Tuberculin and lepromin reactions in Nigeria; an analysis of the data of Lowe and McNulty.

Eastern Nigeria presents today a situation of great interest as concerns the relationship of leprosy to tuberculosis. Leprosy is declining rapidly while tuberculosis is increasing, and if there is any truth in the hypothesis that the retreat of one disease is induced by the advance of the other, circumstances are now unfolding in which it should be possible to demonstrate the facts. Against this background the immunological studies of Lowe and McNulty (1, 2) are of particular interest and importance. Among 278 healthy adults there were found very high proportions of positive reactors to both the tuberculin and lepromin tests, and a very close degree of correspondence between the results of the two tests. Among 81 healthy children the tuberculin positivity rate was also relatively high, and although it was decidedly higher than the rate of positive lepromin reactions, a relationship between the results of the two tests was established. Tuberculin was used in two strengths in this work: (a) the von Pirquet test was made in all cases, the dose equivalent to approximately 10 TU, and (b) all negative reactors to this test then received a Mantoux test of a strength of 50 TU. The results of these two tests were combined in the published findings. At that time it was not known that nonspecific positive reactions to tuberculin are common in Nigeria. That type of reactivity is unlikely to have produced positive results with the von Pirquet test, but it is more than likely that such reactions were induced in some individuals by the 50 TU tuberculin dose. 2 R esults in healthy adults.-Combining the results of both tuberculin tests, it was found that of the 278 healthy adults, 223 gave positive reac-