Characteristics and outcomes of tuberculosis patients who fail to smear convert at two months in Sri Lanka

Setting:

Five districts in Sri Lanka.

Objectives:

To determine: 1) the proportion of sputum smear-positive pulmonary tuberculosis (PTB) cases who failed to smear convert at 2 months, 2) their management, and 3) whether baseline characteristics and final treatment outcomes were different from those who did smear convert.

Design:

Cross-sectional retrospective review of medical files, tuberculosis (TB) registers and TB treatment records of new smear-positive PTB patients registered from January to December 2010.

Results:

Of 925 patients, 840 were available to submit sputum at 2 months, of whom 137 (16%) were smear-positive. Baseline sputum smears showing 3+ acid-fast bacilli and missing doses of anti-tuberculosis drugs during the initial phase of treatment were significantly associated with being smear-positive at 2 months. Management was poor: of 137 patients, 46 (34%) submitted sputum for culture and drug susceptibility testing and Mycobacterium tuberculosis was cultured in six cases; 120 (88%) received a 1-month extension of the initial phase, and of the 30 patients still smear-positive at 3 months there were no culture results available. Final treatment outcomes were similar, regardless of smear conversion at 2 or 3 months.

Conclusion:

Certain characteristics were risk factors for failure to smear convert at 2 months. However, treatment outcomes for all patients were good. These findings have implications for the modification of national programme recommendations.