tuberculosis is still an important problem, a careful study of mycobacteria in suspect cases of meningitis is recommended.