Transmission Reduction Intervention Project (TRIP), Athens, Greece Site, 2013-2015

Half or more of HIV transmission events may occur within the period of high infectivity (and often high risk behavior) that can last 11 months or more after a person is initially infected. The study sought to develop effective intervention techniques against HIV transmission during the recent infection period using a combination of injection-, sexual- and social-network-based contact tracing methods; community alerts in the networks and venues of recent infectees; and the logic of going "up" and "down" infection chains. The investigators' first aim was to develop and evaluate ways to locate "seeds", defined as drug users and other people who have recently been infected. The investigators' second aim targeted members of seeds' networks and people who attend their venues. The investigators tested them for acute and for recent infection, and alerted them to the probability that their networks contain highly-infectious members so they should reduce their risk and transmission behaviors for the next several months to minimize their chances of getting infected. This may also reduce transmission by untested people with recent infection. Community, network and venue education about the need and value of supporting those with recent infection should reduce stigma. The investigators' third aim was to reduce HIV transmission and to develop new ways to evaluate "prevention for positives" generally as well as the investigators own success in reducing transmission. The investigators did this using a combination of follow-up interviews and testing, including of viral loads; phylogenetic techniques; and discrete event simulation modeling to assess the investigators effectiveness.