HIV transmission dynamics: Infectivity, sexual partnership patterns, and the role of early infection

Although remarkable progress has been made in the diagnosis, treatment, and prevention of HIV, a cure is unavailable and many of the most promising prevention interventions have failed. At this critical juncture in the epidemic, there is a necessity for improved understanding of the fundamental drivers of the epidemic, as well as an urgent need for innovative interventions against HIV. This dissertation focuses on two of these fundamental drivers - the heterosexual infectivity of HIV-1 and the details of sexual partnership patterns - as well as the power of interventions initiated during the highly infectious period of early HIV infection (EHI). We conducted a systematic review and meta-analysis of the heterosexual infectivity of HIV-1, defined as the per-contact probability of HIV-1 transmission in a single heterosexual contact between an infected and a susceptible individual. Infectivity estimates were extremely heterogeneous, ranging from zero transmissions after more than 100 penile-vaginal contacts in some sero-discordant couples to one transmission for every 3.1 episodes of heterosexual anal intercourse. Several co-factors were associated with increased infectivity. Infectivity differences (95% confidence intervals), expressed as number of transmissions per 1000 contacts, were 8 (0-16) comparing uncircumcised to circumcised male susceptibles, 6 (3-9) comparing susceptible individuals with and without GUD, 2 (1-3) comparing late-stage to mid-stage index cases, and 3 (0-5) comparing early-stage to mid-stage index cases. We also analyzed recent sexual partnership patterns in a sexually transmitted infections (STI) clinic in Lilongwe, Malawi. We found that multiple sexual partnerships were uncommon (14%), and partnerships were long on average (mean=858 days). Among those reporting multiple recent partners, patterns ranged from long-term concurrency (mean overlap=246 days) to narrowly spaced consecutive partnerships (mean gap=21 days), presenting a substantial risk for efficient HIV transmission. Finally, we conducted a mathematical modeling study to determine the contribution of EHI to epidemic spread in Lilongwe, Malawi. Our analyses suggest that 38.4% (95% CI: 18.6%-57.5%) of ongoing HIV transmissions in Lilongwe can be attributed to EHI index cases, and that interventions targeting the entire duration of infection will be needed to have a significant, lasting effect on the epidemic

Impact of early-stage HIV transmission on treatment as prevention

Timely HIV treatment improves health (1) and reduces transmission (2). These individual- level benefits of HIV treatment for both clinical and preventive purposes are well established, but several questions remain about the population-level impact of HIV treatment as prevention (3). In PNAS, Eaton and Hallett (4) use a mathematical model to address one such question: Does the proportion of transmission during early HIV infection affect the impact of HIV treatment on HIV incidence

It doesn\u27t hurt to smile ...Or Does It? Tend and Befriend Reactions to Stress During Hookups

Acquiring clear consent during hookups can be challenging. Previous research suggested that humans engage in a fight or flight response under stress. More recently, a tend and befriend model was hypothesized by Taylor (2000, 2002) to explain how many people, especially women, respond with friendly or nurturant behavior in stressful situations. Young adults completed a survey assessing their various behaviors during stressful hookup encounters. Behaviors were categorized as either tend and befriend or fight or flight response. Tend and befriend behaviors included smiling nervously and more. This study looked at gender differences in regards to stressful hookup situations.https://orb.binghamton.edu/research_days_posters_spring2020/1028/thumbnail.jp

Gender asymmetry in concurrent partnerships and HIV prevalence

The structure of the sexual network of a population plays an essential role in the transmission of HIV. Concurrent partnerships, i.e. partnerships that overlap in time, are important in determining this network structure. Men and women may differ in their concurrent behavior, e.g. in the case of polygyny where women are monogamous while men may have concurrent partnerships. Polygyny has been shown empirically to be negatively associated with HIV prevalence, but the epidemiological impacts of other forms of gender-asymmetric concurrency have not been formally explored. Here we investigate how gender asymmetry in concurrency, including polygyny, can affect the disease dynamics. We use a model for a dynamic network where individuals may have concurrent partners. The maximum possible number of simultaneous partnerships can differ for men and women, e.g. in the case of polygyny. We control for mean partnership duration, mean lifetime number of partners, mean degree, and sexually active lifespan. We assess the effects of gender asymmetry in concurrency on two epidemic phase quantities (R0 and the contribution of the acute HIV stage to R0) and on the endemic HIV prevalence. We find that gender asymmetry in concurrent partnerships is associated with lower levels of all three epidemiological quantities, especially in the polygynous case. This effect on disease transmission can be attributed to changes in network structure, where increasing asymmetry leads to decreasing network connectivity

Transformation of Public Relations Agencies Through Evaluation of Golin Harris’ Evolution to the G4 Model Using Public Relations Theories

The study developed a critical analysis of public relations agency Golin Harris and their new G4 Model. This analysis was conducted by an upper-level undergraduate class PR Leadership: From an Agency Perspective. The eight-member, advanced class, team-researched, compared, and contrasted the new model with their previous approach to agency functions. Using key public relations theories, this PR evolution was examined to assess just what this change means to consumers, clients, and other public relations agencies. The theories used were Speech Act Theory, Social Constructionism, Weikian, Strategic Issues Management, and Diffusion of Innovation Theory. An evaluation of the documents provided by Golin Harris which documented the changes from generalized to specialized functions within their new model were identified for analysis. These functions are clustered into four communities: catalyst (coordinator role), connectors, creative, and strategist. Findings from the research and evaluation concluded that GH has moved to a more process approach to communication (less hierarchy or management emphasis) including a leveling of titles to emphasize openness (includes designing a new building with open space for offices). This seems like a strong step in the right direction for an agency, especially to see how some of the theories are integrated into this more communicative approach

Transformation of Public Relations Agencies Through Evaluation of Golin Harris’ Evolution to the G4 Model Using Public Relations Theories

The study developed a critical analysis of public relations agency Golin Harris and their new G4 Model. This analysis was conducted by an upper-level undergraduate class PR Leadership: From an Agency Perspective. The eight-member, advanced class, team-researched, compared, and contrasted the new model with their previous approach to agency functions. Using key public relations theories, this PR evolution was examined to assess just what this change means to consumers, clients, and other public relations agencies. The theories used were Speech Act Theory, Social Constructionism, Weikian, Strategic Issues Management, and Diffusion of Innovation Theory. An evaluation of the documents provided by Golin Harris which documented the changes from generalized to specialized functions within their new model were identified for analysis. These functions are clustered into four communities: catalyst (coordinator role), connectors, creative, and strategist. Findings from the research and evaluation concluded that GH has moved to a more process approach to communication (less hierarchy or management emphasis) including a leveling of titles to emphasize openness (includes designing a new building with open space for offices). This seems like a strong step in the right direction for an agency, especially to see how some of the theories are integrated into this more communicative approach

Modeling viral and drug kinetics: Hepatitis C virus treatment with pegylated interferon alfa-2b

Administration of peginterferon alfa-2b plus ribavirin results in an early hepatitis C virus (HCV) RNA decay followed by an increase as the drug concentration declines between doses. Upon administration of the next dose 1 week later, the same pattern is observed. We have incorporated pharmacokinetic/pharmacodynamic analysis into a model of viral dynamics to describe the effect that changes in drug concentration and effectiveness can have on viral levels. To illustrate the relationship between pharmacokinetics and viral dynamics, we fit the model to data from four HCV/human immunodeficiency virus co-infected patients, and obtained good agreement with the measured serum HCV RNA levels. We were able to account for the observed increases in HCV RNA, and estimate virion and drug half-lives that are in agreement with previous reports. Models incorporating pharmacokinetics are needed to correctly interpret viral load changes and estimate drug effectiveness in treatment protocols using peginterferon alfa-2b

Repeat Human Immunodeficiency Virus Testing by Transmission Risk Group and Rurality of Residence in North Carolina

Background Understanding of repeat human immunodeficiency virus (HIV) testing (RHT) is limited and the impact of rural residence as a potential barrier to RHT is unknown. Rural populations are of particular interest in the Southeastern United States because of their disproportionate HIV burden. Methods We used HIV surveillance data from publicly funded HIV testing sites in North Carolina to assess repeat testing by transmission risk group and residential rurality in a retrospective cohort study. Linear binomial regression models were used to estimate adjusted, 1-year cumulative incidences and cumulative incidence differences comparing RHT within transmission risk populations by level of rurality. Results In our total study population of 600,613 persons, 19,275 (3.2%) and 9567 (1.6%) self-identified as men who have sex with men (MSM) and persons who inject drugs (PWID), respectively. A small minority, 13,723 (2.3%) resided in rural ZIP codes. Men who have sex with men were most likely to repeat test (unadjusted, 1-year cumulative incidence after an initial negative test, 16.4%) compared with PWID (13.2%) and persons who did not identify as either MSM or PWID (13.6%). The greatest effect of rurality was within PWID; the adjusted, 1-year cumulative incidence of RHT was 6.4 (95% confidence interval, 1.4-11.4) percentage points higher among metropolitan versus rural PWID. Conclusions One-year cumulative incidence of RHT was low among all clients of publicly funded HIV testing sites in North Carolina, including MSM and PWID for whom annual testing is recommended. Our findings suggest a need for public health efforts to increase access to and support for RHT, particularly among rural PWID