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

Abstract

for the UK Collaborative HIV Cohort (UK CHIC) StudyObjective: 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.

Tuberculosis incidence in country of origin is a key determinant of the risk of active tuberculosis in people living with HIV: Data from a 30‐year observational cohort study

“…However, our data support the previously noted strong association of high TB risk when the CD4 count is low [4,7,15,28,30,42]. Concomitant HIV/TB diagnoses had a median CD4 count of 90 cells/μL, and although those with incident TB had a higher median CD4 count of 290 cells/μL, fewer than a third of those for whom CD4 count data were available had a CD4 count of > 350 cells/μL, and only just over 10% had a CD4 count > 500 cells/μL.…”

“…Overall, 20% of our total non-UK-born HIV cohort has had TB, in contrast to only 2.3% of our UK-born cohort. This pattern was also present when assessing ethnicity: 20% of black Africans in this cohort have had TB, and at all time points of TB diagnosis in relation to HIV, this ethnic group predominates and makes up the bulk of the cases, as has been seen in other studies of HIV/TB coinfection [11,13,15]. The peak incidence of TB cases in this study occurred in 2005, corresponding with high migration from sub-Saharan Africa.…”

“…Incident TB risk in this study was higher than that seen in other studies of PLWH from elsewhere in the UK and other low TB incidence settings which found incidence rates of 0.43-3/1000 person-years [4,5,9,15,29,30]. Even though HIV/TB coinfection comprises only 3.8% of the overall cases of TB in the UK [31] the documented post-HIV incidence in this current study exceeds the risk of TB in the UK population as a whole [22].…”

“…TB may occur at any time after acquisition of HIV infection, including in the early period following HIV seroconversion, potentially due to early depletion of Mycobacterium tuberculosis (Mtb)-specific CD4 cells in primary HIV infection [4] and also immediately after commencing antiretroviral treatment (ART) [4,5], which may represent unmasking of TB due to immune reconstitution inflammatory syndrome (IRIS) [6]. Among PLWH, the risk of developing active TB is dependent upon a number of key factors, principally HIV control through ART, as well as ethnicity/migration status [4,[7][8][9][10][11][12][13][14][15].…”

<p>Magnitude and Associated Factors of Pulmonary Tuberculosis Among HIV/AIDS Patients Attending Antiretroviral Therapy Clinic at Debre Tabor Specialized Hospital, Northwest Ethiopia, 2019</p>

“…In sub-Saharan Africa, up to 80% of individuals with active TB are HIV-positive. [6][7][8] Globally, there were an estimated 10 million incident cases and 1.5 million TB deaths (251000 among HIV-positive) according to the 2018 report of the world health organization (WHO). 3,6 In Ethiopia, TB remains one of the leading causes of mortality, especially multi-drug resistant TB (MDR-TB).…”