As individuals and organisations across the globe mark World Tuberculosis day on the 24th of March, CABI Global Health looks at the major advances in treatment of TB and the biggest threat faced on the way to achieve a TB-free world.
The World Health Organization promotes World TB Day to raise public awareness about the devastating health, social and economic consequences of tuberculosis (TB) and to step up efforts to end the global TB epidemic.
Tuberculosis (TB) is estimated in affect one quarter of the world’s population, found in all countries and all age groups, and infecting almost 10 million individual’s every year – 1.1million of the newly infected cases are children.
The WHO’s Global Tuberculosis Report, published in 2021, reinforces the goal of the world being TB free by 2030’s (disease incidence reduced by 90% by 2035). While incidence levels of TB have being dropping across Europe and the WHO African Region, progress has been slower in Eastern Mediterranean Region, 11% in the South-East Asia Region and 6.7% in the Western Pacific Region and sadly there seems to be reversal of incidence rates in the Latin American region.
Effective drug treatments for TB were first developed in the 1940’s, along with a vaccination in 1920 and pasteurisation techniques, collectively millions of lives have been saved since. While TB treatment regimens have changed considerably over time, including mass immunization programs utilising the BCG vaccine, the current recommendations for people with drug-susceptible TB disease is a 6-month regimen of four first-line drugs: isoniazid, rifampicin, ethambutol and pyrazinamide. However, TB treatment can take 4, 6, or 9 months depending on the regimen and resistance level, says the CDC.
Threats to achieving a TB-free world
Mycobacterium tuberculosis, the causative organism of TB, is constantly acquiring new methods of overcoming treatment options – resistance was first noted in 1970 in the US.
Increasing drug resistance in TB poses a dangerous threat to eradicating the disease. Currently the WHO have identified three main types of drug resistant TB: Multidrug-Resistant TB (MDR TB), Pre-Extensively Drug-resistant TB (pre-XDR TB) and Extensively Drug-resistant TB (XDR TB).
Extensively drug-resistant TB (XDR TB) is a rare type of drug resistance TB which is resistant to isoniazid and rifampin, a fluroquinolone, and a second-line injectable (amikacin, capreomycin, and kanamycin) OR resistant to isoniazid, rifampin, a fluroquinolone, and bedaquiline or linezolid.
Drug resistance is on the increase across the globe, but particularly in developing countries, but the issue is reported in every country surveyed by the WHO.
MDR TB has a severe economic impact on those diagnosed with the disease, with the CDC quoting: “The average cost of treating a person with TB disease increases with greater resistance. Direct costs (in 2016 U.S. dollars) average from $18,000 to treat drug-susceptible TB to $513,000 to treat the most drug-resistant form of the disease (XDR TB).”
COVID-19 pandemic has a major negative impact on the battle to reduce TB incidence rates, as well as causing an increase in those dying from TB. The pandemic made it difficult for individuals to access suitable screening, delaying diagnosis and those already diagnosed with the infection found it difficult to access therapy and treatment.
On CABI Global Health to read more on TB and multidrug resistant infections, follow this search string: (Tuberculosis or TB) AND ("drug resistance")
To access the WHO’s coverage on TB including the Global TB Report follow the link: https://www.who.int/publications/i/item/9789240037021
World Health Organization (2021) Global tuberculosis report 2021. Global Tuberculosis Programme ISBN: 9789240037021 57 pp.