Outbreak of group A streptococcal infection in a day-care center.

During an outbreak of streptococcal infections in a day-care center it is often difficult to determine the source and extent of the outbreak and the optimal means of management. An intervention strategy based on repeated throat cultures and initial antibiotic treatment of culture-positive individuals was used during an outbreak of respiratory tract infections with Group A streptococci at a day-care center. The spread of streptococci to the environment and the importance of streptococcal carriers was studied. Two weeks after the diagnosis of the index case, 61% of the 30 children were colonized with Group A streptococci. From 20 to 30% of the children remained streptococcal carriers, but they did not give rise to secondary cases. Initially the environment was heavily contaminated with Group A streptococci. Damp material might constitute a potential source of streptococcal spread. All Group A streptococcal strains belonged to the same serotype, T12M12. Prompt recognition and intervention are important to prevent spread of streptococcal infection to many day-care attenders.