Overview of Tuberculosis Update in Spain, Western Pacific, etc.

In 2021, Spain reported 3,754 tuberculosis (TB) cases, of which 151 were imported. The remaining 3,603 cases, with a notification rate (NR) of 7.61 per 100,000, marked Spain as a low-incidence country for TB. Compared to 2020, cases declined by 2.18% (from 3,686 cases, NR = 7.78) and by 28.07% since 2015 (4,913 cases, NR = 10.59). TB incidence was notably higher in men than women, with a rate ratio of 1.7. Nearly half of all cases occurred among foreign-born individuals, who were on average younger than native-born cases. Among these, individuals from Morocco, Romania, Bolivia, Peru, and Pakistan comprised the largest groups, with over half having resided in Spain for more than 10 years. Mortality rates were 2.6 times higher in men, further emphasizing gender disparities in TB outcomes.

Regional differences in TB burden were stark, with the highest notification rates observed in Ceuta, Galicia, Catalonia, Rioja, and the Basque Country, while the Canary Islands, Castilla La Mancha, Extremadura, and Navarre recorded the lowest rates. Spain’s TB control and prevention efforts achieved significant milestones by 2020, surpassing national goals. Overall TB rates decreased by 26.5%, far exceeding the target of 15–21%, and pulmonary TB rates saw a 6% annual reduction against the 4% goal. However, challenges remain, particularly in the implementation of directly observed therapy (DOT), which is limited to high-risk patients and features flexible but slow-to-adopt guidelines for non-daily supervision.

Globally, innovative TB management strategies have shown promise. Active case finding (ACF), using mobile and community-based approaches, effectively reduces TB burden, albeit with resource constraints. The XACT model, a scalable mini-mobile clinic equipped with a portable Xpert diagnostic system, has emerged as a cost-effective solution. This approach requires screening only 18 individuals to identify one active TB case, compared to 99 for smear microscopy, and significantly expedites treatment initiation. Mobile units have outperformed traditional methods in resource-limited settings, emphasizing the importance of point-of-care diagnostics in high-burden areas.

In the Western Pacific Region, home to 1.9 billion people and an ageing population with an average life expectancy of 77.7 years, TB control faces unique challenges. Diverse healthcare systems and socioeconomic disparities influence transmission risks, particularly among older adults, diabetics, and malnourished individuals. Institutional settings, such as care homes and hospitals, are high-risk environments due to delayed disease detection. Older adults, in particular, present diagnostic challenges as typical TB symptoms and radiological signs are often masked by comorbidities. Additionally, adverse drug reactions, including hepatotoxicity, are more common in this demographic, especially when combined with herbal medicine use.

Efforts to mitigate TB in ageing populations require tailored strategies. The World Health Organization (WHO) advocates for age-friendly healthcare, emphasizing decentralized TB services, geriatric training, and reduced waiting times. Social support measures, such as financial grants and income replacement, can alleviate the burden on vulnerable groups. Active screening programs targeting high-risk populations, including those with diabetes or a history of TB, are more effective than passive case detection. Innovations like mobile diagnostics and community-based interventions remain critical in addressing the global TB burden.

Co-morbidities further complicate TB management. Diabetes increases TB risk, particularly in individuals with low body mass index (BMI), while cholesterol levels exhibit complex interactions. Low cholesterol has been linked to higher TB risk and poorer outcomes, whereas elevated cholesterol appears protective, correlating with reduced disease severity. Cholesterol influences TB pathogenesis by enhancing macrophage phagocytosis of Mycobacterium tuberculosis and limiting bacterial growth. However, elevated triglycerides predict worse treatment outcomes, underscoring the importance of monitoring lipid profiles during TB care.

In conclusion, effective TB control requires a holistic approach that integrates tailored medical, social, and systemic interventions. For older adults, age-friendly healthcare and comprehensive support systems are vital. In resource-limited settings, mobile diagnostics and community-driven case finding can bridge gaps in care. Addressing TB in high-risk groups demands a nuanced understanding of co-morbidities, innovative diagnostic tools, and sustainable healthcare models that prioritize accessibility and equity.

References:

1. Guillén, S.M., et al., 2023. Tuberculosis in Spain: An opinion paper. Rev Esp Quimioter, 36(6), pp.562-583. https://tbreadingnotes.blogspot.com/2024/11/tuberculosis-in-spain-tb0116.html
2. Adam, N., Pallikadavath, S., Cerasuolo, M. and Amos, M., 2021. Investigating the risk factors for contraction and diagnosis of human tuberculosis in Indonesia using data from the fifth wave of RAND’s Indonesian Family Life Survey (IFLS-5). Journal of Biosocial Science, 53(4), pp.577-589.
3. Esmail, A., Randall, P., Oelofse, S. et al. Comparison of two diagnostic intervention packages for community-based active case finding for tuberculosis: an open-label randomized controlled trial. Nat Med 29, 1009–1016 (2023).
4. Teo, A.K.J., Morishita, F., Islam, T., Viney, K., Ong, C.W., Kato, S., Kim, H., Liu, Y., Oh, K.H., Yoshiyama, T. and Ohkado, A., 2023. Tuberculosis in older adults: challenges and best practices in the Western Pacific Region. The Lancet Regional Health-Western Pacific, 36, p.100770.
5. Ngo, M.D.; Bartlett, S.; Ronacher, K. Diabetes-Associated Susceptibility to Tuberculosis: Contribution of Hyperglycemia vs. Dyslipidemia. Microorganisms 2021, 9, 2282.

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