To determine whether the oropharyngeal microbial flora changes after adenotonsillectomy (ATY) in children with mild to moderate symptoms of throat infections or adenotonsillar hypertrophy and to relate these findings to recurrence of throat infections.
Randomized controlled trial.
Twenty-three general hospitals and 3 academic centers.
Three hundred children aged 2 to 8 years who were selected for ATY because of recurrent throat infections (3-6 episodes per year) or obstructive complaints. Children with a history of 7 or more throat infections in the previous year and those with a high suspicion of obstructive sleep apnea according to current medical practice were excluded.
Children were randomly assigned to either ATY or watchful waiting. Oropharyngeal swabs were taken at baseline and at 3 and 12 months after baseline.
Main Outcome Measures
The primary outcome measure was the prevalence of potentially pathogenic bacteria in the oropharynx at 3 and 12 months. The secondary outcome measure was the association between carriage of group A β-hemolytic streptococci (GABHS) at baseline and at 3 months' follow-up and the number of throat infections during the 12 months of follow-up.
In the ATY group, prevalences of Haemophilus influenzae, GABHS, and Staphylococcus aureus decreased from 40%, 13%, and 5%, respectively, at baseline to respective levels of 24%, 0%, and 0% at 3 months and 26%, 0%, and 0% at 12 months. In the watchful waiting group, prevalences of H influenzae, GABHS, and S aureus did not change substantially. In neither the ATY nor the watchful waiting group was carriage of GABHS associated with recurrence of throat infections.
Adenotonsillectomy reduced oropharyngeal carriage of potential respiratory pathogens. Changes in the carriage rate of GABHS, however, had no beneficial effect on recurrence of throat infections.