Modeling prevention interventions requires insights into epidemiological and biological factors affecting HIV transmission. Project 1 of the proposed Program Project addresses the epidemiological determinants of HIV transmission by examining the per contact transmission probability (P), the rate of partner change/ contact rate (c), and the duration of infectiousness (D), which all contribute to the reproductive number (R0= pcD), defined as the average number of secondary infections arising from a single infection in a completely susceptible population. To achieve this objective, we will address the following specific aims:
Aim 1 : Per contact transmission probability (P) - The per contact sexual transmission probability of HIV will be estimated, taking into account stage of HIV infection in the source partner, presence of viral and bacterial sexually transmitted infections, circumcision status, and other biological cofactors investigated in Project 2. The absolute and relative difference of transmission probability for insertive versus receptive anal sex will also be considered.
Aim 2 : Rate of partner change (c) - The role of partner selection in HIV acquisition and transmission risk will be examined at individual, partnership, and network levels. At the individual level, the relative contribution of HIV risk due to number of sexual acts versus number of sexual partners will be examined. At the partnership level, risk characteristics will be compared between transmitting and seroconcordant non-transmitting partnerships. At the network level, risk of acquisition and transmission of HIV based on the location of individuals within networks of venues used to meet sex partners, and correlates of being in a transmission cluster, will be elucidated.
Aim 3 : Duration of infectiousness (D) - To determine how duration of the infectious stages of HIV infection intersects with risk behaviors and time to antiretroviral treatment. We will use data from Aims 1-3 to develop a stochastic, individual-based model to predict the number of secondary infections arising from individuals diagnosed during recent HIV infection as they transit to chronic infection, and the potential impact of short-course antiviral therapy on reducing transmission. Project 1 depends on well-characterized clinical data and specimens collected by the Clinical and Specimen Core and the subsequent measurement of transmission correlates in Project 2. Epidemiological data contributing to HIV transmission collected in Project 1 will help to define correlates of HIV transmission in Project 2. The Administrative Core will coordinate administrative, fiscal, data, and statistical support for Projects 1 and 2. These data will provide critical information on epidemiological determinants of HIV transmission in a setting where HIV-1 subtype B predominates, which are lacking for MSM, and will generate important exploratory data for other populations.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Research Program Projects (P01)
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Special Emphasis Panel (ZAI1-MH-A)
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University of California San Diego
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Hoenigl, Martin; Green, Nella; Camacho, Martha et al. (2016) Signs or Symptoms of Acute HIV Infection in a Cohort Undergoing Community-Based Screening. Emerg Infect Dis 22:532-4
Gianella, Sara; Letendre, Scott (2016) Cytomegalovirus and HIV: A Dangerous Pas de Deux. J Infect Dis 214 Suppl 2:S67-74
Hoenigl, Martin; Little, Susan J (2016) How can we detect HIV during the acute or primary stage of infection? Expert Rev Mol Diagn 16:1049-1051
Hoenigl, Martin; Graff-Zivin, Joshua; Little, Susan J (2016) Costs per Diagnosis of Acute HIV Infection in Community-based Screening Strategies: A Comparative Analysis of Four Screening Algorithms. Clin Infect Dis 62:501-11
Chaillon, Antoine; Hoenigl, Martin; Mehta, Sanjay R et al. (2016) A practical online tool to estimate antiretroviral coverage for HIV infected and susceptible populations needed to reduce local HIV epidemics. Sci Rep 6:28707
Hoenigl, Martin; Chaillon, Antoine; Moore, David J et al. (2016) Clear Links Between Starting Methamphetamine and Increasing Sexual Risk Behavior: A Cohort Study Among Men Who Have Sex With Men. J Acquir Immune Defic Syndr 71:551-7
Hoenigl, Martin; Chaillon, Antoine; Kessler, Harald H et al. (2016) Characterization of HIV Transmission in South-East Austria. PLoS One 11:e0151478
Dan, Jennifer M; Massanella, Marta; Smith, Davey M et al. (2016) Brief Report: Effect of CMV and HIV Transcription on CD57 and PD-1 T-Cell Expression During Suppressive ART. J Acquir Immune Defic Syndr 72:133-7
Kassanjee, Reshma; Pilcher, Christopher D; Busch, Michael P et al. (2016) Viral load criteria and threshold optimization to improve HIV incidence assay characteristics. AIDS 30:2361-71
Yang, S; Lok, J J (2016) A goodness-of-fit test for structural nested mean models. Biometrika 103:734-741

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