Time to sputum culture conversion and associated factors among rifampicin-resistant pulmonary tuberculosis patients treated with Bedaquiline at Mulago hospital, Uganda.
6 affiliations
- 1Department of Clinical Epidemiology and Biostatistics, School of Medicine, College of Health Sciences, Makerere University, Kampala, Uganda. [email protected].
- 2Department of Medical Microbiology and Immunology, Faculty of Medicine, Gulu University, Gulu, Uganda.
- 3Department of Clinical Epidemiology and Biostatistics, School of Medicine, College of Health Sciences, Makerere University, Kampala, Uganda.
- 4The Lung Institute, College of Health Sciences, Makerere University, Kampala, Uganda.
- 5The Tuberculosis Control Unit, Department of Pulmonology, Mulago National Referral Hospital, Kampala, Uganda.
- 6Department of Internal Medicine, School of Medicine, College of Health Sciences, Makerere University, Kampala, Uganda.
Abstract
Introduction
Sputum culture conversion in patients with pulmonary tuberculosis (PTB) is the most important interim indicator for drug-resistant (DR) tuberculosis (TB) treatment effectiveness. Bedaquiline-based regimens offer the possibility of more effective and less toxic treatment for DR TB. Bedaquiline-based regimens have been adopted as the new standard of care for DR TB, replacing the oto-and nephrotoxic aminoglycosides. We determined the median time to sputum culture conversion (TTCC) and associated factors among RR and MDR TB patients treated with Bedaquiline-based regimens, at Mulago National Referral Hospital, Uganda.Methods
In a longitudinal type of observational study performed at Mulago Hospital, between January 2020 and June 2023, RR and MDR TB patients' records were reviewed to obtain data on socio-demographic and clinical factors, and TTCC. The study outcome was TTCC, recorded as time from RR/MDR TB treatment initiation to sputum culture conversion, which was defined as at least 2 consecutive negative TB sputum cultures, at least 30 days apart, for a RR/MDR PTB patient who was sputum culture positive at baseline. Analysis for median TTCC was done using Kaplan-Meier analysis, and the log-logistic parametric survival regression model was used to identify predictors for TTCC.Results
Of the 265 participants, 196 (74.0%) were male, with median age of 35(IQR:27-42) years. The median TTCC was 7 (IQR:4-8) weeks from treatment initiation. Grade 2 + baseline smear positivity (adjusted Time Ratio (aTR):1.24, 95% CI:1.02-1.51, p = 0.029), grade 3 + baseline smear positivity (aTR:1.62, 95% CI:1.30-2.01, p < 0.001), cavitary disease on CXR (aTR:1.36, 95% CI:1.18-1.56, p < 0.001), and pleural effusion on CXR (aTR:1.81, 95% CI:1.43-2.31, p < 0.001) significantly prolonged the TTCC. Diabetes mellitus (7/265) significantly reduced the TTCC (aTR: 0.37, 95% CI: 0.22 - 0.60, p < 0.001).Conclusion
The WHO long regimen (9 months) was indistinguishable from the shorter 6-months regimen for the time to culture conversion. Integration of TB screening at points of care of high-risk patients like diabetics remains important for early detection and prompt initiation of DR TB treatment for better outcomes. The TB program and clinicians should enhance and individualize support for RR/MDR TB patients with more severe disease, to ensure optimum TTCC and successful treatment outcomes.Clinical trial number
Not applicable.
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BibTeX
@article{namusobya2026time,
title = {{Time to sputum culture conversion and associated factors among rifampicin-resistant pulmonary tuberculosis patients treated with Bedaquiline at Mulago hospital, Uganda.}},
author = {Martha Namusobya and Felix Bongomin and Lois Keren Kisakye and Charles Batte and Akello Susan Adakun and Irene Andia-Biraro and Joan Kalyango and Lydia Nakiyingi},
journal = {BMC infectious diseases},
year = {2026},
month = aug,
doi = {10.1186/s12879-026-14131-7},
url = {https://europepmc.org/article/MED/43009822},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Time to sputum culture conversion and associated factors among rifampicin-resistant pulmonary tuberculosis patients treated with Bedaquiline at Mulago hospital, Uganda.
AU - Martha Namusobya
AU - Felix Bongomin
AU - Lois Keren Kisakye
AU - Charles Batte
AU - Akello Susan Adakun
AU - Irene Andia-Biraro
AU - Joan Kalyango
AU - Lydia Nakiyingi
PY - 2026
DA - 2026/08/13
JO - BMC infectious diseases
DO - 10.1186/s12879-026-14131-7
UR - https://europepmc.org/article/MED/43009822
AB - Introduction Sputum culture conversion in patients with pulmonary tuberculosis (PTB) is the most important interim indicator for drug-resistant (DR) tuberculosis (TB) treatment effectiveness. Bedaquiline-based regimens offer the possibility of more effective and less toxic treatment for DR TB. Bedaquiline-based regimens have been adopted as the new standard of care for DR TB, replacing the oto-and nephrotoxic aminoglycosides. We determined the median time to sputum culture conversion (TTCC) and associated factors among RR and MDR TB patients treated with Bedaquiline-based regimens, at Mulago National Referral Hospital, Uganda.Methods In a longitudinal type of observational study performed at Mulago Hospital, between January 2020 and June 2023, RR and MDR TB patients' records were reviewed to obtain data on socio-demographic and clinical factors, and TTCC. The study outcome was TTCC, recorded as time from RR/MDR TB treatment initiation to sputum culture conversion, which was defined as at least 2 consecutive negative TB sputum cultures, at least 30 days apart, for a RR/MDR PTB patient who was sputum culture positive at baseline. Analysis for median TTCC was done using Kaplan-Meier analysis, and the log-logistic parametric survival regression model was used to identify predictors for TTCC.Results Of the 265 participants, 196 (74.0%) were male, with median age of 35(IQR:27-42) years. The median TTCC was 7 (IQR:4-8) weeks from treatment initiation. Grade 2 + baseline smear positivity (adjusted Time Ratio (aTR):1.24, 95% CI:1.02-1.51, p = 0.029), grade 3 + baseline smear positivity (aTR:1.62, 95% CI:1.30-2.01, p < 0.001), cavitary disease on CXR (aTR:1.36, 95% CI:1.18-1.56, p < 0.001), and pleural effusion on CXR (aTR:1.81, 95% CI:1.43-2.31, p < 0.001) significantly prolonged the TTCC. Diabetes mellitus (7/265) significantly reduced the TTCC (aTR: 0.37, 95% CI: 0.22 - 0.60, p < 0.001).Conclusion The WHO long regimen (9 months) was indistinguishable from the shorter 6-months regimen for the time to culture conversion. Integration of TB screening at points of care of high-risk patients like diabetics remains important for early detection and prompt initiation of DR TB treatment for better outcomes. The TB program and clinicians should enhance and individualize support for RR/MDR TB patients with more severe disease, to ensure optimum TTCC and successful treatment outcomes.Clinical trial number Not applicable.
SN - 1471-2334
ER -