Abstract

ABSTRACT:Tuberculin PPD-Battey skin were simulataneously applied to 3,882 emplouees of Charity Hospital and 408 medical students at Louisiana State University. The PPD was doubtful(5 to 9 mm induration) in 253 of the total 4,290 persons tested(5.9%). In 86 of these 253 persons, the reaction to PPD-Battey was greater than the reaction to PPD, presumably identifying a subpopulation with a falsely postive PPD and therefore at considerably lower risk of (19.6%) were classified by the skin tests as having atypical mucobacterial sensitization as compared to six (1.45%) who were classified positive or probably positive to Mycobacterium tuberculosis (p<.001).In the Southeastern United States, where the includence of atypical mycobacterial infection is relative high and occurs at a young age, dual skin testing may have its greatest applicability in identifying tuberculous infection when the PPD falls in the "doubtful" 5 to 9 mm range.