回複：綠卡體檢時，做結核檢查，

A positvie test may mean you (1) once exposed to TB, (2) or had BCG vaccine before, (3) or have active disease of TB. There is a vaccine plan in China that children should be given shots of BCG (Ka3 Jia1 Miao4). I can't say for sure if this plan could cover those rurual people; but for urban residence, it does. So, for your case, probably because of your history of getting BCG if you don't have other symptoms of TB. Yet, health worker would ask you these info if you have a positive result, and ask you to have an X-ray so as to prove you are not an active TB patient. It is just a routine check-up. No worry about it, because my son encountered the same thing when he initially came to the states.