To reduce the number of undiagnosed cases of HIV, the National Institute on Drug Abuse launched a research initiative to seek out people with undiagnosed HIV. Called the “Seek, Test, Treat and Retain (STTR) model,” the objective is to test those with undiagnosed HIV and provide medical care to those infected in a timely fashion.
“Undiagnosed HIV is a serious public health issue,” said Marya Viorst Gwadz, PhD, Principal Investigator from the Center for Drug Use and HIV Research (CDUHR) at New York University Rory Meyers College of Nursing. “At least a third of new HIV transmission events are linked to those with undiagnosed HIV, yet finding people withundiagnosed HIV is very challenging.”
Those At Risk
Although HIV incidence rates in the United States have decreased, at least 44 000 people still contract the virus every year. According to additional estimates, about 15% of people nationwide are unaware that they are living with HIV.
Particularly at risk is the heterosexual population, which accounts for 24% of newly reported infections annually and is the primary means of transmission among women. Heterosexuals are also less likely to be tested for HIV.
According to Noelle R. Leonard, PhD, a CDUHR Co-Investigator, heterosexuals at high risk for HIV live in urban environments where there are high rates of poverty — a primary risk factor for HIV infection — and high rates of prevalent HIV.
“Heterosexuals at high risk for HIV, who are mainly African American/Black and Hispanic, have serious barriers to HIV testing,” Dr Leonard explained. “Many of the barriers are related to race/ethnicity and lower social status, including: fear of HIV stigma; distrust of medical settings; substance use problems; and the sense that heterosexuals are not at risk for HIV compared to other risk groups — such as men who have sex with men or persons who inject drugs.”
The STTR Model
Dr Gwadz and her research team compared the efficacy of 3 social/behavioral intervention strategies for heterosexual individuals at high risk (HHR) for HIV within an urban high-risk area (HRA) in central Brooklyn, New York.
The study examined 3 Seek/Test methods: Respondent Driven Sampling with Anonymous Single-session Testing (RDS-AST), Respondent Driven Sampling with Confidential Two-session Testing (RDS-CTT), and Venue-based Sampling (VBS).1
“The 3 interventions were designed to address the specific barriers to HIV testing that HHR experience, and all 3 interventions were culturally appropriate for African American/Black and Hispanic HHR,” said Dr Gwadz.
Participants in all 3 interventions had high rates of behavioral factors that pose a risk for HIV: poverty, unemployment, substance use, and incarceration. But the participants also demonstrated low rates of regular, annual HIV testing.
The prevalence of confirmed newly diagnosed HIV infection was higher in the RDS-AST (4%) and RDS-CTT (1%) interventions than VBS (0.3%). Those in RDS-AST were least likely to have regular, annual HIV testing and most likely to have both sexual and substance use risk factors compared with RDS-CTT and VBS.
Of those in RDS-AST, 60% evidenced substance use problems at a clinically significant level in the past year, compared with 37% in RDS-CTT. RDS-AST and RDS-CTT yielded comparable overall HIV prevalence rates (10.3% and 7.4%) — substantially higher than national estimates among HHR. VBS was feasible but produced a sustainability lower proportion of newly diagnosed HIV than the 2 RDS approaches.
“Our study findings suggest VBS is not an optimal approach for HHR, perhaps because heterosexuals at high-risk for HIV are embedded in physical spaces that include lower-risk individuals, and VBS is an inefficient means of gaining access to those at highest risk,” said Dr Leonard. “These findings, on the other hand, underscore the utility of peer-to-peer recruitment methods such as RDS, particularly in conjunction with low-threshold and easy-access interventions that provide HIV testing at the first contact, and which directly ameliorate potential barriers such as perceived HIV stigma.”
The researchers noted that rates of newly diagnosed HIV found in this study were lower than initially hypothesized, which could result from effective HIV prevention strategies implemented in New York City. Lower rates of newly diagnosed HIV in RDS-CTT intervention compared with RDS-AST also suggest that variations in the timing and content of intervention components could affect sample composition and the intervention’s efficiency with respect to uncovering undiagnosed HIV infection.
Nonetheless, this study — the first to demonstrate the value of potentially replicable Seek and Test interventions to identify HHR with undiagnosed HIV — offers further support for utility of community network approaches to identify undiagnosed HIV in vulnerable populations.
“Implemented on a continual basis in urban HRAs, such approaches can complement institutionally-based HIV testing programs and play a vital role in eliminating HIV transmission by promoting regular HIV testing among populations at high risk for HIV, including substance users,” Dr Gwadz said.
1. Cleland C, Gwadz M, Hagan H, Perlman D, et al. Public Health Benefit of Peer-Referral Strategies for Detecting Undiagnosed HIV Infection among High-Risk Heterosexuals in New York City. JAIDS Journal of Acquired Immune Deficiency Syndromes. 2016; doi:10.1097/QAI.0000000000001257