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Diseases / Tuberculosis (TB)

Tuberculosis (TB)

What is it?: 

The causative agent of human tuberculosis (TB) is the bacterium Mycobacterium tuberculosis.1

TB is preventable and curable but the majority of cases are not diagnosed. In children TB occurs most commonly in those aged <5 years. While pulmonary TB (PTB) is the predominant form of TB in children in most populations, extrapulmonary TB is also common (around 30–40% of cases). Globally, 1.7 billion people are estimated to be infected with M. tuberculosis and 5–15% of these individuals will develop active TB during their lifetime. 1

BCG is currently the only available TB vaccine. While BCG has demonstrated significant effectiveness in several populations, protection has not been consistent against all forms of TB and in all age groups. 1

Clinical features: 

The symptoms of pulmonary TB include low-grade fever, night sweats, fatigue, weight loss, a persistent cough and blood in sputum. Some people may not have obvious symptoms.2

Mode of transmission: 

Tuberculosis is spread through the air. When a person with infective pulmonary tuberculosis coughs or sneezes, the bacteria gets into the air and causes disease if a susceptible person inhales it. Effective antibiotic treatment usually shortens the infectious period to within a few weeks.2

Incubation period: 

Symptoms may occur as early as several weeks after infection, or it may occur after many years. An infected person has the greatest risk of developing TB within the first two years after infection.2

  1. Maintain good personal and environmental hygiene.2
  2. Adopt a healthy lifestyle, i.e., have balanced diet, adequate exercise and rest.2
  3. Keep hands clean and wash hands properly.2
  4. Wash hands when they are dirtied by respiratory secretions e.g. after sneezing.2
  5. Cover nose and mouth while sneezing or coughing and dispose of nasal and mouth discharge properly.2
  6. Seek treatment promptly if symptoms similar to tuberculosis appear, particularly persistently cough for more than one month.2
  7. Receive BCG immunization according to immunization schedule. (Please refer to programme of immunization)2

People with tuberculosis should seek medical treatment as soon as possible. They are prescribed multiple drug therapy for at least six months. In order to eradicate the bacteria, patients should follow their doctors' instruction and complete the course of treatment.2


  1. World Health Organization. Weekly epidemiological record. BCG vaccines: WHO position paper - February 2018. 2018;8(93):73-96.
  2. Centre for Health Protection. Communicable diseases – Tuberculosis. 10 April 2019. [ONLINE] Accessed 16 Mar 2021.