title: Influence of previous tuberculosis treatment history on acid-fast bacilli smear and culture conversion.
abstract: METHODS
  A teaching hospital in the Republic of Korea, 2003-2009.
  
  
  OBJECTIVE
  To evaluate the effect of previous tuberculosis (TB) treatment history on sputum smear and culture conversion.
  
  
  METHODS
  Data, including sputum acid-fast bacilli (AFB) results at baseline and at weeks  2, 4, 8, 12, 16, 20 and 24, were collected from patients with AFB sputum smear-positive and culture-confirmed pulmonary TB. Patients with multidrug-resistant TB or those with poor adherence were excluded. AFB conversion was compared between patients with a previous history of anti-tuberculosis  treatment and those without.
  
  
  RESULTS
  The median age of the 208 patients was 49.0 years; 58.3% were male, while 43 (20.7%) had a history of previous anti-tuberculosis treatment. Patients with a history of previous treatment had significantly lower sputum smear-negative conversion at 2 weeks  of treatment compared with patients without (70.0% vs. 44.8%, P = 0.005). However, the two groups did not differ in culture conversion and in smear conversion at 4, 8, 12, 16, 20 and 24 weeks of anti-tuberculosis treatment.
  
  
  CONCLUSIONS
  Patients with a history of previous anti-tuberculosis  treatment are more likely to have positive sputum AFB smear at 2 weeks of treatment. However, sputum culture conversion is not affected by previous treatment history.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: J
authors.initials: J
authors.lastname: Lee
authors.forename: B J
authors.initials: BJ
authors.lastname: Lee
authors.forename: H I
authors.initials: HI
authors.lastname: Yoon
authors.forename: C-T
authors.initials: CT
authors.lastname: Lee
authors.forename: J H
authors.initials: JH
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000995:Antitubercular Agents / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000302:isolation & purification*; D015995:Prevalence; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D013183:Sputum / Q000382:microbiology*; D017211:Treatment Failure; D018088:Tuberculosis, Multidrug-Resistant / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology
chemical_list: D000995:Antitubercular Agents