What is tuberculosis
What is tuberculosis?
Your healthy lungs
What happens if you get infected with M. tuberculosis?
- Latent tuberculosis - this means you are infected with tuberculosis bacteria, but you do not feel sick or have any signs or symptoms of tuberculosis disease. In this case, your immune system limits the infection by enclosing the tuberculosis bacteria within a tough calcified shell, known as a granuloma. The granulomas protect your lungs from any damage the bacteria might do. As long as the bacteria are contained, you will not have any symptoms, and are not contagious, which means you can’t infect anyone else. The presence of tuberculosis granulomas can be seen on a chest X-ray.
- Active tuberculosis - whether or not tuberculosis remains latent, or progresses to active tuberculosis depends on the health of your immune system. When you are healthy and everything is functioning properly, your body is able to keep the bacteria contained and under control. Sometimes, your immune system may become weaker and is no longer able to control the growth of the tuberculosis bacteria; for example, if you have a disease that attacks your immune system, like HIV/AIDS. When this happens, the calcified shell of the granuloma can deteriorate and your tuberculosis infection may transition from latent to active. This can occur anytime from weeks, to years after you were first infected. Once the tuberculosis granulomas open, the bacteria are able to emerge, inhabit your lungs, and damage the surrounding tissue. The damage causes the spongy, balloon-like tissue of the alveoli to harden and become fibrous, making them useless for gas exchange.
What puts you at risk of catching tuberculosis?
How likely are you to get tuberculosis?
How to avoid getting tuberculosis
How is tuberculosis diagnosed and treated?
Consider the following:
- Drug resistant tuberculosis is very widespread, and strains of tuberculosis that are resistant to a single anti-tuberculosis drug have been found in all countries surveyed worldwide.2 Unfortunately, multidrug resistant strains known as multidrug resistant tuberculosis (MDR-tuberculosis), that don’t respond to isoniazid and rifampin, the two most important 1st-line anti-tuberculosis drugs, have also appeared. MDR-tuberculosis is curable using combinations of other 2nd-line anti-tuberculosis drugs; although these are expensive and not always available, especially in countries with limited resources. More recently, even more extreme drug resistant strains have appeared, called extensively drug-resistant tuberculosis (XDR-tuberculosis). These strains can be treated with aggressive drug regimens, but many more people die of this form of tuberculosis than MDR-tuberculosis or drug-sensitive tuberculosis.
- It is very important for people with HIV infection to be tested for tuberculosis. Why do you think that might be? People with HIV and latent tuberculosis are at very high risk of progression to active tuberculosis because their immune system is already weakened by the HIV infection. Without treatment, active tuberculosis can quickly become a serious illness leading to death. If detected early, people with HIV/tuberculosis co-infection can start treatment for latent tuberculosis and prevent its progression to more serious disease.