A retrospective study of the occurrence of beta-haemolytic streptococci of various Lancefield groups in routine cultures from the County of Uppsala.

During the months October to December of the years 1971-1974 the incidence of beta-haemolytic streptococci of the Lancefield groups, A, B, C and G from patients in the County of Uppsala was studied. The proportion of culture positive patients increased during the period studied from 7.2% to 13.7%. The increase was not only due to group A. In cultures from the respiratory tract the finding of group A streptococci increased from 4.1% to 10.7% and group C from 0.1% to 1.6%, while group B and G streptococci remained constant. In cultures from wound infections the percentage of patients culture positive for group A streptococci increased from 6.2% to 8.7%, group B from 0.8% to 1.9%, and group G from 0.5% to 0.9%, while group C remained constant. During the same months of the years 1972 to 1974 the frequency of sera with an antistreptolysin O titre of more than 1 000 U/ml increased from 0.6% t0 2.3% in the same region. A clinical study of scarlet fever and pharyngotonsillitis at the Department of Infectious Diseases showed a similar trend concerning group A streptococcal infections. These results stress the great importance of group A beta-haemolytic streptocci in human infections and indicate that the recent interest in non-group A infections should be continued.