Growler,
A bit of info on BCG & prior TB exposure. ALWAYS consult with your care team about anything from the net.
Page 11 and 12 of the following document briefly addressed the positive PPD patient issue in 2015. The section WITH FOOTNOTE REFFERENCES is about 11 pages into the document, in a section selectable from the sidebar and titled,
Practical issues of BCG administration
www.nature.com/nrurol/journal/v12/n4/full/nrurol.2015.58.html
Among the authors of the article are Donald Lamm and Michael O'Donnell, both of whom are highly trusted researchers and treaters.
Follow the footnotes,
Best
Jack