TB Risk Factors & Progression Risk

· TB Diagnostic Strategies & Cost-Effectiveness

• Varies based on HIV prevalence, drug resistance, and healthcare access.
• Discrete-event simulation (DES) helps assess MDR-TB diagnostics.
• DES tool enhances decision-making in resource-limited settings.
• Incorporating disease transmission models improves predictions.

· Novel TB Vaccines & Impact

• Delay beyond 2025 could reduce effectiveness.
• Adolescent/adult-targeted vaccines may prevent 44M cases & 5M deaths by 2050.
• Accelerated rollout could prevent 65.5M cases & 7.9M deaths.
• Greatest impact in Africa, South-East Asia, and low-income nations.
• High-efficacy, long-lasting vaccines could cut TB mortality by 27%.
• Urgency for policymakers to fast-track vaccine introduction.

· TB & Air Pollution (PM2.5 Exposure)

• PM2.5 linked to higher MDR-TB infection risk and lung damage.
• Different exposure durations impact radiographic severity.
• Smoking, indoor air pollution, and biomass fuel use increase TB risk.
• Air pollution’s TB impact may be underestimated due to socioeconomic factors.

· Household & Environmental Risk Factors

• Solid fuel use contributes to TB risk but evidence remains weak.
• Fine particles, nitrogen oxides, and CO exposure linked to TB.
• Tobacco taxes could fund TB control and clean energy programs.

· Latent TB Infection (LTBI) & Progression Risk

• WHO guidelines prioritize high-risk groups for screening & treatment.
• 11 key risk populations include HIV-positive individuals, healthcare workers, and prisoners.
• Preventive treatment is crucial in the absence of an effective TB vaccine.

· TB Risk Factors by Health Condition

• Corticosteroids: Highest risk when used 30 days before TB diagnosis.
• Diabetes: TB risk 2.33x higher.
• Glomerular Diseases: TB risk 23.36x higher.
• HCV Infection: Higher risk in untreated cases (HR 2.9).
• Cancer: Children with cancer have a 16.82x higher TB risk.
• Rheumatoid Arthritis & Psoriasis: Increased risk with corticosteroid use.
• Vitamin D Deficiency: 5.68x higher risk of progressing to active TB.

See also: Lin TB Lab

Feasible TB Intervention Suggestions

1. Expand Rapid Diagnostic Tools: Increase access to cost-effective and rapid TB diagnostic methods like GeneXpert in resource-limited settings. Implement discrete-event simulation (DES) models to optimize diagnostic strategies for MDR-TB.
2. Accelerate TB Vaccine Development & Rollout: Prioritize fast-track introduction of novel TB vaccines to prevent millions of cases and deaths. Focus on high-burden regions (Africa, South-East Asia) and at-risk populations (adolescents, adults).
3. Strengthen Air Pollution Control Policies: Enforce air quality regulations to reduce PM2.5 and other TB-aggravating pollutants. Promote clean energy solutions (e.g., LPG, electricity) over biomass fuel for cooking and heating.
4. Enhance LTBI Screening & Preventive Treatment: Implement systematic LTBI screening in high-risk groups (HIV-positive individuals, healthcare workers, prisoners). Expand access to preventive therapy (e.g., isoniazid, rifapentine) to reduce progression to active TB.
5. Integrate TB Control into Non-Communicable Disease (NCD) Programs: Strengthen TB screening in diabetes, cancer, and immunosuppressed patients, given their increased TB risk. Provide corticosteroid alternatives or monitor TB risk in patients requiring immunosuppressants.
6. Tax & Regulate Tobacco to Reduce TB Risk: Increase tobacco taxes to discourage smoking, a major TB risk factor. Use tax revenue to fund TB treatment and prevention programs in low-income communities.
7. Improve TB Awareness & Health Education: Conduct public health campaigns on TB transmission, symptoms, and prevention. Educate healthcare workers on early TB detection, drug-resistant TB, and infection control practices.

References:

1. Langley, I., Doulla, B., Lin, H.H., Millington, K. and Squire, B., 2012. Modelling the impacts of new diagnostic tools for tuberculosis in developing countries to enhance policy decisions. Health care management science, 15, pp.239-253.
2. Clark, R.A., Mukandavire, C., Portnoy, A., Weerasuriya, C.K., Deol, A., Scarponi, D., Iskauskas, A., Bakker, R., Quaife, M., Malhotra, S. and Gebreselassie, N., 2023. The impact of alternative delivery strategies for novel tuberculosis vaccines in low-income and middle-income countries: a modelling study. The Lancet Global Health, 11(4), pp.e546-e555.
3. Makrufardi, F., Chuang, H.C., Suk, C.W., Lin, Y.C., Rusmawatiningtyas, D., Murni, I.K., Arguni, E., Chung, K.F. and Bai, K.J., 2024. Particulate matter deposition and its impact on tuberculosis severity: A cross-sectional study in Taipei. Science of the Total Environment, 924, p.171534.
4. Lin, H.H., Suk, C.W., Lo, H.L., Huang, R.Y., Enarson, D.A. and Chiang, C.Y., 2014. Indoor air pollution from solid fuel and tuberculosis: a systematic review and meta-analysis. The International journal of tuberculosis and lung disease, 18(5), pp.613-621.
5. Lai, T.C., Chiang, C.Y., Wu, C.F., Yang, S.L., Liu, D.P., Chan, C.C. and Lin, H.H., 2016. Ambient air pollution and risk of tuberculosis: a cohort study. Occupational and environmental medicine, 73(1), pp.56-61.
6. Lin, H.H., Murray, M., Cohen, T., Colijn, C. and Ezzati, M., 2008. Effects of smoking and solid-fuel use on COPD, lung cancer, and tuberculosis in China: a time-based, multiple risk factor, modelling study. The Lancet, 372(9648), pp.1473-1483.
7. 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).

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