Sputum conversion in HIV-infected and HIV-uninfected pulmonary TB patients on anti-TB treatment. Sputum samples were collected from TB patients before (baseline), and at days 14, 28 and 56 of anti-TB treatment. The grade of smear positivity at direct microscopy and days to positivity (DTP) for MGIT liquid cultures was used as a surrogate measure of bacterial load in sputum samples. DTP inversely correlates with the bacillary load. Culture conversion was calculated by determining the proportion of patients whose sputum samples did not grow bacilli in culture or whose sputum smear microscopy was negative for acid-fast bacilli. A) Comparison of bacillary load in sputum samples from HIV-infected and HIV-uninfected TB patients before and after 14 days of anti-TB treatment (Day 0 HIV− n = 23, HIV+ n = 19; Day 14 HIV− n = 22 HIV+ n = 18). Data were analysed using the Mann–Whitney U test; black horizontal bars represent medians and IQRs. B and C) Sputum smear and culture conversion in HIV-infected and HIV-uninfected patients during the intensive phase of anti-TB treatment (Day 0 HIV− n = 23, HIV+ n = 19; Day 14 HIV− n = 23 HIV+ n = 19; Day 28 HIV− n = 19, HIV+ n = 18; Day 56 HIV− n = 19, HIV+ n = 16). The bars represent medians.