Haemophilus influenzae meningitis. A comparison between chloramphenicol and ampicillin therapy with special reference to impaired hearing.

131 patients suffering from meningitis due to Haemophilus influenzae or parainfluenzae were re-examined after 1-15 years, using hospital records, questionnaires, and audiological examination, especially to compare chloramphenicol and ampicillin therapy. Mortality was 3.8%. Subdural effusions occurred in 14.5% of cases uni- or bilaterally. There was deafness in 2.3%, and moderate hearing loss in 8.4%. Convulsions appeared later in 6.9%. The final outcome was good in 60%. The most important factors in prognosis seemed to be the severity of the symptoms and the condition of the patient on admission to hospital. No clear difference was seen between the results of chloramphenicol and ampicillin therapy, but total loss of vestibular function was found in 3 cases in the ampicillin group, and in none in the chloramphenicol group. In mortality and deafness, the differences in outcome were similar, although not statistically significant. As these observations show, the therapy used in Haemophilus influenzae meningitis needs re-evaluation.