title: Comparison of diagnostic tools with multiplex polymerase chain reaction for pediatric lower respiratory tract infection: a single center study.
abstract: OBJECTIVE
  Acute respiratory tract infections are a leading cause of morbidity and mortality in children worldwide. Most have a viral etiology, with pneumococcus as an important pathogen. This single-center study compared the use of conventional diagnostic tools and two multiplex polymerase chain reaction (PCR) examinations for determining pathogens in lower respiratory tract infections (LRTIs) among children aged <5 years.
  
  
  METHODS
  From July to October 2010, 45 patients aged 2 months to 60 months and diagnosed as having LRTIs were enrolled. Their nasopharyngeal aspirates were evaluated through viral culture and two multiplex PCR examinations. The patients' clinical course, symptoms, signs, and laboratory findings were recorded and analyzed.
  
  
  RESULTS
  Among the 45 patients, 38 (84.4%) had detectable pathogens. Conventional viral and blood cultures had 35.6% positive rate, which increased to 51.1% when the quick antigen tests (Influenza A+B test and respiratory syncytial virus) and urine pneumococcal antigen test were combined. The positive rate further increased to 84.4% when the two multiplex PCR methods were combined. Twelve patients had co-infection, including 10 detected by the multiplex PCR methods. The co-infection rate was 26.7% (12/45).
  
  
  CONCLUSIONS
  Most LRTIs in children have a viral etiology. Multiplex PCR tests are rapid assays that can increase the diagnostic yield rate and detect slow-growing viruses and can detect more pathogens than conventional viral culture to enable, thereby helping clinicians to provide appropriate and timely treatment.
authors.affiliation: Department of Pediatrics, Kaohsiung Veterans General Hospital, Taiwan, ROC.
authors.forename: Yu-Shen
authors.initials: YS
authors.lastname: Chen
authors.affiliation: Department of Pediatrics, Kaohsiung Veterans General Hospital, Taiwan, ROC.
authors.forename: Po-Yen
authors.initials: PY
authors.lastname: Liu
authors.affiliation: Department of Pediatrics, Kaohsiung Veterans General Hospital, Taiwan, ROC. Electronic address: yf5012@hotmail.com.
authors.forename: Yung-Feng
authors.initials: YF
authors.lastname: Huang
authors.affiliation: Section of Clinical Microbiology, Department of Pathology and Laboratory Medicine, Kaohsiung Veterans General Hospital, Taiwan, ROC.
authors.forename: Chiao-Shan
authors.initials: CS
authors.lastname: Chen
authors.affiliation: Section of Clinical Microbiology, Department of Pathology and Laboratory Medicine, Kaohsiung Veterans General Hospital, Taiwan, ROC.
authors.forename: Ling-Hui
authors.initials: LH
authors.lastname: Chiu
authors.affiliation: Section of Clinical Microbiology, Department of Pathology and Laboratory Medicine, Kaohsiung Veterans General Hospital, Taiwan, ROC.
authors.forename: Nuan-Ya
authors.initials: NY
authors.lastname: Huang
authors.affiliation: Department of Pediatrics, Kaohsiung Veterans General Hospital, Taiwan, ROC.
authors.forename: Kai-Sheng
authors.initials: KS
authors.lastname: Hsieh
authors.affiliation: Section of Infectious Diseases, Department of Internal Medicine, Kaohsiung Veterans General Hospital, Taiwan, ROC.
authors.forename: Yao-Shen
authors.initials: YS
authors.lastname: Chen
mesh_terms: D002675:Child, Preschool; D060085:Coinfection / Q000175:diagnosis / Q000382:microbiology / Q000821:virology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D060885:Multiplex Polymerase Chain Reaction / Q000379:methods*; D018410:Pneumonia, Bacterial / Q000175:diagnosis* / Q000382:microbiology; D011024:Pneumonia, Viral / Q000175:diagnosis* / Q000821:virology; D012141:Respiratory Tract Infections / Q000175:diagnosis*; D012680:Sensitivity and Specificity