Re: tb test question
Your employer will have to follow the state/national laws regarding how recent the test must be. The reason that it might have to be repeated if it's been several years is because it's possible that you could have been exposed to the bacteria between the negative test and now.
The test uses a very small needle that goes just under the skin. They inject a small amount of fluid and take out the needle. It might cause a little blister-like bubble, but that will go away within 15-30 minutes after administration of the test. The needle stick doesn't really hurt much, since it's a very small needle (smaller than they usually use to draw blood). It may sting a little bit when they inject the fluid. But really, the pain is over in 10 seconds. It is still done on the inside of the forearm. You then have to return a few days later (they will tell you when) to get the test read, where they just look at and maybe run their hand over your arm where they gave the test.
So yeah, it is a needle. But it's a very small one. And it's fast. It really doesn't hurt for more than 10-15 seconds. Just take a few deep breaths and it will all be over with.