Evaluating HIV-infected persons is complicated by the lack of sensitivity of stool testing in schistosomiasis and the many etiologies for eosinophilia in HIV-infected persons (including dermatologic disease and low CD4+ cell counts) in addition to those seen among HIV-uninfected persons (e.g. allergies, connective tissue disease) [23]–[25]. Here, CD4 is linked to allergic disease.