[Mendel-Mantoux tuberculin test with GT 1 in the public health office]

Within the German Public Health Service, the recommendation of the German Central Committee für Combatting Tuberculosis to use the intracutaneous tuberculin test according to Mendel-Mantoux as a standard test has led to demands for additional investigations on sensitivity and specificity of different tuberculin doses. In routine everyday work of the Public Health Office of the German provincial capital Stuttgart the Mendel-mantoux tuberculin test with tuberculin GT 1 Behring was examined in respect of sensitivity and incidence of excessive reactions and compared to a former study with GT 5. 2,592 persons for whom the tuberculin test was prescribed according to the German infectious diseases law were tested for tuberculosis by the Stuttgart Public Health Office between May and October 1998, using the Mendel-Mantoux test with GT 1 Behring. Of these, 202 persons did not return for checking the result. The 2390 checked persons were 28.4 years old on the average, the majority being female (59.0% against 41.0% males) and of German nationality (59.6% against 40.1% other nationals). A positive reaction was seen in 16.2% (induration > or = 6 mm), in 7.2% Germans against 29.6% other nationals. In 51% of the positive results the indurations had a diameter of more than 10 mm, in 12.6% more than 15 mm, 9 probands, i.e. 0.4% of all tested persons, had an excessive reaction (formation of blisters with local necrosis). Especially among the other nationals, the share of strongly positive results (> 15 mm) did not decrease to the same extent as did the share of positive results as a whole. 94 persons belonging to the surrounding of a bacillary index case got a second test with GT 10. Of these, 30 (31.9%) had a positive reaction. The use of a low tuberculin concentration (GT 1) for the intracutaneous test according to Mendel-Mantoux cannot be recommended. The sensitivity is significantly lower than with GT 5 which leads to seeming tuberculin conversions (because of the low sensitivity of GT 1) without avoiding excessive reactions. For tuberculin surveys in areas adjacent to bacillary index cases, the intracutaneous test according to Mendel-Mantoux should be performed with the usual dose (GT 10) as a standard test. For other purposes, the multipuncture-stamp test may be sufficient.