What Causes Tuberculosis?
October 19, 2013
What causes tuberculosis – Only people with active TB infection can transmit the bacteria. Coughing, sneezing and even speaking can release bacteria into the air, and people breathing this air can become infected. Infection is more likely to occur in people who live with an infected person, or if a room is poorly ventilated.
After infection, the bacteria settled in the alveoli and the passages of the lungs and, in most cases, is countered by the immune system.
The risk of infection is higher for people who come from certain countries where TB is common, or traveling in those countries. Individuals exposed to greater risks of TB infection include the elderly, homeless, drug users, people who have spent time in a correctional institution in which people with HIV or AIDS (acquired immunodeficiency syndrome) has weakened the immune system. Naturally, the risks increase when close or frequent contact with a person with active symptoms, especially in the case of workers in the health system that can be exposed to patients with active tuberculosis.
The following factors may play a role in the promotion of active disease in people who have an inactive infection:
cancer of the head or neck;
a disease that compromises the immune system (eg, HIV or AIDS);
the use of drugs that suppress the immune system such as certain drugs against cancer (eg, cyclosporine, tacrolimus). *;
prolonged use of steroids.
TB can be caused by different germs
Mycobacterium tuberculosis ( Mycobacterium tuberculosis , the most common);
Mycobacterium bovis ;
Mycobacterium africanum ;
Mycobacterium canetti (is essentially Djibouti ).
Mycobacterium microti (supposedly rare infections) 6 , 7