title: Contribution of Xpert® MTB/RIF to the diagnosis of pulmonary tuberculosis among TB-exposed children in The Gambia.
abstract: METHODS
  Greater Banjul Area, The Gambia.
  
  
  OBJECTIVE
  To conduct a pragmatic evaluation of the Xpert(®) MTB/RIF assay in the diagnosis of tuberculosis (TB) among child contacts.
  
  
  METHODS
  In this prospective study, one induced sputum sample was obtained from TB contacts aged <15 years and tested using fluorescent microscopy, culture and Xpert. The diagnostic accuracy of the microbiological tests was evaluated against culture and 'all TB diagnosis and treatment' as separate reference standards.
  
  
  RESULTS
  Using culture as a reference standard, Xpert was positive for Mycobacterium tuberculosis in 6/14 culture-positive and 6/473 culture-negative children, giving a sensitivity and specificity of respectively 42.9% (95%CI 17.7-71.1) and 98.7% (95%CI 97.2-99.5). With 'all TB diagnosis and treatment' as a composite reference standard, combined Xpert and culture tests were positive for M. tuberculosis in 20/62 children with TB disease (32.3%, 95%CI 20.9-45.3), which was comparable to the yield from microscopy, culture and Xpert combined (33.9%, 95%CI 22.3-47.0), but significantly higher than individual yields from each test.
  
  
  CONCLUSIONS
  The sensitivity of Xpert is low in actively traced child contacts, but a combination of Xpert and mycobacterial culture has incremental benefits for the bacteriological confirmation of TB disease.
authors.affiliation: Vaccines and Immunity Theme, Medical Research Council Unit, Fajara, The Gambia.
authors.forename: T O
authors.initials: TO
authors.lastname: Togun
authors.affiliation: Vaccines and Immunity Theme, Medical Research Council Unit, Fajara, The Gambia.
authors.forename: U
authors.initials: U
authors.lastname: Egere
authors.affiliation: Vaccines and Immunity Theme, Medical Research Council Unit, Fajara, The Gambia.
authors.forename: A K
authors.initials: AK
authors.lastname: Sillah
authors.affiliation: Vaccines and Immunity Theme, Medical Research Council Unit, Fajara, The Gambia.
authors.forename: A
authors.initials: A
authors.lastname: Ayorinde
authors.affiliation: Vaccines and Immunity Theme, Medical Research Council Unit, Fajara, The Gambia.
authors.forename: F
authors.initials: F
authors.lastname: Mendy
authors.affiliation: Vaccines and Immunity Theme, Medical Research Council Unit, Fajara, The Gambia.
authors.forename: L
authors.initials: L
authors.lastname: Tientcheu
authors.affiliation: Vaccines and Immunity Theme, Medical Research Council Unit, Fajara, The Gambia.
authors.forename: J
authors.initials: J
authors.lastname: Otu
authors.affiliation: Vaccines and Immunity Theme, Medical Research Council Unit, Fajara, The Gambia.
authors.forename: M
authors.initials: M
authors.lastname: Antonio
authors.affiliation: Vaccines and Immunity Theme, Medical Research Council Unit, Fajara, The Gambia.
authors.forename: J
authors.initials: J
authors.lastname: Sutherland
authors.affiliation: Centre for International Health and the Otago International Health Research Network, Department of Preventive and Social Medicine, University of Otago School of Medicine, Dunedin, New Zealand.
authors.forename: P C
authors.initials: PC
authors.lastname: Hill
authors.affiliation: Vaccines and Immunity Theme, Medical Research Council Unit, Fajara, The Gambia; Academic Department of Paediatrics, St Mary's campus, Imperial College London, London, UK.
authors.forename: B
authors.initials: B
authors.lastname: Kampmann
mesh_terms: D001431:Bacteriological Techniques / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005714:Gambia; D006801:Humans; D008297:Male; D008853:Microscopy; D009169:Mycobacterium tuberculosis / Q000235:genetics; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis*