Tuberculosis in Papua New Guinea

A study exploring the implementation of Tuberculosis Infection Prevention and Control (TB-IPC) guidelines in rural Papua New Guinea (PNG) used a socio-ecological model (SEM) to examine barriers and strategies at multiple levels, including individual, institutional, and policy factors. Conducted across four rural hospitals, the research employed a qualitative multiple case study design, gathering insights from 32 healthcare workers (HCWs) and 10 patients through interviews and document reviews. The findings revealed that governance gaps, funding delays, and cultural beliefs—such as associations between TB and sorcery—significantly impact TB-IPC implementation.[1] See also: https://tbreadingnotes.blogspot.com/2024/10/patient-health-system-population.html

Key challenges included limited prioritization of TB-IPC in national health plans, leadership and accountability issues, and HCW burnout due to staff shortages. Many HCWs highlighted the lack of timely funding approvals at the Provincial Health Authority level, which directly affects infection control efforts. Additionally, stigma and misinformation hinder community acceptance of TB-IPC measures, requiring targeted engagement strategies. Participants also emphasized the importance of intersectoral collaboration, particularly with NGOs and development agencies, to sustain TB-IPC initiatives in resource-limited settings.[1] See also: https://tbreadingnotes.blogspot.com/2024/09/tb-in-patients-with-hiv-and-diabetes.html

The study concludes that a multi-level, coordinated approach is essential for effective TB control in PNG. Strengthening healthcare infrastructure, enhancing HCW training, fostering community engagement, and ensuring policy commitment at all levels are critical for success. While the research offers valuable qualitative insights, future studies could incorporate quantitative impact assessments and longitudinal data to track progress. Addressing both structural and cultural barriers through policy reform and cross-sector partnerships is vital for improving TB-IPC implementation in PNG’s rural hospitals.[1] See also: https://tbreadingnotes.blogspot.com/2024/10/tb-treatment-and-resulting-abnormal.html

Papua New Guinea (PNG) is among the 30 high-burden countries for tuberculosis (TB) and multidrug-resistant TB (MDR/RR-TB), as identified by the World Health Organization (WHO). In 2022, PNG recorded a TB incidence rate of 432 per 100,000 people, with MDR/RR-TB cases at 22 per 100,000. As a middle-income country with 22 provinces and a population of approximately 12 million, PNG faces significant challenges in controlling TB, particularly in its rural and remote areas, where 80% of the population resides. The country's young demographic, with 75% under the age of 35, is especially vulnerable, contributing to high rates of transmission. However, the treatment success rate remains low at 50%, far below the national target of 90%, and is compounded by a 22% loss to follow-up (LTFU) rate, particularly among individuals aged 15–34 years.[2]

LTFU is driven by socioeconomic and geographic barriers, including difficult treatment regimens that involve long durations, toxic drugs, high pill burdens, and painful injections. Many rural patients struggle to access healthcare facilities for daily TB treatment, increasing the risk of untreated cases leading to complications and further community transmission. Addressing these challenges requires decentralizing TB services and expanding rapid molecular diagnostics at the primary care level to enhance accessibility and coverage while ensuring effective treatment outcomes.[2]

References:

1. Marme, G., Kuzma, J., Zimmerman, P.A., Harris, N. and Rutherford, S., 2024. Investigating socio-ecological factors influencing implementation of tuberculosis infection prevention and control in rural Papua New Guinea. Journal of Public Health, 46(2), pp.267-276.

2. Charles, F., Lin, Y.D., Greig, J., Gurra, S., Morikawa, R., Graham, S.M. and Maha, A., 2024. Loss to follow-up among adults with drug-resistant TB in Papua New Guinea. Public Health Action, 14(3), pp.85-90.

Glycemic Control Effect on Acid-Fast Bacteria Conversion

A study conducted at Khon Kaen Hospital in Thailand analyzed data from the Tuberculosis Database spanning from January 2018 to January 2021, focusing on adult outpatients. The research included 669 patients divided into three groups based on their diabetes status: a non-diabetic group with 512 patients, a controlled diabetes group with 30 patients (HbA1c <7%), and an uncontrolled diabetes group with 127 patients (HbA1c ≥7%). Key demographics and health conditions varied significantly among these groups; notably, the non-diabetic group was significantly younger and less likely to have hypertension, while chronic kidney disease was most prevalent in the controlled diabetes group.[1]

In terms of treatment efficacy, the study found that sputum acid-fast bacilli (AFB) conversion rates were similar across groups, with 77.9% of non-diabetic patients and 77.7% of diabetic patients achieving conversion. The odds ratio for sputum AFB conversion between diabetic and non-diabetic groups showed no significant difference (OR: 0.987; 95% CI: 0.625–1.559; P=0.955). Furthermore, when looking at treatment outcomes, there was no significant variation in cure rates between the controlled and uncontrolled diabetic groups, nor in treatment duration or mortality rates, indicating that diabetes control might not markedly influence TB treatment outcomes.[1]

Additionally, the study highlighted some associations with treatment results. Female gender was found to be significantly linked with a higher rate of sputum AFB conversion at 2 months (OR: 2.285; 95% CI: 1.376–3.794; P=0.074). However, no significant associations were observed between HbA1c levels and key outcomes like sputum conversion, cure rate, treatment duration, or mortality. This suggests that while diabetes does not substantially alter TB treatment efficacy, other factors such as gender might play a role in treatment response.[1]

In another study, subjects with controlled Random Blood Glucose (RBG) and controlled HbA1C levels exhibited a higher percentage of negative sputum smear conversion. Notably, those with a 31-50% decrement in RBG achieved the highest rate of conversion at 42%, while subjects with more than a 50% RBG decrement had a lower conversion rate of 24%, suggesting that a moderate control of blood glucose might be more beneficial for sputum smear conversion compared to either uncontrolled or excessively controlled glucose levels.[2]

References:

1. Suwannacho, R., Anantachina, N. and Sornprom, C., 2024. Glycated hemoglobin level and sputum acid—fast bacilli conversion in pulmonary tuberculosis. The Clinical Academia, 48(3), pp.84-91.

2. Septa, D. and Surjadi, L.M., 2023. Glycemic Control Effect on Acid-Fast Bacteria Conversion in Diabetic Patients with Tuberculosis. Jurnal Biomedika dan Kesehatan, 6(1), pp.62-70. 

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).

Air pollution and tuberculosis

A cross-sectional study of 1,073 patients aged 19 to 90 years, recruited from the chest department clinic of a TB center in Taipei, Taiwan, was conducted from April 2014 to November 2022. Most participants were male (59.9%), with an average age of 64.7 years and a mean BMI of 21.45 kg/m². Alcohol consumption was reported by 10.4% of participants, while smoking status included 13.2% current smokers, 20.0% ex-smokers, and 66.7% non-smokers. The average annual family income was $30,493 USD. Daily mean ambient PM2.5 levels over 1, 7, and 30 days ranged from 16.81 to 17.15 µg/m³.[1] See also: Lin TB Lab Taiwan

Patients with pulmonary nontuberculous mycobacteria (NTM) displayed distinct characteristics compared to other groups, including higher age, a lower proportion of males, shorter height, lower smoking rates, reduced income, and fewer chest X-ray (CXR) abnormalities. Pulmonary NTM patients were exposed to lower PM2.5 levels over 1- and 7-day periods in both regional and lobar lung deposits, while pulmonary multidrug-resistant TB (MDR-TB) patients were exposed to lower PM2.5 levels over 30 days.[1]

A 1 µg/m³ increase in ambient PM2.5 was linked to a higher risk of pulmonary MDR-TB infections and increased lung abnormalities, particularly in the upper and middle lobes. PM2.5 deposition over 1-, 7-, and 30-day periods showed significant exposure-response relationships with radiographic severity in TB, MDR-TB, and NTM patients. While PM2.5 exposure reduced nodules and cavities in some regions, it increased abnormalities in others. Overall, higher PM2.5 levels were strongly associated with worsened lung conditions and greater TB infection risks.[1]

A systematic review and meta-analysis found that the association between household use of solid fuels and tuberculosis (TB) is supported by very low levels of evidence. Burning solid fuels can pose serious health risks, particularly when stoves are inefficient, and ventilation is poor. These conditions contribute to acute lower respiratory infections in children under five, chronic obstructive pulmonary disease (COPD), and lung cancer. Pollutant concentrations from burning solid fuels vary depending on the stove type, burning location, and ventilation quality. These factors play a critical role in quantifying pollutant levels.[2]

Respirable risk factors, such as active and passive smoking and indoor air pollution from biomass, may impair airway defense mechanisms, increasing the risk of tuberculosis (TB). High levels of ambient air pollution in developing countries are associated with persistently high TB rates, highlighting the need for further research into its impact on global TB control. Fine particles and traffic-related pollutants, including nitrogen dioxide, nitrogen oxides, and carbon monoxide, have been linked to an increased risk of active TB. Laboratory and ecological studies indicate a positive association between ambient air pollution and TB incidence. However, the true relationship may be underestimated due to potential residual confounding by area-level socioeconomic factors.[3]

Tobacco smoking and indoor air pollution from solid fuel use are key risk factors for COPD, lung cancer, and tuberculosis (TB), particularly in developing countries. Reducing these risks through measures like tobacco taxation, cleaner fuel adoption, and targeted programs could significantly lower disease mortality and TB incidence. These diseases disproportionately affect low-income communities, imposing economic burdens through healthcare costs and reduced productivity. Revenue from tobacco taxes could fund TB treatment programs, clean energy initiatives, and nutritional support, improving health outcomes in marginalized populations.[4]

References:

1. 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.

2. 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.

3. 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.

4. 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.

TB Diagnostic Technologies

· TB Diagnostic Technologies and Hospital Impact

• Medical Center A in Taipei transitioned to auramine-rhodamine staining from Ziehl-Neelsen staining by 2014, aiming to improve TB detection and patient isolation.
• Enhanced diagnostic sensitivity resulted in doubling the positive sputum smear rate from 22.8% to 48.1%, especially for non-cavitary lung lesions.
• The median duration of non-isolated infectiousness reduced significantly from 12.5 days to 3 days, and the total number of non-isolated infectious patient-days decreased by 69% from 2001 to 2014.
• Suggestion: Implement continuous training for healthcare staff on the latest TB diagnostic technologies to maintain high detection rates and reduce the time to isolation.

· Risk Factors and Control Measures in Healthcare Settings

• Inadequate ventilation and insufficient environmental cleaning in healthcare settings heighten TB transmission risks.
• Frequent healthcare visits are closely linked to increased TB incidence, necessitating robust infection control measures in high-traffic areas like internal medicine and family medicine.
• Suggestion: Prioritize the installation of germicidal ultraviolet systems and upgraded ventilation in outpatient areas to minimize airborne transmission.

· Epidemiological Insights and Trends

• TB incidence and related mortality have declined in younger populations (<20 and 20–50 years) in mainland China, reflecting effective control measures.
• However, SS- TB cases and mortality in the >50 age group remained high, indicating ongoing vulnerabilities.
• Suggestion: Develop targeted health campaigns and screening programs focused on the elderly to address the persistently high TB rates in this demographic.

· Regional and Systemic Challenges in Taiwan

• Increased Health System Delay (HSD) in diagnosing TB was noted between 2003 and 2008, influenced by factors such as patient’s age, gender, and the type of health facility visited.
• Eastern Taiwan showed shorter HSDs due to a higher concentration of TB-specialized providers, while medical centers experienced longer delays.
• Suggestion: Enhance the distribution and accessibility of specialized TB healthcare services across different regions to ensure timely diagnosis and treatment.

· Link Between TB and Chronic Conditions

• Tuberculosis is a significant risk factor for developing chronic obstructive pulmonary disease (COPD), with risks increasing due to delays in TB treatment initiation.
• Early diagnosis and timely treatment of TB are crucial to mitigate COPD risk.
• Suggestion: Strengthen the integration of TB and COPD management protocols to improve patient outcomes and reduce the incidence of COPD among former TB patients.

See also: https://lintblab.weebly.com

References:

1. Sun H-Y, Wang J-Y, Chen Y-C, Hsueh PR, Chen Y-H, Chuang Y-C, et al. (2020) Impact of introducing fluorescent microscopy on hospital tuberculosis control: A before-after study at a high caseload medical center in Taiwan. PLoS ONE 15(4): e0230067.
2. Pan, S.C., Chen, C.C., Chiang, Y.T., Chang, H.Y., Fang, C.T. and Lin, H.H., 2016. Health care visits as a risk factor for tuberculosis in Taiwan: a population-based case–control study. American journal of public health, 106(7), pp.1323-1328.
3. Liu, K.H., Xiao, Y.X. and Jou, R., 2024. Multidrug-resistant tuberculosis clusters and transmission in Taiwan: a population-based cohort study. Frontiers in Microbiology, 15, p.1439532.
4. Huang, F. and Bello, S.T., 2024. Spatiotemporal analysis of regional and age differences in tuberculosis prevalence in mainland China. Tropical Medicine & International Health, 29(9), pp.833-841.
5. Fu, H., Lin, HH., Hallett, T.B. et al. Explaining age disparities in tuberculosis burden in Taiwan: a modelling study. BMC Infect Dis 20, 191 (2020).
6. Chen, C.C., Chiang, C.Y., Pan, S.C., Wang, J.Y. and Lin, H.H., 2015. Health system delay among patients with tuberculosis in Taiwan: 2003–2010. BMC infectious diseases, 15, pp.1-9.
7. Lee C-H, Lee M-C, Lin H-H, Shu C-C, Wang J-Y, et al. (2012) Pulmonary Tuberculosis and Delay in Anti-Tuberculous Treatment Are Important Risk Factors for Chronic Obstructive Pulmonary Disease. PLoS ONE 7(5): e37978.

TBC 036

Modelling the impacts of new approaches for TB management

Different diagnostic strategies for tuberculosis (TB) vary in cost-effectiveness depending on local factors such as the prevalence of HIV, drug resistance, and access to health facilities. The discrete-event simulation (DES) tool is particularly valuable for assessing diagnostic methods for multidrug-resistant TB (MDR-TB) in central reference facilities. This tool enables policymakers to evaluate the impact of TB diagnostic tools in resource-limited settings, improving decision-making processes. By incorporating a disease transmission component, the DES model gains enhanced predictive capabilities, offering insights into TB incidence and its effects on health systems and patient outcomes. Furthermore, a visual and interactive DES tool empowers national policymakers to validate diagnostic strategies, explore new approaches, and effectively engage with simulation outcomes.[1]

A study explored the potential impact of introducing novel tuberculosis (TB) vaccines, addressing critical questions about the consequences of delaying vaccine introduction beyond 2025, the health benefits of different rollout strategies, and variations in impact across WHO regions, income levels, and TB burden. Using a dynamic transmission model incorporating epidemiological data and socioeconomic factors, the study found that introducing vaccines, particularly for adolescents and adults, could prevent 44 million TB cases and 5 million deaths by 2050 in the base-case scenario. Accelerated rollouts could further amplify the benefits, averting 65.5 million cases and 7.9 million deaths, with the greatest impact in the African and South-East Asian regions and low-income countries.[2]

The findings highlight the transformative potential of novel TB vaccines, particularly when paired with accelerated rollout strategies. High-efficacy vaccines or those offering lifelong protection could significantly enhance outcomes, saving millions of lives and reducing TB incidence and mortality by up to 27%. Policymakers are urged to prioritize rapid vaccine introductions, modeled on the success of COVID-19 vaccine campaigns, to maximize global health benefits and address the TB burden in high-need regions.[2]

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.

Achieving the global tuberculosis targets

Aggressive scaling of a single intervention is insufficient to achieve the post-2015 End TB Strategy targets on a global scale. In South Africa, a combination of targeted measures could significantly reduce tuberculosis rates. These include continuous isoniazid preventive therapy for individuals receiving antiretroviral treatment, expanded facility-based screening for tuberculosis symptoms at health centers, and enhanced tuberculosis care. Together, these interventions make substantial reductions in tuberculosis feasible, increasing the likelihood of meeting the 2025 targets. In other high-burden countries such as China and India, additional country-specific strategies are essential. In China, addressing latent tuberculosis among the elderly is a critical focus, while in India, tackling undernutrition is key to achieving the global tuberculosis targets.[1]

Active Case Finding (ACF) for tuberculosis under India’s National TB Elimination Program (NTEP) faces both enabling factors and significant barriers, as perceived by healthcare providers. Key enablers include well-structured operational planning with sufficient budget allocation, systematic ACF cycles, and strong stakeholder engagement through local collaboration and community-friendly initiatives. Technological advancements, such as the use of rapid diagnostic tests and digital tools, also facilitate streamlined ACF implementation. However, barriers such as administrative burdens, logistical challenges like delayed incentives and transport issues, and socio-cultural factors like stigma and healthcare distrust undermine the effectiveness of ACF activities.[2]

To address these barriers, providers suggest adopting a more integrated health approach, combining TB ACF activities with other health programs to enhance community participation. Timely incentives for Accredited Social Health Activists (ASHAs) are essential for maintaining motivation, while external quality monitoring mechanisms and physical oversight during ACF cycles are recommended for data reliability. Simplifying the Ni-kshay portal to make it user-friendly and enabling easier data entry can also enhance the program’s efficiency. These changes, coupled with optimized laboratory diagnostic tools, improved sputum transport mechanisms, and mobile applications for field data entry, are seen as vital improvements.[2]

The study emphasizes the importance of capacity building to strengthen ACF implementation. Training gaps among ASHAs can be addressed through tailored modules that enhance their knowledge and skills. Scaling up resources, such as recruiting more staff and introducing mobile tools, is also critical. By focusing on these multi-pronged strategies—improving community engagement, ensuring adequate incentives and resource allocation, streamlining technological platforms, and enhancing training and infrastructure—India can overcome current challenges and accelerate progress toward its TB elimination goals.[2]

References:

1. Houben, R.M., Menzies, N.A., Sumner, T., Huynh, G.H., Arinaminpathy, N., Goldhaber-Fiebert, J.D., Lin, H.H., Wu, C.Y., Mandal, S., Pandey, S. and Suen, S.C., 2016. Feasibility of achieving the 2025 WHO global tuberculosis targets in South Africa, China, and India: a combined analysis of 11 mathematical models. The Lancet Global Health, 4(11), pp.e806-e815.

2. Shewade, H.D., Ravichandran, P., Pradeep, S.K., Kiruthika, G., Shanmugasundaram, D., Chadwick, J., Iyer, S., Chowdhury, A., Tumu, D., Shah, A.N. and Vadera, B., 2024. Bridging the “know-do” gap to improve active case finding for tuberculosis in India: A qualitative exploration into national tuberculosis elimination program staffs’ perspectives. PloS one, 19(11), p.e0309750.

Economic and Healthcare Aspects of Tuberculosis Management

A study focuses on understanding the impact of gaps and delays in the tuberculosis (TB) care cascade on TB incidence and mortality across three countries: India, Kenya, and Moldova. By employing deterministic transmission models that incorporate epidemiological data and specific challenges within each country's care cascade, the research identifies critical shortcomings in TB control efforts. These models, which are well-suited to the task due to their ability to tailor analyses to country-specific dynamics and health care practices, highlight the importance of addressing these gaps and delays to enhance TB control strategies effectively.[1]

In detail, the study examines various factors affecting the TB care cascade, including independent variables like the proportion of symptomatic individuals seeking care and treatment adherence rates, and dependent variables such as TB incidence and mortality. It also considers control variables specific to each country, such as HIV prevalence in Kenya and multidrug-resistant TB burden in Moldova, along with confounding variables like socioeconomic factors. The findings underscore the significant potential for reducing TB incidence and mortality through targeted interventions that address both gaps in care provision and delays in care seeking, which vary markedly between different settings and patient demographics.[1]

The conclusions drawn from the study assert that while strategic interventions in the TB care cascade can substantially reduce TB incidence and mortality, they alone are insufficient to achieve TB elimination in high-burden settings by the projected year 2035. The research advocates for the integration of broader public health measures, such as improving nutrition and enhancing urban development, alongside more targeted TB control strategies. This comprehensive approach aligns with the research question by demonstrating that the care cascade framework is crucial for guiding effective interventions and monitoring progress in the fight against TB, yet must be part of a broader strategy to address the global challenge posed by tuberculosis.[1]

Substantial health improvements were observed in India, China, and South Africa as a result of expanded access to tuberculosis care, with most intervention strategies proving to be highly cost-effective against conventional thresholds. These efforts not only enhanced access but also demonstrated notable cost-effectiveness in each setting analyzed. However, the implementation of such expanded services would necessitate careful planning due to the significant differences in the effectiveness and efficiency of various approaches, alongside the need for substantial new funding. Although the incremental costs for tuberculosis services varied, potentially more than doubling existing funding needs, the economic and health benefits included generally reduced patient-incurred costs and, in India and China, net cost savings from a societal perspective.[2]

Another study reveals a strong correlation between economic indicators and health expenditures, finding that per-capita GDP, income, poverty rates, unemployment, healthcare expenditure, and healthcare resources such as general practitioners and TB-specific hospital beds are significant predictors of tuberculosis incidence rates. It identifies two crucial factors—economic development and healthcare capacity—that both have a substantial negative impact on TB incidence, suggesting that stronger economies and more robust healthcare systems contribute to lower TB rates. However, these findings, derived from population-level data, emphasize that while they highlight general trends, they should not be directly extrapolated to individual cases.[3]

References:

1. Vesga, J.F., Hallett, T.B., Reid, M.J., Sachdeva, K.S., Rao, R., Khaparde, S., Dave, P., Rade, K., Kamene, M., Omesa, E. and Masini, E., 2019. Assessing tuberculosis control priorities in high-burden settings: a modelling approach. The Lancet Global Health, 7(5), pp.e585-e595.

2. Menzies, N.A., Gomez, G.B., Bozzani, F., Chatterjee, S., Foster, N., Baena, I.G., Laurence, Y.V., Qiang, S., Siroka, A., Sweeney, S. and Verguet, S., 2016. Cost-effectiveness and resource implications of aggressive action on tuberculosis in China, India, and South Africa: a combined analysis of nine models. The Lancet global health, 4(11), pp.e816-e826.

3. Sorokina, M., Ukubayev, T. and Koichubekov, B., 2023. Tuberculosis incidence and its socioeconomic determinants: developing a parsimonious model. Annali di Igiene, Medicina Preventiva e di Comunita, 35(4): 468-479.

Tuberculosis in Healthcare Workers

This study investigates the factors affecting the implementation of active tuberculosis (TB) surveillance in rural and urban districts of the Eastern Cape, South Africa, from the perspective of healthcare workers. Utilizing a cross-sectional survey method, data was gathered via an electronic questionnaire through REDCap software. The approach effectively captures healthcare workers' views on systemic and contextual challenges at a specific time, though self-reported data may introduce bias, and the focus solely on healthcare workers might overlook patient and community stakeholder insights.[1]

Variables in this study include independent variables such as geographical settings (rural vs. urban districts) and healthcare worker demographics and roles. Dependent variables involve factors impacting TB surveillance like training, transportation, coordination, and community acceptance. Confounding factors include socioeconomic disparities and variations in clinic resources, while control variables were demographic comparatives of the survey participants. Key results indicated significant challenges like CHW transport issues and community distrust, alongside a substantial discrepancy in resource allocation between rural and urban settings. The study concludes that multiple barriers, including leadership and resource deficiencies, affect TB surveillance, necessitating tailored interventions for different locales.[1]

In Taiwan, Tuberculosis (TB) poses a significant occupational risk for healthcare workers (HCWs), who exhibit a higher incidence of active TB compared to the general population when adjusted for age, sex, and diagnosis year. Notably, the outcomes of TB in HCWs are more favorable than those of non-HCW patients treated in the same settings, primarily due to factors such as the healthy worker effect, expedited diagnosis, and reduced treatment delays, all contributing to lower TB mortality rates among healthcare workers.[2]

References:

1. Ajudua, F.I. and Mash, R.J., 2024. Implementing active surveillance for TB: A descriptive survey of healthcare workers in the Eastern Cape, South Africa. African Journal of Primary Health Care & Family Medicine, 16(1), p.4217.

2. Pan S-C, Chen Y-C, Wang J-Y, Sheng W-H, Lin H-H, Fang C-T, et al. (2015) Tuberculosis in Healthcare Workers: A Matched Cohort Study in Taiwan. PLoS ONE 10(12): e0145047.

Ceasing universal BCG vaccination

A study investigates the impact of discontinuing universal Bacillus Calmette-Guérin (BCG) vaccination on the epidemiology of childhood tuberculosis (TB). By analyzing retrospective data from seven countries that ceased universal BCG vaccination, the research compares TB notification trends around the cessation year, focusing on disease types, patient birthplace, and common challenges. Data were collected through communications with TB focal bodies and secondary sources such as PubMed and official health databases. The mixed-method approach effectively highlights epidemiological trends post-policy changes, though it faces potential biases from inconsistent data availability and varied surveillance systems.[1] See also: Lin TB Lab

The findings reveal that only Slovakia experienced a significant increase in childhood TB notification rates after stopping universal BCG vaccination, with notable rises in both age groups studied. In contrast, countries like Norway, France, and the UK maintained stable or declining TB rates. Pulmonary TB and TB lymphadenitis remained the most prevalent forms, while severe TB types stayed below 4% across all nations. Additionally, a majority of TB cases in France and Norway involved children born abroad or with foreign-born parents, underscoring the influence of migration patterns. Vaccination coverage varied widely, indicating the necessity for targeted vaccination programs in high-risk populations.[1] See also: Jago Beasiswa

The study concludes that halting universal BCG vaccination does not universally escalate childhood TB cases, but effects vary by country and population. It emphasizes the importance of robust surveillance systems and selective vaccination strategies to address specific high-risk groups, such as migrant communities. These outcomes align with the research objectives, highlighting the need for tailored public health interventions to mitigate TB risks post-BCG cessation.[1]

Discontinuing the BCG vaccine could increase the tuberculosis (TB) burden, especially in regions with high vaccine efficacy (VE), where the health impact of increased TB cases may outweigh the reduction in vaccine side effects. While the immunity provided by BCG wanes over time, leaving the elderly less protected, improving early TB detection and prompt treatment may be more effective in controlling the disease. Even with strong long-term BCG protection, older adults are least affected by its cessation. Therefore, instead of fully discontinuing the vaccine, selective vaccination may be a more viable alternative.[2]

Diagnosing tuberculosis (TB) in children is challenging due to difficulties in collecting sputum samples and the paucibacillary nature of pediatric pulmonary TB. Alternative methods like induced sputum and gastric aspirates require specialized equipment and trained personnel, often unavailable at primary health centers (PHCs) and sometimes even at district hospitals (DHs). Easier-to-collect specimens, such as stool samples and nasopharyngeal aspirates (NPA), can be used for Xpert MTB/RIF testing and offer similar diagnostic sensitivity to gastric aspirates or induced sputum. However, many children with TB symptoms remain undiagnosed due to limited diagnostic accessibility.[3]

Decentralizing pediatric TB services to the DH level could be cost-effective in high-prevalence areas like Cambodia and Côte d’Ivoire, but extending services to the PHC level is generally less feasible due to higher costs and lower diagnostic efficiency. DH-focused strategies benefit from higher TB detection rates, likely because more severely ill children are brought there or referred from PHCs, where fewer diagnostic tools are available. Additionally, DHs perform chest X-rays (CXR) for all symptomatic children, while PHCs typically only refer children with persistent symptoms, further contributing to higher TB detection at DHs.[3]

The introduction of a new diagnostic tool is expected to accelerate the decline in pulmonary tuberculosis (TB) burden compared to reliance on smear microscopy. Its greatest epidemiological impact is seen in settings with good access to TB care but limited diagnostic sensitivity, such as where chest X-rays are unavailable for smear-negative cases. Conversely, the tool’s impact may be less pronounced in reference laboratories that already have sensitive diagnostic methods like culture but are less accessible to the general population.[4]

Beyond its diagnostic performance, the new tool could increase patient trust in the healthcare system, encouraging physicians to prioritize TB diagnosis and reducing delays for both patients and providers. Additionally, a test with quick turnaround times would minimize the need for repeated healthcare visits, significantly lowering the risk of patients defaulting on diagnosis and improving overall TB care efficiency. Contextual factors such as healthcare access and existing diagnostic capacity play a crucial role in determining the tool’s population-level effectiveness.[4]

References:

1. Kobayashi, S., Yoshiyama, T., Uchimura, K., Hamaguchi, Y. and Kato, S., 2021. Epidemiology of childhood tuberculosis after ceasing universal Bacillus Calmette–Guérin vaccination. Scientific Reports, 11(1), p.15902.

2. Fu, H., Lin, H.H., Hallett, T.B. and Arinaminpathy, N., 2018. Modelling the effect of discontinuing universal Bacillus Calmette-Guérin vaccination in an intermediate tuberculosis burden setting. Vaccine, 36(39), pp.5902-5909.

3. d'Elbée, M., Harker, M., Mafirakureva, N., Nanfuka, M., Nguyet, M.H.T.N., Taguebue, J.V., Moh, R., Khosa, C., Mustapha, A., Mwanga-Amumpere, J. and Borand, L., 2024. Cost-effectiveness and budget impact of decentralising childhood tuberculosis diagnosis in six high tuberculosis incidence countries: a mathematical modelling study. EClinicalMedicine, 70, p.102528.

4. Lin, H.H., Dowdy, D., Dye, C., Murray, M. and Cohen, T., 2012. The impact of new tuberculosis diagnostics on transmission: why context matters. Bulletin of the World Health Organization, 90, pp.739-747.

NCD Screening in TB Contact Tracing

Diabetes and TB Incidence

• Korea's National Health Insurance Data Analysis: Diabetic individuals exhibit a 48% increased risk of tuberculosis (TB).Risk escalates with diabetes duration; over 5 years of diabetes corresponds to a 57% heightened TB risk. Stronger diabetes-TB links observed in men and younger adults. Newly diagnosed diabetics with high fasting plasma glucose (FPG) levels face a 79% greater TB risk. See also: Lin TB Lab

TB Treatment Outcomes

• Study from Taiwan NHIRD (2002-2013): Post-TB treatment phases see elevated risks of diabetes, acute myocardial infarction (AMI), and stroke, especially with treatment durations of 7-12 months. Risks are influenced by age, gender, and pre-existing non-communicable diseases (NCDs).Emphasizes the need for vigilant monitoring for NCDs following TB treatment.

Latent TB in Type 1 Diabetes Patients

• Cross-Sectional Study in Dar es Salaam: 14.9% prevalence of latent TB among type 1 diabetes mellitus (T1DM) patients, with variations across developmental stages. Significant correlation found between uncontrolled HbA1c levels and higher latent TB prevalence.

Observational Challenges and Mendelian Randomization Insights

• Challenges in Diabetes and PTB Relationship Studies: Issues include reverse causality, confounding factors, and type differentiation (T1DM vs. T2DM).Poor glycemic control linked to increased TB risk; metabolic disturbances in T1DM enhance susceptibility to PTB.
• Mendelian Randomization Findings: Genetic studies suggest a link between T1DM and PTB, with correlations to higher HDL-C levels but no direct causal relationships with other T1DM-related traits.

TB and Non-Communicable Diseases in Myanmar

• Yangon, Myanmar Cross-Sectional Study: TB patients often exhibit behavioral risk factors like smoking and drinking more frequently than general population. Nutritional disparities show TB patients more likely to be underweight; significantly lower incidence of overweight/obesity. Higher diabetes prevalence among TB patients, with implications for integrated screening of NCDs during TB contact tracing.

Integration of NCD Screening in TB Contact Tracing

• Efficiency and Cost-Effectiveness: Incorporating NCD screening during TB contact investigations can identify undiagnosed conditions, improving early intervention and management. Highlights the necessity for community-wide screening initiatives, particularly for diabetes, to address the dual burden of TB and NCDs.

References:

1. Yoo JE, Kim D, Han K, Rhee SY, Shin DW, Lee H. Diabetes status and association with risk of tuberculosis among Korean adults. JAMA network open. 2021 Sep 1;4(9):e2126099.
2. Salindri, A.D., Wang, J.Y., Lin, H.H. and Magee, M.J., 2019. Post-tuberculosis incidence of diabetes, myocardial infarction, and stroke: retrospective cohort analysis of patients formerly treated for tuberculosis in Taiwan, 2002–2013. International Journal of Infectious Diseases, 84, pp.127-130.
3. Majaliwa, E.S., Muze, K., Godfrey, E., Byashalira, K., Mmbaga, B.T., Ramaiya, K. and Mfinanga, S.G., 2023. Latent tuberculosis in children and youth with type 1 diabetes mellitus in Dar es Salaam, Tanzania: a cross section survey. BMC Infectious Diseases, 23(1), p.740.
4. Jiang, Y., Zhang, W., Wei, M., Yin, D., Tang, Y., Jia, W., Wang, C., Guo, J., Li, A. and Gong, Y., 2024. Associations between type 1 diabetes and pulmonary tuberculosis: a bidirectional mendelian randomization study. Diabetology & Metabolic Syndrome, 16(1), pp.1-9.
5. Zayar, N.N., Chotipanvithayakul, R., Bjertness, E., Htet, A.S., Geater, A.F. and Chongsuvivatwong, V., 2023. Vulnerability of NCDs and Mediating Effect of Risk Behaviors Among Tuberculosis Patients and Their Household Contacts Compared to the General Population in the Yangon Region, Myanmar. International Journal of General Medicine, pp.5909-5920.
6. Hamada, Y., Lugendo, A., Ntshiqa, T., Kubeka, G., Lalashowi, J.M., Mwastaula, S., Ntshamane, K., Sabi, I., Wilson, S., Copas, A. and Velen, K., 2024. A pilot cross-sectional study of non-communicable diseases in TB household contacts. IJTLD OPEN, 1(4), pp.154-159.

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