Chest X-ray vs. Xpert® MTB/RIF assay for the diagnosis of sputum smear-negative tuberculosis in Uganda

Int J Tuberc Lung Dis. 2014 Feb;18(2):216-9. doi: 10.5588/ijtld.13.0464.

Abstract

Setting: An out-patient clinic in a country with high rates of tuberculosis-human immunodeficiency virus (TB-HIV) co-infection.

Design: Cross-sectional analytical study of 123 adults with chronic cough and no previous anti-tuberculosis treatment. Demographic, clinical, chest X-ray (CXR) and GeneXpert® MTB/RIF data were collected. Proportions of TB diagnoses using both tests were calculated and compared using an unpaired t-test.

Results: Sixty-six patients (53.7%) were female and 35 (28.5%) tested positive for HIV; 21 (17.1%) were Xpert-positive, while 51 (42.5%) had CXR suggestive of TB (P = 0.0018), of whom only 15 (29.4%) were Xpert-positive. CXR was suggestive of pulmonary TB in 15 (71.4%) of the 21 patients with a positive Xpert test.

Conclusions: The majority of the sputum smear-negative patients did not have TB on single Xpert testing. CXR gave an overestimate of sputum smear-negative TB cases.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Ambulatory Care
  • Antitubercular Agents / therapeutic use
  • Bacterial Proteins / genetics
  • Coinfection
  • Cross-Sectional Studies
  • DNA, Bacterial / isolation & purification
  • DNA-Directed RNA Polymerases
  • Drug Resistance, Bacterial / genetics
  • False Positive Reactions
  • Female
  • HIV Infections / diagnosis
  • HIV Infections / epidemiology
  • Humans
  • Male
  • Middle Aged
  • Mycobacterium tuberculosis / drug effects
  • Mycobacterium tuberculosis / genetics
  • Mycobacterium tuberculosis / isolation & purification*
  • Predictive Value of Tests
  • Prevalence
  • Radiography, Thoracic*
  • Rifampin / therapeutic use
  • Sputum / microbiology*
  • Tuberculosis, Pulmonary / diagnosis*
  • Tuberculosis, Pulmonary / diagnostic imaging
  • Tuberculosis, Pulmonary / drug therapy
  • Tuberculosis, Pulmonary / epidemiology
  • Tuberculosis, Pulmonary / microbiology
  • Uganda / epidemiology
  • Young Adult

Substances

  • Antitubercular Agents
  • Bacterial Proteins
  • DNA, Bacterial
  • rpoB protein, Mycobacterium tuberculosis
  • DNA-Directed RNA Polymerases
  • Rifampin