[Comparative study of human cutaneous sensitivity to 2 and 5 international units of the PPD RT 23 tuberculin with Tween 80].

BACKGROUND

The aim of this study was to know whether the human reaction to the Mantoux test with 5 UT of PPD RT 23 is similar to that achieved with the same test but with 2 UT of the same substance.

METHODS

A simultaneous double Mantoux test was used at doses of 2 UT and another of 5 UT of the same trade mark of tuberculin PPD RT 23 with Tween 80 in 2,575 individuals. The subjects were distributed into two different groups of different ages, taking into consideration the possible presence of BCG vaccination.

RESULTS

The doses of 5 UT produced a greater number of tuberculin positive individuals and a greater diameter of induration of reaction than that of the doses of 2 UT in both groups and with significant statistical differences. One hundred ninety-six (7%) subjects were tuberculin positive with 5 UT and negative with 2 UT.

CONCLUSIONS

The reactions produced by the Mantoux test with 5 and 5 UT PPD RT were different since the two doses are not bioequivalent.