Etiology Analysis Of Bronchoalveolar Lavage In Infant With Severe Pneumonia

Objective To understand the characteristics of etiology distribution and drug resistance in infant with severe pneumonia through virus antigen detection, bacteria culture and drug susceptibility test in the bronchoalveolar lavage fluid(BALF).Methods 745 infants with severe pneumonia were enrolled from department of respiration and pediatric intensive care unit(PICU) in the Children’ s Hospital of Chenzhou from January 2012 to December 2015.The enrolled infants were divided into experimental group and control group according to whether conduct of fiberoptic bronchoscopy alveolar lavage or not. Experimental group had 383 cases infant and collected BALF. Seven kinds of respiratory virus antigen detection by direct immunofluorescence assay(DIF), bacteria culture and drug susceptibility test was conducted in the BALF, respectively. Control group had 362 cases infants using nasopharyngeal swab to conduct seven kinds of respiratory virus antigen detection and sputum to conduct bacteria culture and drug susceptibility test, respectively.Result1. 745 infants with severe pneumonia were enrolled. 378 cases were male and 367 were female, and the ratio of male to female was 1.03:1.The age was from 1 month to 36 month.2. In the experimental group, 257 cases had one virus positive at least. The total detected rate was 67.1%. Among them, respiratory syncytial virus(RSV) were 161(42.04%), parainfluenza virus 3(PIVIII)were 39(10.18%), adenovirus(ADV) were 25(6.53%), influenza virus A(IFA) were 16(4.18%), influenza virus B(IFB) were 10(2.16%),parainfluenza virus 1(PIVI) were 4(1.04%) and parainfluenza virus 2(PIVII) were 2(0.52%). In the control group, 235 cases had one virus positive at least. Among them, 153 cases were RSV(42.27%), 35 cases were PIVIII(9.67%), 21 cases were ADV(5.80%), 12 cases were IFA(3.31%), 8 cases were IFB(2.21%), 3 cases were PIVI(0.83%) and 3cases were PIVII(0.83%). The virus detected rate was no significant differences between experimental group and control group(P>0.05).3. In the experimental group, 69 cases had one bacteria positive at least. Among them, 17 cases were Klebsiella pneunoniae(4.44%), 15 cases were escherichia coli(3.92%), 8 cases were enterobacter taylorae(2.09%), 7 cases were pseudomonas aeruginosa(1.83%), 11 cases were streptococcus pneumoniae(2.87%), 6 cases were staphylococcus aureus(1.57%) and 5 cases were staphylococcus haemolyticus(1.31%). In the control group, 37 cases had one bacteria positive at least. Among them,10 cases were Klebsiella pneunoniae(2.76%), 8 cases were escherichia coli(2.21%), 4 cases were enterobacter taylorae(1.1%), 3 cases were pseudomonas aeruginosa(0.83%), 7 cases were streptococcus pneumoniae(1.93%), 3 cases were staphylococcus aureus(0.83%) and 2cases were staphylococcus haemolyticus(0.55%). The bacteria detected rate was no significant differences between experimental group and control group(P>0.05).However, the total bacteria culture positive rate was higher in the experimental group than in the control group(P<0.05).4. Total cultured 106 kinds of pathogen bacterial in the experimental and control group, including 72 stains were G-(67.92%) and 34 stains were G+(32.08%). Klebsiella pneunoniae, escherichia coli, enterobacter taylorae and pseudomonas aeruginosa as high as 70% were resistant to semi-synthetic penicillins antibiotic; Klebsiella pneunoniae and escherichia coli as high as 80% were resistant to ceftazidime and ceftriaxone, and had high sensitivity to cefoperazone/sulbactam and meropenem. Pseudomonas aeruginosa 30% were resistant to meropenem,and had high sensitivity to cefoperazone/sulbactam. Gram positive bacteria strains had high resistant to penicillin, semi-synthetic penicillins antibiotic, Cephalosporin, erythrocin and sulfonamides, but we had not found resistant to vancomycin.Conclusions1. BALF virus antigen detection and bacteria culture were better mode of etiology detection in infants with severe pneumonia.2. Most etiology of infant severe pneumonia were virus, and RSV infection is the main cause.3. The total positive rate of bacteria culture was higher in the BALF than in the sputum.4. Bacteria infection was the important cause of infant severe pneumonia, and the main were gram-negative bacteria. Early detection of pathogenic bacteria and drug resistance were very important to improve curative effect and prognosis.