What is TB screening?

Tuberculosis or TB screening is a worldwide program promoted by health experts to reduce the spread of pulmonary tuberculosis. It is a health screening test that is often done to identify people with a TB infection and those with active pulmonary tuberculosis, and to give them appropriate treatment. The TB screening test also screens the close contacts of those who have tested positive for TB, including each member of their households. This is an important method of contracting TB infection and giving proper treatment to prevent the disease from becoming active and contagious.

Screening for TB often includes a skin test, called a Mantoux test, where a small amount of purified protein derivative (PPD) is injected just under the skin of the forearm. After 48 to 72 hours, the doctor checks for any reaction that might indicate TB infection. Other important TB screening tests include chest x-rays, blood tests, sputum smears, and sputum cultures.

Pulmonary tuberculosis is a lung infection caused by the bacteria Mycobacterium tuberculosis . Symptoms of active pulmonary tuberculosis include fever, unexplained weight loss, night sweats, fatigue, and persistent cough. Victims sometimes cough up blood, and chest pain may accompany breathing or each coughing episode.

When people with active TB cough, spit, talk, or even sing, they release TB bacteria into the air. Close contacts of TB patients can inhale these bacteria, which can enter one or both lungs, causing TB infection. When a person is healthy, their immune system can usually kill bacteria or block them in the lungs, preventing disease from becoming active. These bacteria in the lungs can remain dormant for many years, until the individual's immune system is weakened for any reason. Tuberculosis bacteria can multiply in the lungs, making the person infectious and often presenting with the signs and symptoms of active tuberculosis.

People showing signs and symptoms of active TB should immediately see a lung specialist or pulmonologist. If the specialist suspects tuberculosis, she will usually order a tuberculosis screening test. When the patient tests positive for TB, their family members and close contacts will also need to undergo a TB test to determine where the TB came from and to identify if any of them are also infected. One person with active TB can infect up to 10 to 15 people a year if left untreated.

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