Long-term Mortality in Children Diagnosed With Haemophilus influenzae Meningitis

Abstract

The long-term mortality in children diagnosed with Haemophilus influenzae meningitis is poorly documented. We performed a nationwide, population-based cohort study including all Danish children diagnosed at the age between 0 and <5 years with H. influenzae meningitis from 1977 through 1996 and who were alive 1 year after diagnosis. Data were retrieved from medical databases in Denmark. For each H. influenzae meningitis patient, 6 age- and gender-matched population controls were indentified. We constructed Kaplan-Meier survival curves and used Cox regression analysis to estimate mortality rate ratios (MRR) and analyze causes of death. The risk of inpatient admission and of requiring hospital outpatient services during follow-up was calculated. We identified 1242 H. influenzae meningitis patients and 7452 population controls, with a median follow-up time of 21.3 years. The MRR for patients with H. influenzae meningitis was 1.08 (95% confidence interval, 0.57-2.05), adjusted MRR was 0.97 (95% confidence interval, 0.50-1.89). No increased mortality due to infections, respiratory diseases, or cancer was observed. The overall risk of inpatient admission and of requiring hospital outpatient services for the H. influenzae meningitis patients was increased the first 15 years of follow-up, mainly due to the nervous system diseases and ear diseases, thereafter the risk decreased to that of the population controls. In a developed country, children younger than 5 years surviving the acute phase of H. influenzae meningitis have no increased long-term mortality and only moderately increased morbidity.