Tuberculosis: a disease of the past?

Tuberculosis: a disease of the past?

Published date: 23 Mar 2018

What is the first image that enters your head when I say “tuberculosis”? For me, a self-professed history nerd, I picture old Victorian England with everyday people wearing corsets and top hats.

Although in the UK we’ve reached the lowest rate of incidence since 2000, tuberculosis (TB) is still a global disease, despite the fact that it is curable and preventable (1,2). In 2016, worldwide 1.7 million people died from TB and 10.4 million people were infected (3).

What is TB?

TB in humans is primarily caused by the bacteria Mycobacterium tuberculosis. Active TB is spread by droplet infection, meaning the old rhyme “coughs and sneezes spread diseases” really does apply in this case. The tiny bacteria travel to the tips of the lungs and begin to replicate in the body’s own immune cells. They can then use their new home to travel out of the lungs, causing infection across multiple systems in the body (4,5). In healthy people the immune system fights and kills the bacteria, but when these defences fail or cannot contain the bacteria, people are defined as having active TB (6). This also means that people with weakened immune systems are at a higher risk of becoming unwell, including those with HIV (2).

Why should we worry about TB right now?

For starters, it ranks above HIV/AIDS as the leading cause of death worldwide from a single infectious agent, and it is the ninth leading cause of death in general (3). Over 95% of deaths from TB occur in low- and middle-income countries, with 64% coming from just seven countries (3). The clever bacterium has also become resistant to multiple drugs, meaning there remains a serious public health crisis; 600,000 new cases were predicted by the World Health Organization (WHO) to be resistant to the most effective first-line drug – rifampicin – and extremely drug-resistant strains often leave individuals without any other treatment options (2,3). These statistics clearly illustrate why TB remains a global crisis today.

What is being done to reduce the incidence and prevalence of this curable and preventable disease?

The WHO’s End TB Strategy aims to reduce TB deaths by 95% and see a 90% reduction in new cases by 2030 through three key initiatives: integrated patient-centred care and prevention, bold policies and supportive systems, and intensified research and innovation (3).

The WHO global tuberculosis report for 2017 outlines a few key areas that are being explored: diagnostics, treatment regimens and vaccines (3). Some of the big pharma names have drug and treatment regimens in the pipeline. Yet, surprisingly, it is the smaller companies, alliances and institutions that are carrying out more pre-clinical, phase 1, 2 and 3 trials (7).

How can we help?

Where possible, we should encourage the larger institutions to play their part in reducing TB incidence, whether that be through research and development or disease awareness campaigns with charities or governing bodies, to help the WHO tackle the TB epidemic.

We should certainly help spread the word that TB is not just a disease of the past but remains a part of many people’s everyday lives across the globe.

TB Awareness Day: 24 March 2018

To find out more, please visit: http://www.who.int/campaigns/tb-day/2018/en/

 

References

1. Public Health England. Tuberculosis in England 2017 report. https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/686185/TB_Annual_Report_2017_v1.1.pdf [Last accessed: March 2018]

2. World Health Organization. Tuberculosis fact sheet. http://www.who.int/mediacentre/factsheets/fs104/en/ [Last Accessed: March 2018]

3. World Health Organization. Global tuberculosis report 2017. http://www.who.int/tb/publications/global_report/en/ [Last accessed: March 2018]

4. Teitelbaum R, Schubert W, Gunther L, et al. The M cell as a portal of entry to the lung for the bacterial pathogen Mycobacterium tuberculosisImmunity. 1999;10(6):641–650.

5. Bermudez LE, Sangari FJ, Kolonoski P, Petrofsky M and Goodman J. The efficiency of the translocation of Mycobacterium tuberculosis across a bilayer of epithelial and endothelial cells as a model of the alveolar wall is a consequence of transport within mononuclear phagocytes and invasion of alveolar epithelial cells. Infection and Immunity. 2002;70(1):140–146.

6. NHS. Tuberculosis (TB). https://www.nhs.uk/conditions/tuberculosis-tb/ [Last accessed: March 2018]

7. Working Group on New TB Drugs. http://www.newtbdrugs.org/ [Last accessed: March 2018]