Incidence, capsular types, and antibiotic susceptibility of invasive Streptococcus pneumoniae in Sweden.

The number of reported cases of invasive pneumococcal infections in Sweden increased more than threefold from 1988 through 1992. We studied the capsular types and the antibiotic susceptibility of 619 pneumococcal strains isolated from blood or CSF at 18 Swedish microbiological laboratories in 1987 and in 1992. These strains belonged to 35 of the 84 recognized capsular types. We noted a remarkable increase in the prevalence of invasive infections with type 14 from 1987 (8.2%) to 1992 (18%) (P = .001), which correspond to a sevenfold increase in absolute numbers. The most prominent increase in infections was seen among elderly people; in 1992, type 14 accounted for 22.5% of the isolates from infected persons who were >64 years of age. The majority of the strains were susceptible to all antibiotics tested. However, there was a significant increase in trimethoprim-sulfamethoxazole resistance from 1.4% in 1987 to 7.1% in 1992. Nine multiresistant isolates (1.5%) were found.