What are TB Skin Test Results?
TB skin test results can help healthcare providers understand if you have been exposed to tuberculosis (TB) bacteria. TB is a contagious bacterial infection that usually affects the lungs, but can affect other parts of the body. TB can be spread from person to person through the air when an infected person coughs, sneezes, talks, or spits. TB skin tests are used to determine if a person has been infected with TB bacteria.
What Does a TB Skin Test Involve?
A TB skin test involves injecting a small amount of fluid called tuberculin, which contains proteins from the TB bacteria, just under the skin on the inner surface of the forearm. The injection site will be examined after 48 to 72 hours for signs of a reaction to the tuberculin. If a reaction to the tuberculin occurs, it usually appears as a raised, red area on the skin.
What Do Positive TB Skin Test Results Mean?
A positive TB skin test result means that the person has been infected with the TB bacteria. This does not necessarily mean that the person has active TB disease. In many cases, the person’s immune system is able to fight off the bacteria and prevent them from causing disease. This is known as latent TB infection. People with latent TB infection do not feel sick and cannot spread the bacteria to others, but they can develop active TB disease if their immune system gets weak.
What Do Negative TB Skin Test Results Mean?
A negative TB skin test result means that the person has not been infected with the TB bacteria. This does not necessarily mean that the person will never get TB. People can still become infected with the TB bacteria at any time, so it is important to take steps to protect yourself from exposure to TB bacteria.
What Other Tests Are Used to Diagnose TB?
If a person has a positive TB skin test result, other tests such as chest X-rays, sputum tests, and tissue samples may be done to diagnose active TB disease. In some cases, a course of antibiotics may be prescribed to treat the infection. In other cases, the healthcare provider may recommend that the person take a course of preventive antibiotics to prevent the infection from becoming active.
What Steps Can You Take to Reduce Your Risk of TB?
The best way to reduce your risk of TB is to avoid activities or places where you might be exposed to TB bacteria. This includes avoiding close contact with people who have active TB disease, not sharing eating utensils, towels, or other items with people who have active TB, and not living or working in overcrowded conditions.
When Should You Get Tested?
It is recommended that people who are at high risk for TB get tested for TB, including those who live or work in places with a high prevalence of TB, people who travel to countries with high rates of TB, and people with certain medical conditions such as HIV infection, diabetes, or cancer. It is also important to get tested if you have been in contact with someone who has active TB disease.
Conclusion
TB skin test results can help healthcare providers determine if a person has been exposed to the TB bacteria. A positive result means that the person has been infected with the TB bacteria, but it does not necessarily mean that the person has active TB disease. If a person has a positive TB skin test result, other tests may be done to diagnose active TB disease. It is important to take steps to reduce your risk of TB, and to get tested if you are at high risk for TB.