Background: Tuberculosis (TB) and HIV makeup a deadly synergy of infectious disease, and the combined effect is apparent in resource limited countries like Ethiopia. Previous studies have demonstrated inconsistent results about the protective effect of isoniazid preventive therapy (IPT) on active TB incidence among HIV patients on ART. Therefore, the aim of this meta-analysis was, first, to determine the protective effect of IPT on active tuberculosis incidence, and second, to figure out the pooled incidence of active TB among HIV patients on ART with and without IPT intervention in Ethiopia.

Methods: PubMed, Google scholar and Cochran library databases were searched from April 1 to 30, 2018. Two authors, DG and SE searched and assessed the studies for eligibility, and extracted data based on predefined criteria. Heterogeneity of the included studies was checked by I² statistics, whereas publication bias was determined by funnel plot and Egger’s regression test. A random effects model was used to estimate risk ratios and pooled incident TB with the respective 95% confidence intervals using Stata version 11.0 statistical software.

Results: Totally, 423 titles were retrieved and 7 studies met the inclusion criteria. Accordingly, IPT has decreased the risk of active TB incidence by 73%, risk ratio (RR) 0.27 (95% CI; 0.16%–0.43%), compared to no IPT group. Moreover, IPT treatment for 12 months has reduced incident TB by 91% (RR: 0.09, 95% CI: 0.04 to 0.21), whereas 6 months IPT intervention has averted TB incidence by 63% (RR: 0.37, 95% CI: 0.26 to 0.52). The overall pooled incidence of active TB among HIV patients on ART with and without IPT was 3.79% (95% CI; 2.03%–5.55%) and 16.32% (95% CI; 11.57%–21.06%) respectively.

Conclusion: IPT has reduced the risk of incident TB among HIV patients on ART in Ethiopian settings. Moreover, the duration of IPT intervention has effect on its protective role. Thus, scaling up the isoniazid preventive therapy program and its strict compliance is necessary to avert HIV fueled tuberculosis in Ethiopia.

Keywords: Tuberculosis, HIV, ART, Isoniazid preventive therapy, Meta-analysis