Tuberculosis (TB) is a contagious disease caused by bacteria and usually affects the lungs. When you breathe in TB bacteria, they can settle in the lungs and begin to multiply. They can also travel through the blood to other parts of the body, such as the kidneys, spine and brain.

Not all people who become infected will develop TB disease, some have a so-called latent TB infection. If you have latent TB infection, you don’t have any symptoms and aren’t contagious. Only a small percentage of people infected with TB will develop TB disease. These conditions or life stages make it more likely for TB disease to develop: very young age (infants and young children), old age, diabetes, HIV infection, illegal drug use via injections, compromised immune system, improper TB treatment in the past, malnourished state, tobacco use.

If you develop TB disease, there may be only mild symptoms for months, so you may not realise you’re seriously ill and you may spread TB to others. Common symptoms of TB include persistent, long-term cough (sometimes with blood), chest pain, weakness and fatigue, weight loss, fever and night sweats. You should see a doctor if you experience these symptoms – early treatment can help stop the spread of disease and improve your chances of recovery.

If TB infection spreads from the lungs to other parts of the body, there may be other symptoms, depending on what part of the body gets infected.

People who are infected with TB but not ill with the disease are not infectious. TB spreads when people with TB disease cough, sneeze, speak, sing or spit – they expel tiny droplets containing the bacteria into the air and people close to them may breathe these bacteria in and become infected.

If you have TB disease, protect others by covering your mouth and nose when coughing or sneezing, wearing a facemask or respirator, avoiding close contact with others and maintaining good personal hygiene, including disposing of used tissues safely.

Tuberculosis disease is treated with a very long-term course of antibiotics – they must be taken daily for four to six months to be effective. If TB doesn’t respond to standard antibiotics, it becomes very difficult to treat and more toxic treatment is needed. Without treatment, 60 per cent of people with TB disease die.

People who are HIV-positive are much more likely to develop TB disease and become ill with TB disease than HIV-negative people. Without treatment, almost all HIV-positive people with TB die.Do not underestimate TB symptoms and even if you’re not ill but think you may have been infected, see a doctor. Early treatment can literally save your life.