The relapse of a respiratory tract infection (RIRT) is the most common reason why a child needs a pediatrician consultation. In addition, they are a serious medical problem. To date, there is little data on the role of atypical bacteria in the development of RIRT. Scientists from the University of Milan conducted a study to determine the roles of Mycoplasma pneumoniae (Mp) and Chlamydia pneumoniae (Cp) in the occurrence of relapse of respiratory tract infections in children. We examined 364 patients aged 6 months to 14 years (mean age 3.5 years) with acute respiratory infection and a history of RIRT (more than 6 episodes per year if the child is more than 3 years old, or more than 8 episodes per year if a child under 3 years old). The control group consisted of 208 healthy children of the same age.

Blood samples and nasopharyngeal swabs were taken from each child on admission and 4 to 6 weeks after the onset of disease to determine specific antibodies and DNA diagnoses of Mycoplasma pneumoniae and Chlamydia pneumoniae, respectively. When prescribing macrolides, azithromycin was preferred (10 mg / kg / day for 3 days for 3 weeks). In the future, to establish the frequency of relapses, patients were observed for 6 months.

Acute Mr infection was diagnosed in 138 patients (37.9%) in the main group and in 5 children (2.4%) in the control group (p less than 0.0001). Acute Cp infection was detected in 27 (7.4%) and 3 (1.4%) patients, respectively (p = 0.003). The acute Mr-CP co-infection was only diagnosed in 30 patients (8.2%) in the main group (p less than 0.0001). During the study, among patients with atypical bacterial infection treated with azithromycin, a relatively lower percentage of relapse of respiratory system infections (21/77, 27.2%) was noted compared those who received another antibacterial treatment (51/118, 43.2%; p = 0.035).

In accordance with the results of the study, it was found that the atypical bacteria Mycoplasma pneumoniae and Chlamydia pneumoniae play an important role in the development of relapses of acute respiratory diseases in 'child. Treatment with azithromycin for infections caused by atypical bacteria greatly reduces the incidence of relapse.

Thus, M. and Cp can be considered among these main factors, the identification and elimination of which are necessary in order to avoid the recurrence of respiratory infections during the childhood.