Epidemiological and clinical features of group A Streptococcus pharyngitis in children.

In order to understand the prevalence of childhood streptococcal pharyngitis, isolation of group A Streptococcus (GAS) was attempted from throat swabs of pharyngitis patients. Children aged between 1 and 15 years presenting to the outpatient department with pharyngeal erythema were prospectively enrolled in the study. Demographic data and presenting symptoms and signs for each patient were recorded and a throat swab was taken. Of 1175 throat cultures obtained, GAS was isolated in 252 cases (21.4%). Of these, 142 (56.3%) were boys and 110 (43.7%) girls. A higher proportion of boys was found with GAS pharyngitis (1.29: 1). The mean age of GAS culture-positive patients was 7.8 +/- 2.3 years old. Patients aged between 6 and 11 years were more prevalent in GAS pharyngitis. Ninety (35.7%) of our GAS pharyngitis patients occurred between March and May. A second smaller peak occurred between October and December. The following factors showed independent positive correlation with GAS infection: sore throat (p < 0.001), no coryza (p = 0.011), tonsillar swelling (p < 0.001), anterior cervical adenopathy (p = 0.029) and scarlatiniform rash (p < 0.001). However, GAS was found in less than half of the patients who had these clinical manifestations. In conclusion, pharyngeal infection with GAS in children is not uncommon. The prevalence of GAS pharyngitis is related to patient gender, age, and month of the year. Diagnosis of GAS pharyngitis based on clinical features alone is unreliable.