I was diagnose with latent TB: positive skin test and negative chest x-ray. I was a bit skeptical about my positive skin test because several reasons: I didn't get a bubble at the injection site right after the injection. Then I got a mild sloopy lump after JUST a few hours, not two days later. Also, I keep touching the site when it got a mild sloopy lump. I've read that the reading and interpretation of skin test is not easy. Many trained professionals read them differently. Anyways, my primary doctor and my pulmonary doctor both told me to be treated with INH for 6 or 9 months. After I did the research in the web, I noticed there is a blood test for TB. This blood test is fairly new and only two places have it where I lived, I had to drive 30+ miles to get the blood test at Long Beach Public Health. Of course, I had to pay for it, about $112. Really, I would pay anything to confirm my tb skin test because I really don't want to take a liver toxic medication for 6 or 9 months IF I really don't have TB bateria in my body. Sure enough, I took the blood test and it is "NEGATIVE". The nurse told me that means I DON'T have the bacteria in my body, no further testing is necessary. However, I know if the skin test is negative but blood test is positive, then they will recommend further testing. I am typing this to hope that people who got positive skin test should go to get a blood test done. You can search to see where http://www.quantiferon.com.