Time to Sputum Culture Conversion and Its Predictors Among Multidrug Resistant Tuberculosis Patients in Tigray, Northern Ethiopia: Retrospective Cohort Study

Letebrhan Weldemhret; Ataklti Hailu Atsbaha; Hadish Bekuretsion; Abraham Desta; Lemlem Legesse; Atsebaha Gebrekidan Kahsay; Dawit Hagos

doi:10.2147/IDR.S413495

Time to Sputum Culture Conversion and Its Predictors Among Multidrug Resistant Tuberculosis Patients in Tigray, Northern Ethiopia: Retrospective Cohort Study

Infect Drug Resist. 2023 Jun 9:16:3671-3681. doi: 10.2147/IDR.S413495. eCollection 2023.

Authors

Letebrhan Weldemhret¹, Ataklti Hailu Atsbaha¹, Hadish Bekuretsion¹, Abraham Desta¹, Lemlem Legesse¹, Atsebaha Gebrekidan Kahsay², Dawit Hagos²

Affiliations

¹ Tigray Health Research Institute, Mekelle, Tigray, Ethiopia.
² Department of Medical Microbiology and Immunology, College of Health Sciences, Mekelle, University, Mekelle, Tigray, Ethiopia.

Abstract

Background: Sputum culture conversion status is a cardinal index of treatment response and patient outcome for MDR TB patients on longer anti-TB drugs. But, there is limited information on time to sputum culture conversion of MDR TB patients on a longer anti-TB treatment regimen. Therefore, this study aimed to evaluate time to sputum culture conversion and its predictors among MDR TB patients in Tigray, Northern Ethiopia.

Methods: A retrospective cohort study was conducted from January 2017 through September 2020 among MDR TB patients in Tigray, Northern Ethiopia. Demographic and clinical characteristics including bacteriological data were extracted from the TB registration book and electronic database in Tigray Health Research Institute. Statistical analysis was performed using SPSS version 25. The time to initial sputum culture conversion was analyzed using the Kaplan-Meier method. Bivariate and multivariate Cox proportional hazards regression analyses were used to identify predictors for culture conversions. P <0.05 was considered statistically significant.

Results: A total of 294 eligible study participants with a median age of 30 years (IQR: 22.75-40) were included. The participants were followed for a total of 1066.7 person months. Sputum culture conversion was achieved in 269 (91%) of the study participants. The median time of sputum culture conversion was 64 days (IQR: 49-86). In our multivariate model, HIV-positive (aHR=1.529, 95% CI: 1.096-2.132, P=0.012), patients new to anti-TB treatment (aHR=2.093, 95% CI: 1.100-3.982, P=0.024) and baseline AFB smear grading of +1 (aHR=1.982, 95% CI: 1.428-2.750, P=0.001) significantly affected time to initial sputum culture conversion.

Conclusion: The median time of culture conversion was 64 days. Moreover, the majority of the study participants achieved culture conversion within the first six months of treatment commencement, which supports predefined standard treatment durations.

Keywords: Ethiopia; conversion; culture; multi-drug resistance; smear; sputum; tuberculosis.