Histoplasmin Sensitivity Investigation in Japan (Nagoya District)

¹ First Department of Internal Medicine, Nagoya University School of Medicine

(1) The investigation of histoplasmin sensitivity in the central parts of Japan, i.e., Nagoya district, in 1958 revealed that 37 persons (1.02 per cent) in 3,614 persons tested gave positive reaction to histoplasmin. With the individuals whose work is closely related to sands and soils, a positivity of 1.4 per cent was obtained, whereas those who are not engaged in such work gave only 0.4 per cent positive reaction.

(2) In order to determine whether or not the positivity of the histoplasmin reaction was caused by Histoplasma capsulatum infection, all 37 positive reactors were examined by various methods. Negative results were obtained.

(3) The results of some examinations, including chest roentgenogram in all the 48 persons who gave positive reaction to histoplasmin in the first survey (1952-53), showed no evidence that chenges were caused by Histoplasmin capsulatum infection. The results of this investigation may suggest, as far a the central parts of occurrence of some other fungus in sands and soils which cause a positive reaction to histoplasmin by cross reaction.