Drug adherence and efficacy of smear microscopy in the diagnosis of pulmonary tuberculosis after 2 months of medication in North-western Tanzania

Objectives: The study aimed at assessing the Tuberculosis (TB) medication adherence level and the efficacy of smear microscopy in the diagnosing pulmonary TB at month 2.

Methods: A prospective study was conducted at the four sites located in the Northern-western Tanzania. New smear positive, pulmonary TB patients were followed up and their adherence to TB medication assessed after 2 months of the treatment. In addition, the acid fast bacilli (AFB) smear microscopy was performed after 2 and 5 months of the treatment. All smear positive samples were subjected to geneXpert (MTB/RIF) assay and culture on the Lowenstein Jensen (LJ) media.

Results: A total of 331 smear positive, newly diagnosed patients with pulmonary TB were enrolled. The median age was 36 [Interquartile range (IQR): 28-45] years and males formed the slightly majority, 187 (56.5%) of the participants. A total of 105 (31.7%) patients were infected with HIV. Out of 331 patients, 36 (10.9%) were still AFB smear positive at the end of two month. Of these 19 (52.8%) were positive on GeneXpert MTB RIF and none was Rifampicin resistant. Of note, only 13 (31.1%) were culture positive (viable). None of the patients was positive at month 5. Poor adherence to TB medications in the first 2 months of treatment was observed in 56/331 (16.9%) [95% CI=12.9-21.0] of the patients.

Conclusion: Over two thirds of smear positive patients are wrongly put in one month extension of the intensive phase treatment; this may cause increased costs and drug toxicity. Culture should be advocated to confirm smear positivity after 2 months of medications. TB treatment drug adherence in our setting is good and is associated with successful cure. No multidrug resistant tuberculosis (MDR-TB) was observed. Continued surveillance and emphasizing of TB drug adherence should be kept upbeat in order to control tuberculosis in developing countries.