A cross-sectional assessment of injection of "salts" and HIV transmission-related behaviours among a cohort of people who inject drugs in Kyrgyzstan.

INTRODUCTION: Despite the increasing availability of new psychoactive substances (hereafter referred to as "salts") in Eastern Europe and Central Asia, there is a dearth of epidemiological data on the relationship between injecting "salts" and HIV risk behaviours. This is particularly relevant in settings where injection drug use accounts for a substantial proportion of the HIV burden, such as in Kyrgyzstan, a former Soviet Republic. This study assessed whether injecting "salts" is associated with sexual and injection-related HIV risk behaviours among people who inject drugs in Kyrgyzstan. METHODS: The Kyrgyzstan InterSectional Stigma Study is a cohort of people who inject drugs in Kyrgyzstan's capital of Bishkek and the surrounding rural administrative division of Chuy Oblast. We conducted a cross-sectional analysis using survey data collected from cohort participants between July and November 2021, which included information on injection drug use (including "salts") and HIV risk behaviours. To minimize confounding by measured covariates, we used inverse-probability-weighted logistic and Poisson regression models to estimate associations between recent "salt" injection and HIV risk behaviours. RESULTS: Of 181 participants included in the analysis (80.7% men, 19.3% women), the mean age was 40.1 years (standard deviation [SD] = 8.8), and 22% (n = 39) reported that they had injected "salts" in the past 6 months. Among people who injected "salts," 72% (n = 28) were men, and most were ethnically Russian 59% (n = 23), with a mean age of 34.6 (SD = 9.6). Injecting "salts" was significantly associated with a greater number of injections per day (adjusted relative risk [aRR] = 1.59, 95% confidence interval [CI] = 1.30-1.95) but lower odds of using syringe service programmes in the past 6 months (adjusted odds ratio [aOR] = 0.20, 95% CI = 0.12-0.32). Injecting "salts" was also significantly associated with lower odds of condomless sex in the past 6 months (aOR = 0.42, 95% CI = 0.24-0.76) and greater odds of having ever heard of pre-exposure prophylaxis (aOR = 4.80, 95% CI = 2.61-8.83). CONCLUSIONS: (PWID) people who inject drugs who inject "salts" are a potentially emergent group with increased HIV acquisition risk in Kyrgyzstan. Targeted outreach bundled with comprehensive harm reduction and pre-exposure prophylaxis services are needed to prevent transmission of HIV and other blood-borne viruses.

Characteristics of Injurious Shootings by Police Along the Urban-Rural Continuum.

INTRODUCTION: Much research on shootings by police has focused on urban jurisdictions, but most U.S. law enforcement agencies are not located in cities. Prior research suggests that rates of fatal shootings by police are comparable between urban and nonurban areas. Yet, shooting characteristics across the urban-rural continuum are unknown. This study describes and compares fatal and nonfatal injurious shootings by officers in U.S. urban, suburban, and rural areas from 2015 to 2020. METHODS: Characteristics of fatal and nonfatal injurious shootings by police were abstracted from Gun Violence Archive. In 2023-2024, using ZIP-code and county-based rurality designations, the national distribution, incidence, and characteristics of injurious shootings by police were compared across urban, suburban, and rural areas of the U.S. RESULTS: Rates of injurious shootings in rural areas approached or exceeded those of urban rates. As rurality increased, proportionately more injurious shootings involved single responders, sheriffs, or multiple agency types. Across the urban-rural continuum, characteristics of precipitating incidents were similar. Injurious shootings were most frequently preceded by domestic violence incidents, traffic stops, or shots-fired reports; co-occurring behavioral health needs were common. After accounting for local demographic differences, Black, indigenous, and Hispanic residents were injured at higher rates than White residents in all examined areas. CONCLUSIONS: Shootings by police represent an overlooked and inequitable source of injury in rural areas. Broadly similar incident characteristics suggest potential for wide-reaching reforms. To prevent injuries, crisis prevention, dispatch, and response systems must assure proportionate rural-area coverage. In addition, legislative prevention and accountability measures should include sheriffs' offices for optimal rural-area impact.

Cost-effectiveness of a police education program on HIV and overdose among people who inject drugs in Tijuana, Mexico.

Background: Incarceration is associated with drug-related harms among people who inject drugs (PWID). We trained >1800 police officers in Tijuana, Mexico on occupational safety and HIV/HCV, harm reduction, and decriminalization reforms (Proyecto Escudo). We evaluated its effect on incarceration, population impact and cost-effectiveness on HIV and fatal overdose among PWID. Methods: We assessed self-reported recent incarceration in a longitudinal cohort of PWID before and after Escudo. Segmented regression was used to compare linear trends in log risk of incarceration among PWID pre-Escudo (2012-2015) and post-Escudo (2016-2018). We estimated population impact using a dynamic model of HIV transmission and fatal overdose among PWID, with incarceration associated with syringe sharing and fatal overdose. The model was calibrated to HIV and incarceration patterns in Tijuana. We compared a scenario with Escudo (observed incarceration declines for 2 years post-Escudo among PWID from the segmented regression) compared to a counterfactual of no Escudo (continuation of stable pre-Escudo trends), assessing cost-effectiveness from a societal perspective. Using a 2-year intervention effect and 50-year time horizon, we determined the incremental cost-effectiveness ratio (ICER, in 2022 USD per disability-adjusted life years [DALYs] averted). Findings: Compared to stable incarceration pre-Escudo, for every three-month interval in the post-Escudo period, recent incarceration among PWID declined by 21% (adjusted relative risk = 0.79, 95% CI: 0.68-0.91). Based on these declines, we estimated 1.7% [95% interval: 0.7%-3.5%] of new HIV cases and 12.2% [4.5%-26.6%] of fatal overdoses among PWID were averted in the 2 years post-Escudo, compared to a counterfactual without Escudo. Escudo was cost-effective (ICER USD 3746/DALY averted compared to a willingness-to-pay threshold of $4842-$13,557). Interpretation: Escudo is a cost-effective structural intervention that aligned policing practices and human-rights-based public health practices, which could serve as a model for other settings where policing constitutes structural HIV and overdose risk among PWID. Funding: National Institute on Drug Abuse, UC MEXUS CONACyT, and the San Diego Center for AIDS Research (SD CFAR).

Longitudinal patterns of use of stimulants and opioids in the AIDS linked to the IntraVenous experience cohort, 2005-2019.

BACKGROUND: Overdoses involving opioids and stimulants are on the rise, yet few studies have examined longitudinal trends in use of both substances. We sought to describe use and co-use of opioids and stimulants, 2005-2019, in the AIDS Linked to the Intravenous Experience (ALIVE) cohort - a community-based cohort of people with a history of injection drug use living in or near Baltimore, MD. METHODS: We included 2083 ALIVE participants, who had at least two visits during the study period. Our outcome was based on self-reported use of opioids and stimulants in the prior 6 months. We estimated prevalence of 4 categories of use (neither stimulants nor opioids, only stimulants, only opioids, stimulants and opioids), using a non-parametric multi-state model, accounting for the competing event of death and weighting for informative loss to follow-up. All analyses were stratified by enrollment cohort, with the main analysis including participants who enrolled prior to 2015 and a sub-analysis including participants who enrolled 2015-2018. RESULTS: In the main analysis, prevalence of using stimulants and opioids decreased from 38 % in 2005 to 12 % 2013 but stabilized from 2014 onwards (13-19 %). The prevalence of using only stimulants (7-11 %) and only opioids (5-10 %) was stable across time. Participants who reported using both were more likely to report homelessness, depression, and other substance use (e.g., marijuana and heavy alcohol use) than participants in the other use categories. On average, 65 % of visits with use of both were followed by a subsequent visit with use of both; of participants transitioning out of using both, 13% transitioned to using neither. CONCLUSIONS: While use of stimulants and opioids declined in the cohort through 2013, a meaningful proportion of participants persistently used both. More research is needed to understand and develop strategies to mitigate harms associated with persistent use of both stimulants and opioids.

Costing analysis of a point-of-care drug checking program in Rhode Island.

BACKGROUND: Drug checking is a harm reduction strategy that provides greater awareness and information about the drug supply to the community. While fentanyl test strips are low-cost and available in most parts of the U.S., community-based organizations are considering using more sophisticated technologies, such as Fourier-transform infrared (FTIR) spectroscopy to test drugs. FTIR can detect multiple substances in a non-destructive manner that can be rapidly communicated to the program client by a trained technician, however implementation costs in community-based settings have not been assessed. METHODS: We conducted a costing analysis of a new pilot drug checking service that employed an FTIR spectrometer, fentanyl test strips and confirmatory testing in Rhode Island from January 2023-May 2023. We used microcosting methods to determine the overall cost during this period and cost per drug checked, reflecting realistic service capacity. RESULTS: Among 101 drug samples that were voluntarily submitted and tested, 53% tested positive for fentanyl, 39% for cocaine, 9% for methamphetamine and 13% for xylazine, a powerful sedative. The total cost during this period was $71,044 and the cost per drug checked was $474, though sensitivity analyses indicated that the cost would rise to $78,058 - $83,058 or $544 - $593 for programs needing to pay for specialized training. CONCLUSIONS: These findings demonstrate feasibility and inform the resources needed to scale-up drug checking services to reduce overdose risk.

Time-to-completion of COVID-19 vaccination primary series varies by HIV viral load status among people who inject drugs in Baltimore, Maryland.

People who inject drugs (PWID) may have diminished access to essential preventive services like COVID-19 vaccination given structural and substance use barriers. We aimed to assess the role of HIV on COVID-19 vaccination uptake among adult PWID participating in the ALIVE cohort study in Baltimore, Maryland who were alive as of April 2021. We abstracted COVID-19 vaccination data from electronic medical records via the regional health information exchange. We used Kaplan-Meier method to estimate time from universal vaccine eligibility (April 6, 2021) to completion of the COVID-19 vaccination primary series (1 dose J&J or 2 doses mRNA) by HIV viral load status (uninfected, PWH [HIV-RNA < 400 copies/mL], PWH [HIV-RNA ≥ 400 copies/mL]) and Cox Proportional Hazards regression to adjust for potential confounders. Our sample (N = 960) was primarily black (77%) and male (65%) with 31% reporting recent injection drug use. Among 265 (27%) people living with HIV (PWH) in our sample, 84% were virally suppressed. As of February 22, 2022, 539 (56%) completed the primary series, 131 (14%) received a single dose of mRNA vaccine and 290 (30%) remained unvaccinated. Compared to PWID without HIV, virally suppressed PWH were more likely to complete the primary series (Adjusted Hazard Ratio [aHR]:1.23,95% Confidence Interval [95 %CI]:1.07,1.50), while PWH who were not virally suppressed were less likely (aHR:0.72,95 %CI:0.45,1.16), although this was not statistically significant. We conclude that among PWID, HIV infection and viral suppression is associated with quicker vaccination uptake, likely due to HIV care engagement. Targeted improvements along the HIV care continuum may bolster vaccine uptake.

Unit costs of needle and syringe program provision: a global systematic review and cost extrapolation.

BACKGROUND: Needle and syringe programs (NSPs) are effective at preventing HIV and hepatitis C virus (HCV) among people who inject drugs (PWID), yet global coverage is low, partly because governments lack data on the cost and cost-effectiveness of NSP in their countries to plan and fund their responses. We conducted a global systematic review of unit costs of NSP provision to inform estimation of cost drivers and extrapolated costs to other countries. METHODS: We conducted a systematic review to extract data on the cost per syringe distributed and its cost drivers. We estimated the impact of country-level and program-level variables on the cost per syringe distributed using linear mixed-effects models. These models were used to predict unit costs of NSP provision, with the best performing model used to extrapolate the cost per syringe distributed for 137 countries. The total cost for a comprehensive NSP (200 syringes per PWID/year) was also estimated for 68 countries with PWID population size estimates. RESULTS: We identified 55 estimates of the unit cost per syringe distributed from 14 countries. Unit costs were extrapolated for 137 countries, ranging from $0.08 to $20.77 (2020 USD) per syringe distributed. The total estimated spend for a high-coverage, comprehensive NSP across 68 countries with PWID size estimates is $5 035 902 000 for 10 887 500 PWID, 2.1-times higher than current spend. CONCLUSION: Our review identified cost estimates from high-income, upper-middle-income, and lower-middle-income countries. Regression models may be useful for estimating NSP costs in countries without data to inform HIV/HCV prevention programming and policy.

Trajectories of drug treatment and illicit opioid use in the AIDS Linked to the IntraVenous Experience cohort, 2014-2019.

BACKGROUND: Medication for opioid use disorder (MOUD) is an effective intervention to combat opioid use disorder and overdose, yet there is limited understanding of engagement in treatment over time in the community, contextualized by ongoing substance use. We aimed to identify concurrent trajectories of methadone prescriptions, buprenorphine prescriptions, and illicit opioid use among older adults with a history of injection drug use. METHODS: We used data on 887 participants from the AIDS Linked to the IntraVenous Experience cohort, who were engaged in the study in 2013 and attended ≥1 visit during follow-up (2014-2019). Outcomes were self-reported MOUD prescription and illicit opioid use in the last 6 months. To identify concurrent trajectories in all 3 outcomes, we used group-based multi-trajectory modeling. We examined participant characteristics, including sociodemographics, HIV status, and other substance use, overall and by cluster. RESULTS: We identified 4 trajectory clusters: (1) no MOUD and no illicit opioid use (43%); (2) buprenorphine and some illicit opioid use (11%); (3) methadone and no illicit opioid use (28%); and (4) some methadone and illicit opioid use (18%). While prevalence of each outcome was stable across time, transitions on/off treatment or on/off illicit opioid use occurred, with the rate of transition varying by cluster. The rate of transition was highest in Cluster 3 (0.74/person-year) and lowest in Cluster 1 (0.18/person-year). We saw differences in participant characteristics by cluster, including that the buprenorphine cluster had the highest proportion of people with HIV and participants who identified as non-Hispanic Black. CONCLUSIONS: Most participants had discontinued illicit opioid use and were also not accessing MOUD. Trajectories defined by engagement with buprenorphine or methadone had distinct sociodemographic and behavioral characteristics, indicating that tailored interventions to expand access to both types of treatment are likely needed to reduce harms associated with untreated opioid use disorder.

Association Between Co-Occurring Anxiety and Depression With Drug Overdose Encounters in the Emergency Department Among Adolescents and Young Adults in the Era of COVID-19.

PURPOSE: COVID-19 risk mitigation efforts could have negatively impacted anxiety, depression, and substance use among adolescents and young adults. METHODS: We analyzed 45,223 emergency department visits from April 2018 to March 2022 of patients aged 12-21 in Pinellas County, Florida. RESULTS: Frequency of overdose, anxiety, and depression significantly increased from the pre-COVID-19 to the COVID-19 period. Anxiety (adjusted odds ratio: 1.49, 95% confidence interval: 1.11, 1.98) and depression (adjusted odds ratio: 2.89, 95% confidence interval: 2.15, 3.88) were associated with significantly higher odds of overdose during COVID-19. DISCUSSION: Mental health and overdose among adolescents and young adults worsened during COVID-19, necessitating greater screening and treatment in primary care.

COVID-19 Vaccine Hesitancy and Vaccination Status in a Community-Based Cohort of People Who Inject Drugs in Baltimore, Maryland, March-June 2021.

OBJECTIVE: People who inject drugs are a population who are often unengaged with health care services. The objective of this study was to characterize COVID-19 vaccine hesitancy and uptake in a community-based sample of people who inject drugs in Baltimore, Maryland. METHODS: The ALIVE study (AIDS Linked to the IntraVenous Experience) in Baltimore is a community-based cohort study of people with a history of injection drug use. From March 2 through June 28, 2021, 346 ALIVE participants completed a survey on substance use, structural determinants of health, and COVID-19 vaccine hesitancy. The exposure of interest was COVID-19 vaccine hesitancy, and the primary outcome was vaccination status as of June 30, 2021. We extracted data on the dates of vaccination from electronic medical records linked to study participants. RESULTS: The median age of the sample was 60 years; most participants were male (66%) and non-Hispanic Black (87%). Most (55%) trusted the COVID-19 vaccine, and 68% had received ≥1 dose. After age standardization, survey participants were more likely than the Maryland general population to be unvaccinated (prevalence ratio = 1.20; 95% CI, 0.97-1.49; P = .10). Participants who somewhat trusted or did not trust the COVID-19 vaccine had 6-fold higher odds of being unvaccinated than participants who trusted the vaccine (odds ratio = 6.30; 95% CI, 3.74-10.60). CONCLUSION: Uptake of COVID-19 vaccine among people with a history of injection drug use was high. Attitudes and knowledge about vaccination were important predictors of vaccine uptake. Education and outreach efforts could be effective in reducing hesitancy and increasing vaccination in substance-using populations.

Impact of Hepatitis C Treatment Uptake on Cirrhosis and Mortality in Persons Who Inject Drugs : A Longitudinal, Community-Based Cohort Study.

BACKGROUND: Hepatitis C virus (HCV) infection can be cured, and the United States has joined the World Health Organization in calling for HCV elimination by 2030. However, historically low uptake of HCV treatment among people who inject drugs (PWID) threatens HCV elimination and exacerbates social and racial health disparities. OBJECTIVE: To assess whether all-oral HCV treatments were accessed by PWID and reduced liver disease burden and mortality. DESIGN: Community-based, longitudinal cohort study of persons with a history of injection drug use. SETTING: Baltimore, Maryland. PARTICIPANTS: 1323 participants enrolled in the ALIVE (AIDS Linked to the IntraVenous Experience) study from 2006 to 2019 and chronically infected with HCV. MEASUREMENTS: Liver stiffness measures (LSMs) by transient elastography, HCV RNA, and mortality from the National Death Index. RESULTS: Among 1323 persons with evidence of chronic HCV infection at baseline, the median age was 49 years. Most were Black (82%), male (71%), and HIV-negative (66%). The proportion in whom HCV RNA was detected decreased from 100% (by definition) in 2006 to 48% in 2019. Across 10 350 valid LSMs, cirrhosis was detected in 15% of participants in 2006, 19% in 2015, and 8% in 2019. Undetectable HCV RNA was significantly associated with reduced odds of cirrhosis (adjusted odds ratio, 0.28 [95% CI, 0.17 to 0.45]) and reduced all-cause mortality risk (adjusted hazard ratio, 0.54 [CI, 0.38 to 0.77]). LIMITATION: Noninvasive markers of liver fibrosis have not been validated in persons with sustained virologic response. CONCLUSION: Many community-based PWID in Baltimore are receiving HCV treatment, which is associated with sharp decreases in liver disease and mortality. Additional efforts will be needed to reduce residual barriers to treatment and to eliminate HCV as a public health threat for PWID. PRIMARY FUNDING SOURCE: National Institutes of Health.

Impact of SHIELD Police Training on Knowledge of Syringe Possession Laws and Related Arrests in Tijuana, Mexico.

Between 2015 and 2018, we provided training for 1806 municipal police officers in Tijuana, Mexico, in an effort to improve their knowledge and behaviors related to HIV and injection drug use. Correct knowledge of syringe possession laws improved from 56% before training to 94% after training and was sustained at 24 months (75%). Knowledge improvement was associated with decreases in arrests for syringe possession over time (adjusted odds ratio [AOR] = 0.87; 95% confidence interval [CI] = 0.85, 0.90). Officers with correct knowledge had significantly lower odds of reporting arrests (AOR = 0.63; 95% CI = 0.44, 0.89). Training was associated with sustained improvements in knowledge and practices that advance public health. (Am J Public Health. 2022;112(6):860-864. https://doi.org/10.2105/AJPH.2021.306702).

Assessing HIV and overdose risks for people who use drugs exposed to compulsory drug abstinence programs (CDAP): A systematic review and meta-analysis.

BACKGROUND: Evidence supports integrating drug use treatment, harm reduction, and HIV prevention services to address dual epidemics of drug use disorders and HIV. These dual epidemics have spurred a rise in legally-enforced compulsory drug abstinence programs (CDAP), despite limited evidence on its effectiveness. We conducted a systematic review and meta-analysis evaluating the association between CDAP exposure and HIV and overdose-related risk. METHODS: We searched PubMed, EBSCOhost and Sociological Abstracts for studies that contained an individual-level association between CDAP exposure and related HIV or overdose risks, with no date restrictions. Meta-analyses were conducted on data abstracted from eligible studies, using pooled random-effects models and I-squared statistics. We assessed quality of the studies across 14 criteria for observational studies. RESULTS: Out of 2,226 abstracts screened, we included 8 studies (5253 individuals/776 events) across China, Mexico, Thailand, Norway, and the United States. All but two were cross-sectional analyses, limiting strength of observed associations. In the two studies that reported association between CDAP and HIV seropositivity or receptive syringe sharing, findings were inconsistent and did not indicate that those with exposure to CDAP had increased odds of HIV or syringe sharing. However, we found the odds of experiencing non-fatal overdose in lifetime and in the last 6-12 months were 2.02 (95% CI 0.22 - 18.86, p = 0.16) to 3.67 times higher (95% CI 0.21 - 62.88, p = 0.39), respectively, among those with CDAP exposure than those without. CONCLUSION: Research assessing HIV risk associated with CDAP is scant and inconclusive, while evidence of robust associations between CDAP and overdose risk continues to mount. More rigorous, longitudinal studies are needed to evaluate the causal relationships between CDAP and these health outcomes. Aside from the growing evidence base on collateral harms, ethical considerations dictate that voluntary, evidence-based drug treatment should be prioritized to address the drivers of excess morbidity and mortality among people who use drugs.

Municipal police support for harm reduction services in officer-led referrals of people who inject drugs in Tijuana, Mexico.

BACKGROUND: Police constitute a structural determinant of health and HIV risk of people who inject drugs (PWID), and negative encounters with law enforcement present significant barriers to PWID access to harm reduction services. Conversely, police may facilitate access via officer-led referrals, potentiating prevention of HIV, overdose, and drug-related harms. We aimed to identify police characteristics associated with support for officer-led referrals to addiction treatment services and syringe service programs (SSP). We hypothesized that officers who believe harm reduction services are contradictory to policing priorities in terms of safety and crime reduction will be less likely to support police referrals. METHODS: Between January and June 2018, police officers (n = 305) in Tijuana, Mexico, completed self-administered surveys about referrals to harm reduction services during the 24-month follow-up visit as part of the SHIELD police training and longitudinal cohort study. Log-binomial regression was used to estimate adjusted prevalence ratios and model policing characteristics and attitudes related to officers' support for including addiction treatment and SSP in referrals. RESULTS: Respondents were primarily male (89%), patrol officers (86%) with a median age of 38 years (IQR 33-43). Overall, 89% endorsed referral to addiction services, whereas 53% endorsed SSP as acceptable targets of referrals. Officers endorsing addiction services were less likely to be assigned to high drug use districts (adjusted prevalence ratio [APR] = 0.50, 95% CI 0.24, 1.08) and more likely to agree that methadone programs reduce crime (APR = 4.66, 95% CI 2.05, 9.18) than officers who did not support addiction services. Officers endorsing SSPs were younger (adjusted prevalence ratio [APR] = 0.96 95% CI 0.93, 0.98), less likely to be assigned to high drug use districts (APR = 0.50, 95% CI 0.29, 0.87), more likely to believe that methadone programs reduce crime (APR = 2.43, 95% CI 1.30, 4.55), and less likely to believe that SSPs increase risk of needlestick injury for police (APR = 0.44, 0.27, 0.71). CONCLUSIONS: Beliefs related to the occupational impact of harm reduction services in terms of officer safety and crime reduction are associated with support for referral to related harm reduction services. Efforts to deflect PWID from carceral systems toward harm reduction by frontline police should include measures to improve officer knowledge and attitudes about harm reduction services as they relate to occupational safety and law enforcement priorities. TRIAL REGISTRATION: NCT02444403.

Cost-effectiveness of hepatitis C virus (HCV) elimination strategies among people who inject drugs (PWID) in Tijuana, Mexico.

BACKGROUND AND AIMS: In Latin America, Mexico was first to launch a hepatitis C virus (HCV) elimination strategy, where people who inject drugs (PWID) are a main risk group for transmission. In Tijuana, HCV seroprevalence among PWID is > 90%, with minimal harm reduction (HR). We evaluated cost-effectiveness of strategies to achieve the incidence elimination target among PWID in Tijuana. METHODS: Modeling study using a dynamic, cost-effectiveness model of HCV transmission and progression among active and former PWID in Tijuana, to assess the cost-effectiveness of incidence elimination strategies from a health-care provider perspective. The model incorporated PWID transitions between HR stages (no HR, only opioid agonist therapy, only high coverage needle-syringe programs, both). Four strategies that could achieve the incidence target (80% reduction by 2030) were compared with the status quo (no intervention). The strategies incorporated the number of direct-acting anti-viral (DAA) treatments required with: (1) no HR scale-up, (2) HR scale-up from 2019 to 20% coverage among PWID, (3) HR to 40% coverage and (4) HR to 50% coverage. Costs (2019 US$) and health outcomes [disability-adjusted life years (DALYs)] were discounted 3% per year. Mean incremental cost-effectiveness ratios (ICER, $/DALY averted) were compared with one-time per capita gross domestic product (GDP) ($9698 in 2019) and purchasing power parity-adjusted per capita GDP ($4842-13 557) willingness-to-pay (WTP) thresholds. RESULTS: DAAs alone were the least costly elimination strategy [$173 million, 95% confidence interval (CI) = 126-238 million], but accrued fewer health benefits compared with strategies with HR. DAAs + 50% HR coverage among PWID averted the most DALYs but cost $265 million, 95% CI = 210-335 million). The optimal strategy was DAAs + 50% HR (ICER $6743/DALY averted compared to DAAs only) under the one-time per-capita GDP WTP ($9698). CONCLUSIONS: A combination of high-coverage harm reduction and hepatitis C virus treatment is the optimal cost-effective strategy to achieve the HCV incidence elimination goal in Mexico.

Is hepatitis C virus (HCV) elimination achievable among people who inject drugs in Tijuana, Mexico? A modeling analysis.

BACKGROUND: In 2019, Mexico became the first Latin American country committed to hepatitis C virus (HCV) elimination, but the amount of intervention scale-up required is unclear. In Tijuana, HCV among people who inject drugs (PWID) is high; yet there is minimal and intermittent harm reduction, and involuntary exposure to compulsory abstinence programs (CAP) occurs which is associated with increased HCV risk. We determined what combination intervention scale-up can achieve HCV elimination among current and former PWID in Tijuana. METHODS: We constructed a dynamic, deterministic model of HCV transmission, disease progression, and harm reduction among current and former PWID parameterized to Tijuana (~10,000 current PWID, 90% HCV seropositive, minimal opiate agonist therapy [OAT] or high coverage needle/syringe programs [HCNSP]). We evaluated the number of direct-acting antiviral (DAA) treatments needed from 2019 to achieve elimination targets (80% incidence reduction, 65% mortality reduction by 2030) with: (a) DAAs alone, (b) DAAs plus scale-up of OAT+HCNSP (up to 50% coverage of OAT and HCNSP separately, producing 25% of PWID receiving both), (c) DAAs plus CAP scale-up to 50%. Scenarios examined the number of DAAs required if prioritized to current PWID or provided regardless of current injection status, and impact of harm reduction interruptions. RESULTS: Modeling suggests among ~30,000 current and former PWID in Tijuana, 16,160 (95%CI: 12,770-21,610) have chronic HCV. DAA scale-up can achieve the incidence target, requiring 770 treatments/year (95%CI: 640-970) if prioritized to current PWID. 40% fewer DAAs are required with OAT+HCNSP scale-up to 50% among PWID, whereas more are required with involuntary CAP scale-up. Both targets can only be achieved through treating both current and former PWID (1,710 treatments/year), and impact is reduced with harm reduction interruptions. CONCLUSIONS: Elimination targets are achievable in Tijuana through scale-up of harm reduction and DAA therapy, whereas involuntary CAP and harm reduction interruptions hamper elimination.

Preferences and acceptability of law enforcement initiated referrals for people who inject drugs: a mixed methods analysis.

BACKGROUND: Law enforcement officers (LEOs) come into frequent contact with people who inject drugs (PWID). Through service referrals, LEOs may facilitate PWID engagement in harm reduction, substance use treatment, and other health and supportive services. Little is known about PWID and LEO attitudes and concerns about service referrals, however. The objective of this mixed-methods study was to examine the alignment of service referral preferences and acceptability among PWID and LEOs in Tijuana, Mexico. METHODS: We assessed service referral preferences and perceived likelihood of participation in health and social services, integrating data from structured questionnaires with 280 PWID and 306 LEOs, contextualized by semi-structured interviews and focus groups with 15 PWID and 17 LEOs enrolled in two parallel longitudinal cohorts in Tijuana, Mexico. RESULTS: Among potential service referral options, both PWID (78%) and LEOs (88%) most frequently cited assistance with drug- and alcohol-use disorders. Over half of PWID and LEOs supported including harm reduction services such as syringe service programs, overdose prevention, and HIV testing. The majority of PWID supported LEO referrals to programs that addressed basic structural needs (e.g. personal care [62%], food assistance [61%], housing assistance [58%]). However, the proportion of LEOs (30-45%) who endorsed these service referrals was significantly lower (p <  0.01). Regarding referral acceptability, 71% of PWID reported they would be very likely or somewhat likely to make use of a referral compared to 94% of LEOs reporting that they thought PWID would always or sometimes utilize them. These results were echoed in the qualitative analysis, although practical barriers to referrals emerged, whereby PWID were less optimistic that they would utilize referrals compared to LEOs. CONCLUSIONS: We identified strong support for LEO service referrals among both LEO and PWID respondents, with the highest preference for substance use treatment. LEO referral programs offer opportunities to deflect PWID contact with carceral systems while facilitating access to health and social services. However, appropriate investments and political will are needed to develop an evidence-based (integrated) service infrastructure.

Estimating the contribution of stimulant injection to HIV and HCV epidemics among people who inject drugs and implications for harm reduction: A modeling analysis.

BACKGROUND: Stimulants, such as amphetamines and cocaine, are widely injected among people who inject drugs (PWID). Systematic reviews indicate stimulant injection is associated with HIV and HCV among PWID. Using these associations, we estimated the contribution of stimulant injection to HIV and HCV transmission among PWID. METHODS: We modeled HIV and HCV transmission among PWID, incorporating excess injecting and sexual risk among PWID who inject stimulants. We simulated three illustrative settings with different stimulants injected, prevalence of stimulant injecting, and HIV/HCV epidemiology. We estimated one-year population attributable fractions of stimulant injection on new HIV and HCV infections, and impact of scaling up needle-syringe programs (NSP). RESULTS: In low prevalence settings of stimulant injection (St. Petersburg-like, where 13 % inject amphetamine), 9% (2.5-97.5 % interval [95 %I]: 6-15 %) and 7% (95 %I 4-11 %) of incident HIV and HCV cases, respectively, could be associated with stimulant injection in the next year. With moderate stimulant injection (Montreal-like, where 34 % inject cocaine), 29 % (95 %I: 19-37 %) and 19 % (95 %I: 16-21 %) of incident HIV and HCV cases, respectively, could be associated with stimulant injection. In high-burden settings like Bangkok where 65 % inject methamphetamine, 23 % (95%I:10-34%) and 20 % (95%I: 9-27%) of incident HIV and HCV cases could be due to stimulant injection. High-coverage NSP (60 %) among PWID who inject stimulants could reduce HIV (by 22-65 %) and HCV incidence (by 7-11 %) in a decade. DISCUSSION: Stimulant injection contributes substantially to HIV and HCV among PWID. NSP scale-up and development of novel interventions among PWID who inject stimulants are warranted.