High Prevalence of Rifampicin Resistance Associated with Rural Residence and Very Low Bacillary Load among TB/HIV-Coinfected Patients at the National Tuberculosis Treatment Center in Uganda

Abstract

Background. Rifampicin resistance (RR) is associated with mortality among tuberculosis (TB) patients coinfected with HIV. We compared the prevalence of RR among TB patients with and without HIV coinfection at the National Tuberculosis Treatment Center (NTTC) in Uganda, a TB/HIV high burdened country. We further determined associations of RR among TB/HIV-coinfected patients. Methods. In this secondary analysis, we included adult (≥18 years) bacteriologically confirmed TB patients that were enrolled in a cross-sectional study at the NTTC in Uganda between August 2017 and March 2018. TB, RR, and bacillary load were confirmed by the Xpert® MTB/RIF assay in the primary study. A very low bacillary load was defined as a cycle threshold value of >28. We compared the prevalence of RR among TB patients with and without HIV coinfection using Pearson’s chi-square test. We performed logistic regression analysis to determine associations of RR among TB/HIV-coinfected patients. Results. Of the 303 patients, 182 (60.1%) were male, 111 (36.6%) had TB/HIV coinfection, and the median (interquartile range) age was 31 (25-39) years. RR was found among 58 (19.1%) patients. The prevalence of RR was 32.4% (36/111) (95% confidence interval (CI): 24-42) among TB/HIV-coinfected patients compared to 11.5% (22/192) (95% CI: 7–17) among HIV-negative TB patients (p<0.001). Among TB/HIV-coinfected patients, those with RR were more likely to be rural residents (adjusted odds ratio (aOR): 5.24, 95% CI: 1.51–18.21, p=0.009) and have a very low bacillary load (aOR: 13.52, 95% CI: 3.15–58.08, p<0.001). Conclusion. There was a high prevalence of RR among TB/HIV-coinfected patients. RR was associated with rural residence and having a very low bacillary load among TB/HIV-coinfected patients. The findings highlight a need for universal access to drug susceptibility testing among TB/HIV-coinfected patients, especially in rural settings.