SummaryThe risk of contracting a meningococcal or Haemophilus meningitis for subjects in contact with a patient suffering from one of these diseases can be very high for some of them such as those in close contact with the patient, as well as children attending day-care centers or nursery schools; on the other hand, for subjects in more distant contact with the patient, the risk is negligible. The prophylactic strategy of bacterial meningitis consists in locating the high-risk subjects, submitting them to careful clinical supervision and administering prophylactic chemotherapy. Of all the recommended antibiotics for the prevention of meningococcal infections, we would mention the sulphonamidcs, spiramycin and minocycline: amongst the latter, minocycline is of proven clinical efficacy against the meningococcus; for the prevention of Haemophilus meningitis, only rifampicin is efficient. The indications and modalities of meningococcal infections prophylaxis arc reasonably well established. However, the effic...