Sputum conversion at the end of intensive phase of Category-1 regimen in the treatment of pulmonary tuberculosis patients with diabetes mellitus or HIV infection: An analysis of risk factors

Indian J Med Res. 2007 Nov;126(5):452-8.


Background & objective: New smear-positive pulmonary tuberculosis (PTB) patients in the Revised National Tuberculosis Control Programme (RNTCP) are treated with a 6-month short-course chemotherapy (SCC) regimen irrespective of co-morbid conditions. We undertook this retrospective analysis to compare sputum conversion rates (smear, culture) at the end of intensive phase (IP) of Category-1 regimen among patients admitted to concurrent controlled clinical trials: pulmonary tuberculosis alone (PTB) or with type 2 diabetes mellitus (DM-TB) or HIV infection (HIV-TB), and to identify the risk factors influencing sputum conversion.

Methods: In this retrospective analysis sputum conversion rates at the end of intensive phase (IP) in three concurrent studies undertaken among PTB, DM-TB and HIV-TB patients, during 1998 - 2002 at the Tuberculosis Research Centre (TRC), Chennai, were compared. Sputum smears were examined by fluorescent microscopy. HIV infected patients did not receive anti-retroviral treatment (ART). Patients with DM were treated with oral hypoglycaemic drugs or insulin (sc).

Results: The study population included 98, 92 and 88 patients in the PTB, DM-TB and HIV-TB studies. At the end of IP the smear conversion (58, 61, and 62%) and culture conversion (86, 88 and 92%) rates were similar in the three groups respectively. The variables associated with lack of sputum smear or culture conversion were age >45 yr, higher pre-treatment smear and culture grading, and extent of the radiographic involvement.

Interpretation & conclusion: Our findings confirm that the current policy of the control programme to treat all pulmonary TB patients with or with out co-morbid conditions with Category-I regimen appears to be appropriate.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Antitubercular Agents / therapeutic use*
  • Comorbidity
  • Diabetes Mellitus, Type 2 / physiopathology*
  • Female
  • HIV Infections / physiopathology*
  • Humans
  • India
  • Male
  • Middle Aged
  • Retrospective Studies
  • Risk Factors
  • Sputum / microbiology*
  • Treatment Outcome
  • Tuberculosis, Pulmonary / drug therapy*


  • Antitubercular Agents