Relevance: Bronchiolitis is the most common disease of the lower respiratory tract during the first years of life. It usually presents with cough, increased work of breathing, and it often affects a child's ability to feed. In primary care, the condition may often be confused with a common cold, though the presence of lower respiratory tract signs (wheeze and/or crackles on auscultation) in an infant in mid-winter would be consistent with this clinical diagnosis.

In 60-85% of cases, the causative agent of this disease is a respiratory syncytial virus (RSV) of Pneumovirus genera, family Paramyxoviruses. Also it could be cytomegalovirus, adenovirus, mycoplasma and chlamydia.

Purpose: To analyze the frequency of bronchiolitis detection in children undergoing in-patient treatment at the infectious-diagnostic department of Ternopil Regional Children's Hospital (TRCH) and to compare it with the world data.

Materials and methods: This study is retrospective descriptive analysis. We have been revising medical cards of children which received inpatient treatment at the infection-diagnostic department of TRCH, during 2016-2017. Patients, diagnosed with acute pneumonia and acute bronchiolitis on the basis of approved protocols, were selected for analysis. Thus, the study group comprised 199 patients. Their average age was (15.85 ± 1.23) years. 109 (54.8%) of them were boys, and 90 (45.2%) – girls.

Study Results: Among 199 cases, bronchiolitis was diagnosed only in 9 (4.5%) children, whereas pneumonia in 189 (95.5%) cases, 54 (28.6%) of which was unilateral and 132 (71.4%) – bilateral. Pneumonia was complicated with broncho-obstructive syndrome in 69 (36.5%) children. In 17 (8.9%) cases the changes on the chest X-ray were minimal and didn’t meet the roentgenological criteria of pneumonia that gives us the possibility to think about the erroneous diagnosis of pneumonia.

Conclusion. This study has demonstrated a tendency of pneumonia hyperdiagnostics during child hospitalizations. Whereas the diagnosis of bronchiolitis is quite rare. Due to different etiological causative agent, this leads to a problem like an unnecessary and excessive antibiotics prescription.