What Is Tuberculosis (TB)?
A serious bacterial infection primarily affecting the lungs, spread through airborne droplets, and one of the leading infectious disease killers globally.
Pathogen: Mycobacterium tuberculosis complex (acid-fast bacillus)
Type: Bacterium
Transmission
Airborne transmission via respiratory droplets produced when a person with active pulmonary TB coughs, sneezes, speaks, or sings. Prolonged close contact in enclosed spaces increases transmission risk. Not spread by surface contact, sharing food, or shaking hands.
Vector: No arthropod vector. Airborne person-to-person transmission.
Symptoms
Active pulmonary TB: persistent cough (>3 weeks), coughing up blood (haemoptysis), chest pain, weight loss, loss of appetite, night sweats, fever, and fatigue. Extrapulmonary TB can affect lymph nodes, bones, kidneys, brain, and other organs.
Incubation period: 14 – 730 days
Latent TB can persist for years or a lifetime without progressing to active disease. When active TB develops, it usually occurs within the first 2 years of infection. Approximately 5-10% of those infected will develop active TB at some point in their lives.
Timeline: Latent TB is asymptomatic. Active TB develops gradually over weeks to months with a progressively worsening cough, constitutional symptoms (weight loss, night sweats, fever), and increasing debility if untreated.
Case fatality rate: About 45% if untreated. With appropriate treatment, cure rates exceed 85%. Drug-resistant TB (MDR-TB, XDR-TB) has lower treatment success rates (50-70%).
Diagnosis & Treatment
Diagnosis: Chest X-ray (suggestive but not diagnostic). Sputum smear microscopy and culture (gold standard). GeneXpert MTB/RIF (rapid molecular test detecting TB and rifampicin resistance in 2 hours). Tuberculin skin test (Mantoux/TST) or interferon-gamma release assay (IGRA, e.g., QuantiFERON) for latent TB detection.
Treatment: Standard treatment: 6-month course of four antibiotics (isoniazid, rifampicin, pyrazinamide, ethambutol for 2 months, then isoniazid and rifampicin for 4 months). Drug-resistant TB requires longer courses (up to 18-20 months) with second-line drugs. Directly Observed Therapy (DOT) is recommended.
Prevention
- BCG vaccination (given in some countries but not routinely in Australia since 1985)
- Avoid prolonged close contact with known TB cases in enclosed spaces
- Ensure good ventilation in accommodation and transport
- Consider pre- and post-travel TB screening (IGRA or Mantoux) for prolonged stays in high-burden countries
- Wear a well-fitted N95/P2 mask if visiting healthcare facilities in high-burden settings
Post-Exposure
If you have had close contact with a person with active TB, or have spent extended time in high-burden countries (especially healthcare settings, prisons, or crowded living conditions), undergo TB screening (IGRA or Mantoux test) 8-12 weeks after return. If positive, chest X-ray and medical assessment are needed.
Long-Term Effects
Even after successful treatment, TB can cause permanent lung damage (fibrosis, bronchiectasis, cavitation). Extrapulmonary TB can cause permanent organ damage. Latent TB can reactivate years later, especially if the immune system is weakened.
📋 Tuberculosis is a nationally notifiable disease in Australia. Approximately 1,200-1,400 cases are notified annually, the majority in people born overseas or recent arrivals from high-burden countries.
Frequently Asked Questions
Do I need a TB vaccine for travel?
BCG vaccination is not routinely recommended for adult Australian travellers. It is most effective in young children and its protection in adults is variable (0-80%). It may be considered for children under 5 who will be living in high-burden countries for extended periods. For adult travellers, the focus is on pre-and post-travel screening rather than vaccination.
Should I get tested for TB after returning from overseas?
Post-travel TB screening is recommended if you spent 3 months or more in a high-burden country (India, Indonesia, Philippines, sub-Saharan Africa, etc.), had close contact with a known TB case, or worked in a healthcare setting. Screening involves an IGRA blood test (QuantiFERON) or Mantoux skin test, done 8-12 weeks after return. See your GP to discuss whether screening is appropriate.
Can you catch TB on a plane?
The risk of TB transmission during air travel is very low. Aircraft ventilation systems with HEPA filters reduce the risk. However, prolonged flights (>8 hours) seated near a person with active pulmonary TB can theoretically pose a risk. Airlines and public health authorities have notification protocols for exposed passengers. Routine use of masks is not necessary for standard travel.
What is the difference between latent and active TB?
Latent TB means the bacteria are in your body but your immune system is keeping them contained — you have no symptoms and cannot spread TB to others. Active TB means the bacteria are multiplying and causing disease — you have symptoms (cough, weight loss, night sweats) and can be infectious to others. About 5-10% of people with latent TB will develop active TB at some point, with the risk highest in the first 2 years.
Is TB still common?
Yes. TB is one of the leading infectious disease killers globally, with approximately 10 million new cases and 1.3 million deaths annually. India, Indonesia, China, the Philippines, and Bangladesh account for the largest share of cases. While Australia has low TB rates (about 5-6 per 100,000), travel to high-burden countries is the most common way Australians are exposed.
What is drug-resistant TB?
Drug-resistant TB occurs when the bacteria are resistant to standard antibiotics. Multidrug-resistant TB (MDR-TB) is resistant to at least isoniazid and rifampicin. Extensively drug-resistant TB (XDR-TB) is additionally resistant to fluoroquinolones and injectable agents. Treatment of drug-resistant TB is more complex, more toxic, and less effective than standard TB treatment. Drug-resistant TB is a growing concern globally.
Why doesn't Australia give the BCG vaccine anymore?
Australia stopped routine BCG vaccination in 1985 because TB rates were low enough that the risks of the vaccine (side effects, interference with TB skin testing) outweighed the benefits for the general population. BCG is still recommended for certain high-risk groups, including Aboriginal and Torres Strait Islander neonates in high-incidence areas and children who will live in high-burden countries.
Can TB be cured?
Yes. Standard drug-susceptible TB is curable with a 6-month course of antibiotics, with cure rates exceeding 85%. However, treatment must be completed in full — stopping early leads to relapse and the development of drug resistance. Drug-resistant TB is harder to treat but newer drugs (bedaquiline, pretomanid, linezolid) have improved outcomes.
Sources & References
Last updated: April 2026