title: Rapid molecular TB diagnosis: evidence, policy making and global implementation of Xpert MTB/RIF.
abstract: If tuberculosis (TB) is to be eliminated as a global health problem in the foreseeable future, improved detection of patients, earlier diagnosis and timely identification of rifampicin resistance will be critical. New diagnostics released in recent years have improved this perspective but they require investments in laboratory infrastructure, biosafety and staff specialisation beyond the means of many resource-constrained settings where most patients live. Xpert MTB/RIF, a new assay employing automated nucleic acid amplification to detect Mycobacterium tuberculosis, as well as mutations that confer rifampicin resistance, holds the promise to largely overcome these operational challenges. In this article we position Xpert MTB/RIF in today's TB diagnostic landscape and describe its additional potential as an adjunct to surveillance and surveys, taking into account considerations of pricing and ethics. In what could serve as a model for the future formulation of new policy on diagnostics, we trace the unique process by which the World Health Organization consulted international expertise and systematically assessed published evidence and freshly emerging experience from the field ahead of its endorsement of the Xpert MTB/RIF technology in 2010, summarise subsequent research findings and guidance on who to test and how, and provide perspectives on scaling up the new technology.
authors.affiliation: Stop TB Dept, World Health Organization, Geneva, Switzerland.
authors.forename: Karin
authors.initials: K
authors.lastname: Weyer
authors.forename: Fuad
authors.initials: F
authors.lastname: Mirzayev
authors.forename: Giovanni Battista
authors.initials: GB
authors.lastname: Migliori
authors.forename: Wayne
authors.initials: W
authors.lastname: Van Gemert
authors.forename: Lia
authors.initials: L
authors.lastname: D'Ambrosio
authors.forename: Matteo
authors.initials: M
authors.lastname: Zignol
authors.forename: Katherine
authors.initials: K
authors.lastname: Floyd
authors.forename: Rosella
authors.initials: R
authors.lastname: Centis
authors.forename: Daniela M
authors.initials: DM
authors.lastname: Cirillo
authors.forename: Enrico
authors.initials: E
authors.lastname: Tortoli
authors.forename: Chris
authors.initials: C
authors.lastname: Gilpin
authors.forename: Jean
authors.initials: J
authors.lastname: de Dieu Iragena
authors.forename: Dennis
authors.initials: D
authors.lastname: Falzon
authors.forename: Mario
authors.initials: M
authors.lastname: Raviglione
mesh_terms: D003362:Cost-Benefit Analysis; D004351:Drug Resistance; D006291:Health Policy; D006801:Humans; D025202:Molecular Diagnostic Techniques / Q000191:economics / Q000379:methods*; D009169:Mycobacterium tuberculosis / Q000235:genetics; D021141:Nucleic Acid Amplification Techniques; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D015995:Prevalence; D015203:Reproducibility of Results; D013183:Sputum / Q000382:microbiology; D018088:Tuberculosis, Multidrug-Resistant / Q000175:diagnosis* / Q000382:microbiology*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000382:microbiology*; D014944:World Health Organization