Human Coronavirus-NL63 infections in Korean children, 2004–2006

BACKGROUND: Human coronavirus-NL63 (HCoV-NL63) has been isolated from children with respiratory tract infections and its prevalence in Korea has not been reported. OBJECTIVES: This study was designed to investigate the presence and the clinical features of HCoV-NL63 during two winter seasons. STUDY DESIGN: During April 2004–April 2006, nasopharyngeal specimens from children hospitalized with acute respiratory disease were tested for common respiratory viruses, including RSV, influenza A, influenza B, parainfluenza viruses, and adenovirus by IFA. hMPV infection was excluded by nested RT-PCR using primers for F-gene. To detect HCoV-NL63, previously described nested PCR assays for 1a and 1b were used. PCR products of the 1a gene for HCoV-NL63 were sequenced. RESULTS: Out of 872 nasopharyngeal aspirate from children aged under 16 years, 14 (1.7%) were positive for HCoV-NL63. Most of the patients had croup (64.2%) or bronchiolitis (21.4%). The peak prevalence was found in November (28.5%). Most were collected between November 2004 and February 2005. CONCLUSIONS: HCoV-NL63 may be one of the causative agents of acute respiratory tract infection, especially croup.