The Impact of Acute Infection, Testing, and Post-Diagnosis Behavior Change on HIV Transmission among Men Who Have Sex with Men (MSM) in Southern California

Aditya Khanna, University of Washington
Steven M. Goodreau, University of Washington
Pamina Gorbach, University of California, Los Angeles

The aims of this work are to integrate temporal infectiousness of HIV with testing behavior of men who have sex with men (MSM) in Southern California, and post-diagnosis behavior change of positive individuals. A considerable fraction of new HIV infections among MSM occur due to transmissions during the 'acute phase' that lasts up to 12 weeks after infection. It is also documented that HIV positive individuals reduce their level of risky sexual behavior post-diagnosis. Therefore, diagnosing HIV positive individuals early may have a major preventative effect at the population level. In this paper, we create micro-simulation network models to quantify the impact of these individual-level phenomena at the population level, parametrized using data collected on men with recent infection in Southern California. Our results will help clarify the impact of different testing strategies in light of men's self-initiated post-diagnosis behavior change.