Invasive pneumococcal infections in Southwestern Sweden: a second follow-up period of 15 years.

In a retrospective study, the incidence, clinical manifestations, concomitant conditions and case fatality rate were studied in patients with invasive pneumococcal infections in the Göteborg area of Sweden during 1981-95, when the pneumococcal polysaccharide vaccine was available but little used. Patients were identified from the records of the Departments of Clinical Bacteriology and from the computer-based hospital discharge registers of the relevant departments. Individual case records were found for 876 patients with invasive pneumococcal infections verified by cultures from blood, cerebrospinal fluid or other sterile body fluids. A study from the same area with the same design covering the years 1964-80 has previously been published. There was an increase in total incidence from 5.3 to 10.3 cases/100,000/y from the previous to the present study. This increase was due to an increase in patients with non-meningitic infections aged > or = 60 y. The incidence of meningitis was virtually unchanged (1.4/100,000/y), as was the incidence of non-meningitic infections in individuals < 60 y. There were no other important changes between the 2 studies, which confirm that invasive pneumococcal infections have the highest incidence rates in children < 2 y and in the elderly, that a wide variety of underlying conditions are seen in the patients and that the case fatality rate, 15% in the present study, is still high.