Researchers from the Munich Tropical Institute, the Tanzanian NIMR-MMRC, DZIF, together with colleagues from Bonn, have discovered a risk factor for HIV infection that has received little attention to date. In an earlier cohort study, they demonstrated for the first time that infection with the worm Wuchereria bancrofti increases the risk of contracting HIV. This link has now been further investigated in the context of a national program in Tanzania to eliminate W. bancrofti.