TUBERCULOSIS (TB) | The Physio Fix

 TUBERCULOSIS: REMAINS A PERSISTENT YET SIGNIFICANT GLOBAL HEALTH CHALLENGE 

A contagious infection spread by a bacterium i.e. Mycobacterium Tuberculosis, still continues to cause suffering to millions worldwide, posing an alarming challenge to the public health authorities and medical health professionals around the globe. It primarily affects the lungs, but it can spread to other organs and tissues in the body as well. 

However, TB i.e. a bacterial infection remains the leading cause of death worldwide, especially in low and middle-income countries where healthcare resources and facilities are limited. The Public health initiatives focus on early diagnosis and prompt treatment, BCG vaccination to prevent and control the spread of TB and reduce its impact on global health.

TB primarily affects the  lungs

CONTENTS

1. Definition

2. Signs & Symptoms

3. Stages of TB

   3.1 Primary TB

   3.2 Latent TB

   3.3 Active TB

   3.4 Extrapulmonary TB

4. Complications

5. Investigations/Diagnosis

   5.1 Tuberculin Skin Test (MANTOUX TEST)

   5.2 IGRAs

   5.3 Sputum Smear Microscopy

6. Treatment

  6.1 Treatment for latent TB

  6.2 Treatment for Active TB

  6.3 DOTS

  6.4 BCG Vaccine

1. DEFINITION 

TB or simply, Tuberculosis can be defined as a highly communicable disease caused by the bacterium i.e. Mycobacterium tuberculosis. 

OR

It can also be defined as, an infectious disease caused by a bacterium that primarily affects the lungs but, can also spread to other organs and tissues of the body. 

Mycobacterium Tuberculosis is also known as Koch's Bacillus. It is a weakly gram-positive and rod-shaped bacteria that is the causative agent of tuberculosis. This bacteria spreads via. droplets that carry it through the air. It can happen when an infected person speaks, coughs, sneezes, sings, or laughs.

2. SIGNS & SYMPTOMS

The signs and symptoms of TB can vary depending on the part of the body that is infected by the bacteria. The early warning signs or common symptoms of TB may include the following:

• fever
• night sweats
• prolonged cough (lasting more than 3 weeks)
• coughing up blood
• fatigue
• chest pain
• shortness of breath
• loss of appetite 
• unintended weight loss
• chills 

These signs and symptoms are observed during the active TB stage. The same symptoms are experienced in TB of parts of the body other than the lungs along with pain in the affected area/organ/tissue of the body.

No symptoms are observed in the case of latent TB infection.

3. STAGES OF TB

There are 4 stages of TB. 

•  3.1. Primary TB/Exposure: The initial stage of infection in which a person is exposed to the bacteria i.e. Mycobacterium tuberculosis. The bacteria may or may not enter the body during this stage.
•  3.2. Latent TB: During this stage, the bacteria is present inside the infected person's body but, it is found in inactive form and causes no symptoms to occur. The disease is not contagious at this stage. It may last for a year or even a lifetime without progressing to active TB infection.
• 3.3. Active TB: The bacteria becomes active at this stage and begins to multiply. The signs and symptoms start to appear including persistent cough with blood, fever, chills, night sweats, weight loss, and fatigue. The infection is highly contagious at this stage.
• 3.4. Extrapulmonary TB: At this stage, the TB bacteria spread from the lungs to other parts of the body. The organs that are commonly affected include the kidneys, liver, and brain, leading to more severe health complications. 

 People with HIV/AIDS and others with weakened immune systems are at a greater risk of developing the disease due to their bodies having a harder time fighting the bacteria.

Majority of the TB cases can be cured by completing the course of prescribed medications properly. It is 100% curable if treated with the approved combination of drugs given and taken for at least 6 months.

4. COMPLICATIONS RESULTING FROM TB

If not diagnosed and promptly treated, TB may lead to many further complications in the body such as:

• lung damage
• pleural effusion 
• pneumothorax
• hemoptysis 
• bronchiectasis
• cardiac tamponade
• TB meningitis
• respiratory failure
• spinal TB
• joint damage 
• hepatic TB
• renal TB
• Addison's disease
• infertility
• intestinal TB
• widespread dissemination of infection throughout the body, affecting several organs and causing severe systemic illness.

5. INVESTIGATIONS/DIAGNOSIS OF TB

The clinical evaluation for diagnosis of TB includes a thorough medical history along with a physical examination of the patient to look for the presence of systemic signs of TB. 

The diagnostic methods used for TB include Tuberculin Skin Tests, IGRAs, Microbiological Tests, Radiological imaging, and Histopathological examination. While the most commonly used methods to  diagnose TB effectively include the following:

• 5.1. TUBERCULIN SKIN TEST (TST): Also known as the Mantoux Test, is a diagnostic tool for detecting the presence of TB infection. It can also be used to detect TB at the latent stage. A small amount of Purified Protein Derivative (PPD) i.e. 0.1 ml is injected intradermally on the inner surface of the forearm. The injection site is observed for a raised bump/induration between 48-72 hours after administration, which indicates a reaction. The size of the bump is measured to determine if the test is positive or not.
• 5.2. INTERFERON GAMMA RELEASE ASSAYS (IGRAs): This blood test measures the response of a patient's immune system to TB proteins. 
• 5.3. SPUTUM SMEAR MICROSCOPY: This test analyzes coughed-up mucus (sputum) for the presence of TB bacteria. 
• 5.4. SPUTUM CULTURE: Grows TB bacteria in culture from the sputum sample to confirm the diagnosis and identify the bacteria.
• 5.5. BIOPSY: A tissue sample from the lungs or the affected organ is collected and observed for the diagnosis of TB. Bronchoscopy with biopsy includes the insertion of a thin tube with a camera through the airways to collect the tissue sample from the lungs. 

Some other methods include:

• TB Acid-Fast Bacilli test (AFB)
• Chest X-rays
• Molecular tests ( GeneXpert MTB/RIF)
• TB blood test, Complete Blood Count
• CT scan/ MRI

6. TREATMENT 

6.1. For Latent TB:

• Antibiotics kill the bacteria and prevent from development of active TB disease. 
• Medication continued for 3 to 9 months. 

Such as,

• Isoniazid (INH)
• Rifapentine (RPT)
• Rifampin (RIF)

6.2. For Active TB:

• Combination of antibiotics for at least 6 to 9 months. Some of the most common antibiotics used to treat TB:

1. Isoniazid
2. Rifampin
3. Ethambutol
4. Pyrazinamide

• Stay home from work or school: This will help to prevent spreading the infection to others.
• Get plenty of rest
• Eat a healthy diet
• Cover your mouth and nose when you cough or sneeze
• Ventilate your home: Open windows to allow fresh air to circulate

6.3. DOTS: THE MOST EFFECTIVE AND WIDELY USED STRATEGY FOR THE TREATMENT OF TB.

• A healthcare worker watches the TB patient swallow each dose of the prescribed drugs.
• During DOT encounters, the healthcare worker also asks the patient about any problems or side effects with the medication.
• DOT can be conducted either in person or remotely 
• DOT conducted remotely is called electronic DOT (eDOT). 
• Should be used for ALL patients with TB disease, including children and adolescents. 
• There is no way to accurately predict whether a patient will adhere to treatment without this assistance.

6.4. BCG VACCINE 

The vaccine named after its inventors i.e. Albert Calmette and Camille Guerin, is primarily used for protection against Tuberculosis. The abbreviation BCG stands for Bacille Calmette-Geurin, respectively. It is considered as a safe vaccine against tuberculosis. 

In countries where tuberculosis is common such as India, Indonesia, China, Nigeria, Pakistan, Philippines, South Africa, Ethiopia, Kenya, Tanzania, Myanmar, Uganda, and Vietnam, one dose of BCG vaccine is recommended in healthy babies as soon as possible after their birth. 

ADMINISTRATION METHOD: BCG vaccine is given via. an injection into the skin i.e. 0.1 ml delivered intradermally, usually in the upper arm. 

The injection site might appear red, swollen, and hard for a few weeks after the vaccination. This reaction is considered completely normal and should go away on its own.