Clindamycin in the treatment of an outbreak of streptococcal pharyngitis in a kibbutz due to beta-lactamase producing organisms.

During the winter of 1987-88, an epidemic of streptococcal pharyngitis (SP) affected almost 25% of the 800 inhabitants of a community settlement (kibbutz), and failed to respond to treatment with penicillin and/or erythromycin, despite the fact that the streptococci were highly sensitive to penicillin (minimum inhibitory concentration: MIC less than 0.001 micrograms/ml). We suggested that the concomitant presence of beta-lactamase producing organisms in the pharyngeal cavities of the affected individuals with SP could inactivate the antibiotics, rendering the streptococci resistant to penicillin. Throat swabs were taken and tested for aerobic and anaerobic beta-lactamase producing organisms and for beta-lactamase activity and clindamycin treatment was given to 110 patients with SP. Beta-lactamase activity was detected in 90 cases and the cultures were positive for Staphylococcus aureus (25 cases), Haemophilus sp. (22 cases) and anaerobes, which we did not identify in 68 cases. Ninety-eight patients completed the ten-day course of treatment with clindamycin and 96 were cured clinically and bacteriologically. The epidemic was controlled.