TB Testing

TB test

Evidence of TB bacteria

The development of TB disease is a two stage process. In the first stage, known as latent TB, a person is infected with TB bacteria. In the second stage, known as active TB or TB disease, the bacteria have reproduced sufficiently to usually cause the person to have become sick.

A diagnosis of active TB can only be confirmed when there is definite evidence of TB bacteria in the person’s body. Some of the diagnostic TB tests look directly for TB bacteria. Others such as the chest X-ray look for the effect of the bacteria on the person suspected of having TB.

Chest X-ray as a TB test

If a person has had TB bacteria which have caused inflammation in the lungs, an abnormal shadow may be visible on a chest x-ray.1 Also, acute pulmonary TB can be easily seen on an X-ray. However, what it shows is not specific. A normal chest X-ray cannot exclude extra pulmonary TB.

Also, in countries where resources are more limited, there is often a lack of X-ray facilities.

The TB skin test

The TB skin test is a widely used test for diagnosing TB. In countries with low rates of TB it is often used to test for latent TB infection. The problem with using it in countries with high rates of TB infection is that the majority of people may have latent TB.

The TB skin test involves injecting a small amount of fluid into the skin in the lower part of the arm. Then the person must return after 48 to 72 hours to have a trained health care worker look at their arm. The health care worker will look for a raised hard area or swelling, and if there is one then they will measure its size. They will not include any general area of redness.

TB drug susceptibility tests

Drug susceptibility testing means testing to find out which drugs the TB bacteria in a patient are susceptible to, and can therefore determine whether the person has got drug resistant TB. Some drug susceptibility tests, such as the Genexpert TB test can be used to diagnose TB, as well as testing for some types of TB drug resistance.


At Summit Urgent Care we offer TB testing for our patients. If you are in need of a test, just walk in to one of our clinics.

When you need to see a doctor NOW for injury or illness, Summit Urgent Care is convenient and available without an appointment, 7 days a week365 Days a Year! We have locations in East Point, Newnan, and Fayetteville, GA. Servicing the nearby cities of Sharpsburg, Peachtree City and College Park. Every member of our team has the same patient focus and is dedicated to delivering the best possible care.

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