THE OUTCOME OF CHILDHOOD HAEMOPHILUS-INFLUENZAE MENINGITIS - A POPULATION-BASED STUDY

Objective: To determine the morbidity and mortality from. childhood Ha emophilus influenzae type b (Hib) meningitis in a well defined populat ion. Design: Retrospective survey 1985-1987 and prospective surveillan ce of hospital laboratories 1989-1990. Information on outcome of menin gitis was obtained from hospital records and attending physicians and, in 1989-1990, from a survey of the children's parents. Setting: Sydne y Statistical Division, which had a population of children aged 0-4 ye ars of 229 165 in 1986 and 263 758 in 1990. Patients: Eligible childre n were aged from one month to four years and had clinical and microbio logical evidence of Rib meningitis on standard criteria. Results: Ther e were 229 eligible children. Twelve were excluded (seven died and fiv e had pre-existing neurological deficits). A neurological deficit was detected at the time of hospital discharge in 45 patients (21%) and pe rsisted for 12 months or longer in 29 patients (13%). Follow-up inform ation was available for 165 (96%) children who were normal at the time of hospital discharge and persistent deficits were recorded in 12 (7% ) of these children. Forty-one children (19%) had readily recognisable neurological or hearing problems: nine (4%) had persistent severe neu rological deficits and seven (3%) had severe hearing loss requiring he aring aids or a cochlear implant. Age had a significant influence on o utcome. The youngest children were significantly more likely to be adm itted to intensive care. Severe neurological deficits showed a signifi cant negative trend with increasing age (P = 0.03). Severe unilateral or bilateral sensorineural loss (odds ratio [OR] 8.0, 95% confidence i nterval [CI] 1.5-81) and ataxia at discharge (OR 13.3, 95% CI 2.8-128) were noticeably more common in children over two years of age, with a significant positive trend (P less than or equal to 0.001) with incre asing age. Patients requiring intensive care were much more likely to have an adverse outcome, particularly if positive pressure ventilation was needed. Conclusions: These data provide population-based estimate s of the minimum incidence of adverse outcomes from Hib meningitis in an urban community with good access to medical services. This is impor tant in assessing the impact of Rib vaccination, as meningitis is resp onsible for most of the long-term morbidity from childhood invasive Ri b disease. Determination of the relationship between morbidity and age is important for assessing alternative vaccine strategies.