Hearing impairment in children after bacterial meningitis: incidence and resource implications.

A retrospective review over ten years of childhood cases of bacterial meningitis treated in two hospitals in Nottingham revealed 301 cases: 88.4% of these children survived. The audiological and clinical hospital records of the survivors were examined to see if the children had been assessed for hearing impairment following the illness. Results indicate that 202/261 (77.4%) of the survivors remaining in the local area had had a formal hearing assessment. Fifteen of these children (7.4% of those assessed) suffered some degree of sensorineural or mixed hearing loss as a direct consequence of meningitis. The impairments ranged from mild unilateral to profound bilateral and the affected children were aged between 0 (i.e. infection at birth) to 15 years. The data indicate that bacterial meningitis of any type can result in sensorineural hearing impairment of any degree in a child of any age. A significantly increased risk of hearing impairment was found for children aged less than one month or over 5 years, for children with associated hydrocephalus, for children admitted between October and March, for those in hospital longer than 16 days and for those with a cerebro-spinal fluid glucose concentration of < or = 2.2 mmol/l. No differential increased risk was noted for different causative pathogens. Abnormal tympanograms indicative of conductive hearing impairment were measured at the first visit in 45% of children attending for hearing assessment. These conductive losses resolved in 75% of cases. These data suggest that an English health district, with a total population of 250,000, would need to provide annual resources for about 30-40 appointments for children after meningitis. Over a period of 5 years it might provide hearing aids for three children and a cochlear implant for one child. Bacterial meningitis is the single most important cause of acquired sensorineural hearing impairment in children and every attempt should be made to assess the child's hearing as soon after recovery as possible.