harka

The fact that you reacted does NOT mean you were exposed to TB. That is the whole point of doing the test. For a person with no risk factors and is not a health care worker, a 15 (fifteen) mm test is positive. Additionally, it's not redness that's positive, it's induration or hardness (which needs to be measured by feel NOT sight).

I'm very surprised your doctor would tell you that.

Now to answer your other question, even if you WERE skin test positive (which you are not) it doesn't mean you have ACTIVE tuberculosis. TB is a bug that 1/3 of the world's population has been exposed to, but <5% of these people actually get active disease. So when you have a positive skin test and have no symptoms of TB you are said to have latent TB and are NOT contagious and therefore pose no risk to your father with COPD.