A clinical study of beta-haemolytic groups A, B, C and G streptococcal bacteremia in adults over an 8-year period.

All of the 88 episodes of beta-haemolytic streptococcal bacteremia (2.9% of all bacteremias) in adult patients during the years 1987-94 in a university hospital were reviewed. 38 bacteremias (43%) were caused by group A, 24 (27%) by group B, 3 (4%) by group C, and 23 (26%) by group G beta-haemolytic streptococcal. There was a statistically significant increase in group A and decrease in group C and G bacteremias (p < 0.02) compared to an earlier 8-year period in the same hospital, although the total number of streptococcal bacteremias remained the same. The most common T types of group A streptococcal strains were T11 (26%), T28 (14%), T6 and T1 (11% each), and T12 (8%). Cardiovascular disease, skin lesions, malignancy, and alcohol abuse were the most common underlying conditions. The most usual types of infection were skin (47%) and respiratory tract infections (23%). The overall mortality was 16%. It was highest in group A (24%) and lowest in group C (0%), 38% of patients with pneumonia died. All streptococcal strains were sensitive to penicillin, vancomycin, and cephalosporins. 11% of group A and 12% of all the strains had decreased sensitivity to erythromycin, 14 and 38% to tetracycline, and 0 and 2% to clindamycin, respectively.