When we analyzed the relationships among CD4+ cell count, HAART treatment and seropositivity for helminths, we found that, with the exception of schistosomiasis, in the group of patients with CD4+ cell count less than 200 cells/μl, those on HAART were more likely to be seropositive, although this was statistically significant only for echinococcosis 23 (39%) (p = 0.008) (Table 3). This evidence concerns the gene CD4 and echinococcosis.