INCIDENCE AND PROGNOSIS OF MENINGITIS DUE TO HAEMOPHILUS-INFLUENZAE, STREPTOCOCCUS-PNEUMONIAE AND NEISSERIA-MENINGITIDIS IN SWEDEN

The incidence, concomitant conditions and case fatality rate of Haemop hilus influenzae (Hi) and pneumococcal meningitis and of invasive meni ngococcal infections were studied retrospectively in Sweden (populatio n 8.4 million) for the years 1987-89, the period before vaccination ag ainst Hi type b started. A total of 1,019 cases with culture-verified infection were found. The incidence rates per 100,000 per year were 1. 8 for Hi meningitis, 1.2 for pneumococcal meningitis and 1.0 for invas ive meningococcal infections. The age-specific incidence was highest i n the 3-23 months age group for the 3 bacterial species. Pneumococcal meningitis was common in individuals greater than or equal to 60 years and meningococcal infections in the age-group 10-24 years. A serious concomitant condition was known in 57% of all patients with pneumococc al meningitis while this was uncommon for the other organisms. The cas e fatality rate was 2% for Hi meningitis, 24% for pneumococcal meningi tis and 10% for meningococcal infections. All 81 pneumococcal isolates which had been serotyped belonged to serotypes in the 23-valent pneum ococcal vaccine, Of the meningococcal isolates, 65% belonged to serogr oup B. In conclusion, the high incidence of Hib meningitis justifies g eneral Hib vaccination. Development of a vaccine against N. meningitis group B should have high priority. Furthermore, improved pneumococcal vaccines are needed for patients with predisposing conditions. The cu rrently available pneumococcal polysaccharide vaccine seems to be unde rused.