就得CDC的指引是有记录5mm以上的就不用再做了，直接x-ray，但是貌似需要civil
surgeon注明。
Q. Are there any exceptions to the initial TB testing requirement?
A. Yes. Under the May 2008 TB Component of the Technical Instructions for
the Medical Examination of Aliens in the United States, and its update, an
applicant may not be required to undergo the initial TB screening testing
with a TST or IGRA under the following circumstances:
Applicants providing written documentation (with a health care provider'
s signature) of a TST reaction of 5 mm or greater of induration. A verbal
history from an applicant of a positive TST reaction is not acceptable.
Applicants who have a history of a severe reaction with blistering to a
prior TST
Applicants providing written documentation (with a health care provider
’s signature) of a prior positive IGRA. If more than one IGRA has
previously been performed, the most recent result should be used by the
civil surgeon. A verbal history from the applicant of a positive IGRA result
is not acceptable.
If one of these exceptions applies, the civil surgeon is directed to
annotate the Form I-693 accordingly and to have the applicant undergo a
chest x-ray.
