OBJECTIVEA new human coronavirus, HCoV-NL63, was identified recently from two Dutch children with acute respiratory infection (ARI) by two scientists in the Netherlands in 2004. To investigate if this newly discovered virus is associated with acute respiratory infections in pediatric patients in Beijing, tests were developed to detect HCoV-NL63 gene fragments from throat swab and nasopharyngeal aspirates collected from children in outpatient and inpatient departments with ARI in Beijing from Dec. 2003 to Mar. 2004.

METHODSA total of 245 clinical samples, which were negative either for diagnostic tests of human respiratory syncytial virus, influenza virus A and B, adenovirus, parainfluenza virus 1, 2 and 3 by indirect immunofluorescence assay or human metapneumovirus by RT-PCR, were screened for HCoV-NL63 by nested PCR amplifying gene fragments located on the 1b and 1a genes. Amplicon of PCR from 1a gene of HCoV-NL63 was sequenced and the sequences were compared with those in GenBank nucleotide sequence database.

RESULTSThree (1.2%) out of the 245 samples were positive for HCoV-NL63 by nested-PCR using primers on 1b gene. These three samples also showed positive results on nested PCR in which primers were designed with sequences complementary to 1a gene segments. These positive samples were collected from hospitalized children under 2 years of age with pneumonia, bronchiolitis and bronchitis, respectively. The partial 1a gene sequences from two positive samples (BJ3140 and BJ3787) of HCoV-NL63 showed 100% homology between each other and high homology (98%-99%) with the sequences of 1a gene of HCoV-NL63 reported from different countries in GenBank. Phylogenetic analysis showed that BJ3140 and BJ3787 fell into the same genetic cluster (group 1).

CONCLUSIONSThese data suggest that some of acute respiratory infections in young children in Beijing area are related to the newly identified HCoV-NL63.