title: Performance of the Xpert® MTB/RIF assay in an active case-finding strategy: a pilot study from Tanzania.
abstract: In this pilot study, we evaluated the Xpert® MTB/RIF assay in an active case-finding strategy, using two spot sputum samples collected within a 1-hour interval from household contacts of smear-positive TB index cases. Tuberculosis (TB) confirmed by culture served as the reference  standard. Among 219 enrolled contacts, the yield of active TB was 2.3%. While the sensitivity of smear microscopy was 60% (95%CI 14.7-94.7), Xpert MTB/RIF achieved a sensitivity of 100% (95%CI 47.81-100.0). All culture-confirmed cases tested positive by Xpert MTB/RIF on the first  submitted sample, suggesting that the evaluation of only one sample could be sufficient for TB diagnosis in this context.
authors.affiliation: National Institute for Medical Research, Mbeya Medical Research Programme, Mbeya, Tanzania. nelias@mmrp.org
authors.forename: E N
authors.initials: EN
authors.lastname: Ntinginya
authors.forename: S B
authors.initials: SB
authors.lastname: Squire
authors.forename: K A
authors.initials: KA
authors.lastname: Millington
authors.forename: B
authors.initials: B
authors.lastname: Mtafya
authors.forename: E
authors.initials: E
authors.lastname: Saathoff
authors.forename: N
authors.initials: N
authors.lastname: Heinrich
authors.forename: G
authors.initials: G
authors.lastname: Rojas-Ponce
authors.forename: D
authors.initials: D
authors.lastname: Kowuor
authors.forename: L
authors.initials: L
authors.lastname: Maboko
authors.forename: K
authors.initials: K
authors.lastname: Reither
authors.forename: P
authors.initials: P
authors.lastname: Clowes
authors.forename: M
authors.initials: M
authors.lastname: Hoelscher
authors.forename: A
authors.initials: A
authors.lastname: Rachow
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D016358:Contact Tracing / Q000379:methods*; D003430:Cross-Sectional Studies; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D010865:Pilot Projects; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology; D013636:Tanzania / Q000453:epidemiology; D014376:Tuberculosis / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology; D055815:Young Adult