The correlation study of viral load of human bocavirus and clinical features of children with acute respiratory tract infection
10.3760/cma.j.issn.1000-6680.2014.06.006
- VernacularTitle:人类博卡病毒载量与儿童呼吸道感染临床特征的相关性
- Author:
Fang YIN
;
Weifang ZHOU
;
Meijuan WANG
;
Yongdong YAN
;
Wei JI
- Publication Type:Journal Article
- Keywords:
Respiratory tract infections;
Bocavirus;
Child;
Viral load;
Clinical characteristics
- From:
Chinese Journal of Infectious Diseases
2014;32(6):343-348
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the detection of human bocavirus (HBoV) in children with acute respiratory infection and to explore the relationship between viral load and clinical characteristics of acute respiratory infection in children.Methods A total of 4 501 nasopharyngeal secretion samples were collected from hospitalized children with acute respiratory infection from January 2013 to June 2013.HBoV-positive children were divided into simple infection group and mixed infection group.Children with HBoV DNA≥1 × 104 copy/mL were categorized into high viral load group,while those with HBoV DNA ＜1 × 104 copy/mL were categorized into low viral load group.HBoV was determined by fluorescence quantitative polymerase chain reaction (PCR).Respiratory syncytial virus (RSV),influenza virus (Inf)-A,Inf-B,parainfluenza virus (Pinf)-Ⅰ 、Pinf-Ⅱ 、Pinf-Ⅲ and adeno virus antigen were detected by direct antigen-specific immunofluorescence assays.Mycoplasm Pnuemonia was detected by real-time fluorescence quantitative PCR.Serum mycoplasma antibodies were detected by enzyme-linked immunosorbent assay (ELISA).Bacteria was detected by sputum culture.Over the same period,23 children undergoing elective inguinal hernia operation with no respiratory infection or fever were considered as control group.The percentage of peripheral blood T lymphocyte subsets were tested by flow cytometry.Inter-group differences were compared using Chi-square test or Fisher exact test.Viral loads were compared using Mann-Whitney test.Results Two hundred and twenty-two HBoV-positive cases were detected with a positive rate of 5.41％ (222/4 105),33.33％ (74/222) of which were with high viral load and 66.67％ (148/222) were with low viral load.There was a high incidence in the age group of 1-2 years.The simple HBoV infection accounted for 24.32％,including 26 cases with high viral load and 28 cases with low viral load.Wheezing was more common in patients with high viral load than those with low viral load,and the difference was statistically significant (88.46 ％ vs 42.86 ％,x2 =12.295,P=0.001).Among the 222 HBoV-positive cases,the median viral load of HBoV in simple infection group was 3.86 × 103 copy/mL,and 1.0× 103 copy/mL in mixed infection group.The difference of the viral load between these two groups was statistically significant (Z =2.906,P =0.004).Mycoplasma and Streptococcus pneumonia were most commonly detected in the 168 patients with mixed infection.Percentages of CD3+ and CD3+/CD8+ subsets were significantly lower in HBoV simple infection group and mixed infection group,compared to control group (both P＜0.05).However,percentages of CD3 /CD19+,CD19+/ CD23+ subsets were significantly higher in HBoV simple infection group and mixed infection group,compared to control group (both P＜0.05).Conclusions HBoV is one of the pathogens causing acute respiratory tract infection in children,which lead to cellular immunity dysfunction in children.Moreover,children with higher HBoV load are more likely to develop wheezing.Co-infection with other pathogens should be considered in children with low HBoV load.
