This study was designed and performed for evaluations of clinical manifestation and course of the children under 2 year of age with respiratory tract infection and positive respiratory syncytial virus(RSV) antigen.

The selection criteria of the patients were children under 24 month-of-age, Clinical manifestation of respiratory tract infection, and positive RSV antigen that was detected by Vitek ImmunoDiagnostic Assay System(VIDAS) from nasal cavity. The additional laboratory and simple chest X-ray findings were reviewed from the chart of children who were admitted Wonkwang university hospital from October 1999 to March 2000.

Total number of patients enrolled on this study was 102. The 48(47%) children were RSV antigen positive by VIDAS method. Abnormal chest X-ray findings were noticed in 38 cases. The male to female sex ratio of 48 RSV antigen positive cases was 1.2 : 1. The mean and range of age was 10.2±5.9 and 1.0~24 months. The peak outbreak of cases was noticed on November, 1999. All of the cases shows coughing but rale was audible in 30 cases(60%). Dyspnea, wheezing, and intercostal retraction were noticed 11(23%), 15(31%), and 10(21%) cases respectively. The most common chest X-ray finding was scattered patch infiltration that was noticed in 30 cases(63%). The mean total white blood cell counts in peripheral blood was 12,608±4,686/mm³ . The mean blood level of IgA and IgE were 50.8±20.9 and 72.1±98.3mg/dL respectively. The C-reactive protein was 16.0±18.5mg/L. Total 5 cases need a mechanical respiraton. The duration of admission was under 7 days in 36 cases(75%).

The RSV antigen was detected commonly in late fall and winter season. The severity of children under 2 years old with RSV respiratory tract infection take in some degree a gave courses.