Clinical disease in children associated with newly described coronavirus subtypes

OBJECTIVES. Coronaviruses cause upper respiratory illness and occasionally lower tract disease in susceptible populations. In this study we examined the prevalence of 4 human coronaviruses, including subtypes OC43, 229E, and the recently described NL63 and HKU1 in a pediatric population presenting to a children's hospital. PATIENTS AND METHODS. Specimens collected over a 1-year period from pediatric patients presenting with acute respiratory illness were analyzed for the presence of 4 coronavirus subtypes using consensus and subtype-specific real-time reverse-transcription polymerase chain reaction assays. The demographic and clinical characteristics associated with coronavirus infection were examined retrospectively. RESULTS. Coronaviruses were detected in 66 of 1043 children. Eight, 11, 19, and 28 specimens were positive for subtypes 229E, NL63, OC43, and HKU1, respectively. Coronaviruses were detected throughout the study period; all 4 of the subtypes were present simultaneously in December. The acute clinical features were similar across subtypes. Of 32 children infected with a coronavirus as the sole respiratory pathogen, 13 had lower respiratory tract disease. Children whose only detectable respiratory virus was a coronavirus were more likely to have underlying chronic disease than were children coinfected with another respiratory virus. CONCLUSIONS. Although 4 subtypes of coronavirus were detected, the recently discovered coronavirus subtypes NL63 and HKU1 accounted for the majority of coronaviruses detected in our cohort of mostly hospitalized children with respiratory symptoms. New subtypes likely represent a substantial portion of previously unexplained respiratory illnesses.