Quantitative sputum bacillary load during rifampin-containing short course chemotherapy in human immunodeficiency virus-infected and non-infected adults with pulmonary tuberculosis

SETTING: National Tuberculosis (TB) Treatment Centre, Mulago Hospital and Joint Clinical Research Centre, Kampala, Uganda. OBJECTIVE: To compare the quantitative sputum bacillary load between TB patients infected with the human immunodeficiency virus (HIV) and those non-infected, during treatment with standard short course chemotherapy (SCC). DESIGN: To compare clinical characteristics and quantitative sputum bacillary load as measured by quantitative acid-fast bacilli (AFB) smears, colony forming unit (cfu) assay and time until positive culture in the BACTEC® radiometric liquid system between 14 HIV-infected and 22 non-HIV-infected adults with initial episodes of smear-positive pulmonary TB at baseline and during treatment with standard four-drug SCC. RESULTS: Other than cavitation (P = 0.042) and adenopathy (P = 0.03), which were more common among non-HIV-infected and HIV-infected patients, respectively, there were no significant differences in baseline demographic, clinical, radiological and laboratory characteristics between the groups. Mean pretreatment sputum bacillary burden (6.5 ± 0.51 log₁₀ AFB/ml, 5.91 ± 0.91 log₁₀ cfu/ml and 1.8 ± 1.7 days until positive BACTEC® culture for HIV-infected patients and 6.32 ± 0.85 log₁₀ AFB/ml, 5.58 ± 0.68 log₁₀ cfu/ml and 1.9 ±1.2 days until positive BACTEC® culture for non-HIV-infected patients) were comparable between HIV-infected and non-HIV-infected patients. Clinical and bacteriological responses to standard SCC and treatment outcome did not differ between the groups. CONCLUSION: Quantitative sputum bacillary load at baseline and during SCC did not differ significantly between HIV-infected and non-HIV-infected adults with initial episodes of smear-positive TB.