Effect of highly active antiretroviral treatment on TB incidence among HIV infected children and their clinical profile, retrospective cohort study, South West Ethiopia

Globally, 1.8 million HIV infected children live with HIV; nearly 53% of them were receiving HIV treatment. People who are infected with HIV are 18 times more likely to develop active TB. Despite antiretroviral treatment has shown marked reduction in TB incidence, TB continues to occur in Sub-Saharan countries including Ethiopia among HIV infected people. The effect of highly active antiretroviral treatment is quite successful in developed countries. However, in developing country TB/HIV co-infection remains perplexing among children on the treatment. The aim of this study was to investigate the impact of ART on the incidence of TB among Children infected with HIV in Southwest Ethiopia. A retrospective cohort study was conducted on randomly selected 800 samples from ART clinic between 2009 and 2014. We used chi-square test, and Mann-Whitney U test to compare HAART naive and HAART cohort. We used marginal structural models to estimate the effect of HAART on survival while accounting for time-dependent confounders affected by exposure. A total of 800 children were followed for 2942.99 child-years. The children were observed for a median of 51 months with IQR 31 and for a total of 2942.99 child-years. From 506 OIs that occurred, the most common reported OIs were Pneumonia (22%) and TB (23.6%). The overall TB incidence rate was 7.917 per 100 child years (95% CI, 6.933-9.002). Whereas among HAART (7.667 per 100-years (95% CI, 6.318-9.217) and 8.1686 per 100 person-years (95% CI 6.772-9.767) for HAART naive. The mortality hazard ratio comparing HAART with no HAART from a marginal structural model was 0.642 (95% CI 0.442-0.931, p<0.02). HAART reduced the hazard of TB in HIV-infected children by 36%. This is by far less than expected.