Updated 14 March 2016

Risk factors for developing tuberculosis (TB)

Examples of factors that increase people's risk for developing TB are HIV infection, intravenous drug users and babies and young children.

Those at high risk for developing active TB include:

  • People with HIV infection. Because HIV weakens the immune system, people with both TB and HIV infection are at high risk of developing TB disease. If you are HIV-positive, you are 30 times more likely to get active TB once infected than someone infected with TB who is HIV-negative. People with HIV should be TB tested and those with a positive skin test should get HIV tested. This way, someone with both infections can take medicine to reduce the chance of developing TB disease. Treatment is more difficult as the infecting bacteria are often resistant to therapy. However, among HIV-related diseases, TB is relatively preventable and curable.
  • Patients receiving certain medical treatments (e.g. corticosteroid treatment, anti-cancer chemotherapy or transplant anti-rejection medication).
  • People who have been in close contact with someone who has infectious TB.
  • People who became infected with TB in the last two years.
  • Babies and young children.
  • People who inject drugs.

People with other conditions that weaken the immune system, especially

  • Diabetes mellitus
  • Silicosis
  • Cancer of the head or neck
  • Leukaemia or Hodgkin's disease
  • Severe kidney disease
  • Low body weight
  • Substance abuse
  • Elderly people
  • People born where TB is common, such as Africa, Asia or Latin America.
  • Low-income groups with poor health care access.
  • People in residential facilities such as nursing homes and correctional facilities.
  • People such as health care workers who are exposed to TB through their work. 


Diagnosing tuberculosis 

What causes tuberculosis?

How tuberculosis (TB) progresses

Reviewed by Dr AW Dreyer, Pathologist and Clinical Microbiologist, Centre for Tuberculosis, National Institute for Communicable Diseases February 2015.

Previously reviewed by Joanna Evans, PhD, Molecular Mycobacteriology Research Unit, Division of Medical Microbiology Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, February 2011.