TABLE 3.

Distribution, smear result, and M. tuberculosis culture of nonrespiratory specimens tested

AMTD test resultAcid-fast smear resultaSpecimen sourceNo. of specimensNo. of AMTD tests performedbResolution of discrepant result
False positiveUrine11Clinical diagnosis of tuberculosis; patient responded to therapy
False positiveGastric washing11Clinical diagnosis of tuberculosis; patient received therapy
False positive+Induced sputum11Culture grew M. xenopi
False positiveInduced sputum12Culture grew M. chelonae
False positiveBronchial washing11Could not resolve; possible contamination in test run
False negativeCerebrospinal fluid12Culture grew M. tuberculosis
False negative+Lymph node11Culture grew M. tuberculosis
False negativeLymph node11Culture grew M. tuberculosis
False negativeLymph node12Possible sampling error of tissue; second AMTD on same day was positive
False negativeSpine11Culture grew M. tuberculosis
False negativeBronchoalveolar lavage fluid1≥3Determined to be a mix-up in patient specimens; result was incorrect
  • a −, negative; +, positive.\

  • b Includes initial AMTD and any additional tests performed on other specimens from the same patient.