Another aspect of the about-to-be-announced
CDC guidelines was this
IGRAs may be used in place of (and not in addition to) TST in all situations
The CDC are quite clearly against using an IGRA to confirm a TST. There could be any number of reasons for this but the one that I most like was
put forward by CDC Field Medical Officer Dr Christine Ho
Training, quality assurance and maintaining proficiency of laboratory personnel performing IGRAs are feasible, achievable and preferable over maintaining TST proficiency of thousands of clinic personnel.
It is illogical to run two systems side-by-side when IGRA alone would do a better job. If the CDC prefer that IGRA be used on BCG vaccinated and or those that find it difficult to return then it would be commonsense to just use the one system, the one that the CDC
prefer
