Prevalence And Genetic Charateristics Analysis Of Human Rhinovirus In Hospitalized Children With Respiratory Infections In Beijing

The study of human rhinoviruses made significant progress in the late 20th century; several important events had been identified in viral life cycle which laid foundation to the further research of the biological characteristics and pathogenic mechanisms of human rhinoviruses. Human rhinoviruses, the most frequently isolated virus, are not only acute, chronic respiratory tract pathogens but also a major factor of human common cold. More and more attention has been given to the research on the worldwide virus in recent years as it often brings about serious sequela to infants, children and susceptible adults with basic respiratory diseases, which seriously influences their life quality and brings heavy financial burden to their families and the society. Epidemiological study is an important means to monitor human rhinovirus, and analysis of genetic characteristics contributes to the detection and epidemiological investigations, helps to identify the source and trace the transmission pathways of the virus.ObjectiveHuman rhinoviruses from children and infants with respiratory tract infection in Beijing China were selected to study, to analyze the prevalence, the epidemic situation, regularity and genetic characteristics, and to find the human rhinoviruses risk so as to accumulate the basic information of etiology and epidemiology of human rhinoviruses in order to provide prevention and control measures.MethodsNasopharyngeal secretion samples from 427 children with acute respiratory infection (158 from girls and 269 from boys) were collected in Beijing Children's Hospital from May 2008 to September 2010 to research the etiology and epidemiology of human rhinoviruses. Real-time reverse transcription PCR (Real-time RT-PCR) was used to screen HRV and other respiratory viruses, and virus isolation was made at the same time. Human rhinovirus positive samples (the Ct value is≤35, the samples have a significant amplification curve) were selected. The capsid protein (VP)4/VP2 gene was sequenced and phylogenetic analysis was carried out.ResultsOut of 427 nasopharyngeal secretion samples, 123 ones were human rhinoviruses positive with the positive rate of 28.81%. The main symptoms in patients were pneumonia accompanied by high fever. Six months and younger were more susceptible to human rhinoviruses, the incidence of boys was higher than that of girls. Human rhinoviruses infection occurred in the winter of 2008 and the spring of 2009 and 2010. The DNA sequencing result based on VP4/VP2 genes indicated that 36 out of 51 belonged to HRV-A (70.6%, 36/51), the rest (36.6%, 15/51) to all HRV-C, HRV-B was not detected, and with low homology in the differences of the nucleotide sequences of human rhinoviruses. The nucleotide homology of 36 strains was 74.5% to 100% in rhinoviruses genome A and 71.4% to 100% in genome C. The A genome of the Beijing strains belonged to different HRV serotypes, the nucleotide difference between groups was 24.2%. The nucleotide differences between genome C were 28.6%. The nucleotide differences between A and C was large, 56.5% in A and 52.7% in C respectively.ConclusionDuring the study period from May 2008 to September 2010, there was a high rhinoviruses detection rate among pneumonia children who presented severe clinical symptoms accompanied by fever and often co-infected with other respiratory viruses. No statistically significant differences were found between children infected with HRV and those with HRV co-infection with other respiratory viruses. Children aged 0 to 1, especially six months and younger were more susceptible to human rhinoviruses. The prevalence of HRV-C in Beijing was between HRV-A and HRV-B, and no predominate viral strain was found among the HRV in Beijing. The nucleotide sequence homology of HRV-A and C was low and their genetic relationship was a little further, suggesting more than one propagating chain of human rhinoviruses.