Acid-fast staining of urine and gastric contents is an excellent indicator of mycobacterial disease

Am Rev Respir Dis. 1987 Nov;136(5):1197-8. doi: 10.1164/ajrccm/136.5.1197.


It is a commonly held opinion that acid-fast staining of urine or gastric aspirates is not a reliable indicator of mycobacterial disease because of the presence of saprophytic mycobacteria. In order to determine the clinical usefulness of acid-fast staining of these body fluids, we reviewed our 10-yr experience with acid-fast stains. Forty-seven of 5,829 urine specimens (0.8%) and 39 of 309 gastric aspirates (12.6%) yielded mycobacteria on culture. Twenty-three urine specimens and 12 gastric aspirates had positive acid-fast stains. Of these, only one possible false positive acid-fast stain of urine (less than 1%) was found and none was found in gastric aspirates. Thus, acid-fast stains of urine and gastric aspirates are, when positive, reliable indicators of true mycobacterial disease.

MeSH terms

  • Bacteriological Techniques*
  • Gastrointestinal Contents*
  • Humans
  • Mycobacterium Infections / microbiology*
  • Mycobacterium Infections, Nontuberculous / microbiology
  • Predictive Value of Tests
  • Staining and Labeling / methods
  • Tuberculosis / microbiology
  • Urine / microbiology*