Incidence of and risk factors for tuberculosis among people with HIV on antiretroviral therapy in the United Kingdom

Abstract

Objective:The United Kingdom has a low tuberculosis incidence and earlier combination antiretroviral therapy (cART) is expected to have reduced incidence among people with HIV. Epidemiological patterns and risk factors for active tuberculosis were analysed over a 20-year period among people accessing HIV care at sites participating in the UK CHIC observational study.Design:Cohort analysis.Methods:Data were included for individuals over 15 years old attending for HIV care between 1996 and 2017 inclusive, with at least 3 months follow-up recorded. Incidence rates of new tuberculosis events were calculated and stratified by ethnicity (white/Black/other) as a proxy for tuberculosis exposure. Poisson regression models were used to determine the associations of calendar year, ethnicity and other potential risk factors after cART initiation.Results:Fifty-eight thousand seven hundred and seventy-six participants (26.3% women; 54.5% white, 32.0% Black, 13.5% other/unknown ethnicity; median (interquartile range) age 34 (29-42) years) were followed for 546 617 person-years. Seven hundred and four were treated for active tuberculosis [rate 1.3; 95% confidence interval (CI) 1.2-1.4/1000 person-years). Tuberculosis incidence decreased from 1.3 (1.2-1.5) to 0.6 (0.4-0.9)/1000 person-years from pre-2004 to 2011-2017. The decline among people of Black ethnicity was less steep than among those of white/other ethnicities, with incidence remaining high among Black participants in the latest period [2.1 (1.4-3.1)/1000 person-years]. Two hundred and eighty-three participants [191 (67%) Black African] had tuberculosis with viral load less than 50 copies/ml.Conclusion:Despite the known protective effect of cART against tuberculosis, a continuing disproportionately high incidence is seen among Black African people. Results support further interventions to prevent tuberculosis in this group.