Tuberculosis (TB) - including symptoms, treatment and prevention

Tuberculosis (TB) is an infection caused by a bacterium Mycobacterium tuberculosis.

Tuberculosis is a notifiable condition1

How TB is spread

Tuberculosis is spread when an infected person talks, breathes, coughs or sneezes tiny particles containing infectious agents into the air. These are called small particle aerosols. Due to their tiny size, small particle aerosols can travel long distances on air currents and remain suspended in the air for minutes to hours. These small particle aerosols may be breathed in by another person.

Signs and symptoms of TB

Tuberculosis most commonly affects the lungs. In about 30% of cases the disease affects other parts of the body, such as lymph glands, bones or kidneys. Initial infection of the lung usually occurs during childhood and goes unnoticed. However, a few bacteria continue to survive at the site of infection. Later in life, the infection can reactivate and a serious lung infection occurs.

Symptoms may include:

  • tiredness
  • fever
  • night sweats
  • weight loss
  • cough
  • blood-stained sputum (phlegm)
  • chest pain
  • swollen lymph glands.

Diagnosis of TB

The diagnosis of tuberculosis is suspected on clinical presentation, chest x-ray and by skin testing.

The diagnosis is confirmed when Mycobacterium tuberculosis is grown from sputum or other specimens.

Incubation period

(time between becoming infected and developing symptoms)

Symptoms, if they occur, are present about 4 to 12 weeks after an initial lung infection. The risk of reactivation of the initial lung infection and the development of serious lung infection is greatest within the first year or two after initial infection but some risk persists for life.

Infectious period

(time during which an infected person can infect others)

Young children with an initial infection rarely spread the disease.

Adults with reactivation of infection are most infectious when they are coughing and have not yet received treatment or are in the first few weeks of treatment.

Treatment for TB

SA Tuberculosis Service is responsible for follow-up and treatment of all cases in South Australia. Clinicians should notify SA Tuberculosis of any person suspected of having tuberculosis.

People with tuberculosis should receive anti-tuberculosis drugs under the care of an infectious diseases or respiratory specialist and/or the Chest Clinic based at the Royal Adelaide Hospital. Completing a full course of therapy (of at least 6 months) is essential.

Prevention of TB

  • Exclude people with tuberculosis from childcare, preschool, school and work until treatment has been given and a medical certificate is received from SA Tuberculosis Service.
  • When a person is diagnosed with tuberculosis, the SA Tuberculosis Service will perform skin testing of family members and other close contacts and may request skin testing of fellow students or employees (to exclude significant exposure to and risk of developing tuberculosis). A contact is any person who has been close enough to an infected person to be at risk of having acquired the infection from that person.
  • Health care workers should have a pre-employment health screen, which may include a tuberculin skin test (Mantoux) to detect previous exposure to tuberculosis.
  • A Bacillus Calmette–Guérin (BCG) vaccine is available, but it is not part of the routine childhood immunisation program. The vaccine can protect against severe forms of tuberculosis when given to young children.
  • In Australia, the BCG vaccine is recommended for some people who are at a high risk of exposure to tuberculosis including:
    • Aboriginal and Torres Strait Islander neonates
    • infants born to parents who have migrated from countries with a high tuberculosis incidence
    • children born to parents with leprosy or a family history of leprosy
    • specific occupational groups including embalmers and some healthcare workers.

Useful links

1 – In South Australia the law requires doctors and laboratories to report some infections or diseases to SA Health. These infections or diseases are commonly referred to as 'notifiable conditions'.