The incidence of skin sensitivity to histoplasmin, tuberculin, and blastomycin in a population of 447 Liberians, predominately working males, was found to be 15.4%, 80.8% and 1.6% respectively.
There was no evidence for cross reaction between any of the antigens used.
Of the histoplasmin reactors 70% were followed by chest x-rays. Of 48 chest films examined only 11 showed pulmonary lesions, and only 9 (18.8%) of these consisted of calcifications. All but one of the positive x-rays were of subjects who were also tuberculin positive, and none of the lesions seen was absolutely typical of histoplasmosis.
College of Physicians and Surgeons, Columbia University, New York City.
Firestone Health Services, Harbel, Liberia.
Supported in part by Grant 2E-55 from National Institutes of Health, Public Health Service.