Because systemic T cell activation potentially contributes to increased HIV transmission risk [8]–[10] through facilitation of early systemic dissemination of the virus, our data support the concept that helminth infections, which are linked to systemic Immune activation and potentially increase CCR5 density on memory CD4 T cells, such as Trichuris infection, could indeed also contribute to increased HIV transmission risk during sexual activity. The gene discussed is CCR5; the disease is helminthiasis.