Mariah has a BCG scar. This means she was vaccinated against TB. This doesn't mean she can't get TB, it means she can't get severe TB.
The BCG vaccine can also cause a positive TB test. However, Mariah's TB test was a 14mm reaction which is rather large, and meant that her Dr. thinks she COULD have been exposed to TB in the orphanage and have latent TB. Latent TB is not infectious. Its like having Chicken Pox and then being at risk later in life to develop Shingles. You cannot give someone Chicken Pox or Shingles just because you had it as a child, but you are always at risk for developing Shingles at some point in your life because you had Chicken Pox. The virus remains dormant until you become very stressed, old, sick, etc.
I've had 2 differing opinions on this so I figured I'd share what I have learned. According to our International Adoption Dr. the BCG vaccine does NOT cause a false positive on the TB test.
According to our pediatrician, it can.
Because of her positive test, the IA doc wanted her to take the 9 months of TB meds just to make sure she would not later in life ever develop TB.
Her pediatrician didn't even think the TB test was necessary, so I had to have it done at the Health Dept. (I felt it was necessary) and then even with a positive result, didn't think the meds were necessary.
I took Mariah to have a chest x-ray just to make sure all was well with her lungs, and it came back clean. She is currently healthy. No active TB.
After a lot of research, talking to different Drs., and other adoptive parents, we decided to go ahead and do the 9 months round of TB meds just to elimiate the risk for her ever developing TB. The IA doc said it is a pretty small risk that she'll ever develop it IF she was exposed but that she most likely does have latent TB so why take the risk?
9 months from now will be December 16th. 270 days to go.... I hope its yummy medicine!