title: Impact of the Xpert MTB/RIF diagnostic test for tuberculosis in countries with a high burden of disease.
abstract: OBJECTIVE
  Control of tuberculosis necessitates prompt diagnosis and access to effective treatment. We discuss the impact of a new nucleic acid amplification test to assist diagnosis and detect rifampicin resistance. Following encouraging clinical performance studies, an automated PCR-based test, the Xpert MTB/RIF (Cepheid, Sunnyvale, CA), has been implemented on a global scale. Clinical trials to assess the impact of the new technology in primary healthcare clinics have been undertaken in tuberculosis (TB) endemic countries.
  
  
  RESULTS
  Clinical trials at the point of care in TB endemic countries demonstrated that increased numbers of TB patients are identified using the Xpert MTB/RIF assay as the frontline diagnostic test in place of sputum smear microscopy. Decreased times from sample collection to initiation of treatment were also reported when using the molecular test. However, overall case notification rates did not improve, and no significant impact on patient outcome (morbidity or mortality) was reported.
  
  
  CONCLUSIONS
  Sensitive molecular tests to assist diagnosis of tuberculosis may provide a faster diagnostic result when used in clinics and laboratories, but the limited impact on patient outcomes suggests additional interventions are needed to enhance TB control.
authors.affiliation: aDepartment of Clinical Sciences, London School of Hygiene and Tropical Medicine bCentre for Clinical Microbiology, Division of Infection and Immunity, University College London and NIHR Biomedical Research Centre at UCL Hospitals, London, UK.
authors.forename: Ruth
authors.initials: R
authors.lastname: McNerney
authors.forename: Alimuddin
authors.initials: A
authors.lastname: Zumla
mesh_terms: D000904:Antibiotics, Antitubercular / Q000494:pharmacology; D002986:Clinical Trials as Topic; D017281:Cost of Illness; D019353:Endemic Diseases; D006801:Humans; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D012293:Rifampin / Q000494:pharmacology; D014376:Tuberculosis / Q000175:diagnosis*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis
chemical_list: D000904:Antibiotics, Antitubercular; D012293:Rifampin