Multidrug-resistant tuberculosis in Ethiopian settings and its association with previous antituberculosis treatment:...

Efforts to control the global burden of tuberculosis (TB) epidemic have now been jeopardized by the rapid evolution of drug-resistant Mycobacterium tuberculosis (MTB), which are resistant to one or more anti-TB drugs. Multidrug resistant (MDR) TB in Ethiopia may be more prevalent than previously appreciated; thus, up-to-date national drug resistance studies are critically needed. Therefore, this meta-analysis aimed, first, to determine pooled prevalence of MDR TB among newly diagnosed and previously treated TB cases, and second, to measure the association between previous anti-TB exposure and acquisition of MDR-MTB infection.

PubMed and Embase databases were consulted. Studies that reported the prevalence of MDR TB among newly diagnosed and previously treated TB patients were selected. Studies or surveys conducted at a national or subnational level, with reported MDR-TB prevalence or sufficient data to calculate the prevalence, were considered for the analysis. Two authors searched and reviewed the studies for eligibility and extracted the data in predefined forms. Forest plots of all prevalence estimates were performed, and summary estimates were also calculated using random effect models. Associations between previous TB treatment and MDR-MTB infection were examined through subgroup analyses stratified by new and previously treated patients.

We identified 16 suitable studies, and found an overall prevalence of MDR TB of 1.7% (95% confidence interval 1.2-2.3%) among newly diagnosed and that of 14.1% (95% confidence interval 10.9-17.2%) among previously treated TB patients, and the observed difference was statistically significant (p<.01). For the past 10years, the overall MDR-TB prevalence showed a stable time trend. There was an odds ratio of 8.1 (95% confidence interval 7.5-8.7) for previously treated TB patients to develop an MDR-MTB infection compared with newly diagnosed cases.

The MDR-TB prevalence remains high, especially in previously treated TB cases. Previous TB treatment was the most powerful predictor for MDR-MTB infection. Hence, strict compliance with anti-TB regimens and improving case detection rate are urgently needed to tackle the problem.