Group A beta-hemolytic streptococcal pharyngitis in children younger than 5 years.

We report on a prospective study of 152 children aged 3 months to 5 years, from a community pediatric clinic, who had signs of pharyngitis, temperature > or = 38 degrees C and were not treated by antibiotics during the preceeding week. Nose and throat cultures were taken from each child. Blood antistreptolysin (ASO) was examined. If the cultures were positive for group A beta hemolytic Streptococcus (GABHS), a second blood sample for ASO was obtained later. True streptococcal infection was defined in a case of a positive culture and an increase in the ASO titer of at least two tubes, while cases of positive cultures without significant changes in ASO titer were defined as carriers. Positive GABHS cultures were found in 23 cases. True group A Streptococcus infection was found only in patients > 2 years old. The carriers of GABHS increased gradually from 3% during the 1st year to 22% by the 5th year. This study demonstrated that in the population evaluated, the incidence of true GABHS infection in children < 2 years of age is low, as was observed in the past.