title: Developments in novel breath tests for bacterial and fungal pulmonary infection.
abstract: OBJECTIVE
  Breath testing has developed over the last 20 years. New techniques that can identify fingerprints for specific diseases and specific markers of respiratory pathogens have been applied to breath analysis. This review discusses the recent advances in breath analysis for the diagnosis of bacterial and fungal lower respiratory tract infections.
  
  
  RESULTS
  The current techniques continue to develop rapidly, but preconcentration techniques are needed to analyse many target volatile organic compounds for most systems. Breath testing with an electronic nose is promising for the diagnosis of tuberculosis (TB), and specific volatiles identifiable by gas chromatography with mass spectrometry have been identified in breath for Mycobacterium tuberculosis, Pseudomonas aeruginosa and Aspergillus fumigatus, but are found at very low concentrations in breath. Contamination from the environment is an ongoing confounding influence. Exhaled breath condensate (EBC) is disappointing as a diagnostic sample.
  
  
  CONCLUSIONS
  Careful attention needs to be paid to the sensitivity and specificity of a technique and confounding from the environment. The role of technologies such as selected ion flow tube-mass spectrometry is emerging. The electronic nose requires further validation for TB. The identification of specific microbial biomarkers aids the quest for improved accuracy. EBC is currently of limited value.
authors.affiliation: Department of Pathology, University of Otago, and Department of Infectious Diseases, Christchurch Hospital, Christchurch, New Zealand. Steve.Chambers@cdhb.govt.nz
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Chambers
authors.forename: Amy
authors.initials: A
authors.lastname: Scott-Thomas
authors.forename: Michael
authors.initials: M
authors.lastname: Epton
mesh_terms: D001424:Bacterial Infections / Q000175:diagnosis; D015415:Biomarkers / Q000032:analysis; D001944:Breath Tests / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D008172:Lung Diseases, Fungal / Q000175:diagnosis; D011014:Pneumonia / Q000175:diagnosis; D012141:Respiratory Tract Infections / Q000175:diagnosis* / Q000382:microbiology; D012680:Sensitivity and Specificity; D055549:Volatile Organic Compounds / Q000032:analysis*
chemical_list: D015415:Biomarkers; D055549:Volatile Organic Compounds