TB is an infection caused by a type of bacteria called Mycobacterium tuberculosis (M. tuberculosis).
About one-third of the world’s population is infected with this type of bacteria. However, only around 10–20 percent of people with this infection develop “active TB.”
A person who carries the bacteria but does not develop symptoms has “latent TB.” This is not contagious, but it can eventually develop into active TB, particularly if a person’s immune system becomes weakened from a condition such as HIV.
TB can become active when the immune system is unable to prevent the bacteria from multiplying. However, many people with latent TB never go on to develop active disease. A doctor can use a skin or blood test to check for the presence of M. tuberculosis.
People with active pulmonary TB exhale the bacteria in tiny water droplets when they cough, sneeze, or speak. These droplets travel through the air and a person can breathe them in.
However, an individual generally needs to be in prolonged close contact with someone who has active TB to contract the infection. A TB infection in a part of the body other than the lungs is not usually contagious.
A TB vaccine called bacillus Calmette-Guérin (BCG) is available, but it is not in wide use in the United States, where TB rates are low. However, doctors may recommend the vaccine for children or healthcare workers who have a high risk of TB exposure.
Content created and supplied by: LufunoSenyela (via Opera News )