Summary Background As countries embark on public health-oriented drug law reform, health impact evaluations are needed. In 2012, Mexico mandated the narcomenudeo reform, which depenalised the possession of small amounts of drugs and instituted drug treatment instead of incarceration. We investigated the past and future effect of this drug law reform on HIV incidence in people who inject drugs in Tijuana, Mexico. Methods In this epidemic modelling study, we used data from the El Cuete IV cohort study to develop a deterministic model of injecting and sexual HIV transmission in people who inject drugs in Tijuana between 2012 and 2030. The population was stratified by sex, incarceration status, syringe confiscation by the police, HIV stage, and exposure to drug treatment or rehabilitation (either opioid agonist treatment or compulsory drug abstinence programmes). We modelled the effect of these exposures on HIV risk in people who inject drugs, estimating the effect of observed and potential future reform enforcement levels. Findings In 2011, prior to the narcomenudeo reform, 547 (75%) of 733 people who inject drugs in the El Cuete cohort reported having ever been incarcerated, on average five times since starting injecting. Modelling estimated the limited reform implementation averted 2% (95% CI 0·2–3·0) of new HIV infections in people who inject drugs between 2012 and 2017. If implementation reduced incarceration in people who inject drugs by 80% from 2018 onward, 9% (95% CI 4–16) of new HIV infections between 2018 and 2030 could be averted, with 21% (10–33) averted if people who inject drugs were referred to opioid agonist treatment instead of being incarcerated. Referral to compulsory drug abstinence programmes instead of prison could have a lower or potentially negative impact with −2% (95% CI −23 to 9) infections averted. Interpretation Mexican drug law reform has had a negligible effect on the HIV epidemic among people who inject drugs in Tijuana. However, appropriate implementation could markedly reduce HIV incidence if linked to opioid agonist treatment. Unfortunately, compulsory drug abstinence programmes are the main type of drug rehabilitation available and their expansion could potentially increase HIV transmission.

Background Policing practices such as syringe confiscation and arrest can act as important social-structural drivers of HIV risk among people who inject drugs (PWID). However, police referral to treatment and other services may improve the health of PWID. Little is known about the role of modifiable attitudinal and knowledge factors in shaping officer behavior. Using baseline findings from a police education program (PEP), we assessed relationships between drug policy knowledge and attitudes towards public health interventions with self-reported syringe confiscation, drug arrest, and service referral among street-level police in Tijuana, Mexico. Methods Between February, 2015 and May, 2016 we surveyed 1,319 police officers who reported syringe contact. The self-administered survey focused on attitudes, knowledge, and behaviors related to drug policy, public health, and occupational safety. We used ordinal logistic regression to model the odds of syringe confiscation, arrest for heroin possession, and referring PWID to health/social programs. Results The sample was mostly male (87%) and had at least a high school education (80%). In the last six months, a minority reported always/sometimes confiscating syringes (49%), arresting someone for heroin possession (43%), and referring PWID to health and social programs (37%). Those reporting needlestick injuries (NSI) had 1.38 (95% CI: 1.02–1.87) higher odds of reporting syringe confiscation. Officers who had favorable views on laws that treat addiction as a public health issue had lower odds (aOR= 0.78; 95% CI: 0.59–1.03) of arresting PWID. Those agreeing that it was their role to refer PWID to health and social programs had higher odds of reporting such referrals (aOR: 3.32, 95% CI: 2.52–4.37). Legal knowledge was not associated with these practices. Conclusion Changing drug policy and knowledge may be insufficient in shifting police behavior. Modifying officers’ occupational risks and attitudes towards harm reduction interventions can facilitate efforts to align police practices with PWID health.

BackgroundMexico’s 2009 “narcomenudeo reform” decriminalized small amounts of drugs, shifting some drug law enforcement to the states and mandating drug treatment diversion instead of incarceration. Data from Tijuana suggested limited implementation of this harm reduction-oriented policy. We studied whether a police education program (PEP) improved officers’ drug and syringe policy knowledge, and aimed to identify participant characteristics associated with improvement of drug policy knowledge.MethodsPre- and post-training surveys were self-administered by municipal police officers to measure legal knowledge. Training impact was assessed through matched paired nominal data using McNemar’s tests. Multivariable logistic regression was used to identify predictors of improved legal knowledge, as measured by officers’ ability to identify conceptual legal provisions related to syringe possession and thresholds of drugs covered under the reform.ResultsOf 1750 respondents comparing pre- versus post training, officers reported significant improvement (p < 0.001) in their technical understanding of syringe possession (56 to 91%) and drug amounts decriminalized, including marijuana (9 to 52%), heroin (8 to 71%), and methamphetamine (7 to 70%). The training was associated with even greater success in improving conceptual legal knowledge for syringe possession (67 to 96%) (p < 0.001), marijuana (16 to 91%), heroin (11 to 91%), and methamphetamine (11 to 89%). In multivariable modeling, those with at least a high school education were more likely to exhibit improvement of conceptual legal knowledge of syringe possession (adjusted odds ratio [aOR] 2.6, 95% CI 1.4–3.2) and decriminalization for heroin (aOR 2.7, 95% CI 1.3–4.3), methamphetamine (aOR 2.2, 95% CI 1.4–3.2), and marijuana (aOR 2.5, 95% CI 1.6–4).ConclusionsDrug policy reform is often necessary, but not sufficient to achieve public health goals because of gaps in translating formal laws to policing practice. To close such gaps, PEP initiatives bundling occupational safety information with relevant legal content demonstrate clear promise. Our findings underscore additional efforts needed to raise technical knowledge of the law among personnel tasked with its enforcement. Police professionalization, including minimum educational standards, appear critical for aligning policing with harm reduction goals.