Human Coronaviruses HCoV-NL63 and HCoV-HKU1 in Hospitalized Children with Acute Respiratory Infections in Beijing, China

The human coronaviruses (HCoVs) HCoV-NL63 and HCoV-HKU1 are two recently discovered coronaviruses that circulate widely and are associated with acute respiratory infections (ARI). We detected HCoV-NL63 and HCoV-HKU1 in specimens collected from May 2008 to March 2010 from patients with ARI aged <7.75 years of age attending the Beijing Children's Hospital. Thirty-two (8.4%) and 57 (14.9%) of 382 specimens tested positive for HCoV-NL63 and HCoV-HKU1, respectively, by real-time RT-PCR. Use of a Luminex xTAG RVP Fast kit showed that coinfection with respiratory syncytial virus and parainfluenza 3 virus was common among patients infected with either virus type. In HCoV-HKU1-infected patients, the predominant clinical symptoms were cough, fever, and expectoration. In HCoV-NL63-infected patients they were cough, fever, and rhinorrhea. Phylogenetic studies showed that the HCoV-HKU1 nucleoprotein gene was relatively conserved compared to NCBI reference sequences, while the 1ab gene of HCoV-NL63 showed more variation.