The purpose of this study is to identify the viral etiology of acute respiratory illnesses and to determine epidemiology in outpatients in Busan, Korea.

We collected nasal wash samples from 990 patients who visited the hospital for acute respiratory illnesses between January 2007 and December 2008. Extracted DNA or RNA from specimens was used for viral detection by an RT-PCR method.

Of a total of 990 samples, viruses were detected in 351 cases (35.5%). The ratio of male to female was 1.6:1 and 93.7% were less than 5 years old. Rhinovirus was detected year-round in 202 cases (57.5%), respiratory syncytial virus from October to March in 57 cases (16.2%), adenovirus year-round in 37 cases (10.5%), influenza virus from December to April in 21 cases (6%), bocavirus from January to August in 15 cases (4.3%), parainfluenza virus from April to July in 9 cases (2.6%), coronavirus from January to July in 7 cases (2%), and enterovirus from June to September in 3 cases (0.9%).

We identified the etiology and epidemiology of viruses that caused the acute respiratory diseases that were prevalent in Busan, 2007-2008. Further surveillance will be necessary.