Risk Factors For Different Grades Of Lower Respiratory Tract Infections In Children With Measles In Hangzhou:based On Chest Radiography

Objective:This study aimed to(1)analyze the risk factors that affect the grades of lower respiratory tract infections(LRTIs)in children with measles in Hangzhou;(2)analyze the types of co-infected pathogenic bacteria in different LRTIs grades,and demonstrate the value of chest radiography(CR)in differentiating types of co-infected pathogenic bacteria in children with measles.Methods:Study 1:Data from 187 hospitalized children with measles complicated with LRTIs were collected from Hangzhou Children’s Hospital.The severity of LRTIs was classified into three grades according to CR findings(normal was assigned to grade 0,mild to moderate abnormalities was assigned to grade 1 and severe abnormalities was assigned to grade 2),which were taken as dependent variables.The factors,e.g.gender,age(in months),living environment,highest temperature in the course,the disease course before admission,the first symptoms,feeding mode,delivery mode,with or without premature birth,with or without vaccination,with or without inducement,Body Mass Index(BMI),with and without other complication,with or without other pathogens,were taken as independent variables.Firstly,all factors were analyzed by univariate logistic regression analysis,and then the factors with P values<0.1 were analyzed by ordered logistic regression analysis.Study 1:Data from 201 hospitalized children with measles complicated with LRTIs were collected from Hangzhou Children’s Hospital.All patients underwent throat swab/sputum bacterial culture,detection of respiratory pathogens serum IgM antibody and CR.Firstly,the types of pathogens associated with lower respiratory tract in children with measles were analyzed according to the results of laboratory examinations.Then,the severity of LRTIs was graded according to the findings of CR,and the effects of different pathogens on the classification of LRTIs were analyzed.Finally,whether other pathogens and types of pathogens could be predicted according to CR was analyzed.Results:Study 1:There were 74(39.57%)cases with Grade 0 LRTIs,77(41.18%)cases with Grade 1 LRTIs and 36(19.25%)cases with Grade 2 LRTIs in the study.After the univariate logistic regression analysis,disease course,gender(male),feeding history(non-breastfeeding),first symptoms(with respiratory symptoms),co-infected with other pathogens,and without measles vaccine with p<0.1 were included in the multiple logistic regression analysis.After multiple logistic regression analysis,disease course(OR=1.110,95%CI:1.022-1.141),non-vaccination of measles vaccine(OR=1.799,95%Cl:1.060-3.053)and co-infected with other pathogens(OR=1.629,95%CI:1.080-2.457)were observed to be the independent predictive variables.Study 2:There were 80(39.80%)cases with Grade 0 LRTls,85(42.29%)cases with Grade 1 LRTIs and 36(17.91%)cases with Grade 2 LRTIs in the study.There were 88 strains of pathogens detected from 62 cases,including 16 strains of Gram-positive bacteria(11 strains of Staphylococcus aureus and 5 strains of Streptococcus pneumoniae),26 strains of Gram-negative bacteria(13 strains of Haemophilus influenzae,6 strains of Army pneumophila,6 strains of Haemophilus parainfluenzae and 1 strain of Acinetobacter baumannii/Acinetobacter calcoacetate),24 strains of virus(9 strains of influenza A,7 strains of influenza B,4 strains of respiratory syncytial viru,3 strains of parainfluenza virus and 1 strain of cytomegalovirus),13 strains of Mycoplasma pneumoniae,6 strains of Chlamydia pneumoniae and 3 strains of yeast-like fungi.The rate of co-infected other pathogenic bacteria were different among the patients with different grades of LRTIs(χ2=23.688,p<0.001),and with the increase of the LRTIs grade,the rate of co-infection increased(Grade 0 vs Grade 1,χ2=10.606,p=0.001;Grade 1 vs Grade 2,χ2=4.783,p=0.029).But no significant difference in the distribution of co-infected pathogens during different grades of LRTIs 088,p=0.580)was observed.There were 45 cases with one type of pathogen and 17 cases with more than one types of pathogens in this group,and there was no significant difference in the distribution of cases with one pathogen or more than two pathogens among different grades of LRTIs(χ2=0.054,p=0.816).Conclusions:Study 1:Three clinical factors including long disease course before admission,without measles vaccine and with other pathogens co-infections were the independent risk factors for infecting advanced LRTIs in children under five years old with measles in Hangzhou.Study 2:(1)Haemophilus influenzae,Mycoplasma pneumoniae,Staphylococcus aureus,influenza A,influenza B,Legionella pneumophila and Haemophilus parainfluenzae were the common pathogens in LRTIs of children with measles in Hangzhou.(2)There was no difference in the distribution of different pathogens among different grades of LRTIs.Children infected with Mycoplasma pneumoniae were more likely to be co-infected with multiple pathogens in their lower respiratory tract,but co-infected one or more than two pathogens could not affect the grade of LRTIs in children with measles.(3)The rates of co-infected other pathogenic bacteria were different among different grades LRTIs,and children with high-grade LRTIs were more likely to co-infect with other pathogenic bacteria,which suggested that when children with measles had high-grade LRTIs,their lower respiratory tract may be co-infected with other pathogenic bacteria,however the CR could not identify which kind of pathogenic bacterial was co-infected in children with measles.