As SARS-CoV-2 continues to spread and evolve, detecting emerging variants early is critical for public health interventions. Inferring lineage prevalence by clinical testing is infeasible at scale, especially in areas with limited resources, participation, or testing and/or sequencing capacity, which can also introduce biases1–3. SARS-CoV-2 RNA concentration in wastewater successfully tracks regional infection dynamics and provides less biased abundance estimates than clinical testing4,5. Tracking virus genomic sequences in wastewater would improve community prevalence estimates and detect emerging variants. However, two factors limit wastewater-based genomic surveillance: low-quality sequence data and inability to estimate relative lineage abundance in mixed samples. Here we resolve these critical issues to perform a high-resolution, 295-day wastewater and clinical sequencing effort, in the controlled environment of a large university campus and the broader context of the surrounding county. We developed and deployed improved virus concentration protocols and deconvolution software that fully resolve multiple virus strains from wastewater. We detected emerging variants of concern up to 14 days earlier in wastewater samples, and identified multiple instances of virus spread not captured by clinical genomic surveillance. Our study provides a scalable solution for wastewater genomic surveillance that allows early detection of SARS-CoV-2 variants and identification of cryptic transmission.

Female sex workers who inject drugs (FSW-IDUs) face elevated risk for HIV/ STIs and constitute a key population for public health prevention. Through direct and indirect pathways including human rights violations, policing practices like syringe confiscation can compound FSW-IDU health risk and facilitate the spread of disease. We studied correlates of experiencing syringe confiscation among FSW-IDUs in northern Mexico, where formal policy allows for syringes to be available over the counter without a prescription, but police practices are often at odds with the law. FSWIDUs reporting recent syringe sharing and unprotected sex with clients in Tijuana and Ciudad Juarez were administered surveys and HIV/STI testing. Logistic regression was used to identify correlates of syringe confiscation. Among 624 respondent FSW-IDUs, prevalence of syringe confiscation in the last 6 months was 48 %. The following factors were positively associated with syringe confiscation: testing positive for HIV (adjusted odds ratio [aOR]=2.54, 95 % confidence interval [CI]=1.11-5.80), reporting sexual abuse by police (aOR=12.76, 95 % CI=6.58-24.72), engaging in groin injection (aOR=1.84, 95 % CI=1.15-2.93), injecting in public (aOR=1.64; 95 % CI=1.14-2.36), and obtaining syringes from pharmacies (aOR=1.54; 95 % CI=1.06-2.23). Higher education level was negatively associated with syringe confiscation (aOR= 0.92, 95 % CI=0.87-0.98) as was frequent injection with clients within the last month (aOR=0.64,). This analysis adds to the body of evidence linking unauthorized law enforcement actions targeting high-risk groups with HIV and other adverse health outcomes. Using a public health lens to conceptualize abuse as a structural risk factor, we advocate for multi-prong prevention, systematic monitoring, and evidence-based intervention response to deleterious police practices.

IntroductionPolicing practices are key drivers of HIV among people who inject drugs (PWID). This paper describes the protocol for the first study to prospectively examine the impact of a police education programme (PEP) to align law enforcement and HIV prevention. PEPs incorporating HIV prevention (including harm reduction programmes like syringe exchange) have been successfully piloted in several countries but were limited to brief pre–post assessments; the impact of PEPs on policing behaviours and occupational safety is unknown.ObjectivesProyecto ESCUDO (SHIELD) aims to evaluate the efficacy of the PEP on uptake of occupational safety procedures, as assessed through the incidence of needle stick injuries (NSIs) (primary outcome) and changes in knowledge of transmission, prevention and treatment of HIV and viral hepatitis; attitudes towards PWID, adverse behaviours that interfere with HIV prevention and protective behaviours (secondary outcomes).Methods/analysisESCUDO is a hybrid type I design that simultaneously tests an intervention and an implementation strategy. Using a modified stepped-wedge design involving all active duty street-level police officers in Tijuana (N=∼1200), we will administer one 3 h PEP course to groups of 20–50 officers until the entire force is trained. NSI incidence and geocoded arrest data will be assessed from department-wide de-identified data. Of the consenting police officers, a subcohort (N=500) will be randomly sampled from each class to undergo pre-PEP and post-PEP surveys with a semiannual follow-up for 2 years to assess self-reported NSIs, attitudes and behaviour changes. The impact on PWIDs will be externally validated through a parallel cohort of Tijuana PWIDs.Ethics/disseminationResearch ethics approval was obtained from the USA and Mexico. Findings will be disseminated through open access to protocol materials through the Law Enforcement and HIV Network.Trial registration numberNCT02444403.

Objective To compare distributions of human rights violations and disease risk; to juxtapose these patterns against demographic and structural environmental variables, and to formulate implications for structural interventions. Methods Female sex workers who inject drugs were surveyed in Tijuana and Ciudad Juarez, Mexico. Structured interviews and testing for sexually transmitted infections (STIs) were conducted (October 2008 to October 2009). Frequencies of individual and environmental factors, including police abuse, risk of HIV infection, and protective behaviors, were compared between sites using univariate logistic regression. Results Of 624 women, almost half reported police syringe confiscation despite syringes being legal; 55.6% reported extortion (past 6 months), with significantly higher proportions in Ciudad Juarez (P < 0.001). Reports of recent solicitation of sexual favors (28.5% in Tijuana, 36.5% in Ciudad Juarez, P = 0.04) and sexual abuse (15.7% in Tijuana, 18.3% in Ciudad Juarez) by police were commonplace. Prevalence of STIs was significantly lower in Tijuana than in Ciudad Juarez (64.2% and 83.4%, P < 0.001), paralleling the lower prevalence of sexual risk behaviors there. Ciudad Juarez respondents reported significantly higher median number of monthly clients (6.8 versus 1.5, P < 0.001) and lower median pay per sex act (US$ 10 versus US$ 20, P < 0.001) (in the past month). Relative to Tijuana, security deployment, especially the army’s presence, was perceived to have increased more in Ciudad Juarez in the past year (72.1% versus 59.2%, P = 0.001). Conclusions Collateral damage from police practices in the context of Mexico’s drug conflict may affect public health in the Northern Border Region. Itinerant officers may facilitate disease spread beyond the region. The urgency for mounting structural interventions is discussed.

Objectives:This commentary seeks to highlight the benefits of community-based participatory research (CBPR) and promote its use in the violence field. Community perspectives remain underrepresented in the CBPR literature despite the emphasis on equitable partnerships and shared ownership in the research process. Method: Informal interviews were conducted with 10 community partners to understand their perspectives on using and participating in research. Results: Several recommendations for strengthening academic-community research partnerships emerged from the community partners' responses. They were: (a) conduct research that is useful to communities, with a focus on evidence-based practices and cost-benefit analyses; (b) involve community partners early in the development of research questions to ensure that local needs are addressed; (c) engage in frequent and open communication and maintain transparency about research goals and roles and responsibilities of each partner; (d) provide benefits to communities during the research process to promote professional development and build capacity; and (e) disseminate findings quickly, using outlets accessible to communities, and translate into strategies for practice. Conclusion: Although the recommendations require significant investments of time and resources by all partners, use of CBPR can contribute to increased development of innovative and sustainable violence prevention programs, services, and policies that are uniquely informed by scientific evidence and community expertise. By emphasizing partnerships with communities, CBPR helps to reduce the gap between research and practice and facilitates the inclusion of community strengths and resilience as valuable components of violence prevention and intervention.

Introduction and Aims. Patterns of polydrug use among people who inject drugs (PWID) may be differentially associated with overdose and unique human immunodeficiency virus (HIV) risk factors. Subgroups of PWID in Tijuana, Mexico, were identified based on substances used, route of administration, frequency of use and co-injection indicators. Design and Methods. Participants were PWID residing in Tijuana age ≥18 years sampled from 2011 to 2012 who reported injecting an illicit substance in the past month (n = 735). Latent class analysis identified discrete classes of polydrug use characterised by 11 indicators of past 6 months substance use. Multinomial logistic regression examined class membership association with HIV risk behaviours, overdose and other covariates using an automated three-step procedure in MPLUS to account for classification error. Results. Participants were classified into five subgroups. Two polydrug and polyroute classes were defined by use of multiple substances through several routes of administration and were primarily distinguished from each other by cocaine use (class 1: 5%) or no cocaine use (class 2: 29%). The other classes consisted primarily of injectors: cocaine, methamphetamine and heroin injection (class 3: 4%); methamphetamine and heroin injection (class 4: 10%); and heroin injection (class 5: 52%). Compared with the heroin-only injection class, memberships in the two polydrug and polyroute use classes were independently associated with both HIV injection and sexual risk behaviours. Discussion and Conclusions. Substance use patterns among PWID in Tijuana are highly heterogeneous, and polydrug and polyroute users are a high-risk subgroup who may require more tailored prevention and treatment interventions. [Meacham MC, Roesch SC, Strathdee SA, Lindsay S, Gonzalez-Zuniga P, Gaines TL. Latent classes of polydrug and polyroute use and associations with human immunodeficiency virus risk behaviours and overdose among people who inject drugs in Tijuana, Baja California, Mexico. Drug Alcohol Rev 2017;00:000-000]

In 2009, Mexico decriminalized the possession of small amounts of illicit drugs for personal use in order to refocus law enforcement resources on drug dealers and traffickers. This study examines the spatial distribution of law enforcement encounters reported by people who inject drugs (PWID) in Tijuana, Mexico to identify concentrated areas of policing activity after implementation of the new drug policy. Mapping the physical location of law enforcement encounters provided by PWID (n = 461) recruited through targeted sampling, we identified hotspots of extra-judicial encounters (e.g., physical/sexual abuse, syringe confiscation, and money extortion by law enforcement) and routine authorized encounters (e.g., being arrested or stopped but not arrested) using point density maps and the Getis-Ord Gi* statistic calculated at the neighborhood-level. Approximately half of the participants encountered law enforcement more than once in a calendar year and nearly one third of these encounters did not result in arrest but involved harassment or abuse by law enforcement. Statistically significant hotspots of law enforcement encounters were identified in a limited number of neighborhoods located in areas with known drug markets. At the local-level, law enforcement activities continue to target drug users despite a national drug policy that emphasizes drug treatment diversion rather than punitive enforcement. There is a need for law enforcement training and improved monitoring of policing tactics to better align policing with public health goals.

Women with histories of child sexual abuse (CSA) are more likely than those without such experiences to report a variety of negative sexual outcomes. This study examines the explanatory power of a CSA summed composite versus dichotomous (presence/absence) measurement in predicting a comprehensive negative sexual behavior outcome. Study participants were obtained from a community based sample examining women’s sexual decision-making. The continuous CSA measurement reflects cumulative histories of CSA through a composite score capturing abuse specific characteristics. Using a cross-validation approach, the sample (n = 835) was randomly split and the explanatory power of each measure was examined through a series of multiple linear regressions comparing model fit indexes and performing a formal likelihood ratio test of one model against another. All CSA measures explained a similar percentage of variance but overall the CSA summed composite explained the data significantly better in terms predicting negative sexual experiences and revictimization than a binary measure as demonstrated with the likelihood ratio test. The results were replicated by cross-validating the predictive power of the CSA composite score between the split samples. Consistency of CSA regression estimates for the summed composite between training and validation samples were also confirmed. Given the superiority of the CSA summed composites over the binary variable, we recommend using this measure when examining associations between CSA histories and negative sexual experiences and revictimization.