title: [Timing of quantiferon TB-G test for the contact examination of tuberculosis].
abstract: OBJECTIVE
  To investigate the timing when Quanti FERON TB-Gold test (QFT-G) for the contact examination of tuberculosis should be done.
  
  
  METHODS
  We examined QFT-G test for the 25 family contacts of sputum smear positive tuberculosis cases diagnosed at Fukujuji Hospital 5 times (soon after the diagnosis of the index case, 2 months later, 3 months later, 4 months later and 6 months later). And we calculated the positivity at these examinations.
  
  
  RESULTS
  Among 25 contacts, 8 persons became QFT-G positive. The positivity was higher among the contacts of cases with longer delay in diagnosis. 2 contacts were positive soon after the diagnosis of index cases, 5 cases became positive 2 months after the diagnosis and 1 case became positive after 3 months.
  
  
  CONCLUSIONS
  3 months interval from the diagnosis of the index case will be enough for the final decision of the infection of contacts.
authors.affiliation: Fukujuji Hospital, Japan Anti-Tuberculosis Association, 3-1-24, Matsuyama, Kiyose-shi, Tokyo 204-8522, Japan. yoshiyama1962@yahoo.co.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshiyama
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Harada
authors.forename: Kazue
authors.initials: K
authors.lastname: Higuchi
authors.forename: Hideo
authors.initials: H
authors.lastname: Ogata
mesh_terms: D000293:Adolescent; D000328:Adult; D016358:Contact Tracing / Q000379:methods*; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000097:blood*; D008297:Male; D013995:Time; D014376:Tuberculosis / Q000175:diagnosis* / Q000635:transmission
chemical_list: D007371:Interferon-gamma