Tuberculosis (TB) is a contagious infection that usually attacks the lungs. It can also spread to other parts of your body, like your brain and spine. It is caused by a type of bacteria called Mycobacterium tuberculosis.
The body’s immune system, however, can stop the bacteria from continuing to reproduce. Thus, the immune system can make the lung infection inactive (dormant). On the other hand, if the body’s immune system cannot contain the TB bacteria, the bacteria will reproduce (become active or reactivate) in the lungs and spread elsewhere in the body.
It may take many months from the time the infection initially gets into the lungs until symptoms develop.
World Tuberculosis Day is celebrated on March 24th to raise public awareness about the devastating health, social and economic consequences of TB, and to step up efforts to end the global TB epidemic.
The theme of World TB Day 2021 – ‘The Clock is Ticking’ –conveys the sense that the world is running out of time to act on the commitments to end TB made by global leaders.
TB infection (latent TB)
A person can have TB bacteria in their body and never develop symptoms. In most people, the immune system can contain bacteria so that they do not replicate and cause disease. In this case, a person will have a TB infection but not active disease.
Doctors refer to this as latent TB. A person may never experience symptoms and be unaware that they have the infection. There is also no risk of passing on a latent infection to another person. However, a person with latent TB still requires treatment.
TB disease (active TB)
The body may be unable to contain TB bacteria. This is more common when the immune system is weakened due to illness or the use of certain medications.
When this happens, the bacteria can replicate and cause symptoms, resulting in active TB. People with active TB can spread the infection.
- A cough that lasts more than 3 weeks
- Chest pain
- Coughing up blood
- Feeling tired all the time
- Night sweats
- Loss of appetite
- Weight loss
M. tuberculosis bacteria causes TB which can spread through the air in droplets when a person with pulmonary TB coughs, sneezes, spits, laughs, or talks.
Only people with active TB can transmit the infection. However, most people with the disease can no longer transmit the bacteria after they have received appropriate treatment for at least 2 weeks.
A person with latent TB will have no symptoms, but the infection can show up on tests.
A doctor will ask about any symptoms and the person’s medical history. They will also perform a physical examination, which involves listening to the lungs and checking for swelling in the lymph nodes.
Two tests can show whether TB bacteria are present:
- the TB skin test
- the TB blood test
However, these two cannot indicate whether TB is active or latent. To test for active TB disease, the doctor may recommend a sputum test and a chest Xray.
Everyone with TB needs treatment, regardless of whether the infection is active or latent.
With early detection and appropriate antibiotics, TB is treatable.
The right type of antibiotic and length of treatment will depend on:
- the person’s age and overall health
- whether they have latent or active TB
- the location of the infection
- whether the strain of TB is drug resistant
Treatment for latent TB can vary. It may involve taking an antibiotic once a week for 12 weeks or every day for 9 months.
Treatment for active TB may involve taking several drugs for 6–9 months. When a person has a drug resistant strain of TB, the treatment will be more complex.