Incidence of tuberculosis and the need of prophylactic treatment in persons living with HIV in Stockholm during the era of anti-retroviral therapy 1996–2013

Abstract

Background: The aim of this observational cohort study was to determine the incidence and risk factors of active tuberculosis (TB) in persons living with HIV in a low endemic setting over a 17-year time period when combination antiretroviral therapy (ART) has been available. We thereby aimed to understand the usefulness of TB chemoprophylaxis among HIV patients with latent TB.Methods: All 2127 adult patients diagnosed with HIV January 1996-December 2013 at the Karolinska University Hospital in Stockholm County were eligible. After exclusion of 259 patients transferred to other clinics, 1868 were followed until TB diagnosis, death or end of study period (December 2013). The median follow-up time was 7.9 years (interquartile range, 3.9-11.5).Results: Active TB was diagnosed in 92 patients, corresponding to an incidence rate of 6.2 cases (95% CI 5.1-7.6) per 1000 person-years with a significant decline over time. The majority (52%) of TB cases were diagnosed within 1 month from HIV diagnosis. Being a migrant from a TB-endemic region, was the only patient characteristic associated with significantly higher risk of active TB (Hazard Ration, HR: 8.54, 95% confidence interval, CI: 3.09-23.61 in a multivariate regression analysis controlling for route of HIV transmission, year of HIV diagnosis and CD4-cell count and viral load at HIV diagnosis. The number needed to treat to prevent one case of TB among patients in this high-risk group was 22 (95% CI 26-47). Conclusion:The incidence of active TB in persons living with HIV in Stockholm County declined significantly after the introduction of ART but was still 80 times higher than in the general population at the end of the study period. The therapeutic gain of chemoprophylaxis in low endemic settings should be weighed against costs and side effects.

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

“…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].…”

Screening and treatment of tuberculosis among pregnant women in Stockholm, Sweden, 2016–2017

“…This may indicate a higher risk of false negative QFT results among HIV-positive pregnant women with LTBI. In a recent report by NORRBY et al [31], the incidence of active TB among HIV-positive subjects was 80-times higher than the general population in Stockholm, which emphasises the importance of TB screening and treatment of pregnant women in this group.…”

“…All were HIV negative. The mean (range) age was 29.2 (23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33) years. Five had their first child.…”

Antiretroviral treatment for HIV infection: Swedish recommendations 2019

“…The majority of PLHIV diagnosed with tuberculosis in low-incidence countries are diagnosed at the time of HIV diagnosis [104,105], but development of active tuberculosis also occurs in individuals on ART. In a Swedish observational study of 1868 PLHIV, 92 developed tuberculosis, of which 24 (26%) were diagnosed with tuberculosis at least one year after being diagnosed with HIV [106]. However, it is not clear how many of these had HIV RNA <50 copies/ml.…”