Understand Tuberculosis (TB)

What is TB?
Tuberculosis (TB) is a disease caused by bacteria called Mycobacterium tuberculosis. The bacteria usually attack the lungs. But, TB bacteria can attack any part of the body such as the kidney, spine, and brain. If not treated properly, TB disease can be fatal. TB is spread through the air from one person to another.

The bacteria are put into the air when a person with active TB disease of the lungs or throat coughs or sneezes. People nearby may breathe in these bacteria and become infected.However, not everyone infected with TB bacteria becomes sick. People who are not sick have what is called latent TB infection. People who have latent TB infection do not feel sick, do not have any symptoms, and cannot spread TB to others. But, some people with latent TB infection go on to get TB disease.People with active TB disease can be treated if they seek medical help. Even better, most people with latent TB infection can take medicine so that they will not develop active TB disease.

TB in India
India has far more cases of tuberculosis than any other country in the world. There are about 2 million new cases each year and India accounts for nearly one third of prevalent cases globally. As reported by researchers in the October 31st issue of the New England Journal of Medicine, by September 2001, 436 million people (more than 40 percent of the entire population) had access to health services in India. About 3.4 million patients had been evaluated for tuberculosis, and nearly 8,00,000 had received treatment, with a success rate greater than 80 percent. More than half of all those treated in the past 8 years were treated in the past 12 months.
According to the study, tuberculosis kills nearly 500,000 people in India each year. Until recently, less than half of patients with tuberculosis received an accurate diagnosis, and less than half of those received effective treatment.(NDTV Report)

How is TB spread?
TB is spread through the air from one person to another. The bacteria are put into the air when a person with active TB disease of the lungs or throat coughs or sneezes. People nearby may breathe in these bacteria and become infected.When a person breathes in TB bacteria, the bacteria can settle in the lungs and begin to grow. From there, they can move through the blood to other parts of the body, such as the kidney, spine, and brain.TB in the lungs or throat can be infectious. This means that the bacteria can be spread to other people. TB in other parts of the body, such as the kidney or spine, is usually not infectious.People with active TB disease are most likely to spread it to people they spend time with every day. This includes family members, friends, and coworkers.

What is latent TB infection?
In most people who breathe in TB bacteria and become infected, the body is able to fight the bacteria to stop them from growing. The bacteria become inactive, but they remain alive in the body and can become active later. This is called latent TB infection. People with latent TB infectionhave no symptoms don't feel sick can't spread TB to others usually have a positive skin test reaction or QuantiFERON-TB Gold test (QFT-G) may develop active TB disease if they do not receive treatment for latent TB infection Many people who have latent TB infection never develop active TB disease. In these people, the TB bacteria remain inactive for a lifetime without causing disease. But in other people, especially people who have weak immune systems, the bacteria become active and cause TB disease.

What is active TB disease?
TB bacteria become active if the immune system can't stop them from growing. The active bacteria begin to multiply in the body and cause active TB disease. The bacteria attack the body and destroy tissue. If this occurs in the lungs, the bacteria can actually create a hole in the lung. Some people develop active TB disease soon after becoming infected, before their immune system can fight the TB bacteria. Other people may get sick later, when their immune system becomes weak for another reason.Babies and young children often have weak immune systems. People infected with HIV, the virus that causes AIDS, have very weak immune systems. Other people can have weak immune systems, too, especially people with any of these conditions: substance abuse diabetes mellitus silicosis cancer of the head or neck leukemia or Hodgkin's disease severe kidney disease low body weight certain medical treatments (such as corticosteroid treatment or organ transplants) specialized treatment for rheumatoid arthritis or Crohn’s disease Symptoms of TB depend on where in the body the TB bacteria are growing. TB bacteria usually grow in the lungs. TB in the lungs may cause symptoms such asa bad cough that lasts 3 weeks or longer pain in the chest coughing up blood or sputum (phlegm from deep inside the lungs) Other symptoms of active TB disease areweakness or fatigue weight loss no appetite chills fever sweating at night

(compiled)