Effect of diabetes on treatment outcome of smear-positive pulmonary tuberculosis--a report from South India.

Aim: To assess the effect of diabetes on tuberculosis (TB) treatment outcome and sputum conversion among new smear-positive (NSP) cases registered under Directly Observed Treatment Short Course in South India.

Methods: Details on sputum conversion and TB treatment outcome were collected from case records of NSP cases (N = 332; M/F 247:85) registered at TB units of three districts in Tamil Nadu. Subjects were screened for diabetes and categorized as diabetic (TBDM) (n = 96; 73:23) and non-diabetic (TBnonDM) (n = 149; 109:40).

Results: Among 245 selected TB patients, 93.5% were cured, 1.6% completed TB treatment, 2% had TB treatment failure (TF), and 0.4% had treatment default (TD), 0.4% with MDR-TB and 2% death rate. At the end of intensive phase of TB treatment, 14.7% remained sputum positive in the TBDM group, whereas it was 3.5% in the TBnonDM group. Mean duration (days) for sputum conversion was higher in the TBDM group (64.2 ± 10.5) compared to the TBnonDM group (61.5 ± 7.5) (p<0.001). TF rate was higher (4.2% vs 0.7%) and MDR-TB (1%) was also seen in the TBDM group. No death and TD were seen among DM whereas it was 3.4 and 0.7% in TBnonDM.

Conclusions: Delayed sputum conversion and high TB treatment failure rates were common in NSP cases with diabetes.