Characterization of human coronavirus OC43 and human coronavirus NL63 infections among hospitalized children <5 years of age.

BACKGROUND: Multiplex molecular assays now make it possible for clinical laboratories to detect human coronaviruses (HCoVs). We investigated the clinical characteristics of HCoV-OC43 and HCoV-NL63 in patients <5 years of age during a recent coronavirus season.

METHODS: Respiratory viruses were detected using a multiplex molecular assay at St. Louis Children`s Hospital starting in November 2012. We analyzed demographic and clinical data from all patients <5 years of age with solo detection of HCoV-OC43 (n = 52) and HCoV-NL63 (n = 44) and for comparison, samples of children with respiratory syncytial virus, parainfluenza virus and picornaviruses.

RESULTS: During the study period, HCoV-OC43 (4%) was the 5th and HCoV-NL63 the 8th (2%) most common respiratory virus. Coinfections were detected in 35% and 38% of children with HCoV-OC43 and HCoV-NL63, respectively. Croup was more common with HCoV-NL63 (30%) than with HCoV-OC43 (2%). Lower respiratory tract infection occurred in 33% of children with HCoV-OC43 and 25% of children with HCoV-NL63. Severe illness was less common in HCoV-NL63, HCoV-OC43 and parainfluenza virus (14%, each) compared with respiratory syncytial virus (30%) and picornaviruses (26%; P = 0.055 for HCoVs combined compared with the other respiratory viruses) and occurred mainly in those with underlying medical conditions.

CONCLUSIONS: Infections caused by HCoV-OC43 and HCoV-NL63 are common and include some with lower respiratory tract involvement and severe disease, especially in children with underlying medical conditions. Overall, a substantial burden of disease associated with both HCoV-OC43 and HCoV-NL63 was observed for hospitalized children <5 years of age.