If I asked you which infectious disease kills the most people globally, what would you say? HIV? Malaria?
YOU’D BE WRONG. TB.
The World Health Organisation estimates there were 10 million TB infections in 2018, killing 1.5 million people, which means TB ranks above HIV/AIDS and Malaria as the leading cause of death from an infectious disease. 1.1 million of those infected were children.
TB is actually right up there in the top ten causes of global death, along with heart disease and cancer. TB currently ranks number nine. This is despite the fact that, with a timely diagnosis and correct treatment, the majority of people developing TB can be cured.
TB has been around since the Ancient Egyptians, and yet none of the 135 countries where this disease persists has managed to eradicate it. The BCG vaccination is not effective for pulmonary TB in adults, and there is growing resistance to first and second line antibiotic drug defences. People with active TB can infect between five and fifteen people in close contact over the course of a year. If we do not address this growing crisis, we could find ourselves confined to sanitariums, as in the old days, praying that fresh air and rest alone will cure us.
If you have read The Waiting Rooms, you may recognise some of these facts from pre-Crisis. You may have thought I’d made them up. Sadly not. For current numbers, check out the WHO Global TB report.
Out of the 10 million new TB cases each year, 4 million go undiagnosed and untreated. There is also a growing problem with drug-resistant TB, with 484,000 new cases in 2018, of which 78% were resistant to the 2 most powerful first-line anti-TB drugs. Multidrug-resistant TB (MDR-TB) caused an estimated 206,000 deaths globally in 2017: a figure that could increase to 2.5 million deaths per year by 2050 under the most alarming scenario, if no action is taken.
Treatment is slow and laborious with significant side effects, and, aided by the complications in giving or completing treatment, new strains of the disease have become resistant to almost all current drugs. Hence the emergence of XDR-TB: extensively drug-resistant TB, which is now present in at least 105 countries.
As if that weren’t worrying enough, it is estimated that 1.7 billion people are infected with latent TB, where the bacteria lie dormant inside the body: this means almost a quarter of the world’s population is at risk of developing the active form of the disease. Even though the risk of this happening during an infected person’s lifetime is between 5% and 15%, over 19 million of these people are estimated to have the latent multi-drug resistant strain (MDR-TB). Despite the concerted efforts of the WHO and other international agencies, this number is growing.
The Western Pacific and European regions have the highest prevalence of the hard-to-treat latent MDR-TB, with China, India, Russia and Indonesia identified as having the largest number of infected individuals.
“Latent TB is a significant reservoir of disease,” Dr Gwen Knight, assistant professor at the London School of Hygiene and Tropical Medicine, and lead author of a new report, told The Telegraph in July 2019. “Our research suggests that, in the future, the level of latent MDR-TB will rise, which could overwhelm our targets to control TB, and is only going to make this disease a bigger threat on the world stage."
For more information see the links below.
It’s Time to End Drug-Resistant TB: The Case for Action.
Report by The Economist Intelligence Unit
https://www.eiu.com/graphics/marketing/pdf/its-time-to-end-drug-resistant-tuberculosis-full-report.pdf
Latent TB growth & risks
https://www.telegraph.co.uk/news/2019/07/04/worryingly-high-number-people-infected-latent-form-drug-resistant/
Drug-resistant TB
http://www.cidrap.umn.edu/news-perspective/2017/03/report-warns-rise-drug-resistant-tuberculosis