Abstract:

Objective To evaluate the value of nasopharyngeal swab bacterial culture in pathogenic diagnosis in children with respiratory tract infection. Methods Nasopharyngeal swab and oral aspirate samples were collected from 403 hospitalized children diagnosed as pertussis-like syndrome or pneumonia. The samples were inoculated in partitions on medium discs with semi-quantitative method. Bacteria were identified,and the isolates growing including and more than "+++" were definited as clinical isolates. The positive rates of culture between nasopharyngeal swab and sputum samples were compared and linked with clinical manifestation and treatment outcomes. Results In the 403 cases,the positive rate of nasopharyngeal swab culture was 31.5%（127/403）,and the top 4 bacteria were Bordetella pertussis（13.4%）,Haemophilus influenzae（7.9%）,Moraxella catarrhalis（4.0%） and Streptococcus pneumoniae（3.5%）. The positive rate of oral aspirate culture was 12.4%（50/403）,and the positive rates of the above 4 bacteria were 0.7%,4.5%,1.0% and 1.2%,respectively. The positive rates of nasopharyngeal swab culture was higher than that of oral aspirate culture（P<0.05）. The same bacteria were isolated from both nasopharyngeal swab and sputum samples in 31 of 50 cases（62.0%）. After treating with sensitive antibiotics,the results of nasopharyngeal swab culture swithed to negative in 98.4%（125/127） of all the patients. Conclusions Nasopharyngeal swab culture improves the determination of pathgens in respiratory tract in children,which plays a role in pathogenic diagnosis in children with respiratory tract infection.

Key words: Bacterium, Nasopharyngeal swab, Respiratory tract infection, Children