Setting: Significance of a positive bacillary examination of sputum at 2 months of treatment in relation to the viability of the bacilli and the final treatment result.
Objective: To compare the results of smear microscopy and sputum culture at the second month of tuberculosis treatment and to follow the progress of the patients.
Methods: Follow-up of 297 patients with smear-positive pulmonary tuberculosis in Madagascar, 152 of whom were smear-positive at 2 months of treatment and 145 smear-negative. The number of bacilli was recorded, as were the culture results and the final outcome of treatment.
Results: Among the 152 patients who were smear-positive at the second month, 77 (51%) were culture-negative; there were 12 (8%) treatment failures and four relapses (4.6%). Among the 145 smear-negative patients, 22 (15%) were culture-positive, of which one was a treatment failure (1%).
Conclusion: The majority of failures and relapses were observed in the group of smear-positive patients. It is important to reinforce the surveillance of these patients in order to reduce the number lost to follow-up. Furthermore, a positive smear microscopy at the end of the second month is not sufficiently specific for early identification of treatment failures. It is preferable to wait until the fifth month, as the great majority of patients who are positive at 2 months achieve cure. The treatment strategy currently recommended in Madagascar is satisfactory.