Optimal site for throat culture: tonsillar surface versus posterior pharyngeal wall.

To determine the optimal site of throat culture for the detection of potential pathogens by comparing culture results from the tonsillar surface and the posterior pharyngeal wall in children selected for adenotonsillectomy and in children without upper respiratory disease. Cotton culture swabs were taken from the tonsillar surface and the posterior pharyngeal wall of 50 children selected for adenotonsillectomy for symptoms of recurrent tonsillitis and/or adenotonsillar hypertrophy and of 50 children without upper respiratory disease. Potential respiratory pathogens were identified. In the overall group (n = 100), positive culture results were found in 67 posterior pharyngeal wall samples and 47 tonsillar surface samples (P = 0.001). Haemophilus influenzae was the most frequently isolated micro-organism both in the posterior pharyngeal wall and the tonsillar surface samples; 55 and 35%, respectively (P = 0.001). Group A beta-haemolytic streptococci were found in the samples of the posterior pharyngeal wall and the tonsillar surface in 17 and 13%, respectively (P = 0.2). When dealing with patients with sore throat, sampling both tonsillar surfaces is enough for the detection of group A beta-haemolytic streptococci. When detection of other bacteria is also important, such as for research purposes, the posterior pharyngeal wall should be sampled as well.