Socially-integrated transdisciplinary HIV prevention

Changes in Stigma and Social Support among Participants in a Randomized Trial of a Novel Expanded Social Network-based HIV Testing Intervention in KwaZulu-Natal, South Africa

HIV-related stigma is a well-documented barrier to HIV testing in South Africa, and may be particularly likely to create reluctance to test among South African men, who have reported feeling blamed for HIV by their partners and communities. The present study presents a novel expanded social network recruitment to HIV testing (E-SNRHT) intervention explicitly designed to reduce stigma as a barrier to testing by asking people to recruit anyone they know to testing, thus allowing them to avoid the potential for increased stigma and/or blame associated with direct risk partner recruitment, and helping to normalize openly discussing HIV among social networks. We examined baseline and 6-10-week follow-up data from a 2022-2023 randomized trial in KwaZulu-Natal, South Africa that recruited 110 individuals who had been newly diagnosed with HIV and randomly assigned them to recruit people to HIV testing either via the E-SNRHT intervention or via risk network recruitment. Participants in the E-SNRHT intervention reported significant decreases in anticipated and enacted HIV-related stigma between baseline and follow-up; and the E-SNRHT intervention was more effective at decreasing enacted HIV-related stigma than was risk network recruitment. Individuals newly diagnosed with HIV by the E-SNRHT intervention reported significant increases in social support between intervention enrollment and follow-up, and all of these individuals reported participating in positive conversations about HIV services with peers in the 6-10 weeks after intervention enrollment. These findings suggest that E-SNRHT is a potentially important strategy to reduce HIV-related stigma as a barrier to HIV testing among peer networks in KwaZulu-Natal.

Impact of war on HIV-related healthcare services and health workers in eastern Ukraine: a qualitative study

The 2022 Russian invasion of Ukraine has caused serious challenges for healthcare workers (HCWs) and HIV-related healthcare services. This study assessed the effects of the invasion on HCWs wellbeing and on continuity of HIV services, using in-depth interviews with HCWs from facilities offering HIV antiretroviral therapy (ART) and pre-exposure prophylaxis (PrEP) services in the Donetsk region of Eastern Ukraine. A directed content analysis, with both inductive and deductive approaches, was conducted. Ten HCWs (6 [60%] doctors, 4 [40%] nurses; 9 [90%] female) were interviewed. Six respondents were displaced from their homes and worksites, and all described stress and threats to emotional wellbeing. HCWs used online consultations, encrypted mobile communication, and multi-month dispensing to support continuity of ART and PrEP services. They noted immediate needs for psychological and financial support, and access to laptop computers and mobile communications to ensure continuity of HIV services. Priorities for restoration of services include repair of health facilities, restoration of laboratory services and supply chains, and return of personnel and patients. HCWs made innovative, rapid adaptations to HIV services to keep ART and PrEP services running, demonstrating the resolve of Ukrainian HCWs to maintain continuity of HIV services despite the disruptions of war.

Integration of a geospatially targeted community-based testing approach with respondent-driven sampling to identify people who inject drugs living with HIV and HCV in Patti and Gorakhpur, India

BACKGROUND

Respondent-driven sampling (RDS), a network recruitment approach, is effective at reaching people who inject drugs (PWID), but other strategies may be needed to reach PWID at risk or living with HIV and/or Hepatitis C (HCV). We examined the impact of integrating geospatially targeted community-based HIV/HCV testing with an RDS survey.

METHODS

PWID were recruited between 2019 and 2021 in Patti and Gorakhpur, India, in a two-phased approach for identifying PWID living with HIV/HCV. Phase 1 was an RDS survey, in which participants reported injection venues. Venues with the highest prevalence of HIV/HCV viremia were selected for Phase 2: community-based testing. All participants underwent rapid HIV and HCV testing and viral load quantification. Using Pearson's chi-squared test, two-sided exact significance tests, and t-tests, we compared prevalence and identification rates for each of the primary outcomes: the number of PWID 1) living with HIV/HCV, 2) undiagnosed, and 3) viremic.

RESULTS

Both approaches identified large numbers of PWID (n∼500 each; N=2011) who were living with HIV/HCV and had transmission potential (i.e., detectable viremia). The community-based approach identified a higher proportion of individuals living with HCV (76.4% vs. 69.6% in Gorakhpur and 36.3% vs. 29.0% in Patti). Community-based testing was also faster at identifying PWID with detectable HIV viremia. Both approaches identified PWID with varying demographic characteristics.

CONCLUSIONS

Community-based testing was more efficient than RDS overall, but both may be required to reach PWID of varying characteristics. Surveillance should collect data on injection venues to facilitate community-based testing and maximize case identification.

Methods for Assessing Spillover in Network-Based Studies of HIV/AIDS Prevention among People Who Use Drugs

Human Immunodeficiency Virus (HIV) interventions among people who use drugs (PWUD) often have spillover, also known as interference or dissemination, which occurs when one participant's exposure affects another participant's outcome. PWUD are often members of networks defined by social, sexual, and drug-use partnerships and their receipt of interventions can affect other members in their network. For example, HIV interventions with possible spillover include educational training about HIV risk reduction, pre-exposure prophylaxis, or treatment as prevention. In turn, intervention effects frequently depend on the network structure, and intervention coverage levels and spillover can occur even if not measured in a study, possibly resulting in an underestimation of intervention effects. Recent methodological approaches were developed to assess spillover in the context of network-based studies. This tutorial provides an overview of different study designs for network-based studies and related methodological approaches for assessing spillover in each design. We also provide an overview of other important methodological issues in network studies, including causal influence in networks and missing data. Finally, we highlight applications of different designs and methods from studies of PWUD and conclude with an illustrative example from the Transmission Reduction Intervention Project (TRIP) in Athens, Greece.

Recent HIV Infection: Diagnosis and Public Health Implications

The early period of infection with human immunodeficiency virus (HIV) has been associated with higher infectiousness and, consequently, with more transmission events. Over the last 30 years, assays have been developed that can detect viral and immune biomarkers during the first months of HIV infection. Some of them depend on the functional properties of antibodies including their changing titers or the increasing strength of binding with antigens over time. There have been efforts to estimate HIV incidence using antibody-based assays that detect recent HIV infection along with other laboratory and clinical information. Moreover, some interventions are based on the identification of people who were recently infected by HIV. This review summarizes the evolution of efforts to develop assays for the detection of recent HIV infection and to use these assays for the cross-sectional estimation of HIV incidence or for prevention purposes.

Mental Health and Perceived Access to Care among People Who Inject Drugs in Athens, Greece

Poor mental health among human immunodeficiency virus (HIV)-positive people who inject drugs (PWID) may contribute to stigma, and together they act as barriers to medical care. This analysis aims to examine factors associated with the mental health of PWID and their network contacts, and the association of poor mental health with the experience of HIV-related stigmatizing events, with HIV-related social support, and with perceived access to care. Data were collected during the Transmission Reduction Intervention Project (TRIP) conducted in Athens, Greece (2013-2015). PWID (n = 292; n = 122 HIV-positive) were interviewed both at baseline and follow-up. Items of depression, anxiety, and general positive affect subscales of the Mental Health Inventory were used to explore the psychological distress and well-being of participants at follow-up. Items of the Access to Care Scale were used to evaluate perceived access to medical care at baseline and follow-up. Linear regression showed that unemployment was positively related to depression (β = 1.49, p = 0.019), while injecting drug use was a risk factor for a low general positive affect score (β = -3.21, p = 0.015). Poor mental health was not linked to HIV-related stigma or social support. Positive perception of access to care was associated in multivariable analyses with low depression (β = -0.22, p = 0.049). The perceived access to care score improved from baseline to follow-up (p = 0.019) and HIV-positive participants had a higher score than HIV-negative participants. Future interventions should include targets to improve the mental well-being of participants, reduce psychosocial distress, and minimize perceived barriers to accessing medical care.

Drug Injection-Related Norms and High-Risk Behaviors of People Who Inject Drugs in Athens, Greece

Drug use involves social interactions. Therefore, norms in the proximal environment of people who inject drugs (PWID) can favor behaviors that may result in HIV transmission. This work aimed at studying drug injection-related norms and their potential association with risky behaviors among PWID in Athens, Greece, in the context of economic recession and political activism that followed the fiscal crisis and soon after a recent HIV outbreak had leveled off. The Transmission Reduction Intervention Project (TRIP) was a social network-based approach (June 2013 to July 2015) that involved two groups of PWID seeds-with recent HIV infection and with long-term HIV infection and one control group of HIV-negative PWID. Network contacts of seeds were also enrolled. TRIP participants answered a questionnaire that included items on injection-related norms and behaviors. TRIP recruited 320 PWID (HIV positive, 44.4%). TRIP participants, especially those without HIV, often recalled or perceived as normative among their partners and in their networks some behaviors that can lead to HIV transmission. TRIP participants who recalled that they were encouraged by their regular drug partners to use an unclean syringe were almost twice as likely to report that they share syringes [odds ratio (OR) = 2.03; 95% confidence interval (CI) = 1.86-2.21], or give syringes to someone else (OR = 1.70; 95% CI = 1.42-2.04) as those who did not recall such an encouragement. Associations were modified by HIV status. HIV negatives, who were reportedly encouraged to share nonsyringe injecting equipment, were almost 4.5 times as likely to share that material as HIV-negative participants who were not encouraged (OR = 4.59, 95% CI = 4.12-5.11). Further research is needed on the multiple determinants (social, economic, and political) of norms in the social environments of PWID. Since peer norms are associated with risky behaviors, interventions should be developed to encourage norms and peer pressure against the sharing of injection equipment.

Sociometric Risk Network Structure, HIV Prevalence, and Drug Injection-Related Norms among People Who Inject Drugs (PWID) in Athens, Greece

Background: Structural properties of sociometric networks have been associated with behaviors related to HIV transmission. Very few studies, however, have explored the correlation between sociometric network factors and drug injection-related norms. Methods: This exploratory work: (i) describes basic structural qualities of a sociometric risk network of participants in the Transmission Reduction Intervention Project (TRIP) in Athens, Greece, in the context of a large HIV outbreak among people who inject drugs (PWID); (ii) measures HIV prevalence within specific structures within the sociometric risk network of PWID in TRIP; and (iii) explores the association of structural properties of the sociometric risk network in TRIP with drug injection-related norms. Results: The sociometric risk network in TRIP consisted of a large component (n = 241, 67.8%), a few small components (n = 36, 10.1%) with 2-10 individuals each, and some isolates (n = 79, 22.2%). HIV prevalence was significantly higher in the large component (55.6%), the 2-core (59.1%) and 3-core (66.3%) of the large component, and the 3-cliques of the cores. Drug injection-related norms were significantly associated with structural characteristics of the sociometric risk network. A safe behavioral pattern (use of unclean cooker/filter/rinse water was never encouraged) was significantly (p = 0.03) less normative among people who TRIP participants of the 2-core injected with (40.5%) than among network contacts of TRIP participants outside the 2-core (55.6%). On the contrary, at drug-using venues, 2-core members reported that safer behaviors were normative compared to what was reported by those without 2-core membership. Conclusions: Sociometric network data can give useful insights into HIV transmission dynamics and inform prevention strategies.Supplemental data for this article is available online at https://doi.org/10.1080/10826084.2021.1914103 .

Phylodynamics Helps to Evaluate the Impact of an HIV Prevention Intervention

Assessment of the long-term population-level effects of HIV interventions is an ongoing public health challenge. Following the implementation of a Transmission Reduction Intervention Project (TRIP) in Odessa, Ukraine, in 2013-2016, we obtained HIV pol gene sequences and used phylogenetics to identify HIV transmission clusters. We further applied the birth-death skyline model to the sequences from Odessa (n = 275) and Kyiv (n = 92) in order to estimate changes in the epidemic's effective reproductive number (Re) and rate of becoming uninfectious (δ). We identified 12 transmission clusters in Odessa; phylogenetic clustering was correlated with younger age and higher average viral load at the time of sampling. Estimated Re were similar in Odessa and Kyiv before the initiation of TRIP; Re started to decline in 2013 and is now below Re = 1 in Odessa (Re = 0.4, 95%HPD 0.06-0.75), but not in Kyiv (Re = 2.3, 95%HPD 0.2-5.4). Similarly, estimates of δ increased in Odessa after the initiation of TRIP. Given that both cities shared the same HIV prevention programs in 2013-2019, apart from TRIP, the observed changes in transmission parameters are likely attributable to the TRIP intervention. We propose that molecular epidemiology analysis can be used as a post-intervention effectiveness assessment tool.

Social network approaches to locating people recently infected with HIV in Odessa, Ukraine

Introduction

This paper examines the extent to which an intervention succeeded in locating people who had recently become infected with HIV in the context of the large‐scale Ukrainian epidemic. Locating and intervening with people who recently became infected with HIV (people with recent infection, or PwRI) can reduce forward HIV transmission and help PwRI remain healthy.

Methods

The Transmission Reduction Intervention Project (TRIP) recruited recently‐infected and longer‐term infected seeds in Odessa, Ukraine, in 2013 to 2016, and asked them to help recruit their extended risk network members. The proportions of network members who were PwRI were compared between TRIP arms (i.e. networks of recently‐infected seeds vs. networks of longer‐term infected seeds) and to the proportion of participants who were PwRI in an RDS‐based Integrated Biobehavioral Surveillance of people who inject drugs in 2013.

Results

The networks of PwRI seeds and those of longer‐term infected seeds had similar (2%) proportions who were themselves PwRI. This was higher than the 0.25% proportion in IBBS (OR = 7.80; p = 0.016). The odds ratio among the subset of participants who injected drugs was 11.17 (p = 0.003). Cost comparison analyses using simplified ingredients‐based methods found that TRIP spent no more than US $4513 per PwRI located whereas IBBS spent $11,924.

Conclusions

Further research is needed to confirm these results and improve TRIP further, but our findings suggest that interventions that trace the networks of people who test HIV‐positive are a cost‐effective way to locate PwRI and reduce HIV transmission and should therefore be implemented.

People with high HIV viral load within risk networks: who are these people and who refers them best?

Introduction:

Viral load is one of the most important determinants for HIV transmission. Identification of people with high viral load (PHVL) can be effective in limiting onward HIV transmission. In order to improve the identification of these individuals within risk networks, we determined a) the number of PHVL recruited through risk networks b) their socio-demographic, behavioural and clinical characteristics and c) the characteristics of individuals who referred these PHVL to the study.

Methodology:

From November 2013 to March 2016, in Odessa, Ukraine, Transmission Reduction Intervention Project (TRIP) was implemented to identify people recently infected with HIV within the risk networks of “seeds” and “venues” where they engaged in risk behaviour.

Results:

TRIP identified 53 PHVL, of whom 32 (60%) injected drugs; 42 (79%) were unaware of their HIV status; 25 (47%) had more than one sex partner, and only 14 (26%) were using condoms. There were 164 people who referred individuals into the study; 33 of them (20%) referred PHVL. In terms of referrers, those with lower than secondary level of education, not living with a sex partner, and reporting regular condom use were significantly more likely (p < 0.05) to refer PHVL. Most PHVL (38, 72%) and their referrers (27, 82%) were found through venues.

Conclusions:

In Odessa city, PHVL are at high risk of transmitting HIV as the majority inject drugs, do not know their HIV status, and have unprotected sex and/or multiple partners. Targeting these individuals for HIV prevention, harm reduction and initiation of antiretroviral treatment (ART) is urgent.

Risk network approaches to locating undiagnosed HIV cases in Odessa, Ukraine

INTRODUCTION

Providing HIV healthcare and Treatment as Prevention both depend on diagnosing HIV cases, preferably soon after initial infection. We hypothesized that tracing risk networks recruits higher proportions of undiagnosed positives than outreach-based testing or respondent-driven sampling (RDS) in Odessa, Ukraine.

METHODS

The Transmission Reduction Intervention Project (TRIP) used risk network tracing to recruit sexual and injection networks of recently-infected and longer-term infected (LTs) seeds (2013 to 2016). Integrated Biobehavioural Surveillance (IBBS) (2013) used RDS to recruit people who inject drugs (PWID). Outreach Testing tested PWID for HIV at community outreach sites (2013 to 2016). Proportions of undiagnosed positives among those tested were compared TRIP versus IBBS; TRIP versus Outreach Testing and between TRIP arms. Costs were compared across the projects.

RESULTS

TRIP tested 1252 people (21% women) in seeds' risk networks; IBBS tested 400 (18% women); Outreach Testing 13,936 (31% women). TRIP networks included a higher proportion of undiagnosed positives (14.6%) than IBBS (5.0%) or Outreach Testing (2.4%); odds ratio (OR) 3.25 (95% CI 2.07, 5.12) versus IBBS and 7.03 (CI 5.95, 8.31) versus Outreach Testing respectively. Findings remained significant in analyses stratified by sex and when PWID in TRIP networks were compared with Outreach Testing and IBBS. Within TRIP, recently-infected participants' networks contained higher proportions of undiagnosed positives (16.3%) than LTs' networks (12.2%); OR 1.41 (CI 1.01, 1.95). TRIP located undiagnosed positives less expensively than did RDS or Outreach Testing.

CONCLUSIONS

TRIP's recruiting techniques, including prioritizing networks of the recently infected, find undiagnosed HIV-positive people efficiently. They should be integrated with standard practice to improve case-finding. Research should test these techniques in other socio-epidemiologic contexts.

CLINICAL TRIAL REGISTRY

Registered ClinicalTrials.gov: NCT01827228.

Experiences of Stigma and Support Reported by Participants in a Network Intervention to Reduce HIV Transmission in Athens, Greece; Odessa, Ukraine; and Chicago, Illinois

A growing body of evidence suggests that network-based interventions to reduce HIV transmission and/or improve HIV-related health outcomes have an important place in public health efforts to move towards 90-90-90 goals. However, the social processes involved in network-based recruitment may pose a risk to participants of increasing HIV-related stigma if network recruitment causes HIV status to be assumed, inferred, or disclosed. On the other hand, the social processes involved in network-based recruitment to HIV testing may also encourage HIV-related social support. Yet despite the relevance of these processes to both network-based interventions and to other more common interventions (e.g., partner services), there is a dearth of literature that directly examines them among participants of such interventions. Furthermore, both HIV-related stigma and social support may influence participants' willingness and ability to recruit their network members to the study. This paper examines (1) the extent to which stigma and support were experienced by participants in the Transmission Reduction Intervention Project (TRIP), a risk network-tracing intervention aimed at locating recently HIV-infected and/or undiagnosed HIV-infected people and linking them to care in Athens, Greece; Odessa, Ukraine; and Chicago, Illinois; and (2) whether stigma and support predicted participant engagement in the intervention. Overall, experiences of stigma were infrequent and experiences of support frequent, with significant variation between study sites. Experiences and perceptions of HIV-related stigma did not change significantly between baseline and six-month follow-up for the full TRIP sample, and significantly decreased during the course of the study at the Chicago site. Experiences of HIV-related support significantly increased among recently-HIV-infected participants at all sites, and among all participants at the Odessa site. Both stigma and support were found to predict participants' recruitment of network members to the study at the Athens site, and to predict participants' interviewer-rated enthusiasm for naming and recruiting their network members at both the Athens and Odessa sites. These findings suggest that network-based interventions like TRIP which aim to reduce HIV transmission likely do not increase stigma-related risks to participants, and may even encourage increased social support among network members. However, the present study is limited by its associational design and by some variation in implementation by study site. Future research should directly assess contextual differences to improve understanding of the implications of site-level variation in stigma and support for the implementation of network-based interventions, given the finding that these constructs predict participants' recruitment of network members and engagement in the intervention, and thereby could limit network-based interventions' abilities to reach those most in need of HIV testing and care.

Knowledge, Normative Beliefs and Attitudes Related to Recent HIV Infection among People who Inject Drugs in Athens, Greece

BACKGROUND

Despite great improvements in prevention over the last years, much has to be done to reduce new human immunodeficiency virus (HIV) infections. Substantial evidence shows that the six-month period of recent HIV infection contributes disproportionately to HIV transmission.

OBJECTIVE

This study aims to investigate knowledge, normative beliefs, and attitudes of people who inject drugs (PWID) regarding recent HIV infection.

METHODS

People who inject drugs in Athens, Greece were recruited in the fifth round of a respondent- driven sampling program (ARISTOTLE). The participants were tested for HIV and answered a structured questionnaire, which also included items on knowledge, normative beliefs, and attitudes regarding recent infection to address needs of the social network-based Transmission Reduction Intervention Project. The multivariable analyses included logistic regression models, which produced odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

In total, 1,407 people (mean age: 36.3 ± 7.9 years old; males: 81.9%) took part in the fifth round of ARISTOTLE. Of these, 61.5% knew that HIV-infected people who are not on treatment are more likely to transmit HIV during the first six months of their infection and 58.4% reported that people in their network would react positively towards a recently HIV-infected person. People who inject drugs who were knowledgeable of recent HIV infection were more likely to disagree with statements such as that one should avoid all contact with a person recently infected by HIV (adjusted OR: 1.510, 95% CI: 1.090, 2.091) or more likely to agree with statements such as that an HIV+ person is much less likely to transmit HIV when h/she is on combination antiretroviral treatment (adjusted OR: 2.083, 95% CI: 1.231, 3.523).

CONCLUSION

A considerable proportion of PWID in Athens, Greece, were aware of the high HIV transmission risk of recent HIV infection, although improvement is needed for some population segments. People who inject drugs who were knowledgeable of the role of recent HIV infection were more likely to have normative beliefs and attitudes that favor behaviors that could help rather than harm or stigmatize people who have recently been infected with HIV. Interventions that are based on the role of recent HIV infection in HIV transmission could be important to HIV prevention.

Identifying, linking, and treating people who inject drugs and were recently infected with HIV in the context of a network-based intervention

Identifying and linking people to care soon after HIV infection could limit viral transmission and protect their health. This work aims at describing the continuum of care among recently HIV-infected people who inject drugs (PWID) and participated in an intervention in the context of an HIV outbreak in Athens, Greece. The Transmission Reduction Intervention Project (TRIP) conducted risk network-based contact tracing and screened people for recent HIV infection. A comprehensive approach with a case management component that aimed to remove barriers to accessing care was adopted. Follow-up data on antiretroviral treatment (ART) and HIV-RNA levels were obtained from HIV clinics. TRIP enrolled 45 recently HIV-infected PWID (80% male) with a median viral load at recruitment of 5.43 log₁₀ copies/mL. Of the recently infected persons in TRIP, 87% were linked to care; of these, 77% started ART; and of those on ART, 89% achieved viral load <200 copies/mL. TRIP and its public health allies managed to get most of the recently HIV-infected PWID who were identified by the program into care and many of them onto ART. This resulted in very low HIV-RNA levels. Treatment as prevention can work if individuals are aided in overcoming difficulties in entry to, or attrition from care.

Predictors of condom use behavior among men who have sex with men in China using a modified information-motivation-behavioral skills (IMB) model

Background

Men who have sex with men (MSM) are at high risk for human immunodeficiency virus (HIV) infection in China. Correct and consistent condom use is one of the most effective strategies for preventing the spread of HIV. This study developed a modified Information-Motivation-Behavioral Skills (IMB) model to predict condom use behavior among Chinese MSM.

Methods

A cross-sectional study was conducted to collect data using self-administered electronic questionnaire. Participants were recruited from HIV Voluntary Counseling and Testing clinics in six district Centers for Disease Control and Prevention in Guangzhou and two community-based HIV service centers (Lingnan Partners and Zhitong Charity) from May to September 2017. Structural equation modeling was performed to develop the modified IMB model with extended multilevel factors.

Results

Among the 976 MSM included, 52.05% had engaged in anal intercourse with a condom every time. The final modified IMB model fitted the data more ideally than the conventional model. The final modified IMB model revealed that behavioral skills positively contributed directly to condom use (β = 0.385, p < 0.001) and partially mediated the associations between information (β = 0.106, p = 0.005) and motivation (β = 0.390, p < 0.001) and condom use. Regarding the extended multilevel factors, education, income, receiving HIV prevention services, sexual partner seeking behavior, depression, intimate partner violence, and child sexual abuse had indirect impacts on condom use that were mediated by information, motivation, and/or behavioral skills (p < 0.05). All paths from the latent variable to the corresponding observed variables were statistically significant (p < 0.001).

Conclusion

The modified IMB model with extended multilevel factors could serve as a theoretical framework for behavioral interventions for condom use among Chinese MSM. Further prospective studies are needed to examine the predictive power of the modified IMB model.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-6593-8) contains supplementary material, which is available to authorized users.

A Network Intervention to Locate Newly HIV Infected Persons Within MSM Networks in Chicago

Individuals with recent/acute HIV-infection have an increased likelihood of disease transmission. To evaluate effectiveness of identifying recent infections, we compared networks of recently and long-term HIV-infected individuals. The Transmission Reduction Intervention Project included two separate arms of recruitment, networks of recently HIV-infected individuals and networks of long-term HIV-infected individuals. Networks of each were recruited and tested for HIV and syphilis infection. The per-seed yield ratios of recruitment were compared between arms. Overall, 84 (41.6%) of 202 participants were identified as HIV-positive. HIV prevalence was higher (p < 0.001) among networks of recent seeds (33/96, 34.4%) compared to long-term seeds (6/31, 19.4%). More individuals were identified with active syphilis infection (p = 0.007) among networks of recent seeds (15/96, 15.6%), compared to networks of long-term seeds (3/31, 9.7%). Network-based recruitment of recently HIV-infected individuals was more effective at identifying HIV and syphilis infection. Allocation of public health resources may be improved by targeting interventions toward networks of recently HIV-infected individuals.

Are HIV Seroconversions Among Young Men Who Have Sex With Men Associated With Social Network Proximity to Recently or Long-Term HIV-Infected Individuals?

Debate remains as to the relative HIV transmission contributions from individuals who are recently HIV-infected and individuals who have long-term infections. In this study, we examine the relationship between new HIV seroconversions occurring among young black men who have sex with men and network proximity to recently or long-term HIV-infected individuals. A cohort of young black men who have sex with men (N = 618) was generated through respondent-driven sampling across 3 waves. A recent HIV infection was defined as either: (1) a confirmed seroconversion ≤9 months before interview date or (2) a laboratory confirmed acute infection; long-term HIV-infected individuals were defined as a diagnosis date ≥9 months before interview date. Respondent-driven sampling-weighted logistic regression was used to examine network proximity of HIV transmission events to HIV-infected individuals in the network. Within the cohort, 343 (55.5%) participants were identified as HIV seronegative at baseline. Of these, 33 (9.6%) seroconverted during the study period. The odds of seroconversion increased significantly with each additional recent HIV-infected individual in one's network [adjusted odds ratio = 12.96; 95% confidence interval: 5.69 to 29.50], but were not significantly altered by the number of long-term infected individuals in one's network. In addition, for each member of one's network who used pre-exposure prophylaxis, the odds of seroconversion decreased significantly (adjusted odds ratio = 0.44; 95% confidence interval: 0.20 to 0.96). Early diagnosis and treatment is a critical first step in the HIV care continuum and together with pre-exposure prophylaxis awareness and use are critical targets for disrupting the transmission of HIV through most at-risk networks.

Pockets of HIV Non-infection Within Highly-Infected Risk Networks in Athens, Greece

As part of a network study of HIV infection among people who inject drugs (PWID) and their contacts, we discovered a connected subcomponent of 29 uninfected PWID. In the context of a just-declining large epidemic outbreak, this raised a question: What explains the existence of large pockets of uninfected people? Possible explanations include “firewall effects” (Friedman et al., 2000; Dombrowski et al., 2017) wherein the only HIV+ people that the uninfected take risks with have low viral loads; “bottleneck effects” wherein few network paths into the pocket of non-infection exist; low levels of risk behavior; and an impending outbreak. We considered each of these. Participants provided information on their enhanced sexual and injection networks and assisted us in recruiting network members. The largest connected component had 241 members. Data on risk behaviors in the last 6 months were collected at the individual level. Recent infection was determined by LAg (Sedia^TM Biosciences Corporation), data on recent seronegative tests, and viral load. HIV RNA was quantified using Artus HI Virus-1 RG RT-PCR (Qiagen). The 29 members of the connected subcomponent of uninfected participants were connected (network distance = 1) to 17 recently-infected and 24 long-term infected participants. Fourteen (48%) of these 29 uninfected were classified as “extremely high risk” because they self-reported syringe sharing and had at least one injection partner with viral load >100,000 copies/mL who also reported syringe sharing. Seventeen of the 29 uninfected were re-interviewed after 6 months, but none had seroconverted. These findings show the power of network research in discovering infection patterns that standard individual-level studies cannot. Theoretical development and exploratory network research studies may be needed to understand these findings and deepen our understanding of how HIV does and does not spread through communities. Finally, the methods developed here provide practical tools to study “bottleneck” and “firewall” network hypotheses in practice.

Molecular Analysis of Human Immunodeficiency Virus Type 1 (HIV-1)-Infected Individuals in a Network-Based Intervention (Transmission Reduction Intervention Project): Phylogenetics Identify HIV-1-Infected Individuals With Social Links

Background

The Transmission Reduction Intervention Project (TRIP) is a network-based intervention that aims at decreasing human immunodeficiency virus type 1 (HIV-1) spread. We herein explore associations between transmission links as estimated by phylogenetic analyses, and social network-based ties among persons who inject drugs (PWID) recruited in TRIP.

Methods

Phylogenetic trees were inferred from HIV-1 sequences of TRIP participants. Highly supported phylogenetic clusters (transmission clusters) were those fulfilling 3 different phylogenetic confidence criteria. Social network-based ties (injecting or sexual partners, same venue engagement) were determined based on personal interviews, recruitment links, and field observation.

Results

TRIP recruited 356 individuals (90.2% PWID) including HIV-negative controls; recently HIV-infected seeds; long-term HIV-infected seeds; and their social network members. Of the 150 HIV-infected participants, 118 (78.7%) were phylogenetically analyzed. Phylogenetic analyses suggested the existence of 13 transmission clusters with 32 sequences. Seven of these clusters included 14 individuals (14/32 [43.8%]) who also had social ties with at least 1 member of their cluster. This proportion was significantly higher than what was expected by chance.

Conclusions

Molecular methods can identify HIV-infected people socially linked with another person in about half of the phylogenetic clusters. This could help public health efforts to locate individuals in networks with high transmission rates.

Comparison of Self-report to Biomarkers of Recent HIV Infection: Findings from the START Trial

Identifying individuals with recent HIV infection is critical to research related to viral reservoirs, outbreak investigations and intervention applications. A multi-assay algorithm (MAA) for recency of infection was used in conjunction with self-reported date of infection and documented date of diagnosis to estimate the number of participants recently infected in the Strategic Timing of AntiRetroviral Treatment (START) trial. We tested samples for three groups of participants from START using a MAA: (1) 167 individuals who reported being infected ≤ 6 months before randomization; (2) 771 individuals who did not know their date of infection but were diagnosed within 6 months before randomization; and (3) as controls for the MAA, 199 individuals diagnosed with HIV ≥ 2 years before randomization. Participants with low titer and avidity and a baseline viral load > 400 copies/mL were classified as recently infected. A significantly higher percentage of participants who self-reported being infected ≤ 6 months were classified as recently infected compared to participants diagnosed ≥ 2 years (65% [109/167] vs. 2.5% [5/199], p < 0.001). Among the 771 individuals who did not know their duration of infection at randomization, 206 (26.7%) were classified as recently infected. Among those diagnosed with HIV in the 6 months prior to enrollment, the 373 participants who reported recent infection (n = 167) or who had confirmed recent infection by the MAA (n = 206) differed significantly on a number of baseline characteristics from those who had an unknown date of infection and were not confirmed by the MAA (n = 565). Participants recently infected by self-report and/or MAA were younger, more likely to be Asian, less likely to be black, less likely to be heterosexual, more likely to be enrolled at sites in the U.S., Europe or Australia, and have higher HIV RNA levels. There was good agreement between self-report of recency of infection and the MAA. We estimate that 373 participants enrolled in START were infected within 6 months of randomization. Compared to those not recently infected, these participants were younger, had higher HIV RNA levels and were more likely to come from high income countries and from populations such as MSM with more regular HIV testing.

Network Research Experiences in New York and Eastern Europe: Lessons for the Southern US in Understanding HIV Transmission Dynamics

PURPOSE

This paper presents an overview of different kinds of risk and social network methods and the kinds of research questions each can address.

RECENT FINDINGS

It also reviews what network research has discovered about how network characteristics are associated with HIV and other infections, risk behaviors, preventive behaviors, and care, and discusses some ways in which network-based public health interventions have been conducted. Based on this, risk and social network research and interventions seem both feasible and valuable for addressing the many public health and social problems raised by the widespread use of opioids in the US South.

Molecular investigation of HIV-1 cross-group transmissions during an outbreak among people who inject drugs (2011-2014) in Athens, Greece

New diagnoses of HIV-1 infection among people who inject drugs (PWID) rocketed in Athens, Greece between 2011 and 2014 (HIV-1 outbreak). Our aim was to identify, during that period, potential cross-group transmissions between the within-Greece PWID and other risk or national groups using molecular methods. Sequences from 33 PWID were outside the PWID-outbreak networks in Greece (PWID-imported transmissions). Phylogenetic analyses on 28 of these sequences (subtypes A and B) showed that 11 subtype B infections originated from Greece, whereas 8 and 7 subtype A strains were from former Soviet Union countries (A_FSU) and Greece, respectively. The putative source in half of the PWID-imported transmissions with Greek origin was an individual who acquired HIV via sexual contact. During four years of an HIV-1 outbreak among PWID in Athens, Greece, 33 individuals in this group (4.6% of all diagnoses with phylogenetic analyses) are likely to represent infections, sexually or injection-acquired, outside the within-Greece-PWID-outbreak networks. Combined molecular and traditional HIV surveillance to monitor introductions of new strains, and interventions that aim at reducing the rate of both injection and sexual risky practices are needed during drug injection-related HIV outbreaks.

Network Viral Load: A Critical Metric for HIV Elimination

BACKGROUND

Associations have been observed between an aggregate viral load measure, the community viral load, and new HIV diagnoses. The community viral load aggregates viral loads within chosen geographic areas, restricting inferences about HIV acquisition risk to these areas. We develop a more precise metric, the network viral load (NVL), to measure the composite viral load within a risk network of a HIV-negative individual.

METHODS

We examined the relationship between NVL and HIV infection among young men who have sex with men in Chicago, United States. Networks were generated using respondent-driven sampling. NVL was defined as the prevalence of viremic individuals in one's risk network, characterized as those with a viral load ≥20 k copies per milliliter. Permutation tests were conducted to account for dependency.

RESULTS

After controlling for total connections, age, substance use during sex, syphilis diagnosis (previous 12 months), and frequency of condomless anal sex (previous 6 months), we found a positive association between NVL and HIV infection. Compared with a network with all HIV-seronegative members, the odds of HIV infection with an NVL of <10% viremia were 1.85 (95% confidence interval: 1.18 to 2.92) times higher and those with an NVL of ≥10% viremia were 2.73 (95% confidence interval: 1.54 to 4.85) times higher.

CONCLUSIONS

We found a positive association between NVL and HIV seroprevalence. Although limited in its ability to infer causality, NVL could have substantial public health implications for persons most at risk for HIV infection, given that this novel metric avoids overreliance on individual level behavior or broad community indices.

Sexual risk taking and the HIV care continuum in an online sample of men who have sex with men

Antiretroviral Therapy (ART) suppresses HIV replication, reducing the risk of transmission. However, many people living with HIV in the US are not virally suppressed even after diagnosis and initiating ART, and may become disengaged from care at each stage of the HIV care continuum (HCC). In the current study we assessed the sexual risk behaviors of MSM by HCC stage. US MSM who completed an online survey (N = 12,995) in 2015 were categorized into 6 HCC groups. Mean age was 39.2 and a majority identified as White (49.6%). At every stage of the HCC, we found higher proportions of individuals engaged in care compared to CDC estimates. A majority of the sample was HIV-positive and engaged in care, with 67.2% of HIV-positive participants reporting viral suppression with ART. Across HCC groups, participants reported high rates of past 6-month condomless anal sex (CAS) (79.2%-84.8%) and CAS with serodiscordant or unknown status partners (38.0%-84.1%). Notably, MSM with unknown HIV serostatus reported the highest proportion of CAS and serodiscordant CAS. HIV-positive MSM not on ART were more likely to report an STI diagnosis (p < .002) compared to those unaware of their HIV status or HIV negative. Moreover, young Black MSM were less likely to be on ART (p < .002) or virally suppressed (p < .002) compared to older White MSM. Our findings highlight potentially problematic sexual risk behaviors among MSM by level of HCC engagement, which can impede the preventive impact of ART. Online platforms provide an avenue to assess the progress of MSM along the HCC, as well as other subpopulations in need of appropriate behavioral interventions to decrease HIV incidence.

Sexual Risk and Transmission Behaviors, Partnerships and Settings Among Young Adult Nonmedical Opioid Users in New York City

Nonmedical prescription opioid use has become widespread. It can lead to heroin use, drug injection and HIV infection. We describe young adult opioid users' sexual risk behavior, partnerships and settings. 464 youth aged 18-29 who reported opioid use in the past 30 days were recruited using Respondent-Driven Sampling. Eligible participants completed a computer-assisted, interviewer-administered risk questionnaire and were tested for STIs and HIV. Participants (33% female; 66% white non-Hispanic) almost all had sex in the prior 90 days; 42% reported more than one partner. Same-sex sex was reported by 3% of men and 10% of women. Consistent condom use was rare. Seven percent reported group sex participation in the last 90 days but lifetime group sex was common among men and women. Young opioid users' unprotected sex, multiple partners and group sex puts them and others at high HIV and STI risk.

Network dynamics of HIV risk and prevention in a population-based cohort of young Black men who have sex with men

Critical to the development of improved HIV elimination efforts is a greater understanding of how social networks and their dynamics are related to HIV risk and prevention. In this paper, we examine network stability of confidant and sexual networks among young black men who have sex with men (YBMSM). We use data from uConnect (2013–2016), a population-based, longitudinal cohort study. We use an innovative approach to measure both sexual and confidant network stability at three time points, and examine the relationship between each type of stability and HIV risk and prevention behaviors. This approach is consistent with a co-evolutionary perspective in which behavior is not only affected by static properties of an individual's network, but may also be associated with changes in the topology of his or her egocentric network. Our results indicate that although confidant and sexual network stability are moderately correlated, their dynamics are distinct with different predictors and differing associations with behavior. Both types of stability are associated with lower rates of risk behaviors, and both are reduced among those who have spent time in jail. Public health awareness and engagement with both types of networks may provide new opportunities for HIV prevention interventions.

A network intervention that locates and intervenes with recently HIV-infected persons: The Transmission Reduction Intervention Project (TRIP)

Early treatment, soon after infection, reduces HIV transmissions and benefits patients. The Transmission Reduction Intervention Project (TRIP) evaluated a network intervention to detect individuals recently infected (in the past 6 months). TRIP was conducted in Greece (2013-2015) and focused on drug injector networks. Based on HIV status, testing history, and the results of an assay to detect recent infections, TRIP classified drug injector "Seeds" into groups: Recent Seeds (RS), and Control Seeds with Long-term HIV infection (LCS). The network members of RS and LCS were traced for two steps. The analysis included 23 RS, 171 network members of the RS, 19 LCS, and 65 network members of the LCS. The per-seed number of recents detected in the network of RS was 5 times the number in the network of LCS (Ratio RS vs. LCS: 5.23; 95% Confidence Interval (CI): 1.54-27.61). The proportion of recents among HIV positives in the network of RS (27%) was approximately 3 times (Ratio RS vs. LCS: 3.30; 95% CI: 1.04-10.43) that in the network of LCS (8%). Strategic network tracing that starts with recently infected persons could support public health efforts to find and treat people early in their HIV infection.

Evaluation of the limiting antigen avidity EIA (LAg) in people who inject drugs in Greece

This analysis assessed the utility of the limiting antigen avidity assay (LAg). Samples of people who inject drugs (PWID) in Greece with documented duration of HIV-1 infection were tested by LAg. A LAg-normalized optical density (ODn) ⩽1·5 corresponds to a recency window period of 130 days. The proportion true recent (PTR) and proportion false recent (PFR) were estimated in 28 seroconverters and in 366 samples collected >6 months after HIV diagnosis, respectively. The association between LAg ODn and HIV RNA level was evaluated in 232 persons. The PTR was 85·7%. The PFR was 20·8% but fell to 5·9% in samples from treatment-naive individuals with long-standing infection (>1 year), and to 0 in samples with the circulating recombinant form CRF35 AD. A LAg-based algorithm with a PFR of 3·3% estimated a similar incidence trend to that calculated by analyses based on HIV-1 seroconversions. In recently infected persons indicated by LAg, the median log10 HIV RNA level was high (5·30, interquartile range 4·56-5·90). LAg can help identify highly infectious HIV(+) individuals as it accurately identifies recent infections and is correlated with the HIV RNA level. It can also produce reliable estimates of HIV-1 incidence.

Acute HIV infection transmission among people who inject drugs in a mature epidemic setting

OBJECTIVE

Estimates for the contribution of transmission arising from acute HIV infections (AHIs) to overall HIV incidence vary significantly. Furthermore, little is known about AHI-attributable transmission among people who inject drugs (PWID), including the extent to which interventions targeting chronic infections (e.g. HAART as prevention) are limited by AHI transmission. Thus, we estimated the proportion of transmission events attributable to AHI within the mature HIV epidemic among PWID in New York City (NYC).

DESIGN

Modeling study.

METHODS

We constructed an interactive sexual and injecting transmission network using an agent-based model simulating the HIV epidemic in NYC between 1996 and 2012. Using stochastic microsimulations, we cataloged transmission from PWID based on the disease stage of index agents to determine the proportion of infections transmitted during AHI (in primary analyses, assumed to last 3 months).

RESULTS

Our calibrated model approximated the epidemiological features of the mature HIV epidemic in NYC between 1996 and 2012. Annual HIV incidence among PWID dropped from approximately 1.8% in 1996 to 0.7% in 2012. Over the 16-year period, AHI accounted for 4.9% (10th/90th percentile: 0.1-12.3%) of incident HIV cases among PWID. The annualized contribution of AHI increased over this period from 3.6% in 1996 to 5.9% in 2012.

CONCLUSION

Our results suggest that, in mature epidemics such as NYC, between 3% and 6% of transmission events are attributable to AHI among PWID. Current HIV treatment as prevention strategies are unlikely to be substantially affected by AHI-attributable transmission among PWID populations in mature epidemic settings.

Accuracy of name and age data provided about network members in a social network study of people who use drugs: implications for constructing sociometric networks

PURPOSE

Network analysis has become increasingly popular in epidemiologic research, but the accuracy of data key to constructing risk networks is largely unknown. Using network data from people who use drugs (PWUDs), the study examined how accurately PWUD reported their network members' (i.e., alters') names and ages.

METHODS

Data were collected from 2008 to 2010 from 503 PWUD residing in rural Appalachia. Network ties (n = 897) involved recent (past 6 months) sex, drug cousage, and/or social support. Participants provided alters' names, ages, and relationship-level characteristics; these data were cross-referenced to that of other participants to identify participant-participant relationships and to determine the accuracy of reported ages (years) and names (binary).

RESULTS

Participants gave alters' exact names and ages within two years in 75% and 79% of relationships, respectively. Accurate name was more common in relationships that were reciprocally reported and those involving social support and male alters. Age was more accurate in reciprocal ties and those characterized by kinship, sexual partnership, recruitment referral, and financial support, and less accurate for ties with older alters.

CONCLUSIONS

Most participants reported alters' characteristics accurately, and name accuracy was not significantly different in relationships involving drug-related and/or sexual behavior compared to those not involving these behaviors.

Suboptimal HIV Testing Uptake Among Men Who Engage in Commercial Sex Work with Men in Asia

PURPOSE

Men who have sex with men and are sex workers (MSMSW) are disproportionately affected by the growing and emerging HIV epidemic. As sex work and same-sex behavior are heavily stigmatized and often illegal in most Asian countries, HIV research focusing on MSMSW has been limited. The goal of this analysis is to examine HIV testing practices and identify correlates of HIV testing among MSMSW in Asia.

METHODS

The Asia Internet MSM Sex Survey, an online cross-sectional survey of 10,861 men who have sex with men (MSM), was conducted in 2010. Data on sociodemographic characteristics, HIV testing behaviors, and sexual behaviors were collected. Five hundred and seventy-four HIV-negative/unknown respondents reported receiving payment for sex with men at least once in the past 6 months and were included in this analysis. Multivariable logistic regression was conducted to identify independent correlates of HIV testing in the past year.

RESULTS

About half (48.6%) of the participants had been tested for HIV at least once within the past year, and 30.5% had never been tested. We also found that MSMSW participants who engaged in risky behaviors were less likely to be tested.

CONCLUSION

While one might expect a high HIV testing rate among MSMSW due to the risks associated with engaging in sex work, we found that HIV testing uptake is suboptimal among MSMSW in Asia. These results suggest that targeted HIV prevention and testing promotion among MSMSW are needed.

Network Characteristics of People Who Inject Drugs Within a New HIV Epidemic Following Austerity in Athens, Greece

BACKGROUND

Greece experienced an unprecedented increase in HIV cases among drug injectors in 2011 after economic crisis. Network-level factors are increasingly understood to drive HIV transmission in emerging epidemics.

METHODS

We examined the relationship between networks, risk behaviors, and HIV serostatus among 1404 people who inject drugs in Athens, Greece. We generated networks using the chain-referral structure within a large HIV screening program. Network proportions, the proportion of a respondent's network with a given characteristic, were calculated. Multiple logistic regression models were used to assess the relationship between network proportions and individual HIV seroprevalence, injection frequency and unprotected sex.

RESULTS

Of note, 1030 networks were generated. Respondent HIV seroprevalence was associated with greater proportions of network members who were HIV infected (ie, those with ≥ 50% of network members HIV positive vs. those with no network members HIV positive) (AOR: 3.11; 95% CI: 2.10 to 4.62), divided drugs (AOR: 1.60; 95% CI: 1.10 to 2.35), or injected frequently (AOR: 1.50; 95% CI: 1.02 to 2.21). Homelessness was the only sociodemographic characteristic associated with a risk outcome measure--high-frequency injecting (AOR: 1.41; 95% CI: 1.03 to 1.93). These associations were weaker for more distal second- and third-degree networks and not present when examined within random networks.

CONCLUSIONS

Networks are an independently important contributor to the HIV outbreak in Athens, Greece. Network associations were strongest for the immediate network, with residual associations for distal networks. Homelessness was associated with high-frequency injecting. Prevention programs should consider including network-level interventions to prevent future emerging epidemics.

The promise of treatment as prevention for hepatitis C: Meeting the needs of people who inject drugs?

Treatment as prevention (TasP) is a concept common to the HIV sector. In this commentary we draw on the literature addressing HIV and HCV TasP, alongside qualitative HCV research, to critically appraise the promise of TasP for HCV and assess the needs of PWID in the future of HCV care. With the advent of highly effective direct-acting antiviral HCV treatments, TasP is now under consideration for HCV. A growing body of literature documents numerous social structural barriers to HCV treatment access and uptake for PWID, among whom HCV is highly prevalent. Yet these barriers - and suggestions for surmounting them - are rarely included in emergent literature on HCV TasP. Although HCV TasP has important advocacy potential for increasing treatment access among PWID, critical reflection on its implications are warranted. We outline potential limitations of TasP for HCV and the conditions under which it might be optimised. We argue that HCV treatment as a prevention strategy can only be realisable in a context of enhanced harm reduction access, meaningful community engagement, and enabling environment interventions informed by the needs and perspectives of PWID.

Big Events in Greece and HIV Infection Among People Who Inject Drugs

Big Events are processes like macroeconomic transitions that have lowered social well-being in various settings in the past. Greece has been hit by the global crisis and experienced an HIV outbreak among people who inject drugs. Since the crisis began (2008), Greece has seen population displacement, inter-communal violence, cuts in governmental expenditures, and social movements. These may have affected normative regulation, networks, and behaviors. However, most pathways to risk remain unknown or unmeasured. We use what is known and unknown about the Greek HIV outbreak to suggest modifications in Big Events models and the need for additional research.

A new approach to prevent HIV transmission: Project Protect intervention for recently infected individuals

Past research suggests that as many as 50% of onward human immunodeficiency virus (HIV) transmissions occur during acute and recent HIV infection. It is clearly important to develop interventions which focus on this highly infectious stage of HIV infection to prevent further transmission in the risk networks of acutely and recently infected individuals. Project Protect tries to find recently and acutely infected individuals and prevents HIV transmission in their risk networks. Participants are recruited by community health outreach workers at community-based HIV testing sites and drug users' community venues, by coupon referrals and through referrals from AIDS clinics. When a network with acute/recent infection is identified, network members are interviewed about their risky behaviors, network information is collected, and blood is drawn for HIV testing. Participants are also educated and given prevention materials (condoms, syringes, educational materials); HIV-infected participants are referred to AIDS clinics and are assisted with access to care. Community alerts about elevated risk of HIV transmission are distributed within the risk networks of recently infected. Overall, 342 people were recruited to the project and screened for acute/recent HIV infection. Only six index cases of recent infection (2.3% of all people screened) were found through primary screening at voluntary counseling and testing (VCT) sites, but six cases of recent infection were found through contact tracing of these recently infected participants (7% of network members who came to the interview). Combining screening at VCT sites and contact tracing the number of recently infected people we located as compared to VCT screening alone. No adverse events were encountered. These first results provide evidence for the theory behind the intervention, i.e., in the risk networks of recently infected people there are other people with recent HIV infection and they can be successfully located without increasing stigma for project participants.

Health behavior change models for HIV prevention and AIDS care: practical recommendations for a multi-level approach

Despite increasing recent emphasis on the social and structural determinants of HIV-related behavior, empirical research and interventions lag behind, partly because of the complexity of social–structural approaches. This article provides a comprehensive and practical review of the diverse literature on multi-level approaches to HIV-related behavior change in the interest of contributing to the ongoing shift to more holistic theory, research, and practice. It has the following specific aims: (1) to provide a comprehensive list of relevant variables/factors related to behavior change at all points on the individual–structural spectrum, (2) to map out and compare the characteristics of important recent multi-level models, (3) to reflect on the challenges of operating with such complex theoretical tools, and (4) to identify next steps and make actionable recommendations. Using a multi-level approach implies incorporating increasing numbers of variables and increasingly context-specific mechanisms, overall producing greater intricacies. We conclude with recommendations on how best to respond to this complexity, which include: using formative research and interdisciplinary collaboration to select the most appropriate levels and variables in a given context; measuring social and institutional variables at the appropriate level to ensure meaningful assessments of multiple levels are made; and conceptualizing intervention and research with reference to theoretical models and mechanisms to facilitate transferability, sustainability, and scalability.