World Tuberculosis Day 2022

World Tuberculosis Day

Tuberculosis (TB) is an infectious disease which affects 10 million people worldwide, each year.1 In order to raise awareness of this disease, World Tuberculosis Day is observed annually on the 24th of March. It was on this day in 1882 that Robert Koch discovered the bacterium that causes the disease: Mycobacterium tuberculosis.

TB primarily infects the lungs as it is spread through the air via droplets from coughing or sneezing. Not all infections by M. tuberculosis will lead to TB disease, however. In most cases, the host’s immune system can keep the bacteria from proliferating, thus no symptoms are shown, and it cannot be spread. This is known as latent TB, and it is estimated to affect almost a quarter of the world’s population.1

In some cases, the host’s immune system cannot suppress the infection and it develops into active TB, the symptoms of which mainly include chest pain, a serious cough (which may produce blood and/or sputum), weight loss, fatigue and fever.2 The World Health Organization estimated that in 2020, 10 million people suffered from active TB worldwide, and from those, 1.5 million died making it the second-most deadly infectious disease after COVID-19.3

Screening tests exist for latent TB and there is a vaccine available, though its use is mainly limited to only the highest risk individuals.2 Currently, treatment of TB consists of various courses of antimicrobial drugs, usually taken over the course of several months. However, strains of M. tuberculosis that are resistant to these drugs have emerged, with some of them even showing resistance to the two most effective anti-TB drugs. Treatment of drug-resistant TB is complicated, expensive, and often causes severe side-effects. In some cases, it may even result in development of even broader drug resistance.3

With this emerging drug resistance, M. tuberculosis joins a worrying number of infectious pathogens posing a serious threat to public health through antimicrobial resistance, such as Methicillin-Resistant Staphylococcus aureus (MRSA), Vancomycin-Resistant Enterococci (VRE) and Candida auris, among others. In 2019, the global burden associated with drug resistant infections was an estimated 4.95 million deaths.4 Infections that were once easily treated are now placing a significant strain on healthcare resources. This is particularly apparent in clinical laboratories, where microbiologists conduct antimicrobial susceptibility testing (AST) and one of these methods is disc diffusion. While this method offers high accuracy and flexibility, it is labour-intensive and time-consuming. Innovative technologies that can help to reduce the clinical laboratory workload, and improve reporting turn-around times for accurate and rapid diagnosis of infectious diseases are crucial in supporting the global fight against antimicrobial resistance.

1 World Health Organization, Tuberculosis [Accessed 22 March 2022]. Available here.

2 Centers for Disease Control and Prevention, Tuberculosis (TB) [Updated 17 March 2022] [Accessed 22 March 2022]. Available here

3 World Health Organization, Fact Sheets: Tuberculosis [Published 14 October 2021] [Accessed 22 March 2022]. Available here

4 Murray, C.J., Ikuta, K.S., Sharara, F., Swetschinski, L., Aguilar, G.R., Gray, A., Han, C., Bisignano, C., Rao, P., Wool, E. and Johnson, S.C., 2022. Global burden of bacterial antimicrobial resistance in 2019: a systematic analysis. The Lancet. [accessed 22 March 2022]. Available here