AIDS Behav (2009) 13:1054–1060 DOI 10.1007/s10461-009-9582-6 O R I G I N A L P A P E R Behavior Change Following Diagnosis with Acute/Early HIV Infection—A Move to Serosorting with Other HIV-Infected Individuals. The NIMH Multisite Acute HIV Infection Study: III Wayne T. Steward Æ Robert H. Remien Æ Jenny A. Higgins Æ Robert Dubrow Æ Steven D. Pinkerton Æ Kathleen J. Sikkema Æ Hong-Ha M. Truong Æ Mallory O. Johnson Æ Jennifer Hirsch Æ Ronald A. Brooks Æ Stephen F. Morin Published online: 6 June 2009 The Author(s) 2009. This article is published with open access at Springerlink.com Abstract Risk reductions behaviors are especially important during acute/early HIV infection, a period of high transmission risk. We examined how sexual behaviors changed following diagnosis of acute/early HIV infection. Twenty-eight individuals completed structured surveys and in-depth interviews shortly after learning of their infection and 2 months later. Quantitative analyses revealed signif- icant changes after diagnosis, including reductions in total partners and decreases in the proportion of unprotected sex W. T. Steward (&) H.-H. M. Truong M. O. Johnson S. F. Morin Center for AIDS Prevention Studies, University of California, San Francisco, 50 Beale St., Suite 1300, San Francisco, CA 94105, USA e-mail: wayne.steward@ucsf.edu R. H. Remien J. Hirsch HIV Center for Clinical and Behavioral Studies, New York State Psychiatric Institute and Columbia University, New York, NY, USA J. A. Higgins Center for Health and Wellbeing, Princeton University, Princeton, NJ, USA R. Dubrow Center for Interdisciplinary Research on AIDS, Yale University, New Haven, CT, USA S. D. Pinkerton Center for AIDS Intervention Research, Medical College of Wisconsin, Milwaukee, WI, USA K. J. Sikkema Duke University, Durham, NC, USA R. A. Brooks Center for HIV Identiﬁcation, Prevention and Treatment Services, University of California, Los Angeles, CA, USA 123 acts occurring with uninfected partners (serosorting). Qualitative ﬁndings indicated that these changes were motivated by concerns about infecting others. However, participants were less successful at increasing the fre- quency with which they used condoms. These results suggest that the initial diagnosis with HIV may constitute an important component of interventions to promote risk reduction during the acute/early stages of the disease. Serosorting Behavior change Keywords Acute HIV HIV prevention Introduction Acute and early HIV infection play a critical role in the spread of the epidemic. Viral loads, and, consequently, infectiousness, are at their highest during the period of acute HIV infection (AHI; the several weeks to about 2 months between acquisition of HIV and completion of seroconver- sion) (Pilcher et al. 2004). Furthermore, although acute HIV shedding is over about 10 weeks post-infection, elevated onward transmission likely extends through the period of early infection (the 6 months after seroconversion) due to ongoing high risk behaviors, associated sexually transmitted infections that increase transmission risk, and transmission ampliﬁcation through high-risk sexual and drug-use net- works. Transmissions during acute/early infection may account for as many as half of new infections. (For more detailed discussion and references, see Kerndt et al. 2009, the ﬁrst paper of this series in this issue of the journal). Because risk reduction is especially critical during these stages of HIV disease, it is important to understand people’s readiness and ability to adopt and sustain rapid behavior change after diagnosis with acute/early HIV infection. On