title: Delayed tuberculosis diagnosis and tuberculosis transmission.
abstract: METHODS
  Tuberculosis (TB) patients and their close contacts reported to the Maryland Department of Health and Mental Hygiene from 1 June 2000 to 30 November 2001.
  
  
  OBJECTIVE
  A recent prospective study found that 49% of pulmonary TB patients had total treatment delays > or = 90 days. This cohort was analyzed to determine the association between total treatment delay and TB transmission.
  
  
  METHODS
  TB patient data were collected as part of a prospective cohort study; contact data were collected from local health departments.
  
  
  RESULTS
  Close contacts of 54 US-born patients (n = 310) and those of 70 foreign-born cases (n = 393) received tuberculin skin tests (TSTs). Among contacts of US-born patients with a total treatment delay of > or = 90 days, 40% had positive TSTs vs. 24% contacts of patients with shorter delays (aOR 2.34; P = 0.03). Other patient factors associated with TST positivity among contacts of US-born cases were black race (aOR 3.03; P = 0.05), sputum smear positive for AFB (aOR 3.29; P = 0.01) and chest radiograph with cavitation (aOR 3.11; P = 0.01). No associations were observed between foreign-born patients and risk of TST positivity among their contacts.
  
  
  CONCLUSIONS
  Among US-born patients, delay in TB diagnosis is associated with greater transmission of infection to contacts and could be used independently of other index patient factors to identify contacts at greatest risk of TB infection.
authors.affiliation: School of Medicine, Johns Hopkins University, 1820 Lancaster St, Suite 300, Baltimore, MD 21231, USA. jgolub@jhmi.edu
authors.forename: J E
authors.initials: JE
authors.lastname: Golub
authors.forename: S
authors.initials: S
authors.lastname: Bur
authors.forename: W A
authors.initials: WA
authors.lastname: Cronin
authors.forename: S
authors.initials: S
authors.lastname: Gange
authors.forename: N
authors.initials: N
authors.lastname: Baruch
authors.forename: G W
authors.initials: GW
authors.lastname: Comstock
authors.forename: R E
authors.initials: RE
authors.lastname: Chaisson
mesh_terms: D016358:Contact Tracing; D004641:Emigration and Immigration; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014374:Tuberculin Test; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000208:ethnology / Q000635:transmission*; D014481:United States