帮忙看看学校发过来的免疫证明什么意思？

lois.ldwUID: 161923

Provide documentation of TB Screening (PPD Mantoux skin test read and documented in millimeters of induration) done in the US or Canada within the past 6 months. Chest X-rays will be required for anyone with a positive skin test. X-rays can e taken at the Health Center or you may bring chest X-rays films taken within the last 6 months. A negative chest X-rays is not a substitute for a skin test.
是不是说必须提供在美国或加拿大6个月内做的TB Screening才行，中国的不被承认？那这样我就不能在国内做了？
谢谢！

lois.ldwUID: 161923

帮忙看一看啊，我想确认一下我理解的对不对，是不是如果我在中国做TB Screening不被承认？