Role of nasopharyngeal culture in antibiotic prescription for patients with common cold or acute sinusitis

The aim of the present study was to assess the hypothesis that, when presen t in nasopharyngeal secretions, Streptococcus pneumoniae, Haemophilus influ enzae, and Moraxella catarrhalis play a pathogenic role early in the course of an upper respiratory tract infection, Adults with a clinical diagnosis of acute sinusitis or common cold were enrolled. Participants were randomly assigned in a double-blind manner to receive azithromycin 500 mg daily or placebo for 3 days. The effect of treatment on symptom evolution in the pre defined subset of patients with Streptococcus pneumoniae, Haemophilus influ enzae, or Moraxella catarrhalis in their nasopharyngeal secretions was asse ssed. Of 265 patients enrolled, B2 received placebo and 133 azithromycin. S treptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis w as identified in nasopharyngeal secretions of 77 patients (29%). In this pr edefined subgroup of patients with Streptococcus pneumoniae, Haemophilus in fluenzae, or Moraxella catarrhalis, resolution of symptoms by day 7 occurre d in 73% of those treated with azithromycin compared with 47% of those who received placebo (P=0.007). The median time before resolution of symptoms w as 5 days in the azithromycin group compared to 7 days in the placebo group . Respiratory complications requiring antibiotic treatment occurred in 19% of patients in the placebo group and in 3% of the azithromycin group (P=0.0 25). In the remaining 188 patients without Streptococcus pneumoniae, Haemop hilus influenzae, or Moraxella catarrhalis, resolution of symptoms by day 7 was similar in both groups (69% in the placebo group vs. 64% in the azithr omycin group [P = 0.75]). Antibiotic treatment is of clinical benefit for p atients with acute sinusitis or common cold when Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis is present in nasopharynge al secretions. This observation provides new insights into the pathogenic r ole of these bacteria in the early stage of the common cold.