Pathogenic Bacteria and Immunologic Mechanism of Recurrent Respiratory Tract Infection in Children / 实用儿科临床杂志

ABSTRACT

Objective To explore the pathogenic bacteria and immunologic mechanism of recurrent respiratory tract infection(RRI) in children.Methods The observation group included 50 children with RRI,26 cases were boys and 24 cases were girls, in Department of Respiratory Medicine of Wuhan Children′s Hospital were enrolled from Apr.2007 to Apr.2008.These children were divided into 3 subset groups28 cases in 6 months-2 years old group,15 cases in 3-5 years old group,and 7 cases in 6-12 years old group.The healthy control group included 50 healthy children aged 6 months -12 years.The specimens were gathered on the next morning after the children entered hospital.The secretions of noses and pharynxes were gathered with clean and aseptic tampon from children with upper respiratory tract infection and placed in aseptic vessel,and were immediately detected with the pathogenic bacteria.The secretions of lower respiratory tract were gathered with suction method from children with lower respiratory tract infection and placed in aseptic vessel, and were immediately detected with the pathogenic bacteria,the number of superinfection with some kind of pathogenic bacteria was calculated.The children in observation group and healthy control group were exsanguinated of vein when the children were hungry to detect the cellular immunity(CD3+,CD4+,CD8+,CD4+/CD8+) and humoral immunity(IgA,IgM,IgG,C3,C4).Results Three hundred and two specimens in 6 months-2 years old group were detected,and 135 pathogenic bacteria were separated,the ratio of positive was 42.2%,and the number of superinfection was 25.One hundred and thirty-seven specimens in 3-5 years old group were detected,and 47 pathogenic bacteria were separated,the ratio of positive was 34.3%,and the number of superinfection was 7.Fifty-four specimens in 6-12 years old group were detected,and 16 pathogenic bacteria were separated,the ratio of positive was 29.6%,and the number of superinfection was 2.The top 5 kinds of bacteria that those children with RRI were easily infected were Ps.aeruginosa,K.pneumoniae,S.aurens,E.coli and streptococcus pneumoniae.The CD3+,CD8+ and CD4+/CD8+ of cellular immunity in the observation group were obviously lower than those in the healthy control group(Pa