Tuberculosis and Chest Service Department of Health - What happens after infection with the tubercle bacilli?
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What happens after infection with the tubercle bacilli?

After infection with the tubercle bacilli, the great majority of persons will not develop disease because of good personal immunity. The infection just remains quiescent and they have no symptoms and they do not suffer any illness. Nor will they transmit the infection to other people. The only thing that can be detected is the conversion of the tuberculin skin test from negative to positive.

About 1 in 10 of the infected persons will develop the disease tuberculosis, which can occur weeks, months, years, or even decades later. Persons whose body defence is not that good will have a higher chance of developing the disease, e.g.:

  • - newborn babies
  • - elderly
  • - diabetes mellitus
  • - malnutrition
  • - malignant disease
  • - chronic kidney disease
  • - alcoholism
  • - silicosis
  • - HIV infected
  • - impaired immunity due to certain drugs (e.g., steroids, anti-cancer drugs)
After infected by tubercle bacilli: Tuberculosis infection is caused by exposure to airborne droplets containing the TB bacillus. Person infected through the lung. Bacilli passing from the lung to hilar lymph node and then spread to other parts of the body. A small proportion will progress to diesease due to unsatisfactory body immunity. Example: newborn babies, immunity defect, HIV infection, malignancy, diabetes mellitus, silicosis, malnutrition, elderly, alcoholic. Most of the infected persons will have the lesions healed by itself due to body. Early appropritate treatment will lead to recovery.