ClassX Video Lessons What makes tuberculosis (TB) the world’s most infectious killer? – Melvin Sanicas
In 2008, archaeologists made a fascinating discovery: two skeletons dating back 9,000 years. While we can’t say for sure what caused their deaths, we do know that their bones were infected by a bacterium that has plagued humanity for centuries. The ancient Greeks called it phthisis, the Incans referred to it as chaky oncay, and today we know it as tuberculosis, or TB. Despite advances in medicine, TB remains one of the deadliest infectious diseases, claiming more lives than malaria or HIV/AIDS.
So, what exactly is TB, and why has it persisted for so long? The disease is caused by a bacterium known as Mycobacterium tuberculosis. It spreads through the air and primarily targets the lungs. When someone inhales the bacteria, immune cells called macrophages rush to the lungs to fight off the invaders. In many cases, this immune response is enough to kill the bacteria. However, people with weakened immune systems—due to conditions like malnutrition, HIV, diabetes, or pregnancy—may not be able to fend off the bacteria effectively. This allows the bacteria to multiply within the macrophages and form colonies in the lung tissue.
As the bacteria infect more cells, they release enzymes that damage the lung tissue, leading to symptoms such as chest pain and coughing up blood. This lung damage can cause oxygen deprivation, which triggers hormonal changes like reduced appetite and iron production. If the bacteria spread beyond the lungs, they can cause back pain, abdominal pain, headaches, and even affect consciousness. These symptoms contribute to the classic image of TB: weight loss, a persistent cough, and pale skin, which earned it the nickname “the White Plague” in Victorian England.
During the Victorian era, TB was often romanticized, as it disproportionately affected impoverished artists and poets with weaker immune systems. The visible symptoms of TB even fueled myths about vampirism. Despite these misconceptions, this period also saw significant progress in combating TB. In 1882, German physician Robert Koch identified the bacterium responsible for the disease. Thirteen years later, physicist Wilhelm Roentgen discovered the X-ray, allowing doctors to diagnose and monitor TB’s progression in the body.
These breakthroughs paved the way for the development of effective vaccines, such as the BCG vaccine introduced in 1921. These innovations laid the groundwork for modern antibiotics, which are currently the most effective treatments for TB. However, antibiotics don’t solve a major diagnostic challenge: about 90% of people infected with TB show no symptoms. In these latent infections, the bacteria can remain dormant, only becoming active when the immune system is compromised, making TB difficult to diagnose.
Even when TB is diagnosed, traditional treatments can take up to nine months and require multiple medications, which can cause side effects. This lengthy treatment often discourages patients from completing their course, allowing the bacteria to develop drug resistance. TB remains prevalent in 30 countries, many of which are grappling with other health crises that exacerbate the situation and trigger latent cases. Access to treatment can be challenging in these regions, and the stigma surrounding TB can further deter individuals from seeking help.
Health experts agree on the need for improved diagnostics, faster-acting antibiotics, and more effective vaccines. Researchers have already developed a urine test that provides results in 12 hours and a new oral treatment that could reduce treatment time by 75%. With advancements like these, there is hope that TB can eventually become a thing of the past.
Investigate the historical impact of tuberculosis on society, focusing on different eras such as the Victorian period. Prepare a presentation that highlights how TB influenced art, literature, and public health policies of the time. Share your findings with the class to foster a discussion on how historical perspectives shape our understanding of diseases.
Analyze a case study of a TB outbreak in a specific region. Examine the factors that contributed to the spread of the disease, the public health response, and the outcomes. Discuss with your peers the challenges faced in controlling the outbreak and propose potential improvements in handling similar situations in the future.
Participate in a structured debate on the effectiveness of current TB treatment strategies versus emerging solutions. Divide into teams to argue for traditional antibiotics and long-term treatments versus new diagnostic tools and faster-acting medications. This will help you critically evaluate the pros and cons of different approaches to TB management.
Engage in a laboratory simulation where you perform mock TB diagnostic tests, such as the Mantoux tuberculin skin test or a simulated urine test. This hands-on activity will give you practical insights into the diagnostic process and the challenges faced in accurately identifying TB infections.
Work in groups to design a public health campaign aimed at raising awareness about TB, its symptoms, and the importance of completing treatment. Use creative mediums such as social media, posters, or videos to convey your message. Present your campaign to the class and discuss the potential impact on public perception and behavior.
In 2008, archaeologists uncovered two 9,000-year-old skeletons. While there is no definitive way to determine the cause of death for these ancient individuals, it is known that their bones were infected by a familiar bacterium. The ancient Greeks referred to its consumptive effects as phthisis, the Incans called it chaky oncay, and in English, it is known as tuberculosis (TB). Today, TB remains one of the world’s leading infectious killers, causing more deaths than malaria or even HIV/AIDS.
So, what exactly is this disease, and how has this pathogen persisted for so long? Typically, TB bacteria, known as Mycobacterium tuberculosis, are airborne and can infect the lungs when inhaled. Immune cells called macrophages rush to the infection site, attempting to absorb and break down the bacterial invaders. In many cases, this immune response is sufficient to eliminate the bacteria. However, individuals with certain medical conditions—such as malnutrition, HIV, diabetes, or during pregnancy—may have a weakened immune response, allowing Mycobacterium tuberculosis to reproduce within the macrophages and form colonies in the surrounding lung tissue.
As the bacteria infect more cells, they produce enzymes that degrade the infected tissue, leading to symptoms like chest pain and coughing up blood. The damage to the lungs can result in oxygen deprivation, triggering hormonal changes that include decreased appetite and iron production. From there, the bacteria can spread to other parts of the body, causing back pain, abdominal pain, headaches, and even impaired consciousness. These symptoms contribute to the classic image of TB: weight loss, a persistent cough, and pale skin, which earned TB the nickname “the White Plague” in Victorian-era England.
During this time, tuberculosis was often romanticized, as it disproportionately affected impoverished artists and poets—those with weaker immune systems. The outward symptoms of TB even contributed to myths surrounding vampirism. Despite these misconceptions, this era also marked significant progress in the fight against TB. In 1882, German physician Robert Koch identified the bacterial cause of the disease. Thirteen years later, physicist Wilhelm Roentgen discovered the X-ray, which enabled physicians to diagnose and monitor TB’s progression in the body.
These advancements paved the way for the development of reliable vaccines, including the BCG vaccine in 1921, which was designed to combat TB. These innovations laid the foundation for modern antibiotics, which are currently the most effective treatments for TB. However, antibiotics do not address a significant diagnostic challenge: approximately 90% of individuals infected with TB do not exhibit symptoms. In these latent infections, the TB bacterium can remain dormant, only becoming active when the immune system is compromised. This makes TB more challenging to diagnose.
Even when TB is correctly identified, traditional treatments can take up to nine months and require multiple medications, which can lead to side effects. This lengthy treatment process often discourages patients from completing their course, allowing bacteria to develop resistance to the drugs. Currently, TB remains prevalent in 30 countries, many of which are facing other health crises that exacerbate the situation and trigger latent cases. Accessing treatment can be difficult in these regions, and the stigma surrounding TB can further deter individuals from seeking help.
Health experts agree on the need for improved diagnostics, faster-acting antibiotics, and more effective vaccines. Researchers have already developed a urine test that provides results in 12 hours, as well as a new oral treatment that could reduce treatment time by 75%. With advancements like these, there is hope that TB can eventually become a thing of the past.
Tuberculosis – An infectious disease caused by the bacterium Mycobacterium tuberculosis, primarily affecting the lungs but can also impact other parts of the body. – The rise in drug-resistant strains of tuberculosis poses a significant challenge to global health efforts.
Bacterium – A single-celled microorganism that can exist either as an independent organism or as a parasite, some of which are pathogenic and can cause diseases. – The bacterium responsible for tuberculosis is highly contagious and can be spread through airborne droplets.
Immune – Relating to the body’s defense system that protects against disease and infection. – A strong immune response is crucial for the body to fight off infections like tuberculosis.
Symptoms – Observable signs or indications of a disease or condition, often prompting further medical investigation. – Common symptoms of tuberculosis include a persistent cough, fever, and weight loss.
Lungs – The pair of respiratory organs located in the chest, responsible for the exchange of oxygen and carbon dioxide with the blood. – Tuberculosis primarily targets the lungs, leading to severe respiratory issues if left untreated.
Antibiotics – Medicines used to treat infections caused by bacteria by killing or inhibiting their growth. – The treatment of tuberculosis typically involves a prolonged course of multiple antibiotics to ensure the complete eradication of the bacteria.
Vaccines – Biological preparations that provide immunity to a particular infectious disease, often by stimulating the body’s immune response. – The BCG vaccine is used in many countries to provide protection against tuberculosis, especially in children.
Diagnostics – Techniques and tools used to identify diseases and conditions, often involving laboratory tests and imaging. – Advances in diagnostics have improved the early detection and treatment of tuberculosis, reducing its spread.
Health – The overall condition of an organism at a given time, encompassing physical, mental, and social well-being. – Public health initiatives aim to control the spread of infectious diseases like tuberculosis through education and vaccination programs.
Resistance – The ability of bacteria or other microorganisms to withstand the effects of an antibiotic or other antimicrobial agent. – The emergence of antibiotic resistance in tuberculosis strains is a major concern for healthcare providers worldwide.
