What is the criteria for po..

you get a large bump on the skin at the site of injection. it should be checked by a doctor or nurse in 2-3 days. sometimes people get false positives if they ever had a vaccine for it, especially in othr countries

Specifically, in otherwise healthy people with no known TB contacts, a diameter of 15mm or more of SWELLING (not just redness) is considered a positive PPD/Mantoux skin test. Report It

They take blood from you inject u with something if a blotchy mark comes up you are a posistive carrier

I had TB before. If the injection site is red swollen and warm after a day or two then it is a positive test. It doesn't mean that you have it you may have just been exposed to it. If your test looks positive have the doc do a chest x-ray and that will tell him if you have it or not. If you do have it, it's not necessarily active. Mine wasn't. you'll just take 6 months of meds to clear it up.

It means you don't need the inoculation.

The skin surrounding the injectino site will be red, warm, and possible raised. The reaction can vary from mild to severe. A positive skin test only means that you have been exposed at some point (that doesn't mean that you have an active case of TB). Once you have a positive skin test, it will continue to be positive with all future test. If your test is positive they will follow up with a chest xray to see if it is an active TB.