dose the bcg test for tb last forever?

Question

i just had a skin tb test and it came up postive but i have had the vaccine for tb in the past and im really freaked out about it my work is going to do a chest x ray do i need to be worried

aslo it kinda looks like a hive is that possible

Answer 1

No, BCG test does not last forever.

The positive effect of BCG in protecting infants and young children from endemic areas from the lethal forms of TB does not extend to the adult years. Thus, many people develop active tuberculosis even though they received BCG, even in multiple doses, in earlier years.

BCG can cause a positive skin test, especially if the vaccine was given after early infancy, if it was given several times, and if it was given within the last five to ten years. Nevertheless, since many persons who have immigrated to the U.S. are at risk of TB even though they received BCG, the recommendation in the United States is to interpret skin tests and recommend treatment regardless of whether you have had BCG. In other words, if you have a positive skin test and are from a part of the world where TB is common, you should assume that it is due to TB exposure and implies a risk of future disease and not that it's positive because of the BCG. Nevertheless, you should let your doctor know if you had a BCG, when and if you had it more than once.

Answer 2

If your in the USA you are not looking for a BCG vaccine. Now when you external the USA BCG is a comon vaccine given to youngsters. The BCG vaccine dosn't constantly (ninety five%) elicit an immune responce. The tb experiment is designed to "react" with antibodies to tb. So if you don't have any response and are living in a nation wherein BCG vaccination is needed or endorsed then you wish to have a BCG booster. This signifies that the non reactant has certainly not visible tb and did not reply to BCG vaccine

Answer 3

It's probably due to the vaccination. The vaccination will make you have antibodies and that is what the tb skin tests is looking for. Many people have false positive TB skin tests and get x-rays. Some take antibiotics just precautionary. I wouldn't worry.

Answer 4

I dont think you should worry.If you had the vaccination before,a false positive result due to the vaccination itself may occur.A chest X-ray is then done to confirm whether the result is true or false.
Positive results may be due to a latent or active TB infection or occasionally due to a false positive. Positive results may also be seen in those who have received a BCG (bacillus Calmette-Guerin) vaccination. [This is a vaccine that is not used in the United States but is often routinely administered in other countries that have a higher incidence of TB.]
Positive results must be followed up by other tests such as chest X-rays to look for signs of active TB disease. If active TB disease is suspected, AFB cultures may be used to confirm the diagnosis.
To ease your mind,read the article here-
http://www.labtestsonline.org/understanding/analytes/tb_skin/test.html

Answer 5

Don't worry for now, there are many things which can cause a false positive for TB. The skin test is just a preliminary screening. Unless you've had other symptoms I wouldn't be too concerned.