Tuberculosis

Tuberculosis (TB) is a disease caused by a type of bacteria that are spread from person to person through the air. TB usually affects the lungs, but it can also affect other parts of the body, such as the brain, the kidneys, or the spine. A person with TB can die if they do not get treatment.

What is TB?

What are the Symptoms of TB?

The general symptoms of TB disease include feeling unwell or weak, weight loss, fever, and night sweats. The symptoms of TB disease of the lungs also include prolonged coughing, chest pain, and the coughing up of blood. Symptoms of TB disease in other parts of the body depend on the area affected.

How is TB Spread?

When a person with TB of the lungs coughs, sneezings, sings or talks, droplets containing the bacteria are released into the air and will be spread. These bacteria can stay in the air for several hours, depending on the environment. Those who breathe in the air contaminated with these bacteria could become infected; this is defined as latent TB infection.

What is the Difference Between Latent TB Infection and TB Disease?

The TB bacteria can live in the body without making you sick. This is called 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. People with latent TB infection

– have no symptoms
– don’t feel sick
– can’t spread TB bacteria to others
– usually have a positive TB skin test reaction or positive TB blood test
– may develop TB disease if they do not receive treatment for latent TB infection

Many people who develop latent TB infection never develop TB disease. In these people, the TB bacteria remain inactive for a lifetime without causing disease. But in other people, especially people who have a weak immune system, the bacteria can become active, multiply, and cause TB disease.

TB disease happens when the TB bacteria becomes active in the immune system and are actively multiplying. People with TB disease are sick and will be able to spread the bacteria to people they spend time with every day. The symptoms for TB disease are:

– a bad cough that lasts three weeks or longer
– pain in the chest
– coughing up blood or sputum
– weakness or fatigue
– weight loss
– no appetite
– chills
– fever
– sweating at night

Many people who have latent TB infection never develop TB disease. Some people develop TB disease soon after becoming infected (within weeks) before their immune system can fight the TB bacteria. Other people may get sick years later when their immune system becomes weak for another reason. For people whose immune systems are weak, especially those with HIV infection, the risk of developing TB disease is much higher than for people with normal immune systems.

What Should I Do if I Have Been Exposed to Someone with TB Disease?

People with TB disease are most likely to spread the bacteria to people they spend time with every day, such as family members or co-workers. If you have been around someone who has TB disease, you should go to your doctor or your local health department for tests.

How Do You Get Tested for TB?

There are tests that can be used to help detect a TB infection: a skin test or TB blood tests. The ‘Mantoux’ tuberculin skin test is performed by injecting a small amount of fluid (called tuberculin) into the skin in the lower part of the arm. A person given the tuberculin skin test must return within 48 to 72 hours to have a trained health care worker look for a reaction on the arm. The TB blood tests measures how the patient’s immune system reacts to the bacteria that cause TB.

What Does a Positive Test for TB Infection Mean?

A positive test for TB infection only tells that a person has been infected with the bacteria. It does not tell whether or not the person has progressed to TB disease. Other confirmation tests, such as a chest x-ray and sputum culture of samples, are needed to see whether the person has TB disease.

What is Bacille Calmette–Guèrin (BCG)?

BCG is a vaccine for TB disease. BCG is used in many countries, but it is not generally recommended in the United States. BCG vaccination does not completely prevent people from getting TB. It may also cause a false positive tuberculin skin test. However, persons who have been vaccinated with BCG can be given a tuberculin skin test or TB blood test.