Comprehensive Guide to Tuberculosis: Causes, Signs, Symptoms, Types and Prevention | Max Hospital

To Book an Appointment

Call Us+91 92688 80303

Understanding Tuberculosis: A Comprehensive Guide

By Dr. Inder Mohan Chugh in Pulmonology

Feb 29 , 2024 | 10 min read

Tuberculosis, often referred to as TB, stands as one of humanity's oldest and most persistent health challenges, captivating the attention of medical professionals and researchers for centuries. Approximately 40% of the Indian population is infected with TB bacteria, the vast majority of whom have latent rather than active TB. The World Health Organization (WHO) has estimated that around 300,000 people die from TB each year in India. According to DAHW (German Leprosy & Tuberculosis Relief Association), every fifth new tuberculosis case in the world lives in the Indian subcontinent. Shocking, right? Tuberculosis or TB is one of the most grave and major diseases facing India today. And that is the reason each and every citizen must be well aware of this malady. In this article, we explore various aspects of tuberculosis, with an aim to help you gain a comprehensive understanding of the disease and the strides being made in its prevention and treatment. Let’s start with answering the most fundamental question. 

What is Tuberculosis?

Tuberculosis is a bacterial infection that usually attacks the lungs first and then can spread to any organ of the body, such as the kidneys, spine, and brain. If not treated properly, TB disease can be fatal. This disease was once associated with the poor, however today, it is known to afflict all classes of society. 

What Causes Tuberculosis?

Tuberculosis is caused by the bacterium Mycobacterium tuberculosis which can survive in the air for extended periods. That’s why people with tuberculosis are advised to take precautions to prevent the bacteria from spreading to other individuals. 

How does Tuberculosis Spread?

Tuberculosis primarily spreads through the air, when a person with active TB disease releases respiratory droplets containing the bacteria Mycobacterium tuberculosis into the air. The key modes of TB transmission include:

Airborne transmission

The primary mode of TB transmission is through the inhalation of respiratory droplets containing the infectious bacteria. When an individual with active TB disease coughs, sneezes, speaks, or even sings, they release these droplets into the air. If another person inhales these contaminated droplets, they may become infected with Mycobacterium tuberculosis.

Close and prolonged contact

TB is more likely to spread in situations where individuals have close and prolonged contact with an infectious person. This is particularly relevant in crowded or enclosed environments, such as households, prisons, or healthcare facilities, where the concentration of respiratory droplets in the air is higher.

Poor ventilation

Inadequate ventilation in enclosed spaces can contribute to the persistence of infectious droplets in the air, increasing the risk of transmission. Well-ventilated areas help disperse and dilute the concentration of respiratory droplets, reducing the likelihood of TB transmission.

Weakened immune system

Individuals with weakened immune systems are more susceptible to TB infection and are at a higher risk of developing active TB disease. Conditions such as HIV/AIDS, malnutrition, and certain medical treatments that suppress the immune system increase the likelihood of progression from latent TB infection to active TB disease.

It's important to note that not everyone exposed to Mycobacterium tuberculosis becomes sick. Some individuals may develop latent TB infection, where the bacteria are present in the body but are inactive and do not cause symptoms. These individuals do not spread TB to others. However, if their immune system becomes compromised, the latent infection may progress to active TB disease, which is contagious. 

What are the Types of Tuberculosis?

Tuberculosis (TB) manifests in different forms, with two primary classifications: latent TB infection (LTBI) and active TB disease.

Latent TB Infection (LTBI)

In this form, individuals are infected with the bacteria Mycobacterium tuberculosis, but the bacteria are in an inactive state. People with latent TB do not exhibit symptoms and cannot spread the infection to others. However, there is a risk that latent TB can progress to active TB disease, particularly in individuals with weakened immune systems.

Active TB Disease

This form occurs when the bacteria become active and cause clinical symptoms. Active TB can affect the lungs (pulmonary TB) or other parts of the body (extrapulmonary TB). Symptoms may include a persistent cough, chest pain, weight loss, fatigue, fever, and night sweats. Active TB is contagious, and individuals with this form of the disease can transmit the bacteria to others through the air.

Beyond these classifications, TB can be further categorized based on the site of infection and the extent of disease:

  • Pulmonary TB: The bacteria primarily infect the lungs, causing symptoms such as cough, chest pain, and difficulty breathing.
  • Extrapulmonary TB: The bacteria affect parts of the body outside the lungs, such as the kidneys, spine, lymph nodes, and brain.
  • Miliary TB: This is a severe and disseminated form of the disease where the bacteria spread through the bloodstream to multiple organs.
  • Drug-resistant TB: Some strains of Mycobacterium tuberculosis have developed resistance to one or more of the antibiotics commonly used to treat TB. Drug-resistant TB poses additional challenges for effective treatment.

Understanding these distinctions is crucial for proper diagnosis, treatment, and prevention efforts in managing tuberculosis.

What are the Signs and Symptoms of Tuberculosis?

Tuberculosis can produce a variety of signs and symptoms, which may differ depending on whether the infection is latent or active. Here are common signs and symptoms associated with active TB disease:

  • Chest pain: Pain in the chest may be experienced, particularly during deep breaths or coughing. This can be a result of inflammation in the lung tissues.
  • Cough: A persistent cough that lasts for three weeks or longer is a common symptom of pulmonary TB. The cough may produce sputum (phlegm or mucus), which can be bloody.
  • Unexplained weight loss: Unexplained weight loss is often observed in individuals with active TB. This can be a result of a combination of factors, including loss of appetite and the body's increased metabolic demands during infection.
  • Fatigue: Persistent fatigue and weakness are common symptoms of active TB. This can be a consequence of the body's efforts to fight the infection.
  • Fever: A low-grade fever or persistent fever, often along with chills, especially during the afternoon or evening, can be a sign of active TB.
  • Night sweats: Profuse sweating, particularly during the night, is a characteristic symptom of TB. Night sweats can contribute to disturbed sleep patterns.
  • Shortness of breath: Difficulty breathing and shortness of breath may occur, especially if the infection has progressed and affected a significant portion of the lungs.
  • Swollen lymph nodes: In cases of extrapulmonary TB, where organs other than the lungs are affected, swollen lymph nodes may be noticeable. These can occur in various parts of the body.

If someone is experiencing symptoms suggestive of TB or has been in close contact with an individual diagnosed with active TB, it's crucial to seek medical attention promptly for proper evaluation, diagnosis, and treatment. Early detection and treatment are essential for managing TB effectively and preventing its spread to others.

What Tests are used to Diagnose Tuberculosis?

The diagnosis of tuberculosis typically involves a combination of clinical evaluation, imaging studies, and laboratory tests. Here are the commonly used tests to diagnose TB:

  • Tuberculin skin test (TST) or Mantoux test: A small amount of purified protein derivative (PPD) is injected under the skin. A positive reaction, indicated by a raised bump at the injection site, suggests exposure to Mycobacterium tuberculosis. However, it does not distinguish between latent and active TB.
  • Interferon-gamma release assays (IGRAs): Blood tests, such as QuantiFERON-TB Gold or T-SPOT.TB, measure the release of interferon-gamma in response to TB-specific antigens. These tests are more specific than the tuberculin skin test and help differentiate between latent and active TB.
  • Chest X-ray: Imaging of the chest helps identify abnormalities in the lungs, such as infiltrates, cavities, or other changes associated with pulmonary TB.
  • Sputum smear microscopy: A sample of sputum (mucus from the lungs) is examined under a microscope after staining to detect the presence of acid-fast bacilli (AFB), including Mycobacterium tuberculosis.
  • Sputum culture: Sputum samples are cultured in a laboratory to allow the growth of Mycobacterium tuberculosis, providing a definitive confirmation of TB and enabling drug susceptibility testing.
  • Nucleic acid amplification tests (NAATs): Polymerase chain reaction (PCR) and other molecular tests can detect the genetic material of Mycobacterium tuberculosis in clinical samples, offering a rapid and sensitive diagnosis.
  • Xpert MTB/RIF assay: A molecular test that simultaneously detects Mycobacterium tuberculosis and assesses rifampicin resistance. It provides results within a few hours, aiding in the rapid diagnosis of TB and determination of drug resistance.
  • Bronchoscopy: In cases of suspected extrapulmonary TB or when sputum samples are challenging to obtain, a bronchoscopy may be performed to collect samples from the lower respiratory tract.
  • Biopsy: For extrapulmonary TB, a biopsy of affected tissues or organs may be performed for microscopic examination and culture.
  • Drug susceptibility testing (DST): This test is used to determine the susceptibility of the TB bacteria to specific antibiotics, helping guide appropriate treatment.

The choice of diagnostic tests depends on various factors, including the clinical presentation, risk factors, and available resources. In some cases, multiple tests may be used to increase the accuracy of diagnosis, especially when dealing with drug-resistant strains or extrapulmonary TB. 

How is Tuberculosis Treated?

The go-to treatment option for tuberculosis is DOTS (Directly Observed Therapy Short Course), whichserves two purposes: on one hand, it ensures that tuberculosis (TB) patients complete their treatment and be fully cured; on the other, it helps prevent the spread of drug resistance in the community.

The DOTS strategy, along with the other components of the Stop TB strategy, implemented under the Revised National Tuberculosis Control Programme (RNTCP) in India, is a comprehensive package for TB control, prescribed by the WHO. 

According to TBC India, the DOTS strategy is cost-effective and is today the international standard for TB control programmes. To date, more than 180 countries are implementing the DOTS strategy. India has adapted and tested the DOTS strategy in various parts of the country since 1993, with excellent results, and by March 2006 nationwide DOTS coverage has been achieved. 

Though modern anti-TB treatment can cure virtually all patients, it is very important that the treatment be taken for the prescribed duration, which in every case is a minimum of 6 months. Because treatment is for such a long duration and the patients feel better after just 1-2 months, treatment is often interrupted. This can lead to the bacteria becoming resistant to the drug administered and will require a stronger dose of the medicine to have effect.

What can be done to Prevent Tuberculosis?

Preventing tuberculosis involves a combination of strategies aimed at reducing transmission, identifying and treating latent and active infections, and addressing risk factors. Here are key measures to prevent TB:

  • BCG vaccine: The Bacillus Calmette-Guérin (BCG) vaccine is used in many countries to prevent severe forms of TB in children. While it may not provide complete protection against all forms of TB, it can reduce the risk of severe complications.
  • Respiratory hygiene: Promote good respiratory hygiene, such as covering the mouth and nose when coughing or sneezing, and try to use a mask while you’re in congested public places like trains, buses, stations etc. 
  • Ventilation: Ensure well-ventilated spaces, especially in crowded settings, to reduce the concentration of infectious droplets in the air. If you can, use a fan or open the windows for cross-ventilation of air. 
  • Identifying and treating latent TB infection: Screen individuals at higher risk for TB, such as those with known exposure to active cases or individuals with immunosuppression. Offer testing for latent TB infection (LTBI) and provide appropriate treatment to prevent progression to active TB.
  • Contact tracing and testing: Identify and test individuals who have been in close contact with someone diagnosed with active TB. This helps in early detection and treatment of latent or active TB in those exposed.
  • Public health education: Raise public awareness about TB transmission, symptoms, and the importance of seeking medical care. Educate communities about the availability of testing and treatment services.

While TB is a highly contagious and dangerous disease, taking these simple precautions can help you in the long run. 

Final Words

Tuberculosis remains a significant health challenge, demanding concerted efforts in prevention, early detection, and effective treatment. If you or someone you know has been experiencing any symptoms suggestive of tuberculosis, seek medical attention at the earliest. Max Healthcare, known for unwavering commitment to excellence in healthcare, offers specialized services for the diagnosis and treatment of tuberculosis. Our experienced specialists employ cutting-edge diagnostics and evidence-based interventions to provide comprehensive care, ensuring the best outcomes for patients. Remember, timely action can make a substantial difference in the management and control of tuberculosis. Consult a tuberculosis specialist at Max Hospitals and ensure that you receive expert, personalized and compassionate care.

Written and Verified by: