title: Yield of close contact tracing using two different programmatic approaches from tuberculosis index cases: a retrospective quasi-experimental study.
abstract: BACKGROUND
  Being a contact of a pulmonary tuberculosis (TB) case is a risk factor for active and latent TB. The objective of this study is to determine the contact tracing yield using two different programmatic definitions of close contact in the city of Rio de Janeiro, Brazil.
  
  
  METHODS
  This is a retrospective quasi-experimental study. Data were obtained by reviewing the medical records from TB index cases and their close contacts admitted to the Outpatient TB Clinic of the Institute of Thoracic Diseases, University of Rio de Janeiro. From January 2001 to December 2004, a close contact was defined as an individual who shared an enclosed space with a TB index case for a total period of ≥ 100 hours, whereas from January 2005 to December 2008 the definition of close contact was changed to an individual who shared an enclosed space with a TB index case ≥ 4 hours a week. The primary outcome of this study was newly diagnosed pulmonary TB cases and the secondary outcome was the prevalence of latent TB infection (LTBI) among close contacts during both periods.
  
  
  RESULTS
  From 2001-2004, 810 close contacts from 257 index cases were evaluated and the prevalence of active TB and LTBI were 2% (16/810) and 62% (496/794), respectively. From 2005-2008, 1,310 close contacts from 369 index cases were identified and the prevalence of active TB and LTBI were 2.7% (35/1,310) and 69% (877/1,275), respectively. There was not a statically significant difference in the detection of active TB (p = 0.3) between the 2 time periods, but the detection of LTBI was significant higher (p = 0.003). The number needed to screen (contacts/new cases) decreased from 50 to 37 and the number need to contact trace (index cases/new cases) decreased from 16 to 10 from 2001-2004 to 2005-2008.
  
  
  CONCLUSIONS
  In conclusion, the findings of this study suggest that the less conservative definition of TB close contacts (sharing space ≥ 4 h/week) can be a helpful tool for increasing the rate of diagnosis for newly active pulmonary TB cases and for the detection of LTBI among contacts of active pulmonary TB cases.
authors.forename: Carla
authors.initials: C
authors.lastname: Loredo
authors.forename: Michelle
authors.initials: M
authors.lastname: Cailleaux-Cezar
authors.forename: Anne
authors.initials: A
authors.lastname: Efron
authors.forename: Fernanda Carvalho Queiroz
authors.initials: FC
authors.lastname: de Mello
authors.affiliation: Institute of Thoracic Diseases of Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. marcusconde@hucff.ufrj.br.
authors.forename: Marcus Barreto
authors.initials: MB
authors.lastname: Conde
mesh_terms: D000328:Adult; D001938:Brazil / Q000453:epidemiology; D016358:Contact Tracing / Q000379:methods* / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D055985:Latent Tuberculosis / Q000175:diagnosis / Q000453:epidemiology*; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000453:epidemiology*; D014505:Urban Population; D055815:Young Adult
references.citation: Int J Tuberc Lung Dis. 2007 Feb;11(2):156-60
references.pmid: 17263285
references.citation: Am J Prev Med. 1997 May-Jun;13(3):175-81
references.pmid: 9181204
references.citation: Int J Tuberc Lung Dis. 2013 Aug;17(8):1049-55
references.pmid: 23827029
references.citation: Lancet Infect Dis. 2010 Feb;10(2):93-102
references.pmid: 20113978
references.citation: Lancet Infect Dis. 2008 Jun;8(6):359-68
references.pmid: 18450516
references.citation: Int J Tuberc Lung Dis. 2007 Oct;11(10):1049-61
references.pmid: 17945060
references.citation: N Engl J Med. 2002 Dec 5;347(23):1860-6
references.pmid: 12466511
references.citation: N Engl J Med. 2001 Jul 19;345(3):189-200
references.pmid: 11463015
references.citation: Am Rev Respir Dis. 1979 Apr;119(4):603-9
references.pmid: 443630
references.citation: J Bras Pneumol. 2009 Oct;35(10):1018-48
references.pmid: 19918635
references.citation: Eur J Epidemiol. 2001;17(2):123-8
references.pmid: 11599684
references.citation: Epidemiol Infect. 2002 Feb;128(1):37-45
references.pmid: 11895089
references.citation: Am J Respir Crit Care Med. 2000 Apr;161(4 Pt 2):S221-47
references.pmid: 10764341
references.citation: Thorax. 1993 Dec;48(12):1257-60
references.pmid: 8303634
references.citation: Eur Respir J. 2013 Jan;41(1):140-56
references.pmid: 22936710
references.citation: Bull Int Union Tuberc. 1974 Aug;49 suppl 1:261-6
references.pmid: 4468015
references.citation: N Engl J Med. 2011 Dec 8;365(23):2155-66
references.pmid: 22150035