By Márcia Costa, Manager, and Shreya Nagpal, Research Analyst, Centre for Health Solutions

Every year, March 24^th marks World Tuberculosis Day (WTBD) in commemoration of the day when 142 years ago, Dr Robert Koch discovered Mycobacterium tuberculosis, the bacteria that causes tuberculosis (TB). While this discovery paved the way for the development of diagnostics and treatments for TB, leading to a general decline the prevalence, it remains one of the world’s deadliest infectious diseases.  WTBD aims to raise public awareness of the devastating health, social and economic consequences of TB, and this year’s theme ‘Yes! We can end TB’, conveys a message of hope that turning the tide against the current TB epidemic is possible. In 2023, at the second United Nations (UN) high-level meeting on the fight against TB, world leaders adopted a historic commitment to accelerate progress to end TB.¹ This year’s focus is intended to turn these commitments into actions through leadership, increased investments and faster uptake of World Health Organisation (WHO) recommendations. This week’s blog explores the progress in preventing, diagnosing and treating TB and the solutions for successful eradication.

What is tuberculosis?                                                                  

Tuberculosis is an infectious disease caused by an airborne bacterium that primarily affects the lungs, leading to a range of symptoms including prolonged coughing, chest pain, fever, fatigue and weight loss. It spreads through the air when an infected individual coughs, sneezes, or spits, making it highly contagious.² Although estimates suggest that one quarter of the world’s population has been infected with the bacteria, only five to ten per cent will develop active disease. The infection can also spread to other organs - extrapulmonary tuberculosis, including the pleura, lymphatic nodes, kidneys, brain and spinal cord. Of these, tuberculosis meningitis is the most serious form of tuberculosis, that despite being quite rare (one per cent of cases), is fatal without treatment and even with treatment has a mortality rate that ranges from 20-67 per cent.³

In 2014, at the World Health Assembly, the WHO’s End TB Strategy (2035) was adopted and in 2015 ‘ending the tuberculosis epidemic’ was also included in Sustainable Development Goal 3 (2030). However, WHO’s Global Tuberculosis Report 2023 indicates that many of the targets included in the strategy are off track.⁴ It estimates that, in 2022, 10.6 million people had the disease and 1.3 million died. Its incidence is highly variable worldwide, with over 80 per cent of cases and deaths concentrated in low and middle income countries (LMICs). In 2022, eight countries - Bangladesh, China, the Democratic Republic of the Congo, India, Indonesia, Nigeria, Pakistan, and the Philippines - contributed to over two-thirds of the global total tuberculosis cases.⁵

There are several risk factors for TB, including a weak immune system; consequently TB presents a high risk to people living with HIV who are 18 times more likely to develop the disease and more likely to die during tuberculosis treatment than those without HIV (in 2022, estimates suggest some 167 000 people living with HIV died of tuberculosis).^6,7 Consequently, strategies to curb both diseases frequently go hand-in-hand. Moreover, poverty is also a strong risk factor with poor nutrition and inadequate living and work conditions contributing to weakened immune systems and the risk of developing active TB or spreading the disease. Lack of access to healthcare facilities and medicines delay diagnosis and adequate treatment, enabling tuberculosis to spread.⁸ A meta-analysis study showed that some 43 per cent of patients with TB faced catastrophic health spending.⁹

Prevention and treatment of tuberculosis

Vaccination

The Bacillus Calmette-Guérin (BCG) vaccine has been the primary defence against tuberculosis for over 100 years. Primarily administered to neonates and children, the vaccine demonstrates significant effectiveness, ranging from 73-90 per cent, against severe tuberculosis forms such as tuberculosis meningitis. The efficacy and effectiveness of BCG vaccination against pulmonary varies considerably between studies and populations (54-82 per cent).  WHO recommends giving a single BCG vaccine dose to all healthy newborns in endemic areas as soon as possible after birth. In low-burden settings, it is generally reserved for neonates and infants of recognised high-risk groups (e.g., neonates born to parents or in households with contacts with tuberculosis or from high-incidence settings).¹⁰ Identifying neonates at high risk of being infected is crucial in protecting against TB.

Screening and early diagnosis

The WHO recommends using rapid molecular diagnostic tests in individuals with symptoms of tuberculosis. These tests are known for their high diagnostic accuracy and implementing them promises significant enhancements in the early detection of tuberculosis. Moreover, active, systematic screening – with computer-aided detection chest radiography, C-reactive protein tests or other molecular diagnostics - is highly recommended for the general population in areas of high incidence of TB and for high-risk groups (such as, poorer communities, homeless people, people with drug and/or alcohol problems, prisoners, immigrants from high-risk countries and those living with HIV).¹¹

In the UK, for example, like many other high-income countries, screening or active case finding using x-rays is provided to health and care professionals that could be at risk, or those coming into close contacts with patients with TB and these other high-risk groups.¹² Early diagnosis, including diagnosis of latent disease, is crucial not only for better outcomes for patients but also to curb the spread of disease through communities.

Adequate treatment

First-line active tuberculosis treatment typically entails a combination of four drugs: isoniazid, pyrazinamide, ethambutol, and rifampin, usually taken for at least six months. If done correctly, the cure rates can be as high as 95-98 per cent.¹³ However, the inadequate use of TB drugs (such as incorrect prescriptions or lack of supervision by healthcare professionals, poor-quality drugs, or interruptions or failure to complete the course of treatment), which is a particular problem in low-resource settings, can result in the emergence of multidrug-resistant tuberculosis (MDR-TB).

MDR-TB means that the bacteria do not respond to isoniazid and rifampicin, the two most effective first-line drugs against TB. In 2022, an estimated 450,000 people developed MDR-TB.¹⁴ Although MDR-TB is manageable and can be cured with second-line drugs, these alternatives entail a regimen of costly and potentially toxic drugs, as well as more prolonged treatments (two years or longer) which makes treatment in LMICs very challenging. In many of these countries MDR-TB is considered a growing public health crisis. Importantly, community engagement, including educating patients and healthcare professionals on the importance of maintaining and supervising the long treatments necessary to tackle MDR-TB alongside a strong commitment to make treatments more affordable are crucial if the number of MDR-TB cases are to be reduced

Conclusion

Despite the high incidence of tuberculosis in some parts of the world, this year’s theme – ‘Yes! We can end TB’ – is a powerful reminder that with the right leadership, investment and actions we can eradicate the tuberculosis epidemic. The success stories of countries that have prioritised vaccination, screening and early diagnosis underscore the effectiveness of these strategies in preventing the disease from spreading through communities, saving millions of lives and mitigating both the health and economic burdens on individuals and societies alike. For that, it is crucial to increase awareness of citizens and healthcare professionals, working with communities to accelerate prevention, vaccination of neonates and identify high-risk groups that would benefit from systemic screening, as well as strengthening diagnostic capabilities and implementing robust surveillance systems. Some steps that we believe could help deliver the UN’s commitments:

• effective management and prevention of transmission requires the deployment of effective vaccination, screening and early diagnosis programmes and early access to adequate treatments
• Universal Health Coverage should include national TB vaccination protocols and plans, alongside parent/carer education and initiatives to ensure that neonates are vaccinated as soon as possible after birth
• involvement with and between local public health teams and the communities they work in, and investment in systematic screening programmes in target populations/areas, are critical to achieving early diagnosis
• adoption of digital technologies and incentives (for example, cash transfers) to complete treatment can substantially increase adherence
• empower patients with information, understanding, incentives and support to complete their treatments.

The successful eradication of TB will only be possible by increasing the affordability of all these strategies and including them under the Universal Health Coverage banner. Ending TB should be seen as an investment to all countries’ health and economy in the upcoming decade alongside more investment in research to develop ground-breaking innovations in science and health technology to further accelerate this goal.

Márcia Costa - Manager, Centre for Health Solutions

Márcia is the research manager for healthcare in the Centre for Health Solutions, providing support and expertise to develop solutions to overcome today’s healthcare challenges. Working with the team, Márcia develops insights based on rigorous data analysis to improve outcomes for patients and increase health systems efficiencies. Originally from Portugal, Márcia has an MSc in biomedical engineering and biophysics and a PhD in cancer research. Márcia has previously worked in publishing for an oncology journal in London. Márcia is passionate about health equity.

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Shreya Nagpal, Research Analyst, Deloitte

Shreya is a Research Analyst within the Insight team based in Hyderabad, India. She supports Deloitte’s UK Centre for Health Solutions by analysing the Lifesciences and Healthcare industry and providing insights into the trends. She has a background in economics and management, and a keen interest in Anthropology, Psychology and Behavioral Economics.

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1. UN declaration on TB (who.int)
2. Tuberculosis (who.int)
3. https://www.ncbi.nlm.nih.gov/books/NBK541015/#:~:text=Tuberculous%20meningitis%20(TBM)%20is%20caused,the%20brain%20or%20spinal%20cord.
4. https://www.who.int/teams/global-tuberculosis-programme/tb-reports/global-tuberculosis-report-2023
5. https://iris.who.int/bitstream/handle/10665/373828/9789240083851-eng.pdf?sequence=1
6. https://www.who.int/teams/global-hiv-hepatitis-and-stis-programmes/hiv/treatment/tuberculosis-hiv
7. https://iris.who.int/bitstream/handle/10665/373828/9789240083851-eng.pdf?sequence=1
8. fiches seules anglaise 1 (stoptb.org)
9. https://www.nature.com/articles/s41598-021-04345-x
10. https://iris.who.int/bitstream/handle/10665/260306/WER9308.pdf?sequence=1
11. https://iris.who.int/bitstream/handle/10665/340255/9789240022676-eng.pdf?sequence=1
12. https://www.gov.uk/guidance/tuberculosis-screening#:~:text=Screening%20for%20TB%20can%20focus,gamma%20release%20assays%20(%20IGRAs%20).
13. https://pubmed.ncbi.nlm.nih.gov/27305904/#:~:text=Although%20cure%20rates%20of%20the,in%20less%20well%20resourced%20countries.
14. 9789240083851-eng.pdf (who.int)