title: Time to sputum conversion in smear positive pulmonary TB patients on category I DOTS and factors delaying it.
abstract: BACKGROUND
  Sputum smear positive pulmonary tuberculosis patients expel infectious viable bacilli for a period following commencement of treatment. Patients on Directly Observed Treatment Shortcourse (DOTS) receive intermittent therapy with multidrug regimen.
  
  
  OBJECTIVE
  To determine the time to sputum smear and culture conversion following initiation of DOTS treatment and study the factors that influence it.
  
  
  METHODS
  A prospective study was undertaken at a tertiary care teaching hospital in Mumbai over a one year period on a cohort of 71 sputum smear positive patients on Category I DOTS treatment. Patients were followed up weekly for upto 20 weeks or until they underwent smear and culture conversion whichever was earlier. At each follow up, specimens were collected and processed for microscopy and culture using standard protocol.
  
  
  RESULTS
  60/71 [84.55%] patients completed the study. 56/60 [93.3%] patients underwent sputum smear and culture conversion. The median time to smear and culture conversion was end of 5th week [day 35] and 6 1/2 weeks [day 45] respectively. Univariate and stepwise regression analysis showed that patients who had cavitatory disease, high pretreatment smear grade and a past history of tuberculosis were more likely to undergo delayed or nonconversion [P < 0.05].
  
  
  CONCLUSIONS
  The time to sputum smear and culture conversion under DOTS is similar to previous antituberculosis regimens. Since viable bacilli continue to be expelled for upto two months, infection control measures should be maintained for such time. Patients with cavitatory disease, high pretreatment smear grade or a past history of tuberculosis need to be monitored more closely.
authors: Department of Microbiology, Seth G.S. Medical College and K.E.M Hospital, Mumbai.
authors: Raunak
authors: R
authors: Parikh
authors: Gita
authors: G
authors: Nataraj
authors: Swapna
authors: S
authors: Kanade
authors: Vijay
authors: V
authors: Khatri
authors: Preeti
authors: P
authors: Mehta
mesh_terms: D000328:Adult; D000995:Antitubercular Agents / Q000627:therapeutic use*; D023801:Directly Observed Therapy / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006784:Hospitals, Teaching; D006801:Humans; D007194:India; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification*; D011446:Prospective Studies; D012044:Regression Analysis; D012307:Risk Factors; D013183:Sputum / Q000382:microbiology*; D063128:Tertiary Health Care; D013997:Time Factors; D016896:Treatment Outcome; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology*
chemical_list: D000995:Antitubercular Agents