TB INH question

Hello! I am a current nursing student and have a two fold question regarding TB.I was wondering if you're PPD test is positive and you do the INH treatment, is it possible to get reinfected after treatment? Would you ever have to do the INH treatment twice?Secondly, I was wondering how many of you have had a positive PPD test? I guess I'm wondering what are the odds/chances of becoming ppd positive? Thanks in advance!
A positive TB screen (PPD) means you have been exposed and require a chest x-ray to see if you have active disease. If you do, you are infecting others. If your x-ray is negative you will need to have it repeated periodically to be sure you have not converted to active disease. The CDC website can give you more information about stats regarding after treatment expectations.