Specimen dilution improves sensitivity of the amplified Mycobacterium tuberculosis direct test for smear microscopy-positive respiratory specimens

J Clin Microbiol. 2008 Jan;46(1):314-6. doi: 10.1128/JCM.01313-07. Epub 2007 Oct 31.

Abstract

Specimen dilution has been proposed as a strategy to minimize amplified Mycobacterium tuberculosis direct (MTD) test inhibition (N. Pollock, J. Westerling, and A. Sloutsky, Am. J. Clin. Pathol. 126:142-147, 2006; A. Sloutsky, L. L. Han, and B. G. Werner, J. Clin. Microbiol. 42:1547-1551, 2004). We evaluated the impact of respiratory specimen dilution on MTD test accuracy in a public health laboratory. The difference in MTD test sensitivity between the dilution and conventional methods was 15.9% (P = 0.001) for smear microscopy-positive specimens and -3.6% (P = 0.38) for smear microscopy-negative specimens.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Body Fluids / microbiology
  • Humans
  • Microscopy
  • Molecular Diagnostic Techniques / methods*
  • Mycobacterium tuberculosis / genetics
  • Mycobacterium tuberculosis / isolation & purification*
  • Predictive Value of Tests
  • Sensitivity and Specificity
  • Tuberculosis / diagnosis*