PIP: Hemophilus influenza, Streptococcus pneumoniae, and Neisseria meningitidis account for over 75% of all cases of bacterial meningitis. S. pneumoniae is the commonest causative organism in many developing countries, particularly in Africa. In developing countries overall case fatality rates of 33-44% have been reported, rising to over 60% in adult groups. S. pneumoniae accounts for the highest mortality worldwide. Sequela rates of 22-26% of survivors have been found in African studies, mostly of a neurological nature. There have been few reports of AIDS-related bacterial meningitis in the USA, and a recent study from Uganda found no association between HIV infection and meningococcal meningitis. Stronger associations have been found between opportunistic infections, both viral (cytomegalovirus, herpes virus) and non-viral (TB, Toxoplasma gondii, Cryptococcus neoformans). A lumbar puncture and analysis of the cerebrospinal fluid should be performed on suspected cases unless there is suspicion of impending coning (decreasing consciousness or focal neurological signs). The intramuscular administration of chloramphenicol alone is comparable with intravenous use, and can be given as a shorter course of therapy (2 or 3 days) followed by an oral course. The use of adjunct therapy with corticosteroids in children is now commonplace in the USA and Europe. It appears reasonable to use dexamethasone, given early and in high dosage (0.15 mg/kg 6 hourly for 4 days), in those patients who are severely ill. Rifampicin is effective for chemoprophylaxis (10 mg/kg twice daily for 2 days for meningococcal contacts, 20 mg/kg once daily for 4 days for hemophilus contacts, maximum 600 mg per dose). The recent development and introduction of conjugate vaccines for H. influenza (HIB) has led to rapid reductions in the incidence of hemophilus meningitis in many European countries. An important step in improving prognosis is to increase awareness in both health workers and the public, to encourage early hospital referral, and early antibiotic therapy.