Human Bocavirus surveillance in children aged 6 years with acute respiratory tract infection in Beijing

Objective To investigate the infection status of Human Bocavirus (HBoV) in children aged 6 years with acute respiratory tract infection in Beijing from 2013 to 2014. Methods A total of 5623 clinical samples were collected from the children aged 6 years with acute respiratory tract infections in 28 sentinel hospitals in Beijing from January 2013 to December 2014. Real time PCR and nest RT-PCR were conducted to detect the nucleic acid of HBoV and subsequent genotyping. Results A total of 38 HBoV infection cases were detected, the overall positive rate was 0.68%. The positive rate was 0.88% in age group 0-1 years, 1.00% in age group 1-3 years and 0.34% in age group 3-6 years. The positive rate was higher in age group 3 years than in age group 3 years(2=10.058, P=0.001). In 2013, the positive rate was 0.48% in March (1/208), 0.90% in August (2/221), 1.52% in September (4/263), 2.00% in October (9/449), 1.52% in November (8/524) and 0.35% in December (2/567). In 2014, the positive rate was 0.19% in March (1/519), 0.57% in May (2/348), 5.56% in August (4/72), 1.14% in September (1/88) and 3.41% in October (3/88). The infections mainly occurred during August-October and the incidence peak was in August. The co-infection rate of HBoV and other respiratory viruses (coronavirus, rhinovirus, respiratory syncytial virus and parainfluenza virus type 3) was 18.42% (7/38). The 38 HBoV1 strains shared 98.4%-99.6% homology of nucleotide sequence and 98.2%-100.0% homology of amino acid sequence respectively with prototype strains ST1 and ST2. Conclusion Some acute respiratory tract infections in children in Beijing were associated with HBoV infection, HBoV1 was predominant and the infection usually occurred during August-November in Beijing.