Role of atypical bacteria and azithromycin therapy for children with recurrent respiratory tract infections

Pediatr Infect Dis J. 2005 May;24(5):438-44. doi: 10.1097/01.inf.0000160949.99560.8d.


Background: The aim of this study of 352 patients, 1-14 years of age, with acute respiratory infections and a history of recurrent respiratory tract infections (RRTIs), and 208 healthy subjects was to evaluate whether Mycoplasma pneumoniae and Chlamydia pneumoniae played a role in causing acute respiratory episodes among children with RRTIs and whether specific antibiotic treatment for these bacteria could improve the acute episodes and reduce recurrences.

Methods: The patients were blindly randomized to receive azithromycin (10 mg/kg/d for 3 days weekly, for 3 weeks) together with symptom-specific agents or symptom-specific agents alone. Acute M. pneumoniae and/or C. pneumoniae infection was diagnosed if the child had a significant antibody response in paired sera and/or if the DNA of the bacteria was detected in nasopharyngeal aspirates.

Results: Atypical bacterial infections were identified for 190 patients (54.0%) and 8 healthy control subjects (3.8%; P < 0.0001). Short term (1-month) clinical success was significantly more frequent among the patients who had received azithromycin together with symptom-specific agents than among those who had received symptom-specific agents alone, but the difference was significant only for the group of patients with atypical bacteria. In contrast, long term (6-month) clinical success was significantly more frequent among the patients who had received azithromycin in addition to symptom-specific agents, regardless of whether they experienced infections with atypical bacteria or other pathogens, although positive outcomes were significantly more frequent among those with atypical bacteria.

Conclusions: Atypical bacteria seem to play a role among children with RRTIs, and prolonged azithromycin therapy can significantly improve the acute episodes and reduce the risk of recurrences.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Ambulatory Care Facilities
  • Azithromycin / administration & dosage*
  • Child
  • Child, Preschool
  • Chlamydophila Infections / diagnosis
  • Chlamydophila Infections / drug therapy*
  • Dose-Response Relationship, Drug
  • Drug Administration Schedule
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Pneumonia, Bacterial / diagnosis
  • Pneumonia, Bacterial / drug therapy
  • Pneumonia, Mycoplasma / diagnosis
  • Pneumonia, Mycoplasma / drug therapy*
  • Probability
  • Recurrence
  • Reference Values
  • Respiratory Tract Infections / drug therapy*
  • Respiratory Tract Infections / microbiology*
  • Risk Assessment
  • Severity of Illness Index
  • Single-Blind Method
  • Treatment Outcome


  • Azithromycin