title: T-cell-based diagnosis of tuberculosis infection in children in Lithuania: a country of high incidence despite a high coverage with bacille Calmette-Guerin vaccination.
abstract: BACKGROUND
  Lithuania is a country with a high incidence of tuberculosis (TB), despite a high coverage with bacille Calmette-Guerin (BCG) vaccination. Until now the only method used to detect latent TB infection was the tuberculin skin test (TST). However, TST may have a cross reactivity to the BCG vaccine and to environmental mycobacteria. The aim of this study was to conduct assessments of the diagnostic accuracy of the T-cell based test (T SPOT TB) for TB in children who had previously been BCG vaccinated and compare these with the results of the TST.
  
  
  METHODS
  Between January 2005 and February 2007, children with bacteriologically confirmed TB, children having contacts with a case of infectious pulmonary TB and children without any known risk for TB were tested with both the TST and T SPOT TB.
  
  
  RESULTS
  The TST and T SPOT TB tests were positive for all patients in the "culture-confirmed TB" group. Whereas, in the "high risk for TB" group, the TST was positive for 60%, but the T SPOT TB test, only for 17.8%. Meanwhile the results for the "low risk for TB" group were 65.4% and 9.6%, respectively. A correlation between the TST and T SPOT TB was obtained in the "culture-confirmed TB" group where the TST > or =15 mm (r = 0.35, p < 0.001).
  
  
  CONCLUSIONS
  The T-cell based method is more objective than the TST for identifying latent TB infection in children who had been previously BCG vaccinated. This method could be useful in countries like Lithuania where there is a high incidence of TB despite a high coverage with BCG vaccination. It may also help to avoid unnecessary chemoprophylaxis when TST reactions are false-positive.
authors.affiliation: Department of Pediatric Diseases, Kaunas University of Medicine, Eiveniu 2, 50009 Kaunas, Lithuania. edita.hansted@gmail.com
authors.forename: Edita
authors.initials: E
authors.lastname: Hansted
authors.forename: Angele
authors.initials: A
authors.lastname: Andriuskeviciene
authors.forename: Raimundas
authors.initials: R
authors.lastname: Sakalauskas
authors.forename: Rimantas
authors.initials: R
authors.lastname: Kevalas
authors.forename: Brigita
authors.initials: B
authors.lastname: Sitkauskiene
mesh_terms: D000293:Adolescent; D001500:BCG Vaccine / Q000627:therapeutic use*; D002648:Child; D005189:False Positive Reactions; D005260:Female; D006403:Hematologic Tests; D006801:Humans; D015994:Incidence; D007371:Interferon-gamma / Q000097:blood; D008097:Lithuania / Q000453:epidemiology; D008297:Male; D012189:Retrospective Studies; D013601:T-Lymphocytes / Q000378:metabolism / Q000473:pathology*; D014374:Tuberculin Test; D014376:Tuberculosis / Q000453:epidemiology* / Q000473:pathology / Q000517:prevention & control*
chemical_list: D001500:BCG Vaccine; D007371:Interferon-gamma
references.citation: JAMA. 2005 Jun 8;293(22):2756-61
references.pmid: 15941805
references.citation: Am J Respir Crit Care Med. 2001 Mar;163(4):824-8
references.pmid: 11282752
references.citation: Medicina (Kaunas). 2007;43(7):519-22
references.pmid: 17768365
references.citation: Clin Microbiol Infect. 2007 Aug;13(8):836-8
references.pmid: 17501976
references.citation: Pediatrics. 2009 Jan;123(1):30-7
references.pmid: 19117857
references.citation: Clin Infect Dis. 2005 Jan 15;40(2):211-7
references.pmid: 15655737
references.citation: Eur Respir J. 2007 Oct;30(4):722-8
references.pmid: 17537773
references.citation: Emerg Infect Dis. 2007 Apr;13(4):553-8
references.pmid: 17553269
references.citation: Clin Med Res. 2006 Dec;4(4):266-72
references.pmid: 17210976
references.citation: Am J Respir Crit Care Med. 2000 Apr;161(4 Pt 2):S221-47
references.pmid: 10764341
references.citation: Am J Respir Crit Care Med. 2006 Oct 1;174(7):736-42
references.pmid: 16799073
references.citation: J Infect. 2007 Mar;54(3):e169-74
references.pmid: 17188363
references.citation: Lancet. 2006 Apr 22;367(9519):1328-34
references.pmid: 16631911
references.citation: Clin Infect Dis. 2007 Aug 1;45(3):322-8
references.pmid: 17599309
references.citation: Eur Respir J. 2006 Jul;28(1):24-30
references.pmid: 16611658
references.citation: Int J Tuberc Lung Dis. 2005 Nov;9(11):1242-7
references.pmid: 16333932
references.citation: Lancet Infect Dis. 2008 Jun;8(6):359-68
references.pmid: 18450516
references.citation: Pediatrics. 2007 Jan;119(1):e1-5
references.pmid: 17200234
references.citation: Am J Respir Crit Care Med. 2007 Mar 15;175(6):618-27
references.pmid: 17170386
references.citation: Int J Tuberc Lung Dis. 2006 Dec;10(12):1342-6
references.pmid: 17167950
references.citation: Ann Rheum Dis. 2004 Nov;63 Suppl 2:ii50-ii56
references.pmid: 15479872
references.citation: Lancet. 2001 Jun 23;357(9273):2017-21
references.pmid: 11438135
references.citation: Am J Respir Crit Care Med. 2007 Feb 1;175(3):282-7
references.pmid: 17082492
references.citation: Ann Intern Med. 2007 Mar 6;146(5):340-54
references.pmid: 17339619
references.citation: Int J Tuberc Lung Dis. 2005 Feb;9(2):170-4
references.pmid: 15732736
references.citation: Clin Infect Dis. 2004 Mar 1;38(5):754-6
references.pmid: 14986262
references.citation: Medicina (Kaunas). 2003;39(1):30-5
references.pmid: 12576763
references.citation: Eur J Clin Microbiol Infect Dis. 2005 Aug;24(8):529-36
references.pmid: 16133410
references.citation: Clin Vaccine Immunol. 2007 Sep;14(9):1239-41
references.pmid: 17626157