The risk of tuberculosis in specific population groups

The risk of progression to tuberculosis (TB) varies among individuals, with certain risk factors significantly increasing the likelihood of progression compared to the general population with latent TB infection (LTBI). In the absence of an effective TB vaccine, preventing progression from LTBI to active TB through preventive treatment remains one of the most critical tools for TB control.

The World Health Organization (WHO) issued its first LTBI management guidelines as part of the post-2015 End TB Strategy. These guidelines prioritized testing and treatment for high-risk groups and identified 11 populations for systematic LTBI screening: people living with HIV, adult and child contacts of pulmonary TB cases, patients initiating anti-tumor necrosis factor (TNF) treatment, patients undergoing dialysis or preparing for organ/hematological transplantation, patients with silicosis, prisoners, healthcare workers, immigrants from high TB-burden countries, homeless individuals, and illicit drug users.

Several studies and meta-analyses have examined the risk of active TB in various populations:

1. Corticosteroid Use: A Taiwanese case–control study found the highest adjusted incidence rate ratio (IRR) for corticosteroid use within 30 days of TB diagnosis (2.76, 95% CI 2.44–3.11), with lower IRRs for usage 31–90 days (1.99, 95% CI 1.73–2.31) and 91–365 days (1.17, 95% CI 1.06–1.29) before diagnosis.
2. Inhaled Corticosteroids (ICS): A 2018 meta-analysis revealed odds ratios for active TB of 4.48 (95% CI 1.85–10.86) from Canadian cohort studies and 1.31 (95% CI 0.94–1.82) from nested case–control studies in East Asia.
3. Diabetes Mellitus: A 2021 meta-analysis estimated a pooled odds ratio of 2.33 (95% CI 2.00–2.71) for active TB in individuals with diabetes, consistent with earlier findings (2.00, 95% CI 1.78–2.24) from a 2017 meta-analysis.
4. Glomerular Diseases: Patients with biopsy-diagnosed glomerular diseases in British Columbia had a standardized incidence ratio (SIR) of 23.36 (95% CI 16.76–31.68) for active TB. Immunosuppressant use further increased the risk (HR 2.13, 95% CI 1.13–4.03).
5. HCV Infection: A Georgian cohort study reported adjusted hazard ratios (HRs) of 2.9 (95% CI 2.4–3.4) for untreated HCV and 1.6 (95% CI 1.4–2.0) for treated HCV, compared with uninfected adults.
6. Cancer: A 2017 meta-analysis found pooled IRRs of 2.61 (95% CI 2.12–3.22) in adults and 16.82 (95% CI 8.81–32.12) in children with cancer. A Korean cohort study reported an IRR of 10.68 (95% CI 8.83–12.99) for newly diagnosed malignancies.
7. Rheumatoid Arthritis: Canadian and U.S. studies found increased IRRs for corticosteroid use (1.7–2.4) in rheumatoid arthritis patients but no significant risk with NSAIDs or COX-2 inhibitors.
8. Psoriasis and Psoriatic Arthritis: A Taiwanese cohort study reported an unadjusted IRR of 1.22 (95% CI 1.18–1.33) for active TB, while a Korean study with ustekinumab users found no increased risk (IRR 0.76, 95% CI 0.59–2.02).
9. Vitamin D Deficiency: A UK cohort study showed that LTBI-diagnosed individuals with profoundly deficient vitamin D levels had an HR of 5.68 (95% CI 2.18–14.82) for progression to active TB.

References:

1. Bigio, J., Viscardi, A., Gore, G., Matteelli, A. and Sulis, G., 2023. A scoping review on the risk of tuberculosis in specific population groups: can we expand the World Health Organization recommendations?. European Respiratory Review, 32(167).