What is Tuberculosis (TB)?
Tuberculosis, also known as TB, is an airborne infection caused by bacteria called Mycobacterium tuberculosis. This infectious disease most commonly affects the lungs, but other parts of the body can become infected as well.
In most cases, people carrying tuberculosis bacteria do not have symptoms and are not contagious. When symptoms of tuberculosis become present, however, the infection is considered active and can be serious and even life-threatening.
When symptoms are present, tuberculosis is highly contagious. The bacteria is spread through the air in tiny droplets when an infected person coughs or sneezes. Just a few of these bacteria can result in the infection spreading to a person who inhales an airborne droplet.
Fortunately, while TB can be potentially serious, it is curable with the right diagnosis and treatment.
What are the Symptoms of TB?
An infection of tuberculosis may be latent or active. When TB is latent, Mycobacterium tuberculosis bacteria are present, but there are no symptoms and the infection is not contagious. However, latent TB can later become active. When TB is active, symptoms are present and the infection can be spread.
Signs and symptoms of active tuberculosis include:
- Coughing that lasts three weeks or more
- Coughing up blood
- Chest pain, or pain when breathing or coughing
- Unintentional weight loss
- Low-grade fever
- Night sweats
- Loss of appetite
If you exhibit these symptoms, visit your doctor or a Physician’s Immediate Care CLINIC NEAR YOU . Whether or not you have symptoms, if you are concerned about a possible tuberculosis exposure, Physicians Immediate Care offers three types of TB testing for patients over 24 months of age.
The first type of tuberculosis test offered at Physicians Immediate Care is known as the PPD test, or the Mantoux tuberculin skin test. The test requires two separate clinic visits: the first for the administration of the test, and the second for an examination and interpretation of the results. On the first visit, the test is administered by a small injection of tuberculin purified protein derivative (PPD) under the skin of the forearm.
To receive results, the patient must return for a second appointment after 48-72 hours. At the second appointment, our staff examines the forearm for signs of a reaction to the protein injected. Our staff, trained in reading the test, if need be, will also have our Provider consider the patient’s medical history, as well as the size of the swelling or of the raised, hard area that may appear.
The Mantoux tuberculin skin test detects the presence of, or exposure to, tuberculosis. A negative response to the test means the patient has not been exposed to Mycobacterium tuberculosis, while a positive response indicates that there is a possibility of exposure. The test result will also be positive if the patient has recently received the BCG vaccine against tuberculosis (this vaccine is not available in the US). Further testing, by blood test and X-ray, is necessary to confirm whether the patient has an active infection of tuberculosis.
What is a TB blood test?
A useful alternative to the Mantoux/PPD test is the QuantiFERON-TB Gold Test (QFT). This blood test requires only one clinic visit. It is a highly sensitive test that detects the presence of tuberculosis, and is not influenced by the BCG vaccine. When you or your child has the QuantiFERON-TB Gold Test for tuberculosis at a Physicians Immediate Care clinic, results are typically available in just a few days.
What is a two-step TB test?
Two-step tests for tuberculosis are available for adults who will be repeatedly tested in the future. This is usually the case for people working in certain professions, such as healthcare. The purpose of the two-step test is to provide an accurate baseline for future testing by observing the body’s natural immune response to subsequent tuberculin injections.
In a two-step test, the Mantoux tuberculin skin test is performed twice, each within three months of the other.