Patient Education
What is Tuberculosis?
Tuberculosis or TB is an infection caused by a bacteria called Mycobacterium Tuberculosis.
Tuberculosis or TB is an infection caused by a bacteria called as Mycobacterium Tuberculosis.
TB is prevalent in areas with low socioeconomic status and is predisposed due to overcrowding, poverty, poor ventilation, unhygienic living conditions, and close contact with patients having tuberculosis. The most common way of acquiring the infection is by droplet or through the air. The germs of TB enter the respiratory tract (breathing passages) into the lungs and after a period of 4 to 8 weeks develop a focus in the lungs. This focus is known as the primary focus. The infection spreads to the adjacent gland (lymph node) and the primary focus with the involvement of the adjacent gland is called as Primary Complex. Untreated, the disease then spreads to other organs of the body through blood leading to TB of various organs such as the brain (TB meningitis), other glands (TB lymphadenopathy), and even spread to other areas of the lungs.
In Western and developed countries primary TB occurs in the teenage period whereas, in developing countries, an infection may occur much earlier.
Does every person exposed to the TB bacteria get the infection?
Infection with TB bacteria varies from person to person. In some individuals exposed to TB germ, no infection may occur. Some individuals may develop the infection but the body's immunity may take care of it and there may be no disease. Some individuals may develop infection and form a primary complex but again maybe self-contained and there may be no progression. It is called a silent primary infection. Here the TB germs may remain dormant and become active when the person's immunity decreases. In patients with lower immunity, the disease may progress and cause symptoms and problems.
In adults, who had developed primary complex in childhood and with lowering of immunity, there may be reactivation of dormant bacteria that can lead to TB of lungs forming a cavity in the lungs and is called as secondary or Reactivation Tuberculosis.
What are the symptoms of TB?
Patients with a silent primary infection have no symptoms. They are incidentally detected on a tuberculin test. Patients with progressive disease present with fever which is especially more at nights, cough, pneumonia (which does not resolve with antibiotics), pain in the chest, poor appetite, loss of weight, weakness, and fatigue.
In patients with TB of the lymph nodes (glands), there may be enlargement of the glands leading to swellings in the neck or cough if involving glands in the lungs.
In patients with TB of the intestine, there may be diarrhea or constipation, pain in the abdomen, and malabsorption additionally.
TB of the brain may present with fever, headache, vomiting, loss of appetite, fits (seizures), and even coma. Accumulation of water in the brain cavity (hydrocephalus) can also occur.
Rarely TB may affect bones and joints. The involvement of the spine may lead to paralysis.
Can TB be prevented?
BCG vaccine has been used for the prevention of severe forms of TB. BCG does not prevent infection with the TB bacteria but it reduces the progression of the disease and hence TB of other organs is less common in patients vaccinated with BCG.