An Innovative Approach to Assess Similarity Between Sex Partners.

We present a simple, comprehensive method for assessing similarity between sex partners of a participant and demonstrate its application using data collected in 2015 as part of CDC's National HIV behavioral surveillance (NHBS) among persons who inject drugs (PWID). We found that the pairwise similarity between sex partners of a survey participant was high. The similarity between second-to-last and third-to-last partners in the past 3 months was significantly higher than that between last and second-to-last partner in partner type, frequency of sex acts, and the contextual characteristics of sex behavior at last sexual encounter. The proposed approach provides an innovative measure of the added value of multi-partner series. The empirical analysis suggests that querying additional sex partners contributes limited data to characterize a participant's sexual behaviors among NHBS PWID. Future studies should apply the proposed method to evaluate the added value of data on multiple sex partners among other populations.

Antiretroviral Therapy Use Among HIV-Infected People Who Inject Drugs-20 Cities, United States, 2009-2015.

BACKGROUND: Approximately 16% of infections among those living with diagnosed HIV infection in the United States are attributable to injection drug use. Antiretrovirals (ARVs) are recommended for all infected persons to improve health and prevent transmission. Using data from National HIV Behavioral Surveillance, we evaluated changes in ARV use from 2009 to 2015 among HIV-positive people who inject drugs (PWID). METHODS: PWID were recruited by respondent-driven sampling in 20 cities. ARV use was defined as self-reported use at the time of interview. Prevalence ratios measuring change in ARV use per 3-year increase in year were estimated using log-linked Poisson regression models with generalized estimating equations. RESULTS: ARV use was 58% (319/548) in 2009, 67% (410/608) in 2012, and 71% (386/545) in 2015. In all 3 cycle years, a higher percentage of ARV treatment was observed among males, PWID of older age (≥50), and PWID with current health insurance. ARV use increased overall, with an adjusted relative increase of 8% per every 3-year increase in year (adjusted prevalence ratio 1.08, 95% confidence interval: 1.03 to 1.12). ARV use also increased among most subgroups. CONCLUSIONS: These findings show progress in ARV treatment, although ARV coverage remains low compared with other populations at risk for HIV. Efforts to improve ARV coverage among PWIDs are needed.

Updated Data on Linkage to Human Immunodeficiency Virus Care and Antiretroviral Treatment Among Men Who Have Sex With Men-20 Cities, United States.

We examined differences in prevalence of linkage to care and antiretroviral (ARV) treatment among human immunodeficiency virus (HIV)-positive men who have sex with men (MSM) between 2008 and 2014 in National HIV Behavioral Surveillance. Prevalence of linkage to care increased from 79% in 2008 to 87% in 2014 (prevalence ratio [PR], 1.05; 95% confidence interval [CI], 1.03-1.07). ARV treatment increased from 69% in 2008 to 88% in 2014 (adjusted PR, 1.15; 95% CI, 1.12-1.18). Despite these increases, a large disparity in ARV treatment between white and black MSM remains. Increased resources are needed to support immediate referrals for ARV treatment for all MSM newly diagnosed with HIV.

Estimated HIV Inter-test Interval Among People at High Risk for HIV Infection in the U.S.

INTRODUCTION: Knowing the HIV testing frequency and its temporal changes are central to evaluate public adherence to HIV testing recommendations and performance of HIV prevention programs. This study intended to estimate the mean HIV inter-test interval (ITI) and monitor its trends among men who have sex with men (MSM); people who inject drugs (PWID); and high-risk heterosexuals (HRH). METHODS: Using National HIV Behavioral Surveillance data collected during 2008-2015, this analysis estimated the mean HIV ITI for each year by race/ethnicity and age among MSM, PWID, and HRH who reported the most recent HIV test date. Separate statistical models based on renewal process theory were fit using PROC NLIN with Newton-Raphson method. Estimated mean HIV ITI lengths were compared using the z-test. RESULTS: Estimated HIV ITI generally decreased in the past decade among MSM, PWID, and HRH who reported the most recent HIV test date. In most recent study years, estimated HIV ITI (in months) ranged from 5.8 to 12.5 among MSM, from 9.0 to 13.1 among PWID, and from 15.3 to 26.7 among HRH. Within each risk group, estimated HIV ITI was shortest among blacks and individuals aged 18-24 years. CONCLUSIONS: People at high risk for HIV infection who ever tested for HIV tested more frequently in the past decade. Most recently, MSM and PWID largely adhered to the Centers for Disease Control and Prevention's HIV testing recommendations, but HRH tested less frequently. Identifying factors associated with infrequent testing among HRH may provide information for future HIV testing initiatives.

Comprehensive HIV Prevention for Transgender Persons.

Transgender persons are at high risk for HIV infection, but prevention efforts specifically targeting these people have been minimal. Part of the challenge of HIV prevention for transgender populations is that numerous individual, interpersonal, social, and structural factors contribute to their risk. By combining HIV prevention services with complementary medical, legal, and psychosocial services, transgender persons' HIV risk behaviors, risk determinants, and overall health can be affected simultaneously. For maximum health impact, comprehensive HIV prevention for transgender persons warrants efforts targeted to various impact levels-socioeconomic factors, decision-making contexts, long-lasting protections, clinical interventions, and counseling and education. We present current HIV prevention efforts that reach transgender persons and present others for future consideration.

Early Linkage to HIV Care and Antiretroviral Treatment among Men Who Have Sex with Men--20 Cities, United States, 2008 and 2011.

Early linkage to care and antiretroviral (ARV) treatment are associated with reduced HIV transmission. Male-to-male sexual contact represents the largest HIV transmission category in the United States; men who have sex with men (MSM) are an important focus of care and treatment efforts. With the release of the National HIV/AIDS Strategy and expanded HIV treatment guidelines, increases in early linkage to care and ARV treatment are expected. We examined differences in prevalence of early linkage to care and ARV treatment among HIV-positive MSM between 2008 and 2011. Data are from the National HIV Behavioral Surveillance System, which monitors behaviors among populations at high risk of HIV infection in 20 U.S. cities with high AIDS burden. MSM were recruited through venue-based, time-space sampling. Prevalence ratios comparing 2011 to 2008 were estimated using linear mixed models. Early linkage was defined as an HIV clinic visit within 3 months of diagnosis. ARV treatment was defined as use at interview. Prevalence of early linkage to care was 79% (187/236) in 2008 and 83% (241/291) in 2011. In multivariable analysis, prevalence of early linkage did not differ significantly between years overall (P = 0.44). Prevalence of ARV treatment was 69% (790/1,142) in 2008 and 79% (1,049/1,336) in 2001. In multivariable analysis, ARV treatment increased overall (P = 0.0003) and among most sub-groups. Black MSM were less likely than white MSM to report ARV treatment (P = 0.01). While early linkage to care did not increase significantly between 2008 and 2011, ARV treatment increased among most sub-groups. Progress is being made in getting MSM on HIV treatment, but more efforts are needed to decrease disparities in ARV coverage.

Trends in HIV prevalence and HIV testing among young MSM: five United States cities, 1994-2011.

We examined trends in cross-sectional HIV prevalence (a surrogate for incidence) and past 12 month testing behavior among young men who have sex with men (MSM). The Young Men's Survey and the National HIV Behavioral Surveillance System conducted interviews and HIV testing among MSM recruited by venue-based sampling during 1994-2011. Using data from five cities, we determined whether interview year was associated with HIV prevalence and recent testing for MSM ages 18-22 and 23-29 years, after adjusting for city, race/ethnicity, and education. Multivariable analysis demonstrated an overall increase in prevalence among MSM ages 23-29 years, driven by an increase in Baltimore. There was no change in HIV prevalence among MSM ages 18-22 years overall, although prevalence increased in Baltimore. HIV testing increased significantly for both age groups. Gains in HIV testing are encouraging, but increasing prevalence among young MSM in Baltimore suggests increasing incidence and the need for additional efforts for this population.

HIV risk, prevention, and testing behaviors among men who have sex with men--National HIV Behavioral Surveillance System, 21 U.S. cities, United States, 2008.

PROBLEM/CONDITION: Approximately 1.1 million persons in the United States are living with human immunodeficiency virus (HIV) infection. More than half of those infected are men who have sex with men (MSM). REPORTING PERIOD: June-December 2008. DESCRIPTION OF SYSTEM: The National HIV Behavioral Surveillance (NHBS) System collects risk behavior data from three populations at high risk for HIV infection: MSM, injection-drug users, and heterosexual adults at increased risk for HIV infection. Data for NHBS are collected in rotating cycles. NHBS participants must be aged ≥18 years, live in a participating metropolitan statistical area, and be able to complete a behavioral survey in English or Spanish. Men who reported being infected with HIV or who had no male sex partners during the past 12 months were excluded from this analysis. RESULTS: This report summarizes data gathered from 8,175 MSM during the second data collection cycle of NHBS. In addition to having at least one male sex partner, 14% of participants had at least one female sex partner during the past 12 months. Unprotected anal intercourse with a male partner was reported by 54% of the participants; 37% reported having unprotected anal sex with a main male partner (someone with whom the participant had sex and to whom he felt most committed, such as a boyfriend, spouse, significant other, or life partner), and 25% reported having unprotected anal sex with a casual male partner (someone with whom the participant had sex but with whom he did not feel committed, did not know very well, or had sex with in exchange for something such as money or drugs). Noninjection drug use during the past 12 months was reported by 46% of participants. Specifically, 38% used marijuana, 18% cocaine, 13% poppers (amyl nitrate), and 11% ecstasy. Two percent of the participants reported injecting drugs for nonmedical purposes in the past 12 months. Of the participants surveyed, 90% had been tested for HIV during their lifetime, 62% had been tested during the past 12 months, 51% had received a hepatitis vaccination, 35% had been tested for syphilis during the past 12 months, and 18% had participated in an individual- or group-level HIV behavioral intervention. INTERPRETATION: MSM in the United States continue to engage in sexual and drug-use behaviors that increase the risk for HIV infection. Although many MSM had been tested for HIV infection, many had not received hepatitis vaccinations or syphilis testing, and only a small proportion had recently participated in a behavioral intervention. PUBLIC HEALTH ACTION: To reduce HIV infection among MSM, additional effort is needed to decrease the number of men who are engaging in risk behaviors while increasing the number who recently have been tested for HIV. The National HIV/AIDS Strategy for the United States delineates a coordinated response to reduce infections and HIV-related health disparities among MSM and other disproportionately affected groups. NHBS data can be used to monitor progress toward the goals of the national strategy and to guide national and local planning efforts to maximize the impact of HIV prevention programs.

HIV prevalence and associated risk behaviors in New York City's house ball community.

OBJECTIVES: We measured HIV seroprevalence and associated risk factors among persons in New York City's house ball community. METHODS: In 2004 we conducted a venue-based risk-behavior survey and HIV testing in the house ball community. RESULTS: Of the 504 study participants, 67% were male, 14% female, and 18% transgender. Mean age was 24 years (range=15-52 years); 55% were Black, and 40% were Latino. More than 85% of participants had previously been tested for HIV, although only 60% had been tested in the previous 12 months. Of the 84 (17%) persons who tested positive for HIV in our study, 61 (73%) were unaware of their HIV status. A logistic regression analysis on data from 371 participants who had had a male sexual partner in the previous 12 months showed that HIV-infected participants were more likely than were HIV-negative participants to be Black, to be older than 29 years, and not to have been tested for HIV in the previous 12 months. CONCLUSIONS: Culturally specific community-level prevention efforts are warranted to reduce risk behaviors and increase the frequency of HIV testing in New York City's house ball community.

Estimating HIV prevalence and risk behaviors of transgender persons in the United States: a systematic review.

Transgender populations in the United States have been impacted by the HIV/AIDS epidemic. This systematic review estimates the prevalence of HIV infection and risk behaviors of transgender persons. Comprehensive searches of the US-based HIV behavioral prevention literature identified 29 studies focusing on male-to-female (MTF) transgender women; five of these studies also reported data on female-to-male (FTM) transgender men. Using meta-analytic approaches, prevalence rates were estimated by synthesizing weighted means. Meta-analytic findings indicated that 27.7% (95% confidence interval [CI], 24.8-30.6%) of MTFs tested positive for HIV infection (four studies), while 11.8% (95% CI, 10.5-13.2%) of MTFs self-reported being HIV-seropositive (18 studies). Higher HIV infection rates were found among African-American MTFs regardless of assessment method (56.3% test result; 30.8% self-report). Large percentages of MTFs (range, 27-48%) reported engaging in risky behaviors (e.g., unprotected receptive anal intercourse, multiple casual partners, sex work). Prevalence rates of HIV and risk behaviors were low among FTMs. Contextual factors potentially related to increased HIV risk include mental health concerns, physical abuse, social isolation, economic marginalization, and unmet transgender-specific healthcare needs. Additional research is needed to explain the causes of HIV risk behavior of transgender persons. These findings should be considered when developing and adapting prevention interventions for transgender populations.

Developing an HIV behavioral surveillance system for injecting drug users: the National HIV Behavioral Surveillance System.

While disease surveillance for HIV/AIDS is now widely conducted in the United States, effective HIV prevention programs rely primarily on changing behavior; therefore, behavioral data are needed to inform these programs. To achieve the goal of reducing HIV infections in the U.S., the Centers for Disease Control and Prevention, in cooperation with state and local health departments, implemented the National HIV Behavioral Surveillance System (NHBS) for injecting drug users (IDUs) in 25 selected metropolitan statistical areas (MSAs) throughout the United States in 2005. The surveillance system used respondent-driven sampling (RDS), a modified chain-referral method, to recruit IDUs for a survey measuring HIV-associated drug use and sexual risk behavior. RDS can produce population estimates for specific risk behaviors and demographic characteristics. Formative assessment activities-primarily the collection of qualitative data-provided information to better understand the IDU population and implement the surveillance activities in each city. This is the first behavioral surveillance system of its kind in the U.S. that will provide local and national data on risk for HIV and other blood-borne and sexually transmitted infections among IDUs for monitoring changes in the epidemic and prevention programs.