Bacterial etiology and their drug resistance in hospitalized children with lower respiratory tract infections in Suzhou during 2008 and 2012

Abstract

Objective To investigate the distribution of bacterial pathogens and drug resistance in hospitalized children with lower respiratory tract infections (LRTIs) in Suzhou. Methods Clinical data of 8 863 hospitalized children with LRTIs from Children's Hospital Affiliated to Soochow University during January 2008 and December 2012 were retrospectively analyzed. Sputum culture were conducted and the bacteria were identified by conventional manual method and antibiotic sensitivity tests were performed by K-B method. The Chi-square or Fisher's exact test were used for statistical analysis. Results Among 8 863 children, 2 980 (33.6%) were positive in sputum culture. A total of 3 283 strains of bacteria were isolated, including 1 182(13.3%) strains of Streptococcus pneumoniae, 530(6.0%) Haemophilus influenzae, 413 (4.7%) Staphyloccocus aureus, 324(3.7%) Moraxella catarrhalis, etc. The positive rate in ≤6 months age group ranked the top (37.6%), followed by>6-12 months (32.3%),>1-3 years (32.7%) and>3-7 years (33.7%) age groups. The lowest positive rate was found in age group >7 years (20.0%). Streptococcus pneumoniae was the predominant bacterial pathogen in children>6 months, while the positive rates of Escherichia coli, Staphyloccocus aureus and Klebsiella pneumoniae increased in children aged ≤6 months. The positive rate of sputum bacterial culture was declined when antibiotics were prescribed before admission (29.4% vs. 38.8%, χ2=26.335, P<0.01), and it was also influenced by the duration of antibiotics therapy. The positive rate of Escherichia coli was increased when antibiotics were prescribed for more than 7 days before admission. Streptococcus pneumoniae and Staphyloccocus aureus were sensitive to amoxicillin and oxacillin, respectively. Escherichia coli and Klebsiella pneumoniae were increasingly resistant to the third generation cephalosporins, but were still sensitive to piperacillin/tazobactam and cefoperazone/sulbactam. Conclusions Streptococcus pneumoniae is the most common bacterial pathogen of LRTIs in hospitalized children in Suzhou. The distribution of bacterial etiologies varies in different age groups, and the positive rate may also be influenced by use of antibiotics prior to admission. Key words: Respiratory tract infections; Bacteriology; Streptococcus pneumoniae; Child; Drug resistance