Skin sensitivity to capsulatum and duboisii histoplasmins in Nigeria.

A total of 1313 persons comprising 1087 healthy subjects and 226 hospital patients with bronchopulmonary disorders were tested for reactivity to histoplasmins prepared from Histoplasma capsulatum and H. capsulatum var. duboisii. The overall sensitivity rates to the two antigens were 3.5 and 3.0% respectively. The incidence of sensitivity in the hospital patients was significantly higher (8.85% for 'capsulatum' antigen and 6.64% for 'duboisii' antigen) than that in different categories of the healthy population (1.66-5.03% and 0.5-4.47%, respectively). The majority of persons who had a positive reaction to duboisii antigen also reacted positively to capsulatum antigen and vice versa.