Incidence and risk factors for HIV-tuberculosis coinfection in the Cologne-Bonn region: a retrospective cohort study

Purpose: The risk of developing active tuberculosis (TB) is considerably increased in people living with HIV/AIDS (PLWH). However, incidence of HIV/TB coinfection is difficult to assess as surveillance data are lacking in many countries. Here, we aimed to perform a quantitative analysis of HIV/TB coinfections within the Cologne/Bonn HIV cohort and to determine risk factors for active TB.

Methods: We systematically evaluated data of patients with HIV/TB coinfection between 2006 and 2017. In this retrospective analysis, we compared HIV/TB-coinfected patients with a cohort of HIV-positive patients. The incidence density rate (IDR) was calculated for active TB cases at different time points.

Results: During 2006-2017, 60 out of 4673 PLWH were diagnosed with active TB. Overall IDR was 0.181 cases/100 patient-years and ranged from 0.266 in 2006-2009 to 0.133 in 2014-2017. Patients originating from Sub-Saharan Africa had a significantly (p < 0.001) higher IDR (0.694/100 patient-years of observation, 95% CI [0.435-1.050]) in comparison to patients of German origin (0.053/100 patient-years of observation, 95% CI [0.028-0.091]). In terms of TB-free survival, individuals originating from countries with a TB incidence higher than 10/100,000 exhibited a markedly reduced TB-free survival compared to those originating from regions with lower incidence (p < 0.001). In 22 patients, TB and HIV infection were diagnosed simultaneously.

Conclusion: Overall, we observed a decline in the incidence density rate (IDR) of HIV/TB coinfections between 2006 and 2017. Patients originating from regions with high incidence bear a higher risk of falling ill with active TB. For PLWH born in Germany, the observed risk of active TB appears to be lower compared to other groups within the cohort. These findings should be considered when developing TB containment and screening strategies for PLWH in low-incidence countries.