Yawanna, just to be certain, I just went back and looked it up to be certain. I suspect you are talking about the "conversion," frequently seen in those vaccinated, especially those vaccinated frequently. When that occurs, chest x-rays are obtained to definitively rule out the presence of actual disease vs. the conversion factor.
That being said, TB is again becoming a serious threat in our society, in part because it did disappear for a period of time and people quit obtaining vaccinations to prevent the spread. Certain groups of people continue to be vaccinated. - EBF
FYI from the John Hopkins Center for TB Research:
* Tuberculin Skin Test Conversion. For persons with negative tuberculin skin-test reactions who undergo repeat skin testing, e.g., health care workers, an increase in reaction size of ¡Ý 10 mm within a two-year period is considered a skin test conversion which is indicative of recent TB infection. TST convertors are high priority candidates for treatment of latent TB infection regardless of their age.
* Reactors vs. Convertors. A ¡°reactor¡± is anyone who has a positive tuberculin skin test. A reactor is a high priority for treatment of latent TB infection only if they have TB risk factors. A ¡°convertor¡± has documented evidence of a TST converting from negative to positive within a 2 ¨Cyear period and is a high priority for treatment because of the risk associated with recent TB infection.
|