From this model, a score may be obtained, where the natural logarithm of the probability of histoplasmosis compared to tuberculosis = +3.917962 × WHO performance score (1 if >2, 0 if ≤2) −1.624642 × pulmonary presentation (1 yes, 0 no) +2.245819 × adenopathies > 2 cm (1 yes, 0 no) −0.015898 × CD4 count − 0.001851*ASAT − 0.000871 × neutrophil count − 0.000018 × platelet count + 6.053793. This evidence concerns the gene CD4 and histoplasmosis.