MICROBIOLOGY OF CEREBRAL ABSCESS - A 4-YEAR STUDY IN MALAYSIA

A prospective study was carried out to determine the aetiology of cere bral abscess in relation to the primary source of infections. Seventy- five patients with cerebral abscess were included in the study in the period January 1985 to December 1988. More than half of the patients s tudied had single lesions and the overall most common sites were in th e frontal and parietal regions. Chronic suppurative otitis media, cyan otic congenital heart diseases and meningitis were among the important predisposing conditions in these patients. Approximately 25% of the p atients with cerebral abscesses had no documented antecedent infection s. Pure cultures were found to be predominant (66.7%) and sterile cult ures were obtained from 10 (13.3% patients. Streptococci were isolated from 23 (30.7%) patients, the commonest species being Streptococcus m illeri. Proteus sp, Pseudomonas aeruginosa, Pseudomonas putrifaciens a nd Bacteroides sp were almost exclusively found in cerebral abscesses secondary to chronic suppurative otitis media; these organisms were fo und in mixed cultures. Streptococcus milleri, Bacteroides sp and Eiken ella corrodens were found in pure cultures in patients with cyanotic c ongenital heart disease. In patients with ventriculoperitoneal shunts in-situ, Staphylococcus aureus, Staphylococcus epidermidis and diphthe roids were common. Anaerobes were found in 15 (20.0%) patients, the ma jority in mixed cultures. Culture, as well as gas-liquid chromatograph ic analysis of volatile fatty acids of cerebral pus, was carried out t o enhance the detection of the anaerobes. Based on these findings, an antibiotic regimen consisting of penicillin, chloramphenicol and metro nidazole is recommended as an initial therapy while awaiting culture a nd sensitivity results.