Hence, in Saint Laurent du Maroni, one of the three biggest cities of French Guiana, and located on the Maroni river bordering Suriname, 42% of HIV patients with less than 200 CD4 per mm3 were hospitalized with fever, 85% of those with less than 50 CD4 per mm3 and had disseminated histoplasmosis: “First think histoplasmosis!” [46]. This evidence concerns the gene CD4 and histoplasmosis.