Analysis Of Serum Pathogen IgM Antibody In Children With Lower Respiratory Tract Infection In A Hospital

Objective To investigate the epidemiological distribution characteristics of IgM antibody(IgM-Ab)of serum respiratory pathogens in children with lower respiratory tract infection.Guide clinicians to select drugs to reduce the occurrence of severe infection,mortality and drug resistance.Methods A total of 5515 children with lower respiratory tract infection admitted to the Department of Pediatrics of General Hospital of Ningxia Medical University from January1,2018 to December 31,2022 were collected.Indirect immunofluorescence assay was used to detect serum IgM antibodies against nine respiratory pathogens(Mycoplasma pneumoniae(MP),Chlamydia pneumoniae(CP),Adenovirus(ADV),Q fever rickettsia(QFR),Respiratory syncytial virus(RSV),Legionella pneumophila(LP),Influenza A virus(INFA),Influenza B virus(INFB)and Parainfluenza virus 1,2,3(PIVs)).Among them,2861 males and 2654 females(aged 0 minutes-14 years)were studied.The age,gender,onset season and region of children with positive serum pathogen IgM antibody were analyzed to obtain whether there were epidemic characteristics in distribution.Results1.In this paper,from 5515 children with lower respiratory tract infection serum nine respiratory pathogens IgM antibody test results : serum pathogens IgM antibody positive children with a total of 1179 people,the positive rate of 21.38 %.There were 1034 people with single positive IgM antibody of serum pathogens,with a positive rate of 18.75 %.The highest positive rate was Mycoplasma pneumoniae,with a positive rate of 15.43 %,followed by influenza B virus,with a positive rate of 1.52 %,followed by respiratory syncytial virus,parainfluenza virus 1,2,3,adenovirus,influenza A virus,Chlamydia,Rickettsia,Legionella pneumophila,with positive rates of 0.82 %,0.42 %,0.27 %,0.15 %,0.09 %,0.04 %,0.02 %,respectively.There were 145 people with mixed positive serum pathogen IgM antibody,with a positive rate of 2.63 %.Among them,the positive rate of Mycoplasma pneumoniae combined with influenza A virus was the highest,with a positive rate of 1.21 %.2.There was no significant difference in the positive rate of IgM antibody between different genders(χ2= 1.055,P = 0.304).The most common serum pathogen in both men and women was MP.3.The positive rate of IgM antibody of serum pathogens in children of different ages was analyzed.There was a significant difference between children of different ages(χ2 = 171.396,P < 0.001).The positive rate was the highest in early childhood,with a positive rate of27.37 %.The positive rate of ≤ 6 years old was significantly higher than that of > 6 years old(χ2 = 43.375,P < 0.001).No positive children were detected in neonatal period.MP was the most detected serum pathogen in all age groups.4.The positive rate of serum pathogen IgM antibody in different seasons was analyzed.There were significant differences between different seasons(χ2 = 10.169,P = 0.017).The positive rate was the highest in autumn,and the positive rate was 24.21 %.There was no significant difference between spring and winter(χ2 = 0.085,P = 0.771).There was a significant difference between summer and autumn(χ2 = 7.070,P = 0.008),and autumn was significantly higher than summer.The most common serum pathogen in different seasons was MP.5.The analysis of the positive rate of serum pathogen IgM antibody in urban and rural children showed that there were significant differences between different regions(χ2 = 42.464,P < 0.001),and the positive rate of rural children was higher than that of urban children.MP is the most common pathogen in both urban and rural areas.Conclusion1.The highest positive rate of IgM antibody against nine respiratory pathogens in serum was Mycoplasma pneumoniae(MP),followed by influenza B virus(INFB)and influenza A virus(INFA).MP is the most common pathogen among all age groups,genders,seasons and regions.2.The season with the highest incidence of serum pathogens in this article is autumn.There are significant differences in pathogens between urban and rural areas,and the incidence of rural areas is significantly higher than that of urban areas.There was no significant difference in the positive rate between different genders.There are differences between different age groups,most of which are early childhood children,and the positive rate of children ≤ 6 years old is higher than that of children > 6 years old.No positive children were detected in neonatal period.