Capsular types and antibiotic sensitivity of pneumococci isolated from patients with serious infections in Belgium 1980 to 1988.

A total of 2,765 strains of Streptococcus pneumoniae isolated in more than 60 Belgian laboratories from blood or normally sterile body fluids between 1 November 1980 and 31 December 1988 were serotyped. From January 1983 onwards susceptibility of the strains to antimicrobial agents was also tested. The 2,765 isolates belonged to 57 of the 84 currently identified serotypes. Overall, 94% of the strains were represented in the current 23-valent vaccine. The remaining 6% of strains were distributed among 18 serotypes. More than 84% of the middle ear fluid isolates came from children under ten years. Meningitis was commonest in children under five years and in adults over sixty years. Two-thirds of pneumococcal bacteremia isolates came from patients over 50 years. Of 1,933 isolates tested for susceptibility to antibiotics, 335 (17%) were resistant to one or more of the agents tested (tetracycline, erythromycin, chloramphenicol, penicillin). Only 19 strains were relatively resistant to penicillin, while six were fully resistant. Resistance to erythromycin increased significantly from 5.2% in 1986 to 11.5% in 1988. The resistance of Streptococcus pneumoniae to other antimicrobial agents did not change significantly during the study period. There was no relationship between age group and resistance to any of the agents tested.