Incidence rate and risk factors for developing active tuberculosis among people living with HIV in Georgia in 2019-2020 cohort

Abstract

Background Tuberculosis is a leading cause of morbidity and mortality among people living with HIV (PLHIV) globally. Our study is the first to evaluate TB incidence and its risk factors among PLHIV in the country of Georgia, where previously no data was available. Methods A retrospective cohort study was conducted among persons newly diagnosed with HIV in Georgia during 2019-2020. Active TB incidence was calculated within a minimum of 2-year follow-up period from HIV diagnosis. Cox proportional hazard model was used for evaluating risk factors for TB development. Results The median age in the final cohort of 1,165 PLHIV was 38 (IQR 30-48) and 76.3% were male. 29% of patients had CD4 cell count <200 at HIV diagnosis and 89.9% initiated antiretroviral therapy (ART). TB incidence rate was 10/1,000 person-years (95%CI 9.6-10.4), with rates being higher within several sub-groups, mainly: PLHIV aged 40-49 (17.5/1,000p-y [95%CI 16.8-18.2]); those not receiving ART (22/1,000p-y [95%CI 20.9-23.1]); those with CD4<200 at baseline (28/1,000p-y [95%CI 27.4-28.6]); and those who developed AIDS (29.1/1,000p-y [95%CI 28.6-29.6]). Age (aHR 1.2, 95%CI 1.03-1.39, p=0.01) and AIDS diagnosis (aHR 3.2, 95%CI 3.06-27.9, p=0.001) were associated with TB development, while high CD4 count was protective against TB (aHR 0.18, 95%CI 0.06-0.61, p=0.005). Conclusions Study results highlight an imperative role of CD4 cell count management and the need for early HIV diagnosis and timely initiation of ART to ensure an effective immune response against tuberculosis, stressing the need for further in-depth evaluation of the TB preventive treatment delivery system’s efficiency and gaps.