title: Screening for TB in high school adolescents in a high burden setting in South Africa.
abstract: Screening for tuberculosis (TB) disease is important for TB control and TB vaccine efficacy trials but this has not been evaluated in adolescents. We conducted a study to determine the prevalence of active TB and performance of specific screening tests for TB in adolescents in a high burden setting. Adolescents aged 12-18 years were recruited from high schools in a rural town in South Africa. Participants were screened for active TB using symptoms, household TB contact, positive interferon gamma release assay (IGRA) and positive tuberculin skin test (TST). Of 6363 adolescents recruited, 21 were newly diagnosed with TB of whom 19 were culture positive. After exclusions, the derived prevalence of smear positive TB was 16/5682 = 3/1000 (95% confidence interval (CI) 1-4/1000). The sensitivity of TST and IGRA for active TB were 85% (95% CI 62-100%) and 94% (95% CI 79-100%) respectively. None of the methods alone or in combination had positive predictive values greater than 2%. The screening tools evaluated in this study may not be practical for routine use owing to low positive predictive values but may be useful in TB vaccine clinical trials.
authors.affiliation: South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa. hmahomed@xsinet.co.za
authors.forename: Hassan
authors.initials: H
authors.lastname: Mahomed
authors.forename: Rodney
authors.initials: R
authors.lastname: Ehrlich
authors.forename: Tony
authors.initials: T
authors.lastname: Hawkridge
authors.forename: Mark
authors.initials: M
authors.lastname: Hatherill
authors.forename: Lawrence
authors.initials: L
authors.lastname: Geiter
authors.forename: Fazlin
authors.initials: F
authors.lastname: Kafaar
authors.forename: Deborah Ann
authors.initials: DA
authors.lastname: Abrahams
authors.forename: Humphrey
authors.initials: H
authors.lastname: Mulenga
authors.forename: Michele
authors.initials: M
authors.lastname: Tameris
authors.forename: Hennie
authors.initials: H
authors.lastname: Geldenhuys
authors.forename: Willem Albert
authors.initials: WA
authors.lastname: Hanekom
authors.forename: Suzanne
authors.initials: S
authors.lastname: Verver
authors.forename: Gregory Dudley
authors.initials: GD
authors.lastname: Hussey
mesh_terms: D000293:Adolescent; D002648:Child; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D059425:Interferon-gamma Release Tests / Q000379:methods; D008297:Male; D008403:Mass Screening / Q000379:methods; D012423:Rural Health / Q000706:statistics & numerical data; D013019:South Africa / Q000453:epidemiology; D013183:Sputum / Q000382:microbiology; D014374:Tuberculin Test; D014376:Tuberculosis / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology