Hearing impairment following therapy of Haemophilus influenzae meningitis.

From 97 children with bacteriologically confirmed Haemophilus influenzae meningitis, 39 were treated with chloramphenicol (before 1970) and 58 with ampicillin (since 1970). In 1977 all patients were followed up with history, clinical examination, and audiometry. Sensorineural hearing defect was found in 5 chloramphenicol patients and in 10 ampicillin patients. Of the 82 patients for whom treatment was begun within 48 h of onset of symptoms, only two showed hearing deficit, while 13 of the 15 patients in whom treatment was begun later suffered from hearing impairment. It appears that it is not the antibiotic, but the delay between onset of symptoms and start of therapy, that is decisive for the occurrence of inner ear impairment.