World Tuberculosis (TB) Day is observed each year on 24 March to raise public awareness of the devastating impact of this disease on the lives of patients [1].
This date marks the announcement in 1882 of the discovery of the bacterium that causes TB, Mycobacterium tuberculosis, which paved the way for effective methods for diagnosis and treatment of the disease [1, 2].
The theme for this year’s World TB Day is ‘Invest to End TB. Save Lives’, which emphasises the urgent need to invest in resources to end the global TB epidemic [1].
Although it is preventable and curable, TB remains a leading cause of death from a single infectious agent worldwide, with more than 4,100 deaths caused by TB occurring each day [1, 3]. In 2020 alone, 1.5 million people died of TB, which is an estimated 314,000 more deaths than in 2017 [1, 3]. The setbacks created by the global COVID-19 pandemic have made the fight against TB more urgent than ever [3]. COVID-19 has limited access to essential diagnostic and treatment services for patients with TB, reversing some of the progress that was made prior to the pandemic [3].
What is TB?
TB is an airborne disease that is spread through inhalation of droplets from the coughs and sneezes of an infected person [2, 4]. The disease most commonly affects the lungs; this is called pulmonary TB, which is the most contagious type. However, it can also affect other parts of the body, including the abdomen, glands, bones and nervous system, in a form called extrapulmonary TB [4].
Most individuals with a healthy immune system will clear the bacterium that causes TB without getting infected [4]. In others, the bacterium infects the body, but the person shows no symptoms of TB and is not contagious; this is known as ‘latent TB’ [2, 4]. When symptoms do occur (often weeks, months or years after the initial infection), it is known as ‘active TB’ and these individuals are contagious [2, 4]. Approximately 5%–10% of patients with latent TB may develop active TB if their immune systems are weakened and the TB bacteria begin to multiply or activate again [2].
Anyone can contract TB, but immunocompromised individuals are some of those at greatest risk of infection [2]. This may be because of factors such as age; conditions that affect the immune system, e.g. diabetes or human immunodeficiency virus (HIV); or medical procedures/treatments, e.g. organ transplants or chemotherapy [2, 5].
What are the signs and symptoms of TB?
General symptoms of TB include lack of appetite, weight loss, extreme fatigue, night sweats and a high temperature [6, 7]. However, other signs and symptoms vary depending on the type of TB [6, 7].
Patients with pulmonary TB often present with a persistent cough that lasts longer than 3 weeks, produce phlegm (which may contain blood), and show worsening breathlessness [6, 7].
Patients with extrapulmonary TB can present with swollen glands, abdominal pain, loss of movement and pain in bones or joints, confusion, persistent headaches and seizures [7, 8].
How is TB managed?
The tests used to diagnose TB depend on the type of infection the patient is suspected to have. For suspected pulmonary TB, phlegm samples and a chest X-ray to look at the appearance of the lungs can be used to confirm the diagnosis [6, 8]. Several tests can be used to confirm suspected extrapulmonary TB, including imaging of or taking tissue samples from the affected area, examining the inside of the body via endoscopy, and carrying out blood or urine tests [8]. If a patient is suspected of having latent TB, several tests, including the widely used Mantoux skin test, can be performed to confirm diagnosis [6, 8].
Treatment of TB is highly effective. In fact, the World Health Organization regularly reports a global treatment success rate of approximately 85% [3]. Both pulmonary TB and extrapulmonary TB are treated using a combination of four antibiotics (isoniazid, rifampicin, pyrazinamide and ethambutol), which are prescribed over a period of at least 6 months [9]. Typically, after 2 months of taking all four drugs, the patient only needs to take isoniazid and rifampicin for the remaining 4 months [9]. It is vital that patients complete their full course of treatment to ensure that the TB bacteria are completely eliminated and to reduce the risk of the bacteria becoming drug resistant [9, 10].
Latent TB does not usually require treatment, as 90% of individuals will not develop active TB [9]. However, the same antibiotics that are used to treat active TB are recommended for immunocompromised patients (e.g. patients with HIV) who have latent TB [9].
What are the hopes for the future?
The United Nations has pledged to end the ‘global TB epidemic’ by 2030 [3]. Despite the challenges imposed by the COVID-19 pandemic, the treatability of TB provides hope for achieving this target. However, the current priority is to reduce the levels of TB cases to what they were in 2019 by reinstating access to diagnosis and treatment for patients around the world [3]. Ultimately, the goal is to ‘invest to end TB’ to ‘save lives’ from this curable disease.
More information and support can be found at:
• World Health Organization (https://www.who.int/news-room/fact-sheets/detail/tuberculosis)
• Asthma and Lung UK (https://www.blf.org.uk/support-for-you/tuberculosis)
• TB Alert (https://www.tbalert.org)
#InvestToEndTB #WorldTBDay #Tuberculosis
The information in this article is not intended or implied to be a substitute for professional medical advice, diagnosis or treatment. All content is for general information purposes only. Always seek the guidance of your doctor or other qualified healthcare professional with any questions you may have regarding your health or medical condition.
References
1. World Health Organization. World Tuberculosis Day 2022: Invest to End TB. Save Lives. Available at: https://www.who.int/campaigns/world-tb-day/2022. Accessed March 2022.
2. Asthma and Lung UK. What is tuberculosis? Available at: https://www.blf.org.uk/support-for-you/tuberculosis/what-is-it. Accessed March 2022.
3. World Health Organization. Global Tuberculosis Report 2021; October 2021.
4. National Health Service. Overview: Tuberculosis (TB). Available at: https://www.nhs.uk/conditions/tuberculosis-tb/. Accessed March 2022.
5. American Lung Association. Learn about tuberculosis. Available at: https://www.lung.org/lung-health-diseases/lung-disease-lookup/tuberculosis/learn-about-tuberculosis. Accessed March 2022.
6. Asthma and Lung UK. What are the symptoms and how is tuberculosis diagnosed? Available at: https://www.blf.org.uk/support-for-you/tuberculosis/symptoms. Accessed March 2022.
7. National Health Service. Symptoms: Tuberculosis (TB). Available at: https://www.nhs.uk/conditions/tuberculosis-tb/symptoms/. Accessed March 2022.
8. National Health Service. Diagnosis: Tuberculosis (TB). Available at: https://www.nhs.uk/conditions/tuberculosis-tb/diagnosis/. Accessed March 2022.
9. TB Alert. Treatment. Available at: https://www.tbalert.org/about-tb/what-is-tb/treatment/. Accessed March 2022.
10. Centers for Disease Control and Prevention. Tuberculosis (TB). Available at: https://www.cdc.gov/tb/publications/factsheets/drtb/mdrtb.htm. Accessed March 2022.
Author: Risa Tomioka | Associate Editor | Porterhouse Medical