Though the WHO task force set a strategic plan to target of 75% successful treatment outcome of MDR-TB by the end of 2015 in global bases [26], many countries including Ethiopia have not yet achieved this ambitious aim. Maximizing the favorable treatment outcome in MDR-TB is a global health priority and one of the key performance indicators of WHO’s End TB strategy [27]. Ethiopia has made the treatment of MDR-TB a national health priority [28].
The national MDR-TB treatment program based on the recommendations from the 2011 update of Guidelines for the programmatic management of drug-resistant tuberculosis [29].The treatment of MDR-TB requires a long lasting drug exposure, and is also significantly associated with high rates of adverse drug events. Recent meta-analysis report documented a lower treatment success rate among patients treated with a longer MDR-TB regimen compared to those treated with a short course MDR-TB treatment [9].
To our knowledge, this is the first combined analysis to evaluate the effectiveness of the currently used MDR-TB treatment program in Ethiopia. In the present analysis, the pooled estimate of successful treatment was 59.2% (95%CI, 48.1–70.4), while 23.3% (95%CI, 19.7–27.0%) had poor treatment outcome. The treatment success observed in this analysis is comparable with the results of recently published meta-analyses of the outcomes of MDR-TB treatment with conventional drug regimens. Notably, a 54% treatment success rate for conventional MDR-TB treatment regimen was found in a meta-analysis conducted by Ahuja et al. [9]. Similar MDR treatment outcome was estimated in a meta-analysis conducted by Orenstein et al. [30], and pooled analysis from 21 countries [31], showed 62% successful outcome. Thus, it is suggested that the need to modify the duration and the composition of the current MDR-TB treatment regimens. Because of the lengthy therapy, toxicity and fewer efficacies of second-line anti-TB drugs resulting high rates of an unfavorable outcome subsequently lead to the rapid emergence of the extensively drug-resistant TB.
Most recently, an effective standardized treatment regimen lasting less than 12 months has been adopted in countries like Bangladesh, Benin, Burkina-Faso, Burundi, Cameroon, Central African Republic, Côte d’Ivoire, DR Congo, Guinea, Niger, Rwanda, Senegal, Swaziland, and Uzbekistan [10,11,12,13,14]. The regimen composed of the initial phase of 4 months therapy with kanamycin, moxifloxacin, prothionamide, clofazimine, isoniazid, pyrazinamide and ethambutol, and followed by 5 months of treatment with moxifloxacin, clofazimine, pyrazinamide, and ethambutol. Based on the data from recent studies, high treatment success has been achieved in above-mentioned countries. Most importantly, meta-analysis studies revealed that the treatment success rate using shorter MDR/RR-TB treatment regimens was ranged from 83.0–83.7% [6, 7], which higher than previously appreciated treatment outcome. Furthermore, an observational survey of nine African countries also noted promising results of using 12-month regimen [10].
Of note, the latest advancement asserted that the effectiveness of the shorter treatment regimen, in May 2016 WHO moves one step forward to update drug-resistant TB treatment guideline, and underscored the recommendation on the use of the 9–12 month treatment regimen [15]. This encouraged the National Tuberculosis Program (NTP) of Ethiopia need to test and implement a similar 12-month regimen. Though there are several positives with this regimen, its use could be restricted by the fact that patients with fluoroquinolones or other 2nd line drug resistance, extra-pulmonary tuberculosis, pregnancy and with severe clinical problems are known not to be considered for shorter MDR/RR-TB regimen. In this case, the NTPs need to preserve the conventional treatment approaches.
In sub-group analysis, it also estimated that 46.1% (34.2–58.0) cured, 12.8% (5.7–20.0) treatment completed, 14.3% (11.5–17.2) died, 7.5% (3.7–11.3) lost to follow uped, 1.6% (1.1–2.2%) experienced treatment failure and 25.0% (14.6–35.5) of the patients whose treatment outcome was not evaluated. Particularly, the cure rate indicated in our analysis is substantially inferior to the results reported with a shorter MDR-TB regimen [15]. Aside from the drug-resistant nature of the infection, the low cure rate might be due to lack of sufficient MDR-TB care centers, poor patient adherence, the low performance of NTPs at central and regional levels, poor efficacy and prolonged duration of the treatment. According to WHO 2017 report [2], achieving high cure rate one of the key pillars of End TB strategy. The result of this study informs the NTPs to update the current treatment approaches as per recently recommended treatment guideline. However, prior to this prospective cohort analysis of a large number of patients required to support the evidence detailed above. Additionally, the Ethiopian Federal Ministry of Health should design smooth platforms to facilitate surveillance data on culture-based drug susceptibility testing; it may be used to identify a population of eligible patients for Short course MDR/RR-TB treatment.
Limitations of the study
One of the limitations of this analysis was observational and few studies have been included to measure MDR-TB treatment outcome. Potential predictors of poor treatment outcome Such as HIV infection and history TB treatment was not evaluated because the association was not measured in the original studies. Besides, sub-group analysis of the MDR-TB outcome was not done based on the mode of patient treatment (hospital and/or ambulatory) because lack of clear information in the reports.
