Background: Respiratory Syncytial Virus (RSV) is a common etiological agent of respiratory infections in neonates and small chil-dren.The aim of the study was to evaluate: frequency and clinical outcome of RSV infections in children, risk factors and coincidence with atopy and humoral immunodeficiency. Material/Methods: Patient ’s history, changes on physical examination, laboratory investigation, chest x-ray, serum IgA, IgG, IgM, IgE levels and specific IgM and IgG antibodies against RSV were analysed in 160 children, aged 2 to 36 months, with respiratory infection.Results: RSV infection was diagnosed on the basis of specific anti-RSV IgM antibodies appearance or increasing anti-RSV IgG level. The group of 61 children with RSV infection included: 13 (21.3%) premature infants, 14 (22.7%) children less than 2 months old and 32 (52.3%) patients over 12 months of age. The main clinical manifestations were: wheezing (obturative) bronchitis (75.4%), pneumonia (44.3%) or both (32.8%). Eight cases of severe bronchiolitis among the youngest infants were noted. Leukocytosis was observed in 77% and increased CRP level in 23% of children. Serum IgA and IgM levels were normal in 82%, IgG in 95.1% and total IgE level in 47.5% of patients. Increased IgE level was observed in 52.5%. Only 26.2% of these children demonstrated clinical features of atopy.Conclusions: RSV infection, usually obturative bronchitis or pneumonia,is commonly observed in young children. Severe bronchi-olitis may occur. Coincidence frequency of RSV infection with total serum IgE elevation and atopy needs further investigation.

Keywords: RSV, Respiratory Tract Infections, Immunoglobulins, children