Tuberculosis: The Leading Infectious Killer Today – Key Facts to Know
, by Tatianna Gerard, 15 min reading time
, by Tatianna Gerard, 15 min reading time
Tuberculosis, a centuries-old disease, has once again claimed the grim title of the world’s most deadly infectious killer. According to recent data from the World Health Organization (WHO), tuberculosis, or TB, led to the deaths of an estimated 1.25 million people globally last year, officially surpassing COVID-19 as the leading infectious disease killer. Despite being preventable and treatable, TB remains a significant global health crisis, largely due to barriers like delayed diagnoses, inadequate healthcare access, and the spread of drug-resistant strains.
In this blog, we’ll explore the critical facts you need to know about tuberculosis, including how it spreads, its symptoms, and the challenges we face in combating this resilient disease.
Tuberculosis, commonly known as TB, is a serious infectious disease that primarily affects the lungs but can spread to other parts of the body, including the kidneys, spine, and brain. TB is caused by a bacterium called Mycobacterium tuberculosis, a resilient microorganism that can survive in harsh conditions and spread easily through airborne particles. Though TB has existed for centuries, it remains a major global health concern, especially in regions where healthcare access is limited.
TB is generally classified into two main types: pulmonary and extrapulmonary tuberculosis.
When TB bacteria enter the lungs, they cause inflammation and tissue damage. For people with healthy immune systems, the body often builds a barrier around the bacteria, containing them in an inactive form known as latent TB. In these cases, the bacteria remain dormant and do not cause symptoms, nor can they be spread to others. However, if the immune system weakens, latent TB can become active TB, meaning the bacteria multiply and cause symptoms, and the person becomes contagious.
Active TB not only impacts the lungs but can also spread to other organs, causing a range of complications. The damage inflicted by TB bacteria on tissues, especially in the lungs, leads to classic symptoms like persistent coughing, chest pain, and fatigue. Without proper treatment, TB can be fatal, making it essential to detect and manage the disease promptly.
Tuberculosis doesn’t always show symptoms right away. In fact, there are two distinct stages of TB infection: latent TB and active TB. Understanding the difference between these stages is crucial, as each has unique implications for both the individual and the community.
In the latent stage, a person is infected with Mycobacterium tuberculosis bacteria, but the body’s immune system effectively contains them, preventing them from multiplying. This means that people with latent TB do not experience any symptoms and, crucially, are not contagious—they cannot spread TB to others. Latent TB can last for years or even a lifetime without causing any noticeable health issues. However, the bacteria remain in the body and can become active later, especially if the immune system is weakened by illness, age, or malnutrition.
Even though latent TB doesn’t present immediate health concerns, treating it is essential to prevent future complications. This is particularly important in communities with high TB rates, where latent TB can contribute to new outbreaks if it progresses to the active stage.
Active TB occurs when the bacteria in the body begin to multiply and cause symptoms. This is the contagious stage of the disease, meaning that people with active TB can spread the infection through airborne droplets when they cough, sneeze, or speak. Active TB usually affects the lungs but can spread to other parts of the body, leading to extrapulmonary TB in severe cases.
The symptoms of active TB are often pronounced and can include:
Active TB is a serious medical condition that requires immediate treatment with a combination of antibiotics. Because of the contagious nature of active TB, timely treatment is essential not only for the individual’s recovery but also to prevent the spread of TB within their community. With proper treatment, most people with active TB recover fully, but delayed treatment can lead to serious complications and even death.
Tuberculosis can present a range of symptoms, some more obvious than others. TB symptoms vary depending on whether the infection is primarily located in the lungs (pulmonary TB) or has spread to other parts of the body (extrapulmonary TB).
When TB affects the lungs, it typically presents a range of respiratory symptoms. These include:
Beyond the respiratory system, TB can impact a person’s general well-being, producing symptoms that affect the entire body. These include:
While TB most often affects the lungs, the bacteria can spread to other parts of the body. When this happens, it is called extrapulmonary TB, and symptoms vary depending on the area affected:
According to the CDC, certain medical conditions and treatments that weaken the immune system can increase the risk of tuberculosis. These include:
Age-related vulnerability to TB
TB risk fluctuates throughout life, with certain age groups being more susceptible to developing the disease. The likelihood of contracting TB is highest among young children under three years of age, drops during later childhood, then rises again during adolescence, young adulthood, and older age. This pattern reflects the balance between immune system development and decline over a lifetime.
Tuberculosis remains a formidable public health challenge across the globe, particularly in low- and middle-income countries, which bear the brunt of the disease. In fact, over 80% of TB cases and related deaths occur in these regions, underscoring the disparity in health resources and support.
TB is found in every corner of the world, but certain areas are particularly affected. According to the fact sheet by the WHO, in 2023, the highest number of new TB cases was reported in the WHO South-East Asia Region, accounting for approximately 45% of all cases, followed by 24% in the African Region and 17% in the Western Pacific Region. Furthermore, about 87% of new TB cases emerged in 30 countries identified as having a high TB burden, with a significant concentration in nations such as Bangladesh, China, Democratic Republic of the Congo, India, Indonesia, Nigeria, Pakistan, and the Philippines. These countries collectively contribute to more than two-thirds of TB cases globally.
One of the major challenges in the fight against tuberculosis is the rise of drug-resistant strains. These drug-resistant types of TB develop primarily due to incomplete or incorrect treatment. When TB patients do not complete their full course of medication—either due to lack of access, inadequate healthcare support, or stopping early when symptoms improve—the bacteria can survive and adapt. Over time, these surviving bacteria develop resistance to the drugs used to treat TB, making standard treatments ineffective.
Some strains of the bacteria have developed resistance to the most commonly used TB drugs, such as isoniazid and rifampicin. Drug-resistant TB, particularly multi-drug-resistant (MDR) TB and extensively drug-resistant (XDR) TB, requires more complex and prolonged treatment with second-line drugs, which are often more toxic, more expensive, and less readily available.
Although the Bacillus Calmette-Guérin (BCG) vaccine provides some protection, particularly in children, it is not highly effective in preventing adult pulmonary TB, which is the most common and contagious form. Researchers are working on new vaccines, but progress has been slow. The lack of an effective, widely available vaccine for TB means that prevention efforts largely depend on diagnosing and treating active cases, which can be challenging in low-resource settings.
TB diagnosis requires specific tests, including a sputum test or chest X-ray, which are not always accessible in resource-limited areas. Additionally, TB treatment is lengthy and requires strict adherence to a regimen lasting at least six months. In many parts of the world, access to treatment can be inconsistent, with patients struggling to complete their courses due to financial, social, or logistical barriers. Incomplete or interrupted treatment can lead to the development of drug-resistant strains and further spread of the disease.
TB disproportionately affects people in low-income communities where overcrowded living conditions, poor nutrition, and limited access to healthcare are prevalent. Factors such as malnutrition and weakened immune systems increase the likelihood of active TB infection. Furthermore, the stigma associated with TB, particularly in some cultures, can prevent individuals from seeking treatment or disclosing their symptoms, contributing to delays in diagnosis and higher transmission rates.
Individuals with weakened immune systems are at a higher risk of developing active TB. For example, people living with HIV are around 18 times more likely to develop TB than those without HIV, as the virus severely compromises immune function. In areas where both TB and HIV are prevalent, the combination poses a double burden on healthcare systems and increases the risk of mortality for those affected.
To curb the spread of tuberculosis, especially in areas with high infection rates, effective infection control measures are essential. These practices not only protect those who are healthy but also prevent contagious patients from passing on the infection. Here are some vital strategies to consider:
Using high-quality masks is one of the most effective ways to reduce TB transmission, particularly in crowded or poorly ventilated spaces. Masks that offer a high filtration efficiency, such as AMD P2 masks, are ideal for this purpose.
These masks boast a Particle Filtration Efficiency (PFE) of ≥99.66% and a Bacterial Filtration Efficiency (BFE) of ≥99.92%, providing a high level of protection against airborne particles, including those that carry TB bacteria. Unlike standard melt-blown P2 masks, AMD P2 masks are made with nano-fibre technology, making them not only more protective but also comparable in quality and function to N95 masks. Their advanced filtration makes them a preferred choice for safeguarding against TB in high-risk settings.
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TB bacteria thrive in closed, poorly ventilated environments. Increasing airflow by opening windows and doors or using ventilation systems can help disperse airborne particles, reducing the concentration of infectious bacteria in indoor spaces. Well-ventilated areas lower the chances of TB transmission significantly.
For individuals diagnosed with active TB, especially those in contagious stages, isolation is crucial. Creating separate spaces or designated areas for TB patients limits their interaction with others, thereby controlling the spread. Healthcare facilities and homes alike can implement this measure to safeguard those who are more vulnerable to infection.
By implementing these infection control practices, communities can reduce the transmission of tuberculosis and protect public health. While TB remains a formidable health challenge worldwide, adopting these preventive measures and encouraging awareness can help us move closer to controlling and eventually eliminating the spread of this infectious disease.
The content provided on this blog is for informational purposes only and is based on research conducted by our team using credible medical and relevant sources. While we strive to ensure the information is accurate and up-to-date, it should not be considered a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a qualified health professional regarding any medical condition or concerns.