Public Health Targeting of PrEP at HIV Positives' Bridging Networks
Condition: HIV
MeSH terms: HIV Seropositivity
Study type: Interventional

Summary: 
      This developmental research grant award (R21) requests funds to explore the feasibility and
      impact of a public health system PrEP intervention in a recently emerging HIV epidemic in
      Athens Greece. The investigators propose a modeling approach using an Agent Based Model (ABM)
      that moves beyond basic pathogen and transmission patterns to dealing with complex social
      interactions, including overlapping social and sexual networks as well as implementation
      realities, like finite PrEP resources, delayed linkage to PrEP care and early PreP care
      retention based upon empirically collected data in Athens Greece.
    

Detailed description: 
      This developmental research grant award (R21) requests funds to explore the feasibility and
      impact of a public health system PrEP intervention in a recently emerging HIV epidemic in
      Athens Greece. As HIV epidemics in most settings globally have plateaued or are in decline,
      emerging epidemics, re-emerging epidemics or outbreaks will become more common, particularly
      when social, political or other "shocks" that impact HIV prevention resources occur. One well
      characterized example is the recent epidemic among people who inject drugs (PWID) that
      started in Athens following austerity measures in 2010. While some success in limiting the
      epidemic within PWID has been observed, recent phylogenetic and surveillance analysis
      demonstrates that the HIV strain from this most recent PWID epidemic (CRF35_AD, CRF14_BG,
      subtypes A and B) has spilled over into MSM in 2013 (see Preliminary Studies).

      In emerging epidemics, oral chemoprophylaxis is a commonly-used public health strategy to
      prevent infectious diseases in susceptible persons. For example, among US and European MSM,
      antibiotic prophylaxis for sex-partners in outbreaks of invasive meningococcal disease has
      limited emerging outbreaks. Similarly, pre-exposure prophylaxis (PrEP) has the potential to
      be used in emerging epidemics to prevent onwards HIV transmission. While this approach would
      seem intuitive, current conceptualizations of PrEP implementation narrowly use a clinical
      model focused on individualized intervention between health provider and client. This is
      problematic because the public health impact of PrEP may be limited due to lack of proper
      targeting. In fact, evidence from "real-world" PrEP use suggests that lower risk clients are
      accessing PrEP. As compared to resource intensive clinical trials or demonstration studies,
      careful modeling approaches can provide insight into who within a new HIV epidemic should be
      targeted for PrEP to prevent onward transmission as well as the strategies used to identify
      these individuals and link them to care. The investigators propose a modeling approach using
      an Agent Based Model (ABM) that moves beyond basic pathogen and transmission patterns to
      dealing with complex social interactions, including overlapping social and sexual networks as
      well as implementation realities, like finite PrEP resources, delayed linkage to PrEP care
      and early PreP care retention based upon empirically collected data in Athens Greece.
      Specifically the investigators aim to: 1) Characterize a bridging MSM network (n=308) by
      measuring individual-level risk factors, network-level connections, and HIV phylogenetic
      clusters; 2) Measure early PrEP cascade outcomes (HIV testing, PrEP linkage to care) of a
      sub-sample (n=50) of HIV uninfected MSM over the short term; and 3) Model the effects of this
      targeted public health PrEP intervention on HIV transmission in Athens. Agent-based models
      that account for empirical network structure are state-of-the-art in modeling HIV
      transmission and are flexible enough to address fundamental questions of who should receive
      PrEP and ultimately how a network-PrEP intervention can impact emerging/reemerging HIV
      epidemics.
    

Intervention name(s): PrEP Intervention
Intervention type(s): Behavioral
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Health Services Research
Keywords: HIV prevention; men who have sex with men; pre-exposure prophylaxis; PrEP; Greece; people who inject drugs