Potential geographic "hotspots" for drug-injection related transmission of HIV and HCV and for initiation into injecting drug use in New York City, 2011-2015, with implications for the current opioid epidemic in the US

Insights into the spatial epidemiology of hepatitis C infection: systematic synthesis of area-level determinants and spatiotemporal analyses

BACKGROUND

Hepatitis C virus (HCV) stands at the forefront of global elimination endeavors by 2030, highlighting the need for a nuanced exploration into disparities and vulnerabilities using innovative spatial epidemiological approaches. This study aimed to systematically review existing literature to summarize area-level factors associated with HCV infection and to examine the application of spatial and spatiotemporal analyses in HCV research.

METHODS

A systematic search following PRISMA guidelines was conducted for peer-reviewed literature published between 2000 and 2023 using PubMed, Web of Science, Scopus, and Embase databases. The synthesis of area-level factors was organized according to four distinct categories of risk environments: social, economic, policy, and physical environments.

RESULTS

Sixty-five studies were selected for this systematic review. 60% of the studies focused on the general population, while 20% of the studies targeted people who inject drugs. The area-level factors explored predominantly were characteristics of the social and economic risk environments. For instance, areas with a higher level of socioeconomic disadvantage, lower education attainment, higher population density, and located more remotely were associated with higher HCV infection rates. Additionally, some studies noted a significant correlation between the accessibility to harm reduction and healthcare services and HCV occurrence, testing, and treatment rates. Furthermore, spatial data exploration and cluster analysis methods were the predominant methods used to explore the nuanced spatial distribution of HCV infection.

CONCLUSION

This review emphasizes the imperative of deciphering the complex interplay of area-level factors in HCV infection dynamics. Understanding the potential risk environment landscape of HCV could facilitate identifying vulnerable areas and communities. Additionally, the limited application of spatial analytics in HCV research highlights the untapped potential, emphasizing the need for enhanced spatial techniques to pinpoint priority areas for intervention.

Geographic information science and the United States opioid overdose crisis: A scoping review of methods, scales, and application areas

BACKGROUND

The Opioid Overdose Crisis (OOC) continues to generate morbidity and mortality in the United States, outpacing other prominent accident-related reasons. Multiple disciplines have applied geographic information science (GIScience) to understand geographical patterns in opioid-related health measures. However, there are limited reviews that assess how GIScience has been used.

OBJECTIVES

This scoping review investigates how GIScience has been used to conduct research on the OOC. Specific sub-objectives involve identifying bibliometric trends, the location and scale of studies, the frequency of use of various GIScience methodologies, and what direction future research can take to address existing gaps.

METHODS

The review was pre-registered with the Open Science Framework ((https://osf.io/h3mfx/) and followed the PRISMA-ScR guidelines. Scholarly research was gathered from the Web of Science Core Collection, PubMed, IEEE Xplore, ACM Digital Library. Inclusion criteria was defined as having a publication date between January 1999 and August 2021, using GIScience as a central part of the research, and investigating an opioid-related health measure.

RESULTS

231 studies met the inclusion criteria. Most studies were published from 2017 onward. While many (41.6%) of studies were conducted using nationwide data, the majority (58.4%) occurred at the sub-national level. California, New York, Ohio, and Appalachia were most frequently studied, while the Midwest, north Rocky Mountains, Alaska, and Hawaii lacked studies. The most common GIScience methodology used was descriptive mapping, and county-level data was the most common unit of analysis across methodologies.

CONCLUSIONS

Future research of GIScience on the OOC can address gaps by developing use cases for machine learning, conducting analyses at the sub-county level, and applying GIScience to questions involving illicit fentanyl. Research using GIScience is expected to continue to increase, and multidisciplinary research efforts amongst GIScientists, epidemiologists, and other medical professionals can improve the rigor of research.

The Association Between Homophily on Illicit Drug Use and PrEP Conversations Among Latino Men Who Have Sex with Men Friends: A Dyadic Network and Spatially Explicit Study

Despite the wide availability of PrEP, Latino men who have sex with men (LMSM) continue to experience access barriers. Novel HIV prevention research strategies to increase PrEP uptake and adherence among the high incidence populations, such as LMSM who misuse drugs, include social network analyses. This study identified the associations of drug use homophily within LMSM friendship networks and PrEP promotion conversations and described the physical overlap between geographic drug risk areas with conversations of PrEP promotion. Respondent-driven sampling was used to recruit 10 sociocentric networks. Quadratic assignment procedure (QAP) correlations and multiple regression QAPs were used to identify influences of drug use homophily, and geocoding and visualizations to describe drug use polygons and PrEP conversations. Friendship relationships in which both friends used cocaine or marijuana were more likely to report PrEP-related conversations in the past six months. The likelihood of talking about PrEP in the next six months was higher among dyads with cocaine use homophily and ecstasy use homophily, while lower among dyads with marijuana use homophily. Participants reported using marijuana and cocaine throughout Miami-Dade County while ecstasy polygons were mostly in urban areas. The majority of drug polygons associated with PrEP conversations were located in north and central Miami. Future interventions can consider enrolling entire sociocentric friendship groups, configuring friendship networks to connect those without PrEP information to those with information, and incorporating peer leaders.

Impact of Local and Demographic Factors on Early COVID-19 Vaccine Hesitancy among Health Care Workers in New York City Public Hospitals

Despite the development of several effective vaccines, SARS-CoV-2 continues to spread, causing serious illness among the unvaccinated. Healthcare professionals are trusted sources of information about vaccination, and therefore understanding the attitudes and beliefs of healthcare professionals regarding the vaccines is of utmost importance. We conducted a survey-based study to understand the factors affecting COVID-19 vaccine attitudes among health care professionals in NYC Health and Hospitals, at a time when the vaccine was new, and received 3759 responses. Machine learning and chi-square analyses were applied to determine the factors most predictive of vaccine hesitancy. Demographic factors, education, role at the hospital, perceptions of the pandemic itself, and location of work and residence were all found to significantly contribute to vaccine attitudes. Location of residence was examined for both borough and neighborhood, and was found to have a significant impact on vaccine receptivity. Interestingly, this borough-level data did not correspond to the number or severity of cases in the respective boroughs, indicating that local social or other influences likely have a substantial impact. Local and demographic factors should be strongly considered when preparing pro-vaccine messages or campaigns.

Chronic hepatitis-C infection in COVID-19 patients is associated with in-hospital mortality

BACKGROUND

There is little evidence about the association of pre-existing hepatitis C infection (HCV) with outcomes in patients with coronavirus disease 2019 (COVID-19).

AIM

To assess the prevalence of history of HCV among patients with COVID-19 and to study the relationship of in-hospital mortality in relation with other predictors of poor outcomes in the presence or absence of COVID-19 induced acute liver injury.

METHODS

In a retrospective single-center study design, 1193 patients with COVID-19 infection were studied. Patients were then classified into those with and without a history of HCV, 50 (4.1%) and 1157 (95.9%) respectively.

RESULTS

Multivariate cox-regression models showed that age, HCV, D-Dimer, and ferritin were the only predictors of in-hospital mortality. Acute liver injury and fibrosis score (Fib-4 score) were not different between both groups. Multivariate cox-regression model for liver profile revealed that aspartate aminotransferase/ alanine aminotransferase ratio, Fib-4 score, and HCV were predictors of in-hospital mortality. After propensity score matching HCV was the only predictor of mortality in the multivariate cox-regression model. A model including HCV was found to add predictive value to clinical and laboratory parameters.

CONCLUSION

In patients with COVID-19, history of HCV infection leads to an accentuated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virulence, irrespective of baseline comorbidities, admission laboratory variables, or COVID-19-induced liver injury, which may be related to extrahepatic effects of HCV leading to enhanced ACE-2/TMPRSS mechanisms of SARS-CoV-2 viral entry, baseline cytokine-mediated pro-inflammation, and endothelial dysfunction.

Role of direct and indirect social and spatial ties in the diffusion of HIV and HCV among people who inject drugs: a cross-sectional community-based network analysis in New Delhi, India

Background:

People who inject drugs (PWID) account for some of the most explosive human immunodeficiency virus (HIV) and hepatitis C virus (HCV) epidemics globally. While individual drivers of infection are well understood, less is known about network factors, with minimal data beyond direct ties.

Methods:

2512 PWID in New Delhi, India were recruited in 2017–19 using a sociometric network design. Sampling was initiated with 10 indexes who recruited named injection partners (people who they injected with in the prior month). Each recruit then recruited their named injection partners following the same process with cross-network linkages established by biometric data. Participants responded to a survey, including information on injection venues, and provided a blood sample. Factors associated with HIV/HCV infection were identified using logistic regression.

Results:

The median age was 26; 99% were male. Baseline HIV prevalence was 37.0% and 46.8% were actively infected with HCV (HCV RNA positive). The odds of prevalent HIV and active HCV infection decreased with each additional degree of separation from an infected alter (HIV AOR: 0.87; HCV AOR: 0.90) and increased among those who injected at a specific venue (HIV AOR: 1.50; HCV AOR: 1.69) independent of individual-level factors (p<0.001). In addition, sociometric factors, for example, network distance to an infected alter, were statistically significant predictors even when considering immediate egocentric ties.

Conclusions:

These data demonstrate an extremely high burden of HIV and HCV infection and a highly interconnected injection and spatial network structure. Incorporating network and spatial data into the design/implementation of interventions may help interrupt transmission while improving efficiency.

Funding:

National Institute on Drug Abuse and the Johns Hopkins University Center for AIDS Research.

Understanding the social and spatial relationships that connect people is a key element to stop the spread of infectious diseases. These networks are particularly relevant to combat epidemics among populations that are hard to reach with public health interventions. Network-based approaches, for example, can help to stop HIV or hepatitis C from spreading amongst populations that use injectable drugs. Yet how social and geographic connections such as acquaintances, injection partners, or preferred drug use places impact the risk of infection is still poorly mapped out.

To address this question, Clipman et al. focused on people who inject drugs in New Delhi, India, a population heavily impacted by HIV and hepatitis C. Over 2500 people were recruited, each participant inviting their injection partners to also take part. The volunteers answered survey questions, including where they used drugs, and provided a blood sample to be tested.

The results showed that, even after adjusting for individual risk factors, where people used drugs and with whom affected their risk of becoming infected with HIV and hepatitis C. In terms of social ties, the likelihood of HIV and hepatitis C infection decreased by about 13% for each person separating a given individual from an infected person. However, geographical networks also had a major impact. Injecting at a popular location respectively increased the odds of HIV and hepatitis C infection by 50% and 69%. In fact, even if the participant was not using drugs at these specific places, having an injection partner who did was enough to increase the risk for disease: for each person separating an individual from the location, the likelihood of being infected with HIV and hepatitis C decreased by respectively 14% and 10%.

The results by Clipman et al. highlight how the relationships between physical spaces and social networks contribute to the spread of dangerous diseases amongst people who inject drugs. Ultimately, this knowledge may help to shape better public health interventions that would take into account the importance of geographical locations.

Methodological approaches for the prediction of opioid use-related epidemics in the United States: a narrative review and cross-disciplinary call to action

The opioid crisis in the United States has been defined by waves of drug- and locality-specific Opioid use-Related Epidemics (OREs) of overdose and bloodborne infections, among a range of health harms. The ability to identify localities at risk of such OREs, and better yet, to predict which ones will experience them, holds the potential to mitigate further morbidity and mortality. This narrative review was conducted to identify and describe quantitative approaches aimed at the "risk assessment," "detection" or "prediction" of OREs in the United States. We implemented a PubMed search composed of the: (1) objective (eg, prediction), (2) epidemiologic outcome (eg, outbreak), (3) underlying cause (ie, opioid use), (4) health outcome (eg, overdose, HIV), (5) location (ie, US). In total, 46 studies were included, and the following information extracted: discipline, objective, health outcome, drug/substance type, geographic region/unit of analysis, and data sources. Studies identified relied on clinical, epidemiological, behavioral and drug markets surveillance and applied a range of methods including statistical regression, geospatial analyses, dynamic modeling, phylogenetic analyses and machine learning. Studies for the prediction of overdose mortality at national/state/county and zip code level are rapidly emerging. Geospatial methods are increasingly used to identify hotspots of opioid use and overdose. In the context of infectious disease OREs, routine genetic sequencing of patient samples to identify growing transmission clusters via phylogenetic methods could increase early detection capacity. A coordinated implementation of multiple, complementary approaches would increase our ability to successfully anticipate outbreak risk and respond preemptively. We present a multi-disciplinary framework for the prediction of OREs in the US and reflect on challenges research teams will face in implementing such strategies along with good practices.

Hepatitis C Virus (HCV) Care Continuum Outcomes and HCV Community Viral Loads Among Patients in an Opioid Treatment Program

BACKGROUND

Hepatitis C virus (HCV) remains endemic among people who use drugs (PWUD). Measures of HCV community viral load (CVL) and HCV care continuum outcomes may be valuable for ascertaining unmet treatment need and for HCV surveillance and control.

METHODS

Data from patients in an opioid treatment program during 2013-2016 were used to (1) identify proportions of antibody and viral load (VL) tested, linked-to-care, and treated, in 2013-2014 and 2015-2016, and pre- and postimplementation of qualitative reflex VL testing; (2) calculate engaged-in-care HCV CVL and "documented" and "estimated" unmet treatment need; and (3) examine factors associated with linkage-to-HCV-care.

RESULTS

Among 11 267 patients, proportions of HCV antibody tested (52.5% in 2013-2014 vs 73.3% in 2015-2016), linked-to-HCV-care (15.7% vs 51.8%), and treated (12.0% vs 44.7%) all increased significantly. Hispanic ethnicity was associated with less linkage-to-care, and Manhattan residence was associated with improved linkage-to-care. The overall engaged-in-care HCV CVL was 4 351 079 copies/mL (standard deviation = 7 149 888); local HCV CVLs varied by subgroup and geography. Documented and estimated unmet treatment need decreased but remained high.

CONCLUSIONS

After qualitative reflex VL testing was implemented, care continuum outcomes improved, but gaps remained. High rates of unmet treatment need suggest that control of the HCV epidemic among PWUD will require expansion of HCV treatment coverage.

Rural risk environments, opioid-related overdose, and infectious diseases: A multidimensional, spatial perspective

BACKGROUND

Much remains unknown in rural risk environments, despite a growing crisis in these areas. We adapt a risk environment framework to characterize rural southern Illinois and describe the relations of risk environments, opioid-related overdose, HIV, Hepatitis C, and sexually transmitted infection rates between 2015 and 2017.

METHODS

Over two dozen risk environment variables are summarized across zip-code (n = 128) or county levels (n = 16) based on availability and theoretical relevance. We calculate data attribute associations and characterize spatial and temporal dimensions of longitudinal health outcomes and the rural risk environment. We then use a "regional typology analysis" to generate data-driven risk regions and compare health outcomes.

RESULTS

Pervasive risk hotspots were identified in more populated locales with higher rates of overdose and HCV incidence, whereas emerging risk areas were isolated to more rural locales that had experienced an increase in analgesic opiate overdoses and generally lacked harm-reduction resources. At-risk areas were characterized with underlying socioeconomic vulnerability but in differing ways, reflecting a nuanced and shifting structural risk landscape.

CONCLUSIONS

Rural risk environment vulnerabilities and associated opioid-related health outcomes are multifaceted and spatially heterogeneous. More research is needed to better understand how refining geographies to more precisely define risk can support intervention efforts and further enrich investigations of the opioid epidemic.

Geographically Focused Collocated Hepatitis C Screening and Treatment in Los Angeles's Skid Row

BACKGROUND

The inequitable prevalence of hepatitis C (HCV) in the homeless is a clinical and public health concern. Prior research estimates, at least one-quarter of homeless persons have been infected with HCV, yet linkage to care and treatment uptake remains marginal.

AIM

To evaluate the feasibility of treating HCV in a homeless population.

METHODS

Retrospective study of homeless individuals treated for HCV. Demographic information including risk factors was collected. Univariate analyses were performed. The proportion of patients linked to care and sustained viral response at 12 weeks post-treatment (SVR12) was measured.

RESULTS

During the study period, 6767 individuals were screened for HCV. A total of 769 (11.4%) were found to have detectable HCV antibodies. Of the individuals with detectable HCV antibodies, 443 (57.6%) were viremic. Of the 443 viremic patients, 375 (84.7%) were linked to care. Among them, 59 patients began antiviral treatment and 95% (56/59) completed the course of therapy. The ITT was 83.1% (49/59), and the per-protocol virologic cure rate was 100% (49/49).

CONCLUSION

The favorable linkage to care and cure outcomes in our study suggests that homeless persons may be more likely to engage in HCV screening and treatment when these services are located in the community for their use. Our study further lends support to the efficacy of care coordination programs to encourage movement through the HCV care continuum in vulnerable populations.

Systematic Review and Meta-Analysis of Global Prevalence of HBsAg and HIV and HCV Antibodies among People Who Inject Drugs and Female Sex Workers

The main objective of this study was to evaluate the prevalence of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), hepatitis C virus (HCV) and hepatitis B virus (HBV) and their co-infections among people who inject drugs (PWID) and female sex workers (FSWs). Data sources were searched from January 2008 to October 2018 in different databases. Data were analyzed in Stata 16 software using the Metaprop command. The results showed that the prevalence of HIV, HCV and HBV among PWID was 15%, 60% and 6%, respectively. The prevalence of HIV, HCV and HBV among FSWs was 5%, 1% and 3%, respectively. The prevalence of HIV/HCV, HIV/HBV, HCV/HBV and HIV/HCV/HBV co-infections among PWID was 13%, 2%, 3% and 2%, respectively. The prevalence of HIV/HCV and HIV/HBV co-infections among FSWs was 3% and 1%, respectively. The results show that the prevalence of HCV and HIV infections in PWID and the prevalence of HIV in FSWs is higher than their prevalence in the general population. Interventions for the prevention of HIV and HCV in PWID appear to be poor, and may not be sufficient to effectively prevent HIV and HCV transmission.

Exploring Awareness of HCV Among Sexual-Minority Black Generation Millennials and Gen Z: a Qualitative Study

Hepatitis C (HCV) is a significant public health burden globally. While HIV-positive men who have sex with men (MSM) have traditionally comprised the majority of sexually acquired HCV cases in the USA, recent studies indicate that HIV-negative MSM and MSM who use pre-exposure prophylaxis (PrEP) in particular are at increasing risk for incident HCV. Further, in the USA, African Americans are disproportionately burdened by chronic HCV compared with other ethnic groups. We sought to better understand awareness and knowledge about HCV and the perceived barriers to HCV testing, among young Black MSM (YBMSM) ages 18-24 in an urban southern California setting. This formative work was conducted in the context of a broader study designed to develop a brief, peer-led intervention to increase hepatitis awareness and testing among young men at risk. Our focus group findings suggest that YBMSM are lacking awareness and knowledge about HCV that are important for self-appraisal of their risk and need for testing. Additionally, YBMSM reported low social support for HCV testing; many indicated they do not discuss HCV with peers, community leaders, or family members. Using study participants' recommendations for engaging YBMSM in HCV prevention efforts, our study emphasizes the need for education and screening efforts targeted to YBMSM, and especially YBMSM who are engaging in high-risk sexual activity with HIV-positive and/or older MSM. We offer recommendations for public health strategies that may be helpful for increasing awareness of HCV risks and HCV screening among vulnerable YBMSM groups.

Geographic distribution of risk ("Hotspots") for HIV, HCV, and drug overdose among persons who use drugs in New York City: the importance of local history

AIMS

To identify geographic "hotspots" for potential transmission of HIV and HCV and for drug overdose among persons who use heroin and cocaine in New York City and to examine historical continuities in problem drug use hotspots in the city.

METHODS

A total of 2714 study participants were recruited among persons entering Beth Israel substance use treatment programs. A structured questionnaire was administered and blood samples for HIV and HCV testing were collected. Hotspots for potential virus transmission were defined as ZIP codes with 10+ participants, 2+ persons infected with the virus and engaging in transmission behavior, and 2+ persons not infected and engaging in acquisition behavior. ZIP codes with 3+ persons with previous overdoses were considered potential hotspots for future overdoses.

RESULTS

Participants resided in 166/178 (93%) of the ZIP codes in New York City. Injecting drug use was reported in 150/178 (84%) of the ZIP codes. No zip codes were identified for injecting-related HIV transmission, 5 zip codes were identified for sexual HIV transmission, 3 for HCV transmission, and 8 for drug overdose. Many of the ZIP code potential hotspots were in neighborhoods long associated with drug use: Lower Eastside and Harlem in Manhattan, the South Bronx, and Central Brooklyn.

DISCUSSION

Heroin and cocaine use requiring treatment were reported from almost all ZIP codes in New York City, indicating needs for widely dispersed harm reduction services. Identified hotspots should be targeted for reducing sexual transmission of HIV, transmission of HCV, and drug overdoses. Some of the hotspots have persisted as problem drug use areas for 40 to over 100 years. Monitoring of drug use patterns in historical hotspot neighborhoods may permit early identification of and response to emerging drug use-related health problems. Persistent historical hotspots for problem drug use present a complex problem for implementing harm reduction services that deserve additional research.

Substance use disorders among African, Caribbean and Black (ACB) people in Canada: a scoping review protocol

INTRODUCTION

Previous research demonstrated that substance use continues to be one of the most complex and prevalent problems among African, Caribbean and Black (ACB) people. A number of studies were conducted to characterise substance use patterns in this population. To our knowledge, this is the first known review in Canada characterising substance use disorders on ACB people.This scoping review seeks to answer the following research questions: What characterises substance use disorders among ACB people in Canada? What are the different types and prevalence of substance use among ACB people in Canada? Do ACB people in Canada use more than one substance? What factors are associated with substance use among ACB people in Canada? What are the health and social impacts of substance use in ACB people in Canada?

METHODS AND ANALYSES

This study will use the methodological framework for scoping reviews developed by Arksey and O'Malley. We will search electronic bibliographic databases including Ovid MEDLINE, PsycINFO and CINAHL. We will limit our search to English articles published between 2000and2019. In addition, we will conduct a grey literature search. Two investigators will independently screen citations and full-text articles. Our findings will be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis for scoping reviews guidelines. We will provide a descriptive summary of the studies and summarise the findings with respect to the outcomes and report any gaps that might require further investigation.

ETHICS AND DISSEMINATION

Our proposed study does not involve human participants; therefore, research ethics approval is not required. This study will provide evidence that will inform the development of strategies for appropriate interventions, as well as policy and further research. The results will be disseminated through publications in open access peer-reviewed journals, presentations at scientific meetings and to the lay public.

Factors Associated with Frequency of Recent Initiation of Others into Injection Drug Use Among People Who Inject Drugs in Los Angeles and San Francisco, CA, USA, 2016-17

Objective: Drug injection initiation is often assisted by a person who injects drugs (PWID). How often PWID provide this assistance has not been examined. We examine frequency of injection initiation assistance and factors associated with high (4+) and low frequency (1-3) initiation assistance as compared to no initiation assistance among PWID. Methods: Participants were 979 Californian PWID. PWID were interviewed about providing injection initiation assistance in the last 6 months among other items. Multinomial regression analysis was used to examine factors associated with levels of frequency of injection initiation assistance. Results: Among participants, 132 (14%) had initiated 784 people into injection (mean = 5.94 [standard deviation = 20.13]; median = 2, interquartile range = 1,4) in the last 6 months. PWID engaged in high frequency initiation (26% of sample) assisted 662 new initiates (84% of total). Using multinomial regression analysis with no initiating as the referent group, we found that high frequency initiating was statistically associated with higher injection frequency, having a paying sex partner, taking someone to a shooting gallery, and providing injection assistance. Lower frequency initiation was statistically associated with having a paying sex partner, illegal income source, and providing injection assistance. Conclusion: Differences between high and low frequency initiators were not found. Sex work and assisting with drug injection were linked to initiating others. Individual-level interventions that reduce this behavior among PWID and structural interventions such as safe consumption sites and opioid medication treatments that interrupt the social process of injection initiation should be considered as ways to reduce injection initiations.

Hepatitis C virus prevalence and estimated incidence among new injectors during the opioid epidemic in New York City, 2000-2017: Protective effects of non-injecting drug use

OBJECTIVE

Assess hepatitis C virus (HCV) prevalence and incidence among person who began injecting drugs during the opioid epidemic in New York City (NYC) and identify possible new directions for reducing HCV infection among persons who inject drugs.

METHODS

846 persons who began injecting drugs between 2000 and 2017 were recruited from persons entering Mount Sinai Beth Israel substance use treatment programs. A structured interview was administered and HCV antibody testing conducted. Protective effects of non-injecting drug use were examined among persons who "reversed transitioned" to non-injecting drug use and persons who used non-injected heroin in addition to injecting.

RESULTS

Participants were 79% male, 41% White, 15% African-American, 40% Latinx, with a mean age of 35. Of those who began injecting in 2000 or later, 97 persons (11%) "reverse transitioned" back to non-injecting drug use. Reverse transitioning was strongly associated with lower HCV seroprevalence (30% versus 47% among those who continued injecting, p < 0.005). Among those who continued injecting, HCV seropositivity was inversely associated with current non-injecting heroin use (AOR = 0.72, 95%CI 0.52-0.99). HCV incidence among persons continuing to inject was estimated as 13/100 person-years. HCV seropositive persons currently injecting cocaine were particularly likely to report behavior likely to transmit HCV.

CONCLUSIONS

Similar to other locations in the US, NYC is experiencing high rates of HCV infection among persons who have begun injecting since 2000. New interventions that facilitate substitution of non-injecting for injecting drug use and that reduce transmission behavior among HCV seropositives may provide additional methods for reducing HCV transmission.