Background: Acute lower respiratory infection (ALRI) is a major cause of hospitalization for children in China, while the etiological diagnosis of ALRI remains a challenge. This study was performed to evaluate the utility of the blind Nasotracheal aspiration (NTA) in the pathogen detection in ALRI through an evaluation of the test's specificity.
Methodology/principal findings: A hospital-based study of children ≤3 years was carried out from March 2006 through March 2007 in Suzhou University Affiliated Children's Hospital, including 379 cases with ALRI from the respiratory wards, and 394 controls receiving elective surgery. Nasopharyngeal swabs (NPS) and NTA specimens were taken on admission. S. pneumoniae was isolated from 10.3% of NTA samples from ALRI children, H. influenzae from 15.3%, and M. catarrhalis from 4.7%. The false positive rate--the strains from NTA in control group children--was 8.4% (95% CI: 5.8%-11.4%) for S. pneumoniae, 27.2% (95% CI: 22.7-31.5%) for H. influenzae, and 22.1% (95% CI: 18.0%-26.2%) for M. catarrhalis. The agreement between NPS and NTA in the control group was over 70%.
Conclusion/significance: The blind NTA test is not a useful test for etiologic diagnosis of ALRI.