Tuberculosis (TB)

Tuberculosis, commonly known as TB, is a bacterial infection that can cause disease in any part of the body, but most often in the lungs.

How TB is spread#

TB is spread from person to person through the air. When someone with active TB disease in the lungs or throat coughs, sings or sneezes, people nearby may breathe in the bacteria and become infected. The bacteria can then settle in the lungs and begin to grow. From there, they can move through the blood or lymphatic system to other parts of the body, such as the kidney, spine and brain.

Although TB in the lungs or throat can be spread to others, TB in other parts of the body is usually not infectious. You cannot get TB from shaking hands, or from clothes, food, dishes or touching things.

How TB affects the body#

Infection with TB means the person has TB bacteria in their body. Usually the immune (defence) system is able to fight these bacteria, causing them to become inactive. People with TB infection are not sick and cannot spread TB to others. This is called latent TB infection.

TB disease is an illness caused by active TB bacteria. It may occur shortly after the bacteria enter the body, or many years later when the immune system is weakened by other factors such as diabetes, HIV infection or cancer. A person with TB disease has active TB bacteria in their body that can cause signs of illness.

TB is uncommon in many regions, and most cases tend to occur in people who were born in areas where TB is more common. TB can be contagious, but to be infected you usually need close, face-to-face contact with someone who has TB disease in the lungs.

High-risk groups for TB#

People who are at higher risk of TB exposure include:

• close contacts of a person with TB disease in the lungs, especially household members
• people who have recently returned from countries with a high number of TB cases, especially those who spent a long period there
• migrants and refugees
• healthcare workers who were born or have worked in countries with a high number of TB cases
• people living in overcrowded conditions where TB is known to occur, such as in some populations or in correctional facilities

People who are at higher risk of developing TB disease once infected include:

• children under the age of 5 years
• elderly people
• people with severe malnourishment
• people living with HIV infection
• people with poorly controlled diabetes
• people with kidney failure
• people receiving treatment or with conditions that weaken the immune system

Symptoms of active TB#

Symptoms of active TB disease can include:

• a persistent cough
• fever
• night sweats
• tiredness or fatigue
• malaise (feeling generally unwell)
• unexplained weight loss
• swollen glands

Sometimes a person with TB may cough up blood-stained sputum (phlegm). Some people with active TB disease may have only mild symptoms.

Diagnosis of TB#

If your doctor thinks you have TB, methods used to diagnose it may include:

• your medical history
• a sputum test, to see if TB bacteria are present in coughed-up sputum
• a skin test (the tuberculin skin test using the Mantoux procedure)
• a blood test
• a chest x-ray, to show whether TB has affected the lungs

You should be tested for TB if you:

• live or work in close contact with someone recently diagnosed with TB disease of the lungs
• have other conditions that put you at higher risk for TB disease, such as HIV infection or poorly controlled diabetes
• have any TB symptoms

Treatment for TB#

If you have TB infection, your doctor may prescribe a course of tablets or suggest regular chest x-rays. If you have TB disease, you will be treated with a combination of special antibiotics taken for at least 6 months, usually at a major hospital or by a specialist physician.

It is very important to remember that TB can be cured if the prescribed treatment is taken correctly and the full course is completed. Your doctor will monitor your progress during treatment to make sure the medication is working, usually with blood, sputum or urine tests and chest x-rays.

Side effects of TB medications#

Like all medications, anti-tuberculosis tablets can cause side effects. These may include:

• nausea or vomiting
• unexplained fever or tiredness
• jaundice (yellowish skin or eyes)
• dark urine (orange or red urine is a normal side effect and is not harmful)
• visual changes, such as blurred vision or a change in red-green colour vision
• tingling (pins and needles) or numbness of the hands or feet, or joint pains
• skin rash, itching skin or bruising

Immunisation against TB#

The vaccine against TB is called Bacillus Calmette-Guérin (BCG). It is no longer recommended for the general population in areas where the risk of exposure to TB is low. BCG vaccination is only recommended for a small number of people at increased risk of TB. These include:

• children under 5 years who are travelling to high-risk countries for long periods, based on an individual risk assessment
• children under 5 years who are a household contact of a person with leprosy (TB and leprosy are caused by similar bacteria)

Speak with your doctor about whether you or your child need immunisation against TB.

Key points#

• TB disease is an illness caused by active TB bacteria.
• A person with TB disease has active TB bacteria in their body, which can cause signs of illness.
• Symptoms of active TB disease can include a persistent cough, fever, night sweats and swollen glands.
• Some people with active TB disease may have only mild symptoms.
• Like all medications, anti-tuberculosis tablets can cause side effects.

Where to get help#