HIV and Sexually Transmitted Infection Epidemic Potential of Networks of Men Who Have Sex With Men in Two Cities.

BACKGROUND: The speed with which a pathogen circulates in a sexual network is a function of network connectivity. Cross-sectional connectivity is a function of network features like momentary degree and assortative mixing. Temporal connectivity is driven by partner acquisition rates. The forward-reachable path (FRP) has been proposed as a summary measure of these two aspects of transmission potential. We use empirical data from San Francisco and Atlanta to estimate the generative parameters of the FRP and compare results to the HIV/sexually transmitted infection epidemics in each city. METHODS: We used temporal exponential random graph models to estimate the generative parameters for each city's dynamic sexual network from survey data. We then simulated stochastic dynamic networks from the fitted models and calculated the FRP for each realization, overall, and stratified by partnership type and demographics. RESULTS: The overall mean and median paths were higher in San Francisco than in Atlanta. The overall paths for each city were greater than the sum of the paths in each individual partnership network. In the casual partnership network, the mean path was highest in the youngest age group and lowest in the oldest age group, despite the fact that the youngest group had the lowest mean momentary degree and past-year partner counts. CONCLUSIONS: The FRP by age group revealed the additional utility of the measure beyond the temporal and cross-sectional network connectivity measures. Other nonnetwork factors are still necessary to infer total epidemic potential for any specific pathogen.

A decision analytics model to optimize investment in interventions targeting the HIV preexposure prophylaxis cascade of care.

OBJECTIVES: Gaps between recommended and actual levels of HIV preexposure prophylaxis (PrEP) use remain among MSM. Interventions can address these gaps but it is unknown how public health initiatives should invest prevention funds into these interventions to maximize their population impact. DESIGN: We used a stochastic network-based HIV transmission model for MSM in the Atlanta area paired with an economic budget optimization model. METHODS: The model simulated MSM participating in up to three real-world PrEP cascade interventions designed to improve initiation, adherence, or persistence. The primary outcome was infections averted over 10 years. The budget optimization model identified the investment combination under different budgets that maximized this outcome, given intervention costs from a payer perspective. RESULTS: From the base 15% PrEP coverage level, the three interventions could increase coverage to 27%, resulting in 12.3% of infections averted over 10 years. Uptake of each intervention was interdependent: maximal use of the adherence and persistence interventions depended on new PrEP users generated by the initiation intervention. As the budget increased, optimal investment involved a mixture of the initiation and persistence interventions but not the adherence intervention. If adherence intervention costs were halved, the optimal investment was roughly equal across interventions. CONCLUSION: Investments into the PrEP cascade through initiatives should account for the interactions of the interventions as they are collectively deployed. Given current intervention efficacy estimates, the total population impact of each intervention may be improved with greater total budgets or reduced intervention costs.

Projected Impact of Concurrently Available Long-Acting Injectable and Daily-Oral Human Immunodeficiency Virus Preexposure Prophylaxis: A Mathematical Model.

BACKGROUND: Long-acting injectable (LAI) human immunodeficiency virus (HIV) preexposure prophylaxis (PrEP) is reportedly efficacious, although full trial results have not been published. We used a dynamic network model of HIV transmission among men who have sex with men to assess the population impact of LAI-PrEP when available concurrently with daily-oral (DO) PrEP. METHODS: The reference model represents the current HIV epidemiology and DO-PrEP coverage (15% among those with behavioral indications for PrEP) among men who have sex with men in the southeastern United States. Primary analyses investigated varied PrEP uptake and proportion selecting LAI-PrEP. Secondary analyses evaluated uncertainty in pharmacokinetic efficacy and LAI-PrEP persistence relative to DO-PrEP. RESULTS: Compared with the reference scenario, if 50% chose LAI-PrEP, 4.3% (95% simulation interval, -7.3% to 14.5%) of infections would be averted over 10 years. The impact of LAI-PrEP is slightly greater than that of the DO-PrEP-only regimen, based on assumptions of higher adherence and partial protection after discontinuation. If the total PrEP initiation rate doubled, 17.1% (95% simulation interval, 6.7%-26.4%) of infections would be averted. The highest population-level impact occurred when LAI-PrEP uptake and persistence improved. CONCLUSIONS: If LAI-PrEP replaces DO-PrEP, its availability will modestly improve the population impact. LAI-PrEP will make a more substantial impact if its availability drives higher total PrEP coverage, or if persistence is greater for LAI-PrEP.

Optimizing Coverage vs Frequency for Sexually Transmitted Infection Screening of Men Who Have Sex With Men.

BACKGROUND: The incidence of bacterial sexually transmitted infections (STIs) in men who have sex with men (MSM) has increased substantially despite availability of effective antibiotics. The US Centers for Disease Control and Prevention (CDC) recommends annual screening for all sexually active (SA) MSM and more frequent screening for high-risk (HR) MSM. The population-level benefits of improved coverage vs increased frequency of STI screening among SA vs HR MSM are unknown. METHODS: We used a network transmission model of gonorrhea (NG) and chlamydia (CT) among MSM to simulate the implementation of STI screening across different scenarios, starting with the CDC guidelines at current coverage levels. Counterfactual model scenarios varied screening coverage and frequency for SA MSM and HR MSM (MSM with multiple recent partners). We estimated infections averted and the number needed to screen to prevent 1 new infection. RESULTS: Compared with current recommendations, increasing the frequency of screening to biannually for all SA MSM and adding some HR screening could avert 72% of NG and 78% of CT infections over 10 years. Biannual screening of 30% of HR MSM at empirical coverage levels for annual SA screening could avert 76% of NG and 84% of CT infections. Other scenarios, including higher coverage among SA MSM and increasing frequency for HR MSM, averted fewer infections but did so at a lower number needed to screen. CONCLUSIONS: The optimal screening scenarios in this model to reduce STI incidence among MSM included more frequent screening for all sexually active MSM and higher coverage of screening for HR men with multiple partners.

Jail, an unappreciated medical home: Assessing the feasibility of a strengths-based case management intervention to improve the care retention of HIV-infected persons once released from jail.

BACKGROUND: Linkage to and retention in care for US persons living with HIV (PLWH) after release from jail usually declines. We know of no rigorously evaluated behavioral interventions that can improve this. We hypothesized that a strengths-based case management intervention that we developed for PLWH leaving jail would increase linkage/retention in care (indicated by receipt of laboratory draws) and a suppressed HIV viral load (VL) in the year following release. METHODS AND FINDINGS: We conducted a quasi-experimental feasibility study of our intervention for PLWH jailed in Atlanta. We recruited 113 PLWH in jail starting in 2014. "SUCCESS" (Sustained, Unbroken Connection to Care, Entry Services, and Suppression) began in jail and continued post-release. Subjects who started the intervention but subsequently began long-term incarcerations were excluded from further analysis. Persons who were retained in the intervention group were compared to contemporaneously incarcerated PLWH who did not receive the intervention. Identities were submitted to an enhanced HIV/AIDS reporting system (eHARS) at the state health department to capture all laboratories drawn. Both community engagement and care upon jail return were assessed equally. For 44 intervention participants released to Atlanta, 50% of care occurred on subsequent jail stays, as documented with EventFlow software. Forty-five receiving usual services only were recruited for comparison. By examining records of jail reentries, half of participants and 60% of controls recidivated (range: 1-8 returns). All but 6 participants in the intervention and 9 subjects in the comparison arm had ≥1 laboratory recorded in eHARS post-release. Among the intervention group, 52% were retained in care (i.e., had two laboratory studies, > = 3 months apart), versus 40% among the comparison group (OR = 1.60, 95% CI (0.71, 3.81)). Both arms showed improved viral load suppression. CONCLUSIONS: There was a trend towards increased retention for PLWH released from jail after SUCCESS, compared to usual services. Measuring linkage at all venues, including jail-based clinics, fully captured engagement for this frequently recidivating population. TRIAL REGISTRATION: ClinicalTrials.gov NCT02185742.

HIV and HCV in U.S. Prisons and Jails: The Correctional Facility as a Bellwether Over Time for the Community's Infections.

Screening and treating correctional populations for HIV and HCV infections is essential to successfully addressing both epidemics in the USA. The prevalence of HIV and HCV infection is high in prisons and jails due to increased rates of incarceration among disproportionately affected groups such as injection drug users. Through a search of the published and grey literature and surveying persons overseeing health programs in prisons, we collected data on efforts to determine prevalence first for HIV and then for HCV. Prevalence of both infections varies geographically and temporally, reflecting epidemics in the community as well as local law enforcement policies. We estimate that seroprevalence of HCV in 2015 for persons in U.S. prisons averaged 18%, over tenfold greater than HIV. For both, transmission and acquisition during incarceration are rare. Screening can identify previously undetected cases: the efficiency of a testing strategy depends on local conditions. Universal opt-out screening of entrants is usually best as conducting risk-based screening has challenges. With HCV, the advent of highly effective regimens makes cure feasible. Treatment within facilities has the potential to reduce HCV incidence and disease burden in the community, especially in difficult-to-reach populations. The extraordinarily high cost of HCV treatment regimens and lack of political will are the main barriers to treatment expansion. Just as community-wide HIV viral suppression has required correctional/community coordination, elimination of HCV infection in the USA will depend on a thoughtful, well-funded effort to manage this disease in populations interacting with the criminal justice system.