National HIV Behavioral Surveillance System Research Articles

Injection Behaviors and Use of Syringe Service Programs over Time among People Who Inject Drugs in Baltimore, Maryland

Introduction: People who inject drugs (PWID) are at increased risk for infectious disease transmission, including hepatitis C and HIV. Understanding trends in injection risk behaviors and syringe service program (SSP) use over time can help improve infectious disease prevention and other harm reduction services. Methods: Using National HIV Behavioral Surveillance System data from Baltimore, Maryland, we examined changes in receptive sharing of (1) syringes, (2) injection equipment, (3) syringes to divide drugs; and (4) receipt of syringes from SSPs among PWID from 2009 to 2018 (n = 518 in 2009, n = 638 in 2012, n = 586 in 2015, and n = 575 in 2018) using unadjusted and adjusted logistic models calculated across time for the total sample. Results: The conditional probability of receptive sharing of syringes and receipt of syringes from SSPs remained relatively stable, while receptive sharing of injection equipment and receptive sharing of syringes to divide drugs dropped substantially after 2009. White race and daily injection frequency were positively associated with sharing syringes and injection equipment and negatively associated with SSP use over time. In 2015, there was a notable shift such that women were twice as likely as men to receive syringes from SSPs and less likely than men to report the use of shared syringes or equipment. Conclusion: Findings indicate overall steady or decreasing trends in injection risk and steady trends in SSP usage over time, with some notable improvements among women and indications of shifting drug market patterns. Injection-related risk behaviors remain high among White PWID and may require targeted outreach and interventions.

Seroprevalence and risk factors associated with hepatitis C: a cross-sectional study of persons who inject drugs in Puerto Rico, 2018

BackgroundPeople Who Inject Drugs (PWID) are at a higher risk of acquiring bloodborne infections. We aimed to estimate the seroprevalence of the Hepatitis C Virus (HCV) in PWID and identify correlates and risk factors using data from the Puerto Rico National HIV Behavioral Surveillance System, PWID cycle 5, conducted in 2018.MethodsA total of 502 San Juan Metropolitan Statistical Area participants were recruited through the Respondent Driven Sampling method. Sociodemographic, health-related, and behavioral characteristics were assessed. Testing for HCV antibodies was completed after the face-to-face survey. Descriptive and logistic regression analyses were performed.ResultsOverall seroprevalence of HCV was 76.5% (95% CI: 70.8-81.4%). A significantly (p < 0.05) higher HCV seroprevalence was observed among PWID with the following characteristics: heterosexuals (78.5%), high school graduates (81.3%), tested for sexually transmitted infections (STI) in the past 12 months (86.1%), frequent speedball injection (79.4%), and knowing the HCV serostatus of the last sharing partner (95.4%). Adjusted logistic regression models showed that having completed high school and reported STI testing in the past 12 months were significantly associated with HCV infection (ORa = 2.23; 95% CI: 1.06–4.69; ORa = 2.14; 95% CI: 1.06–4.30, respectively).ConclusionsWe report a high seroprevalence of HCV infection in PWID. Social health disparities and potential missed opportunities validate the continuing call for local action for public health and prevention strategies.

Population-Level Health Effects of Involuntary Displacement of People Experiencing Unsheltered Homelessness Who Inject Drugs in US Cities

At least 500 000 people in the US experience homelessness nightly. More than 30% of people experiencing homelessness also have a substance use disorder. Involuntary displacement is a common practice in responding to unsheltered people experiencing homelessness. Understanding the health implications of displacement (eg, "sweeps," "clearings," "cleanups") is important, especially as they relate to key substance use disorder outcomes. To estimate the long-term health effects of involuntary displacement of people experiencing homelessness who inject drugs in 23 US cities. A closed cohort microsimulation model that simulates the natural history of injection drug use and health outcomes among people experiencing homelessness who inject drugs in 23 US cities. The model was populated with city-level data from the Centers for Disease Control and Prevention's National HIV Behavioral Surveillance system and published data to make representative cohorts of people experiencing homelessness who inject drugs in those cities. Projected outcomes included overdose mortality, serious injection-related infections and mortality related to serious injection-related infections, hospitalizations, initiations of medications for opioid use disorder, and life-years lived over a 10-year period for 2 scenarios: "no displacement" and "continual involuntary displacement." The population-attributable fraction of continual displacement to mortality was estimated among this population. Models estimated between 974 and 2175 additional overdose deaths per 10 000 people experiencing homelessness at 10 years in scenarios in which people experiencing homelessness who inject drugs were continually involuntarily displaced compared with no displacement. Between 611 and 1360 additional people experiencing homelessness who inject drugs per 10 000 people were estimated to be hospitalized with continual involuntary displacement, and there will be an estimated 3140 to 8812 fewer initiations of medications for opioid use disorder per 10 000 people. Continual involuntary displacement may contribute to between 15.6% and 24.4% of additional deaths among unsheltered people experiencing homelessness who inject drugs over a 10-year period. Involuntary displacement of people experiencing homelessness may substantially increase drug-related morbidity and mortality. These findings have implications for the practice of involuntary displacement, as well as policies such as access to housing and supportive services, that could mitigate these harms.

HIV Self-testing and Risk Behaviors Among Men Who Have Sex With Men in 23 US Cities, 2017

HIV self-testing (HIVST) is a promising strategy to expand the HIV care continuum, particularly among priority populations at high risk of HIV infection. However, little is known about HIVST uptake among men who have sex with men (MSM) outside of clinical trial settings. To evaluate HIVST use among urban MSM in the US who reported testing within the past 12 months. A cross-sectional study of adult MSM in the 2017 National HIV Behavioral Surveillance system, which used venue-based sampling methods to collect data related to HIV testing, receipt of prevention services, and risk factors for HIV, was conducted at 588 venues in 23 urban areas in the contiguous US and Puerto Rico. All participants were offered HIV testing. Adult cisgender MSM who reported HIV-negative or unknown HIV status and obtained HIV testing in the past 12 months were included. Data for this study were collected between June 4, 2017, and December 22, 2017, and analyzed between October 23, 2020, and August 20, 2021. Self-reported HIVST in the past year. Adjusted prevalence ratios (aPRs) using survey weights were calculated to assess factors associated with HIVST. A total of 6563 MSM in 23 urban areas met inclusion criteria, of whom 506 (7.7%) individuals reported HIVST in the past year. The median age of self-testers was 29 (IQR, 25-35) years, 52.8% had completed college, and 37.9% reported non-Hispanic White race. One self-tester reported seroconverting in the prior 12 months, and an additional 10 self-testers were diagnosed with HIV during the survey. HIVST was associated with sexual orientation disclosure (aPR, 10.27; 95% CI, 3.45-30.60; P < .001), perceived discrimination against people with HIV (aPR, 1.53; 95% CI, 1.09-2.03; P = .01), younger age (aPR, 0.74; 95% CI, 0.66-0.84; P < .001), higher educational level (aPR, 1.20; 95% CI, 1.04-1.37; P = .01), and higher income levels (aPR, 1.18; 95% CI, 1.04-1.32; P = .009). No association was noted with condomless anal sex (aPR, 0.96; 95% CI, 0.88-1.06, P = .88), sexually transmitted infections (aPR, 0.96; 95% CI, 0.70-1.30; P = .77), or preexposure prophylaxis use (aPR, 0.99; 95% CI, 0.75-1.30; P = .92). In this study, HIVST was relatively uncommon in this sample of urban MSM. HIVST may not be reaching those with lower socioeconomic status or who have not disclosed their sexual identity. The findings of this study suggest that efforts to increase HIVST should focus on engaging underserved and vulnerable subgroups of MSM.

Injection of Methamphetamine Has Increased in Boston, Massachusetts: 5 Waves of Centers for Disease Control and Prevention State Surveillance Data.

In the United States, the number of overdose deaths related to opioids in combination with stimulants has increased; however, the Northeast has typically been less impacted by stimulant overdose. Injection drug use (IDU) results in high mortality from overdose and infectious disease and there are racial disparities observed in overdose death rates. We examined trends in stimulant and opioid IDU, including trends stratified by race, using 5 waves of cross-sectional state surveillance data. Data came from the Centers for Disease Control and Prevention's National HIV Behavioral Surveillance system Boston, Massachusetts site, which includes 5 waves of data (2005-2018) among adults in the Boston metropolitan area reporting IDU (N = 2550). Outcome measures were type of substance injected in the past 12 months (heroin, prescription opioids, "speedball," cocaine, crack, and/or methamphetamine). Participants were 70% male, 58% non-Hispanic White, and injected a mean of 3 different drugs in the past 12 months. From 2015 to 2018, there was a more than 2-fold increase in injection of methamphetamine (15% vs 38%, P < 0.001), a pattern which held across racial groups. Combination heroin and methamphetamine injection increased from 2015 (15%) to 2018 (35%, P < 0.001). Multiple drug injection (injecting >1 drug) increased significantly across years compared with single drug injection ( P = 0.03). Findings suggest that increased use of methamphetamine and opioids extends to Boston. There is an urgent need for enhanced screening of methamphetamine use among those using opioids and increased access and payor coverage of efficacious treatments for stimulant and opioid use disorders (eg, contingency management and medication treatment for opioid use disorder).

Sexual Behaviors and Human Papillomavirus Vaccination in a Heterosexually Active Adult Population at Increased Risk for HIV Infection.

Human papillomavirus (HPV) is the most common sexually acquired infection in the US. Vaccination is effective against infection with high-risk HPV strains, yet HPV vaccine coverage is lower in the US than the national target. This study aimed to determine the relationship between sexual behaviors and HPV vaccination in a heterosexually active population at increased risk for HIV infection. Data from 380 participants aged 18-45years obtained from the National HIV Behavioral Surveillance system increased risk heterosexuals cycle 5 (2019) in Houston, Texas, was analyzed. RDS-Analyst was used to generate population-based descriptive statistics. Modified Poisson regression models clustered on recruitment chain were conducted in SAS 9.4 to assess the relationship between sexual behaviors and HPV vaccination. Only 11.5% of participants had received at least one dose of the HPV vaccine. Regarding behaviors within the past 12months, 44.8% reported having condomless casual sex, 51.3% reported having concurrent sexual partnerships while in their most recent relationship, 14.5% reported exchanging sex, and participants had an average of 4-5 sex partners. Further, those who exchanged sex had a significantly lower prevalence of HPV vaccine uptake when compared to those who did not exchange sex (adjusted prevalence ratio 0.23; confidence interval 0.10-0.52), while all other measures of sexual behavior were not significantly associated with HPV vaccination. More research is needed to understand the relationship between exchange sex and low prevalence of vaccination, specifically in women who bear the highest burden of poor HPV-related morbidity and mortality.

Exploring Preventive Healthcare in a High-Risk Vulnerable Population.

This study describes preventive care behaviors and explores opportunities to deliver preventive sexual healthcare to a high-risk vulnerable population. Data from the National HIV Behavioral Surveillance (NHBS) system high-risk heterosexuals (HET) cycle (2019) in Houston, Texas, was used to describe preventive care utilization and assess the relationship between healthcare utilization and sociodemographic characteristics. More than 47% reported having no usual source of healthcare, and 94.6% reported receiving no non-HIV STI testing in the past 12 months. Additionally, many sociodemographic factors were associated with healthcare utilization and having a usual source of healthcare. Future efforts should be targeted at increasing preventive healthcare utilization among high-risk vulnerable populations as well as implementing more preventive sexual healthcare services in the community health centers where these populations most frequently encounter healthcare.

Association Between Perceived Community HIV-AIDS Stigma and HIV Testing Behaviors Among High-Risk Heterosexuals in Dallas and Houston, Texas: An Analysis of the National HIV Behavioral Surveillance System

Background: Stigma-related behaviors place a great burden on people with HIV (PWH) or at risk of infection. For high-risk populations, perceived community HIV/AIDS stigma (PCHAS) may prevent early HIV testing, treatment, and care. The objective of this study was to assess the prevalence of PCHAS and its association with sociodemographic characteristics and HIV testing behaviors among high-risk heterosexuals in Dallas and Houston, Texas. Methods: Data from 1,003 high-risk heterosexuals recruited using respondent-driven sampling in 2013 and obtained from the National HIV Behavioral Surveillance system in Dallas and Houston, Texas were used for this study. Data procured were subjected to descriptive and inferential statistics that included frequency run, chi-square test and univariate logistic regression models to explore the associations between perceived community HIV/AIDS stigma index (PCHASi) and HIV testing behaviors, and sociodemographic characteristics. Results: Participants in both cities were primarily Black/African American, of low income, under poverty level, and uninsured. PCHAS was prevalent in Dallas (58.2%) and Houston (57.5%). The majority of participants in Dallas (76.7%) and Houston (86.6%) indicated ever getting tested for HIV, and about a third had tested at least once in the past 2 years. PCHAS was more common among Hispanics/Latinos (p=0.013) in Houston, and annual income (p=0.032), and homelessness (p=0.016) in the past 12 months were associated with PCHAS in Dallas. Participants in Dallas who were afraid of finding out if they had HIV (PR: 4.41, 95% CI: 1.40-13.9) and those who gave other reasons (PR: 2.64, 95%CI: 1.17-5.95) for not testing for HIV in the past year were more likely to perceive community-level support for the rights of PWH. In Houston, participants who had ever tested for HIV (PR: 2.26, 95% CI: 1.27-3.99) and those who tested 3 times (PR: 3.11, 95% CI: 1.18-8.19) in the past 2 years perceived community-level unfriendliness to PWH. Conclusion: Our study did not establish any clear relationship between PCHAS and HIV testing behaviors. However, perceived community-level fears and unfriendliness to PWH were associated with selected HIV testing behaviors suggesting that HIV knowledge and education at individual- and community-level may be important targets for intervention. Future research should consider the role of social and cultural norms in influencing the relationship between PCHAS and HIV testing behaviors.

Structural Issues Associated with Pre-exposure Prophylaxis Use in Men Who Have Sex with Men.

Limited access to healthcare has been associated with limited uptake of pre-exposure prophylaxis (PrEP) for HIV among men who have sex with men (MSM). This descriptive analysis examined, in a near universal healthcare setting, differences between MSM reporting using versus not using PrEP in the past 12months. Data come from the 2017 Boston sample of the National HIV Behavioral Surveillance (NHBS) system, containing a venue-based and time-spaced sample of 530 MSM. The analysis used descriptive frequencies and tests of bivariate associations by PrEP use using Fisher's exact test. Five hundred four respondents had data necessary to determine if PrEP was indicated, and 233 (43.9%) had an indication for PrEP. Of these 233 participants, 117 (50.2%) reported using PrEP in the past 12months. Not being out, in terms of disclosing one's sexual orientation to a healthcare provider, lack of health insurance, limited access to healthcare, and history of incarceration were all significantly associated with not using PrEP in the past 12months. Race/ethnicity was not significantly associated with PrEP use in the past 12months. In the setting of Massachusetts healthcare expansion and reform, and in a sample somewhat uncharacteristic of the population of individuals experiencing difficulties accessing PrEP, structural and demographic factors remain potent barriers to PrEP uptake. Targeted PrEP expansion efforts in Massachusetts may focus on identifying vulnerable subgroups of MSM (e.g., underinsured or criminal justice system-involved MSM) and delivering evidence-based interventions to reduce stigma and promote disclosure of same-sex behavior in healthcare settings.

Increased utilization of buprenorphine and methadone in 2018 compared to 2015 among Seattle-area persons who inject drugs

ObjectiveTo describe utilization patterns of methadone and buprenorphine among persons who inject drugs (PWID) in the Seattle area in 2018, compared to 2015. MethodsData from the 2018 National HIV Behavioral Surveillance (NHBS) system were used to compare the proportions of PWID reporting treatment with buprenorphine or methadone to survey responses in 2015. Temporal trends were assessed by calculating adjusted prevalence ratios (aPR) using Poisson regression. ResultsThe sample included 498 PWID, of whom 39.2% (95% CI: 34.8–43.6%) reported past-year treatment with methadone and 21.9% (95% CI: 18.3–25.8%) reported buprenorphine. Participants in 2018 were significantly more likely to report past year receipt of buprenorphine (aPR = 4.43, 95% CI: 2.81–7.01) or methadone (aPR = 1.38, 95% CI: 1.02–1.87) compared to 2015. Most buprenorphine treated participants (67.6%) reported that they had received buprenorphine through low-barrier, community, or nonprofit programs. ConclusionsAmong PWID who use opioids in the Seattle area, methadone use increased 38%, and buprenorphine use more than quadrupled from 2015 to 2018. Approximately half of surveyed PWID who use opioids still reported no treatment with either medication, highlighting remaining treatment gaps.

Health Care Coverage and Preexposure Prophylaxis (PrEP) Use Among Men Who Have Sex With Men Living in 22 US Cities With vs Without Medicaid Expansion, 2017.

Objectives. To compare health care coverage and utilization between men who have sex with men (MSM) in Medicaid expansion versus nonexpansion states.Methods. We used cross-sectional weighted data from the National HIV Behavioral Surveillance system, which used venue-based methods to interview and test MSM in 22 US cities from June through December, 2017 (n = 8857). We compared MSM in Medicaid expansion versus nonexpansion states by using the Rao-Scott χ2 test stratified by HIV status. We used multivariable logistic regression to model the relationship between Medicaid expansion, coverage, and preexposure prophylaxis (PrEP) use.Results. MSM in expansion states were more likely to have insurance (87.9% vs 71.6%), have Medicaid (21.3% vs 3.8%), discuss PrEP with a provider (58.8% vs 44.3%), or use PrEP (31.1% vs 17.5%).Conclusions. Medicaid expansion is associated with higher coverage and care, including PrEP.Public Health Implications. States may consider expanding Medicaid to help end the HIV epidemic.

Distance matters: The association of proximity to syringe services programs with sharing of syringes and injecting equipment - 17 U.S. cities, 2015

BackgroundSyringe services programs (SSPs) have effectively limited the spread of HIV and hepatitis C (HCV) among people who inject drugs (PWID). Access to SSPs has been shown to reduce injection risk behaviors but the relationship between distance to an SSP and likelihood of sharing injection equipment is not well known. MethodsWe analyzed a sample of 8,392 PWID from 17 U.S. cities recruited through the National HIV Behavioral Surveillance (NHBS) system in 2015. Adjusted prevalence ratios (aPR) and 95% confidence intervals (CI) were estimated from log-linked Poisson regression to explore associations between injecting equipment sharing in the past 12 months and distance to the nearest SSP. ResultsRegardless of SSP use, respondents who lived in zip codes further than the city-specific mean distance to nearest SSP were more likely to report sharing behavior. Among PWID who had not reported using an SSP in the previous 12 months, distributive sharing (aPR=1.13 95% CI=1.05, 1.21), receptive sharing (aPR=1.15, 95% CI=1.06, 1.24), and injection equipment sharing (aPR=1.08, 95% CI=1.03, 1.13) were more prevalent among residents who resided further than the average distance to the nearest SSP. ConclusionsGreater distance to an SSP was associated with increased sharing behaviors. Improved access to an SSP and subsequent decreases in sharing behaviors could reduce transmission of HIV and HCV among PWID. Accessibility should be taken into account when planning provision of SSPs.

The Impact of Syringe Services Program Policy on Risk Behaviors Among Persons Who Inject Drugs in 3 US Cities, 2005-2015.

The impact of a syringe services program (SSP) policy on risk behaviors and its durability are not as well studied as the impact of the SSPs themselves. We examined whether trends in syringe sharing among persons who inject drugs (PWID) were associated with changes to syringe access policies in 3 US cities: Denver, New Orleans, and Philadelphia. PWID were surveyed through National HIV Behavioral Surveillance System surveys in each city in 2005, 2009, 2012, and 2015. We assessed changes in syringe sharing from 2005 to 2015 by city. We used multivariable stepwise logistic regression analysis to measure the associations among syringe sharing and injection works sharing, time, and SSP access. From 2005 to 2015, syringe sharing decreased significantly from 49.1% to 33.1% in Denver (P < .001), increased significantly from 32.0% to 50.5% in New Orleans (P < .001), and remained unchanged in Philadelphia (30.4% to 31.5%; P = .87). Compared with persons who obtained syringes from any nonsterile source, the adjusted odds of syringe sharing among PWID were significantly lower in each city if syringes were obtained from sterile sources only: Denver adjusted odds ratio (aOR) = 0.23 (95% confidence interval [CI], 0.18-0.30; New Orleans aOR = 0.26 (95% CI, 0.19-0.35), and Philadelphia aOR = 0.43 (95% CI, 0.33-0.57). The lowest proportion of PWID reporting syringe sharing was in Philadelphia, which has a long-standing legal SSP. Implementation of a legal SSP in Denver in 2012 corresponded to a decrease in sharing, whereas the lack of a legal SSP in New Orleans corresponded to an increase in sharing. Universal long-term access to legal SSPs could further the progress made in HIV prevention among PWID.

Immigrant Status and Sexual Orientation Disclosure: Implications for HIV/STD Prevention Among Men Who Have Sex with Men in Seattle, Washington.

Men who have sex with men (MSM) are disproportionately affected by HIV and may avoid disclosing their sexual preferences to others. With heightened attention on immigrant status in the United States, foreign-born MSM may be particularly concerned about disclosing their sexual orientation. We sought to examine how immigrant status is associated with sexual orientation disclosure among MSM and to assess the impact of disclosure on HIV/STD prevention outcomes stratified by nativity. We analyzed data from the 2014 and 2017 Seattle-area surveys of MSM from the National HIV Behavioral Surveillance (NHBS) system. Foreign-born MSM were less likely than U.S.-born MSM to have disclosed their sexuality to friends who are not gay, lesbian, or bisexual (85.0% vs. 95.5%; p < .001) or to family members (80.5% vs. 91.3%; p < .001). Further, disclosure to one's health care provider significantly increased the likelihood of having tested for HIV in the past 12months among foreign-born and U.S.-born MSM. Findings highlight the need to better understand the risks and benefits of disclosure among foreign-born MSM. Future research may explore how responses and reactions to disclosure among foreign-born MSM shape pathways to HIV risk and prevention.

The role of syringe exchange programs and sexual identity in awareness of pre-exposure prophylaxis (PrEP) for male persons who inject drugs

BackgroundMale persons who inject drugs (male PWID) are at heightened risk for HIV, particularly if they also have sex with men. Pre-exposure prophylaxis (PrEP) could aid in HIV prevention for this population, but PrEP awareness within different sexual identities among male PWID is not well-understood. We report factors associated with greater awareness among male PWID to identify efficient means of awareness dissemination. MethodsData from the 2015 National HIV Behavioral Surveillance (NHBS) system cycle on injection drug use collected in New York City (NYC) were used. Bivariable analyses, using chi-squared statistics, were conducted to examine correlates of awareness of PrEP with socio-demographic, behavioral, and health care variables. Log-linked Poisson regression with robust standard errors was used to estimate adjusted prevalence ratios and determine differences in awareness of PrEP. ResultsAmong a sample of 332 male PWID (i.e., PWID who identified as male, not transgender) we find awareness of PrEP to be low (23%) among male PWID despite 68% reporting condomless vaginal/anal sex and 32% reporting injection equipment sharing in the last twelve months. Multivariable analysis found greater PrEP awareness associated with gay or bisexual identity (aPR: 2.77, 95% CI: 1.81–4.24) and having a conversation about HIV prevention at a syringe exchange program (SEP) (aPR: 2.71, 95% CI: 1.87–3.94) to be associated with increased PrEP awareness. ConclusionWe found low rates of PrEP awareness among male PWID. However, our findings provide insight into information diffusion that can be utilized to increase PrEP awareness among male PWID and among all PWID. We suggest that gay and bisexual social networks and syringe exchange programs are diffusing PrEP awareness among male PWID and can be harnessed to increase PrEP awareness among male PWID.

Estimating the size of HIV-negative MSM population that would benefit from pre-exposure prophylaxis in Florida

PurposeThis study aimed to estimate the size of the population of men who have sex with men (MSM) in Florida with high-risk behaviors that would indicate eligibility for pre-exposure prophylaxis (PrEP) use. MethodsThree methods were used to estimate the MSM population. Estimates from the three methods were averaged, and the number of MSM living with HIV in each zone improvement plan (ZIP) code was subtracted. ResultsThe average MSM estimate was 1–2184 men (1.5–22.9%) by ZIP code. The size of the MSM population with indications for PrEP use was highest when using estimates of MSM with more than one sex partner in the past year obtained from the National HIV Behavioral Surveillance system and lowest when the MSM estimate was multiplied by 24.7% (percentage of MSM with PrEP indications from other studies). ConclusionAreas with high numbers of MSM with PrEP indications could be targeted with information to reduce HIV acquisition.

Using Syndemics Theory to Examine HIV Sexual Risk Among Latinx Men Who Have Sex with Men in Philadelphia, PA: Findings from the National HIV Behavioral Surveillance.

Latinx men who have sex with men (MSM) continue to be disproportionately impacted by HIV/AIDS. Identifying the role of multiple syndemic factors associated with sexual risk behaviors is imperative in order to develop effective prevention and treatment strategies. Cross-sectional data for this study were derived from three cycles of the Philadelphia portion of the National HIV Behavioral Surveillance System. This study explored the impact of syndemic factors - heavy drinking, exchange sex, and homophobic discrimination - on sexual HIV risk behaviors, operationalized as number of male partners, and condomless anal intercourse (CAI) with main and casual partners among Latinx MSM (n=464). Analyses took two forms: a syndemic approach, using the cumulative number of conditions as an independent variable; and a non-syndemic approach, incorporating each condition as a unique factor. In multivariable syndemic analyses, participants with two or more factors reported more male partners and more CAI casual male partners than those with none. In non-syndemic models, homophobic discrimination and exchange sex were significantly positively associated with total number of male partners, while heavy drinking was associated with more casual CAI partners. Quantitative results indicate that syndemic and non-syndemic approaches vary in their relative capacity to account for sexual risk among Latinx MSM.

Population Size Estimation Using Multiple Respondent-Driven Sampling Surveys.

Respondent-driven sampling (RDS) is commonly used to study hard-to-reach populations since traditional methods are unable to efficiently survey members due to the typically highly stigmatized nature of the population. The number of people in these populations is of primary global health and demographic interest and is usually hard to estimate. However, due to the nature of RDS, current methods of population size estimation are insufficient. We introduce a new method of estimating population size that uses concepts from capture-recapture methods while modeling RDS as a successive sampling process. We assess its statistical validity using information from the CDC's National HIV Behavioral Surveillance system in 2009 and 2012.

Cost-effectiveness of scaling-up HCV prevention and treatment in the United States for people who inject drugs.

To examine the cost-effectiveness of hepatitis C virus (HCV) treatment of people who inject drugs (PWID), combined with medication-assisted treatment (MAT) and syringe-service programs (SSP), to tackle the increasing HCV epidemic in the United States. HCV transmission and disease progression models with cost-effectiveness analysis using a health-care perspective. Rural Perry County, KY (PC) and urban San Francisco, CA (SF), USA. Compared with PC, SF has a greater proportion of PWID with access to MAT or SSP. HCV treatment of PWID is negligible in both settings. PWID data were collected between 1998 and 2015 from Social Networks Among Appalachian People, U Find Out, Urban Health Study and National HIV Behavioral Surveillance System studies. Three intervention scenarios modeled: baseline-existing SSP and MAT coverage with HCV screening and treatment with direct-acting antiviral for ex-injectors only as per standard of care; intervention 1-scale-up of SSP and MAT without changes to treatment; and intervention 2-scale-up as intervention 1 combined with HCV screening and treatment for current PWID. Incremental cost-effectiveness ratios (ICERs) and uncertainty using cost-effectiveness acceptability curves. Benefits were measured in quality-adjusted life-years (QALYs). For both settings, intervention 2 is preferred to intervention 1 and the appropriate comparator for intervention 2 is the baseline scenario. Relative to baseline, for PC intervention 2 averts 1852 more HCV infections, increases QALYS by 3095, costs $21.6 million more and has an ICER of $6975/QALY. For SF, intervention 2 averts 36 473 more HCV infections, increases QALYs by 7893, costs $872 million more and has an ICER of $11 044/QALY. The cost-effectiveness of intervention 2 was robust to several sensitivity analysis. Hepatitis C screening and treatment for people who inject drugs, combined with medication-assisted treatment and syringe-service programs, is a cost-effective strategy for reducing hepatitis C burden in the United States.

Changes in Characteristics and Behavior Among African American Men Who Have Sex with Men and Women in the Context of Reductions in HIV Diagnoses Among Women.

Men who have sex with men and women (MSMW) connect lower prevalence populations of women to higher prevalence populations of men who have sex with men only. We hypothesize that HIV testing and treatment among MSMW have increased in recent years, and this increase can help explain the declining rates of new HIV diagnoses among African American women. We analyzed data from 2008, 2011, and 2014 of the National HIV Behavioral Surveillance system. African American men who have sex with men (MSM) were surveyed from 19 United States cities using venue-based sampling and tested for HIV infection. We used generalized estimating equations, using year of survey as an independent variable, adjusting for age, to determine differences for selected outcomes regarding healthcare and risk behaviors over time. Among the 1299 African American MSMW interviewed, significant increases were observed in the percent of men who had an HIV test in the previous 12months (2008: 54%, 2011: 69%, and 2014: 68%, p-value < 0.001). Among HIV-positive men, the percentage of men who were aware of their infection at the time of the interview increased significantly over time (26, 35, and 48%, p-value = 0.002). Among those men, the percentage who reported currently being on antiretroviral therapy also increased significantly over time (46, 69, and 72%, p-value = 0.050). The percentage of men reporting high-risk sexual risk behaviors increased or remained stable. Our findings support the hypothesis that HIV testing and treatment has increased among African American MSM from 2008 to 2014. Additional research is needed to fully explore the population-level impact it has on HIV transmission among women.