Not all people with TB infection get active TB disease. Only when people infected with the TB bacteria start  showing signs and symptoms associated with TB are they considered to have active TB disease. Some people develop TB disease soon after becoming infected, before their immune system can fight back. Other people may get sick later, when their immune system becomes weak for some reason. People with weak immune systems are more vulnerable to TB. This includes babies and young children, people infected with HIV and those who have the following conditions:

  • diabetes mellitus
  • silicosis
  • cancer of the head or neck
  • leukaemia or Hodgkin’s disease
  • severe kidney disease
  • low body weight
  • certain medical treatments (such as corticosteroid treatment or organ transplants).


Frequently Asked Questions about Tuberculosis. (2013). [ebook] New Delhi-110002, India: Regional Office for South-East Asia, World Health Organization. Available at: en/index.html [Accessed 1 Jan. 2018].