Mary Ellen Mackesy-Amiti

Introduction: The effects of network-based peer education interventions for HIV prevention presumably influence injection-related risk behavior through changes in peer norms and safer injection self-efficacy (SISE). In this paper, we test these mediating effects on receptive syringe sharing (RSS) and ancillary equipment sharing. Methods: The “Migrants’ Approached Self-Learning Intervention in HIV/AIDS for Tajiks” (MASLIHAT) intervention was tested in Moscow in a cluster-randomized controlled trial in comparison with a non-HIV health education training (TANSIHAT). Tajik migrants who inject drugs (N=140) were recruited as peer educators (PEs) to attend the 5-session MASLIHAT training or the TANSIHAT comparison condition. In both conditions, participants recruited two network members who inject drugs with the intent to share with them the information and positive strategies for change they had learned (n=280). PEs and network members in both conditions (n=420) participated in baseline and follow-up interviews at 3-month intervals for one year. We conducted causal mediation analyses to test the direct and indirect effects of intervention arm and psychosocial variables on injection practices. Results: MASLIHAT participants reported greater HIV knowledge, greater SISE, and safer descriptive and injunctive peer norms at 3-month follow-up compared to TANSIHAT participants. In the MASLIHAT arm only, greater HIV knowledge was associated with lower odds of RSS, and greater SISE and safer descriptive peer norms were associated with lower odds of both RSS and equipment sharing at 6-month follow-up. Injunctive peer norms were not associated with either outcome. Causal mediation analysis indicated that treatment effects were mediated by SISE and descriptive peer norms; however the distributions of responses on peer norms were problematic. Conclusions: The MASLIHAT intervention had a strong effect on SISE and descriptive peer norms for safer injection, and these variables were significantly associated with injection risk behaviors at 6-month follow-up. Analysis results are consistent with mediation, however estimates may be sensitive to model assumptions because of restricted overlap in mediator distributions between treatment conditions.

Tajik labor migrants who inject drugs while working in Moscow are subject to the negative effects of stigma within the diaspora community in Russia. They are also at risk of acquiring HIV, which further compounds their stigmatization. An intervention to reduce both drug-related and HIV-related stigma within the Tajik diaspora community is needed to prevent adverse social and health effects among its members who inject drugs. We conducted a series of focus groups and interviews, from January to June 2024, with Tajik migrant workers (n = 65) and health workers (n = 18) who treat migrants in Moscow to inform the development of a four-session anti-discrimination training for Tajik community leaders. The training sessions are designed to educate leaders about substance use disorder and HIV and prepare them to act as change agents in reducing stigma toward both disorders within the Moscow Tajik diaspora community. In September 2025, we pilot tested the Stigma Reduction Intervention Approach Via Leaders of Diaspora (SRI-AVLOD) for cultural acceptability and feasibility with two groups of 8 traditional migrant community (avlod) leaders while residing in Tajikistan before returning to Moscow for work. Measures of drug use and HIV-related stigma were administered prior to the first and after the final training session. We collected participant feedback on the acceptability and feasibility of the intervention and conducted a brief follow-up interview post-training to assess participants' experience in delivering the anti-stigma messages to their community. Participant ratings and comments indicated high acceptability and satisfaction with the training. Ratings of acceptability, feasibility, appropriateness and usefulness were uniformly high. Measures of stigmatizing attitudes among the avlod leaders were reduced following the intervention. In follow-up interviews, participants reported favorable experiences in delivering the anti-stigma message to people in their community. The SRI-AVLOD intervention proved feasible and acceptable to Tajik community leaders and was judged to have considerable potential for effective diffusion within the migrant diaspora community.

Background: People who inject drugs (PWIDs) are at high risk for acquiring and transmitting hepatitis C virus (HCV). Direct-acting antiviral (DAA) therapy leads to high cure rates. However, lack of protective immunity after cure and high re-infection rates in PWID necessitates access to multiple DAA treatments per PWID to reach the World Health Organization HCV elimination goal of 90% incidence reduction. A major public health challenge is determining the proportion of PWID to treat to reach the goal and the continued treatment levels required to maintain decreased incidence. Method: We used an agent-based model to study varying levels of DAA treatment among HCV-infected PWID from Chicago, IL, and the effects of reducing DAA treatment after elimination is reached. The model uses individual temporal viral load profiles to determine transmission probabilities relative to the HCV RNA titers of receptive syringe-sharing PWID. Results: Modeling predicts that insufficient DAA treatment can result in a continuous increase of HCV incidence over a 25-year period, with no significant decrease. Elimination can be achieved within 10 years with sufficient treatment levels. However, when DAA treatment is stopped, rates of new chronic HCV infections rapidly increase, returning to preelimination levels within 5 years. Annual treatment of ≥0.5% would maintain the elimination goal, but identifying and treating small numbers of infected people annually in PWID populations would be resource intensive. Conclusions: The challenge to achieve and maintain the elimination goal underscores the importance of augmenting DAA treatment with intervention strategies such as syringe service programs and vaccines.

The program Migrants’ Approached Self-Learning Intervention in HIV/AIDS for Tajiks (MASLIHAT) trains male Tajik migrants who inject drugs in delivering HIV prevention information within their diaspora social networks. This analysis examines the indirect effect of the intervention on HIV testing among the participants’ regular female sex partners. Modified mixed-effects Poisson regression analyses compared the proportions of participants with a regular female sex partner in the MASLIHAT versus the TANSIHAT control condition who reported that their partner had been tested for HIV. Of the 420 participants, 108 (26%) reported having a regular female sex partner. Regression analyses indicated that HIV partner testing increased significantly in both conditions over the follow-up period, with MASLIHAT participants reporting a higher rate at 12 months than the TANSIHAT control group (IRR = 1.66, 95% CI [1.21, 2.28]). The MAS-LIHAT intervention increased female partner HIV testing over 12 months when compared to a non-HIV focused health education intervention.

Male Tajik labour migrants who inject drugs in Russia are at high risk for HIV and other sexually transmitted infections. The “Migrants’ Approached Self-Learning Intervention in HIV/AIDS for Tajiks” (MASLIHAT) trained Tajik labour migrants who inject drugs in Moscow as peer educators (PEs) in delivering HIV prevention information and promoting risk-reduction norms and practices within their diaspora social networks while reducing their own HIV risk. Our earlier analysis of a cluster-randomized controlled trial testing the intervention’s effects found that MASLIHAT reduced condomless sex, condomless sex with female sex workers, and sex with multiple sexual partners. This analysis draws on data from this parent study to investigate if these observed changes in safer sex translated into fewer reported STIs over 12 months. Male Tajik migrant workers in Moscow who inject drugs (n = 140) were recruited from construction worksites, local bazaars, and diaspora organizations serving labor migrants. Participants were assigned as PEs to either MASLIHAT or a comparison health education intervention. Each PE recruited two migrants who inject drugs from their social networks with whom to share what they learned during the 5 educational sessions of the arm to which they were assigned. All participants completed questionnaires at baseline and 3-month intervals for one year to assess their HIV/STI risk behaviour. Mixed effects robust Poisson regression analyses tested for possible differences between assignment conditions in self-reported STIs during 12 months of follow-up and the contribution of sexual risk behaviours to STI acquisition. We then tested the mediating effects of sexual behaviours during the first six months following the intervention on STIs reported at the 9 and 12-month follow-up. Participants in the MASLIHAT intervention were significantly less likely to report an STI during follow-up (IRR = 0.27). Condomless sex with a casual or commercial partner was significantly associated with STI acquisition (IRR = 2.30). Causal mediation analysis indicated that the intervention’s effect on reported STI was partially mediated by reductions among MASLIHAT participants in condomless sex with a casual or commercial partner. The MASLIHAT peer-education intervention reduced reported STIs among Tajik labour migrants partly through reduced condomless sex with casual and commercial partners. ClinicalTrials.gov, 2021-04-16, NCT04853394.

Global elimination of chronic hepatitis C (CHC) remains difficult without an effective vaccine. Since injection drug use is the leading cause of hepatitis C virus (HCV) transmission in Western Europe and North America, people who inject drugs (PWID) are an important population for testing HCV vaccine effectiveness in randomized-clinical trials (RCTs). However, RCTs in PWID are inherently challenging. To accelerate vaccine development, controlled human infection (CHI) models have been suggested as a means to identify effective vaccines. To bridge the gap between CHI models and real-world testing, we developed an agent-based model simulating a two-dose vaccine to prevent CHC in PWID, representing 32,000 PWID in metropolitan Chicago and accounting for networks and HCV infections. We ran 500 trial simulations under 50 and 75% assumed vaccine efficacy (aVE) and sampled HCV infection status of recruited in silico PWID. The mean estimated vaccine efficacy (eVE) for 50 and 75% aVE was 48% (SD ± 12) and 72% (SD ± 11), respectively. For both conditions, the majority of trials (∼71%) resulted in eVEs within 1 SD of the mean, demonstrating a robust trial design. Trials that resulted in eVEs >1 SD from the mean (lowest eVEs of 3 and 35% for 50 and 75% aVE, respectively), were more likely to have imbalances in acute infection rates across trial arms. Modeling indicates robust trial design and high success rates of finding vaccines to be effective in real-life trials in PWID. However, with less effective vaccines (aVEs∼50%) there remains a higher risk of concluding poor vaccine efficacy due to post-randomization imbalances.

Background. Both stigma and needle-sharing are well-documented as contributing independently to risk for HIV and hepatitis C among people who inject drugs (PWID). Few studies, however, have examined the relationship between drug-related stigma and the practice of sharing syringes. This research examines the effects of enacted and internalized drug-related stigma in relation to receptive syringe sharing among Tajik labor migrants who inject drugs in Moscow. Like other temporary workers in Russia from Central Asian countries, Tajiks constitute a large and highly marginalized migrant population within this host destination.Methods. We recruited 420 male Tajik labor migrants who inject drugs in Moscow for a peer-education HIV prevention trial. Prior to the intervention, participants were interviewed about their injection and sexual risk behavior. Psychosocial measures included substance-use related internalized stigma, family-enacted stigma, police harassment; peer norms for safer injection; and safer injection self-efficacy. A series of regression analyses followed by structural equation modeling investigated for possible relationships among psychosocial variables and receptive syringe sharing in the past three months.Results. The results of the SEM analysis indicate that family-enacted stigma contributed significantly to internalized stigma (b=0.60, p<.01), but had a relatively small effect on safer injection self-efficacy (b=-0.09, p<.05). Police-enacted stigma influenced needle sharing both directly (b=0.83, p<.01), and to a lesser extent indirectly (b=0.06, p<.01) via its effects on peer norms (b=0.52, p<.01) and safer injection self-efficacy (b=-0.28, p<.01). Conclusion. Drug-use related internalized stigma does not appear to be a major driver of receptive syringe sharing among Tajik labor migrants who inject drugs in Moscow. Although family-enacted stigma contributes to internalized stigma, it may be moderately protective against syringe sharing. Police actions against PWID increase the likelihood of syringe sharing through effects on peer network norms and safer injection self-efficacy.

Background: Male Tajik labour migrants who inject drugs in Russia are at high risk for HIV and other sexually transmitted infections. The “Migrants’ Approached Self-Learning Intervention in HIV/AIDS for Tajiks” (MASLIHAT) trained Tajik labour migrants who inject drugs in Moscow as peer educators (PEs) in delivering HIV prevention information and promoting risk-reduction norms and practices within their diaspora social networks while reducing their own HIV risk. Our earlier analysis of a cluster-randomized controlled trial testing the intervention’s effects found that MASLIHAT reduced condomless sex, condomless sex with female sex workers, and sex with multiple sexual partners. This analysis draws on data from this parent study to investigate if these observed changes in safer sex translated into fewer reported STIs over 12-months. Methods: Male Tajik migrant workers in Moscow who inject drugs (n=140) were recruited from construction worksites, local bazaars, and diaspora organizations serving labor migrants. Participants were assigned as PEs to either MASLIHAT or a comparison health education intervention. Each PE recruited two migrants who inject drugs from their social networks with whom to share what they learned during the 5 educational sessions of the arm to which they were assigned. All participants completed questionnaires at baseline and 3-month intervals for one year to assess their HIV/STI risk behaviour. Mixed effects robust Poisson regression analyses tested for possible differences between assignment conditions in self-reported STIs during 12 months of follow-up and the contribution of sexual risk behaviours to STI acquisition. We then tested the mediating effects of sexual behaviours during the first six months following the intervention on STIs reported at the 9 and 12-month follow-up. Results: Participants in the MASLIHAT intervention were significantly less likely to report an STI during follow-up (IRR=0.27). Condomless sex with a casual or commercial partner was significantly associated with STI acquisition (IRR=2.30). Causal mediation analysis indicated that the intervention’s effect on reported STI was partially mediated by reductions among MASLIHAT participants in condomless sex with a casual or commercial partner. Conclusions: The MASLIHAT peer-education intervention reduced reported STIs among Tajik labour migrants partly through reduced condomless sex with casual and commercial partners. Clinical trial registration: ClinicalTrials.gov, 2021-04-16, NCT04853394 .

Introduction: The “Migrants’ Approached Self‐Learning Intervention in HIV/AIDS for Tajiks” (MASLIHAT) recruits and trains Tajik labour migrants who inject drugs as peer educators (PEs) in delivering HIV prevention information and encouragement to adopt risk‐reduction norms and practices within their diaspora social networks while reducing their own HIV risk.Methods: The MASLIHAT intervention was tested in Moscow in a cluster‐randomized controlled trial with 12 recruitment sites assigned to either the MASLIHAT intervention or an equal‐time peer‐educator training focused on other health conditions (TANSIHAT). From October 2021 to April 2022, 140 male Tajik migrants who inject drugs were recruited as PEs to attend the 5‐session MASLIHAT training or the TANSIHAT non‐HIV comparison condition. Each participant in both groups recruited two network members (NMs) who inject drugs with the intent to share with them the information and positive strategies for change they had learned (n = 280). All PEs and NMs (n = 420) participated in baseline and follow‐up interviews at 3‐month intervals for 1 year. All received HIV counselling and testing. Modified mixed effects Poisson regressions tested for group differences in injection practices, sexual risk behaviours and heavy alcohol use over time.Results: At baseline, across both groups, 75% of participants reported receptive syringe sharing (RSS), 42% reported condomless sex and 20% reported binge drinking at least once a month. In contrast to TANSIHAT where HIV risk behaviours remained the same, significant intervention effects that were sustained over the 12 months were observed for receptive syringe and ancillary equipment sharing among both MASLIHAT PEs and NMs (p < 0.0001). Significant declines in the prevalence of sexual risk behaviours were also associated with the MASLIHAT intervention (p < 0.01), but not the comparison condition. Binge alcohol use was not affected in either condition; the MASLIHAT intervention had a transitory effect on drinking frequency that dissipated after 9 months.Conclusions: The MASLIHAT peer‐education intervention proved highly effective in reducing HIV‐related injection risk behaviour, and moderately effective in reducing sexual risk behaviour among both PEs and NMs. Network‐based peer education is an important tool for HIV prevention among people who inject drugs, especially in environments that are not amenable to community‐based harm reduction.