Fig 1.

Semiquantitative culture results for bacterial pathogens with different sampling methods. Conventional culture results were obtained for S. pneumoniae (A), H. influenzae (B), M. catarrhalis (C), or S. aureus (D) in children with an upper respiratory tract infection. Colonies were graded according to the distance from the point of inoculation, ranging from − (no growth) to ++++ (growth at maximum distance). Sampling methods were compared to the “gold standard” by using the Wilcoxon signed-rank test for paired samples. Nasopharyngeal sampling was considered the standard for S. pneumoniae, H. influenzae, and M. catarrhalis (4, 10, 11) and nasal sampling for S. aureus (17).