Writer: Luciana Carbone Calderón
When people hear about tuberculosis, they often assume it is a thing of the past. When people learn about history, such as art and war, tuberculosis is the frequent cause of death for many important figures. The limited media coverage of the disease has led to the misconception that it is no longer a significant issue. Despite this, tuberculosis continues to threaten the lives of millions worldwide, and advancements in its treatment and prevention are not keeping up with the rate of its prevalence.
If this is true, why are there no significant advancements? Why is there so little awareness about it? The answer is the way the healthcare system is capitalized.
What Is Tuberculosis?
Tuberculosis (also referred to as TB) is an infectious illness that usually affects the lungs but can also affect other organs such as the brain, spine, and kidneys [1]. It is caused by the bacteria Mycobacterium tuberculosis and is spread through the air when infected individuals cough, sneeze, or spit [2]. It is possible to contract it without showing any symptoms, known as latent tuberculosis, in which the bacteria remains dormant inside the body.
There are several forms of tuberculosis, including abdominal tuberculosis, ocular tuberculosis, laryngeal tuberculosis, musculoskeletal tuberculosis, pericardial tuberculosis, and tuberculous lymphadenitis [3]. All of them are cases of extrapulmonary tuberculosis (EP-TB), which is TB that affects organs other than the lungs. TB symptoms include a persistent cough (often with blood or mucus), chest pain, weakness, exhaustion, weight loss, fever, and night sweats [2]. Without treatment, tuberculosis can be fatal. Other disorders, such as HIV or AIDS, or long-term use of immune-suppressing medicines, can increase the risk of adverse outcomes [4].
History of Tuberculosis
Tuberculosis (TB) has been a threat to humankind throughout history. It became an epidemic in Europe and North America during the 18th and 19th centuries. However, it was determined that an early progenitor of Mycobacterium tuberculosis was present in East Africa 3 million years ago and infected early hominids [5]. TB began being documented 5,000 years ago by the Egyptians through art and mummies. Evidence of early TB has also been found in America, as demonstrated in Peruvian mummies through DNA testing. There is substantial evidence of TB occurring in the Western Hemisphere before European colonization. The disease was also well-known in classical Greece, although it was not notably mentioned in medical texts of that time [5].
During the Middle Ages in Europe, written records of the disease became infrequent. However, archaeological evidence indicates the widespread presence of TB [5]. After centuries of struggle to understand the disease, significant advancements were made in the early 19th century. Théophile Laennec wrote and researched the concepts of TB, Jean-Antoine Villemin demonstrated the contagiousness of Mycobacterium tuberculosis infection in 1865, and Robert Koch identified the tubercle bacillus as the etiologic agent (the organism that causes the illness) in 1882 [5].
Basic ideas about TB and how to diagnose it were developed in the early 1900s [6]. Effective TB therapy entered a new era in the 1940s with the discoveries of streptomycin and para-amino salicylic acid (PAS). Unfortunately, the emergence of HIV and AIDS resulted in the reappearance of TB, which was declared a worldwide emergency by 1993. Drug-resistant TB (DR-TB) also experienced a resurgence in the late 1990s [6]. It's a prevalent misunderstanding that TB is a disease of the past that is no longer a threat to people. Unfortunately, the truth is very different.
Cure and Prevention
Currently, latent tuberculosis is treated through preventive therapy, which commonly involves a daily dose of the antibiotic isoniazid (INH) for six to nine months. Latent TB in this form is not contagious [7]. On the other hand, active TB is often treated with a combination of antibacterial medications for 6 to 12 months. The most commonly used drugs are isoniazid (INH) in combination with rifampin, pyrazinamide, and ethambutol [7]. Multidrug-resistant TB (MDR-TB) is extremely dangerous; fortunately, there have been developments in the research for ways to treat it, in which it was found that drugs such as levofloxacin and moxifloxacin can be effective against it [8]. Nevertheless, MDR-TB remains a significant public health crisis.
Addressing the Persistent Challenge of Tuberculosis
Tuberculosis remains a significant concern, with 1.3 million people losing their lives to the disease in 2022 [9]. It is the second most deadly infectious disease after COVID-19 [2]. Alas, innovation in tuberculosis is not keeping pace with the rising number of infections. There is only one licensed vaccine for TB—the Bacille Calmette-Guérin (BCG) vaccine. This vaccine is effective almost exclusively for children, while its protection is limited for teenagers and adults. MDR-TB continues to be a public health crisis, and despite advancements, only 2 in 5 people with MDR-TB received treatment in 2022 [2]. The treatment for TB is lengthy, and while new options have emerged that reduce the duration of the treatment and address MDR-TB, they remain inaccessible to people in low-income countries, which are often the most affected by TB [9].
Tuberculosis is most prevalent in Bangladesh, China, India, Indonesia, Nigeria, Pakistan, the Philippines, and South Africa. During the pandemic, reported TB cases decreased by 18%. However, in 2022, the number of cases increased, reaching the highest level since the 1990s. This rise reflects both a recovery in healthcare access and services and an accumulation of delayed diagnoses, as well as an increase in new TB cases [10]. This situation is concerning, yet financing for further research remains persistently low. This is primarily because TB predominantly affects low to middle-income countries (which are around 80% of cases worldwide), leading to fear of not being able to secure sufficient returns on investment [9]. Furthermore, even with new developments in TB treatments, these innovations are often inaccessible to the communities that need them most. The difficulty in capitalizing on patients if there is an increase in healthcare accessibility for individuals with TB has discouraged investors from supporting further developments in TB.
In conclusion, tuberculosis continues to be a critical global health issue, worsened by challenges in innovation, treatment access, and funding. Despite the existing advancements in understanding and treating TB, the disease remains stubbornly prevalent. The imbalance between established treatments’ efficacy and the limited availability of new treatments reinforce the urgent need for more investment in research and fair healthcare solutions. Addressing these gaps is essential in reducing the effects of TB and ensuring that all affected populations receive the care they need.
Sources & Works Cited
[1] Professional, C. C. M. (s. f.). Tuberculosis. Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/11301-tuberculosis
[2] World Health Organization: WHO & World Health Organization: WHO. (2023, 7 noviembre). Tuberculosis. https://www.who.int/news-room/fact-sheets/detail/tuberculosis
[3] S. VIJAYA KUMAR, MANOJ KUMAR DEKA, MANISH BAGGA, M. SASI KALA, K. GAUTHAMAN (2010). A systematic review of different type of tuberculosis. European Review For Medical And Pharmacological Sciences. https://www.europeanreview.org/wp/wp-content/uploads/831-843.pdf
[4] West, M. (2023, 20 diciembre). Is tuberculosis deadly? What to know. https://www.medicalnewstoday.com/articles/is-tuberculosis-deadly#is-it-deadly
[5] Daniel, T. M. (2006). The history of tuberculosis. Respiratory Medicine, 100(11), 1862-1870. https://doi.org/10.1016/j.rmed.2006.08.006
[6] Tuberculosis: From an incurable scourge to a curable. . . : Indian Journal of Medical Research. (s. f.). LWW. https://journals.lww.com/ijmr/fulltext/2013/37030/tuberculosis__from_an_incurable_scourge_to_a.7.aspx
[7] American Lung Association. (s. f.). Diagnosing and Treating Tuberculosis. https://www.lung.org/lung-health-diseases/lung-disease-lookup/tuberculosis/treating-and-managing#:~:text=If%20you%20have%20an%20active,%E2%80%94rifampin%2C%20pyrazinamide%20and%20ethambutol.
[8] Jang, J. G., & Chung, J. H. (2020). Diagnosis and treatment of multidrug-resistant tuberculosis. Yeungnam University Journal Of Medicine, 37(4), 277-285. https://doi.org/10.12701/yujm.2020.00626
[9] Tuberculosis is curable and preventable – why do millions still die? (2024, 23 mayo). Wellcome. https://wellcome.org/news/tuberculosis-curable-and-preventable-why-do-millions-still-die
[10] World Health Organization. (2023). Global Tuberculosis Report. https://iris.who.int/bitstream/handle/10665/373828/9789240083851-eng.pdf?sequence=1
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