| PART Ⅰ PREVALENCE AND VIRAL LOAD OF HUMAN RHINOVIRUS IN HOSPITALIZED CHILDREN WITH ACUTE ASTHMA EXACERBATIONSBackground and objective: Human rhinovirus(HRV) infection is closely related to childhood asthma exacerbations. The objective of present study was to determine the prevalence of HRV infection in children with acute asthma exacerbations also investigate the relationship between HRV viral load of the three HRV types and severity of acute asthma exacerbations.Methods: Children with acute asthma exacerbations from the Department of Respiratory Medicine at the Children’s Hospital of Chongqing Medical University in China were enrolled in the study during March 2012 through November 2015. Nasopharyngeal aspirate(NPA) were collected and assessed for common respiratory viruses then HRV positivesamples were sequenced to identify types and determined viral load by polymerase chain reaction(PCR).Results: 143 children with acute asthma exacerbations were recruited in present study and HRV in 72(50.3%) out of all cases. The VP4/VP2 region was successfully amplified in 56 samples; HRV-A was identified in20 samples(35.7%), HRV-B in 5(8.9%), and HRV-C in 31(55.4%). The number of HRV-C detected positive was more than HRV-A and HRV-B(P=0.037 and P<0.001). HRV-C detection rate in severe groups was significantly higher than mild group(36.1% vs. 6.5%; P=0.004). The viral load of HRV-A in severe exacerbations group was higher than mild and moderate groups(2.5 × 105 copies/m L vs. 1.7 × 103 copies/m L; P<0.001;2.5 × 105 copies/m L vs. 2.1 × 103 copies/m L; P=0.022, respectively), while HRV-C viral load among three severity groups had no significant difference.Conclusion: The virus most frequently detected in asthma exacerbations appears to be HRV, primarily HRV-C which common occur in severe asthma exacerbations. HRV-A with high viral load lead to severe asthma exacerbations and HRV-C viral load and disease severity have no significant correlation.PART Ⅱ PREVALENCE AND FOLLOW-UP OF HUMAN RHINOVIRUS IN OUTPATIENTS WITH ACUTE ASTHMA EXACERBATIONSBackground and objective: The persistent symptoms of asthma exacerbations may be associated with HRV presence. The objective of this study was to determine the relationships between acute asthma exacerbations and HRV infections, also investigate the virus detection after asthma acute attack.Methods: The study was performed in outpatients with asthma exacerbations during November 2014 to December 2015 at the Children’s Hospital of Chongqing Medical University in China. Their nasopharyngeal swabs(NPS) were collected and detected common respiratory virus. A prospective study among these outpatients with asthma exacerbations, NPS were collected and clinical outcomes were recorded after 4 weeks when they visited clinic again.Results: A total of 131 children, including 88 cases with asthma exacerbations and 43 controls with stable asthma were recruited. In asthma exacerbations group HRV positive were in 14(15.9%) cases: HRV-A 3,HRV-B 1, HRV-C 9 and 1 was untyped HRV. The detection rate of total virus in asthma exacerbations group was significantly higher than stableasthma group(43.2% vs. 16.3%; P=0.002). Furthermore, HRV-positive rate in asthma exacerbations group was significantly higher than stable asthma group(15.9% vs. 2.3%; P=0.045). All the HRV-positive acute asthma exacerbations patients participated in follow-up and only one case infected respiratory syncytial virus(RSV) within 4 weeks after first visit; the others were negative and severity of disease controlled well. Another 23 patients were without HRV at first visit while after 4 weeks there were 5 cases appeared acute asthma exacerbations again and among of them 4 patients infected with HRV.Conclusions: Respiratory virus infections is one of the important factors induced asthma exacerbation among outpatients, especially HRV infection. HRV persists no more than 4 weeks in general. |
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