Tuberculosis lung disease, also referred to as TB, is a bacterial infection caused by the bacterium Mycobacterium tuberculosis. Tuberculosis most commonly attacks the lungs, but can also affect the kidney, spine and brain. According to Medline Plus, there are approximately 10 cases of tuberculosis per 100,000 people per year.
Causes
Tuberculosis is spread through airborne droplets that are released when an infected person coughs, sneezes or talks. Uninfected people within close proximity can breathe in these airborne droplets and become infected. The Centers for Disease Control and Prevention note that tuberculosis lung disease cannot be spread by sharing food or drink with an infected person, touching bed linens, toilet seats, skin contact or kissing.
Categories
There are two categories of a tuberculosis lung infection: latent TB infection and active TB disease. A latent TB infection occurs when a person becomes infected with the bacteria but does not develop any active symptoms. The bacteria enter the body, but the immune system is able to stop them from multiplying and causing harm. Those with latent TB infection cannot spread the disease to others.
Active TB disease occurs when the bacteria enter the body and are able to multiply and infect the cells. This causes an active infection that is characterized by chronic cough, chest pain, coughing up blood, weakness, fatigue, weight loss, loss of appetite, chills, fever and night sweats. A person with active TB disease can spread the infection to others easily.
It is important to note that it is possible for those with latent TB infection to develop active TB infection, but not everyone will develop the active form of the disease.
Tests
Testing for tuberculosis lung disease is done with a TB skin test. During the TB skin test, a substance called tuberculin is injected under the skin on the inside of the forearm. After two to three days, someone with tuberculosis lung disease will have developed a positive reaction. A positive reaction is defined as an area of firm swelling at the injection site that is at least 15 mm in diameter, according to Medline Plus. Tuberculosis blood tests may also be used to detect the presence of the bacterium in the blood.
Treatment
According to MayoClinic.com, treatment for tuberculosis lung disease takes longer than treatment for other bacterial infections. A latent TB infection will be treated with a daily or twice-per-week dose of an antibacterial medication that must be continued for nine months. Active TB disease usually requires a combination of four medications that must be taken until lab tests have determined that the infection has gone away.
Complications
If left untreated, tuberculosis lung disease may be fatal. Other possible complications include permanent lung damage, abscesses and destruction of joints, meningitis and military TB, which is a widespread tuberculosis infection.
