Tuberculosis (TB) is caused by the bacterium Mycobacterium tuberculosis. It takes around 1-6 months after infection to develop the disease. Symptoms include fever, night sweats, chills, and cough. TB can lead to pneumonia, lung collapse, and enlarged lymph nodes. Two types of TB that pose threat to life are:
- Miliary TB, which occurs when the bacteria spread throughout the lungs and into the bloodstream
- TB Meningitis, which occurs when the infection spread to the coverings of the spinal cord and/or brain.
Latent TB infection and disease:
Mycobacterium tuberculosis bacteria can stay silent in our body without making us sick and this stage is called latent TB infection. People with strong, active immune response or with vaccine generated immunity, when comes in contact with bacteria become infected but are able to fight the infection. They do not feel sick or do not show symptoms and also, are not contagious. Later, if TB bacteria become active and multiply, the person can become sick with TB disease.
People at high risk of getting TB disease:
Patients who are immunocompromised (have weakened immunity), especially those who are HIV-positive fall prey to the TB pathogen if exposed. They cannot be given vaccine after the disease becomes symptomatic. So, it is wise to give the vaccine at birth, even to babies born to HIV+ve parents. Malnourished people and ones with diabetes and kidney ailments are more prone to the disease if exposed.
How is TB contagious?
It is generally spread by coughing or sneezing of mucus droplets from TB infected people.