1.The incidence of skin sensitivity to histoplasmin among 712 working Liberian males was found to be 18.1 per cent and among 66 school children 3.0 per cent. Of the tested population 4.4 per cent showed positive reactions at only one of the two readings taken. Distribution of reactivity among 16 Liberian tribes is presented.
2.The incidence of positive tuberculin tests among 1,031 working Liberian males was 74.7 per cent, and among 248 school children 38.3 per cent. Of the total tested population 6.6 per cent reacted positively at only one reading. There was no significant cross reactivity between the histoplasmin and tuberculin agents used.
3.The incidence of positive skin tests to coccidioidin in 733 subjects was 1.2 per cent.