Paula J. Lum

Hepatitis C Virus Seroconversion among Young Injection Drug Users: Relationships and Risks

The present study examined reasons for the high incidence of hepatitis C virus (HCV) infection among young injection drug users (IDUs). IDUs <30 years old who tested negative for HCV antibody were enrolled in a prospective cohort. Risk factors for seroconversion were examined using time-dependent regression analyses: 48 of 195 IDUs seroconverted to HCV, for an incidence rate of 25.1/100 person-years (95% confidence interval, 18.7-32.9/100 person-years). Independent risk factors included sharing needles with an HCV-infected sex partner (borderline statistical significance, P=.11) or a person who was not a sex partner, sharing nonsterile drug-preparation equipment, pooling money with another IDU to buy drugs, and exchanging sex for money. Ubiquitous behaviors among young IDUs, such as the forming of injecting or sexual partnerships and consequent sharing of needles and drug preparation equipment, are risk factors for HCV. Interventions to reduce HCV transmission must recognize the importance of relationships on injecting risk.

Gender differences in sexual and injection risk behavior among active young injection drug users in San Francisco (the UFO Study).

Female injection drug users (IDUs) represent a large proportion of persons infected with HIV in the United States, and women who inject drugs have a high incidence of hepatitis B virus (HBV) and hepatitis C virus (HCV) injection. Therefore, it is important to understand the role of gender in injection risk behavior and the transmission of blood-borne virus. In 2000–2002, 844 young (<30 years old) IDUs were surveyed in San Francisco. We compared self-reported risk behavior between 584 males and 260 female participants from cross-sectional baseline data. We used logistic regression to determine whether demographic, structural, and relationship variables explained increased needle borrowing, drug preparation equipment sharing, and being injected by another IDU among females compared to males. Females were significantly younger than males and were more likely to engage in needle borrowing, ancillary equipment sharing, and being injected by someone else. Females were more likely than males to report recent sexual intercourse and to have IDU sex partners. Females and males were not different with respect to education, race/ethnicity, or housing status. In logistic regression models for borrowing a used needle and sharing drug preparation equipment, increased risk in females was explained by having an injection partner who was also a sexual partner. Injecting risk was greater in the young female compared to male IDUs despite equivalent frequency of injecting. Overlapping sexual and injection partnerships were a key factor in explaining increased injection risk in females. Females were more likely to be injected by another IDU even after adjusting for years injecting, being in a relationship with another IDU, and other potential confounders. Interventions to reduce sexual and injection practices that put women at risk of contracting hepatitis and HIV are needed.

Acute Hepatitis C Virus Infection in Young Adult Injection Drug Users: A Prospective Study of Incident Infection, Resolution, and Reinfection

BACKGROUND Hepatitis C virus (HCV) infection, clearance, and reinfection are best studied in injection drug users (IDUs), who have the highest incidence of HCV and are likely to represent most infections. METHODS A prospective cohort of HCV-negative young IDUs was followed up from January 2000 to September 2007, to identify acute and incident HCV and prospectively study infection outcomes. RESULTS Among 1,191 young IDUs screened, 731 (61.4%) were HCV negative, and 520 (71.1%) of the 731 were enrolled into follow-up. Cumulative HCV incidence was 26.7/100 person-years of observation (95% confidence interval [CI], 21.5-31.6). Of 135 acute/incident HCV infections, 95 (70.4%) were followed; 20 (21.1%) of the 95 infections cleared. Women had a significantly higher incidence of viral clearance than did men (age-adjusted hazard ratio, 2.91 [95% CI, 1.68-5.03]) and also showed a faster rate of early HCV viremia decline (P < .01). The estimated reinfection rate was 24.6/100 person-years of observation (95% CI, 11.7-51.6). Among 7 individuals, multiple episodes of HCV reinfection and reclearance were observed. CONCLUSIONS In this large sample of young IDUs, females show demonstrative differences in their rates of viral clearance and kinetics of early viral decline. Recurring reinfection and reclearance suggest possible protection against persistent infection. These results should inform HCV clinical care and vaccine development.

Hiv Treatment Outcomes Among Hiv-infected, Opioid-dependent Patients Receiving Buprenorphine/naloxone Treatment within Hiv Clinical Care Settings: Results From a Multisite Study

Background:Having opioid dependence and HIV infection are associated with poor HIV-related treatment outcomes. Methods:HIV-infected, opioid-dependent subjects (N = 295) recruited from 10 clinical sites initiated buprenorphine/naloxone (BUP/NX) and were assessed at baseline and quarterly for 12 months. Primary outcomes included receiving antiretroviral therapy (ART), HIV-1 RNA suppression, and mean changes in CD4 lymphocyte count. Analyses were stratified for the 119 subjects not on ART at baseline. Generalized estimating equations were deployed to examine time-dependent correlates for each outcome. Results:At baseline, subjects on ART (N = 176) were more likely than those not on ART (N = 119) to be older, heterosexual, have lower alcohol addiction severity scores, and lower HIV-1 RNA levels; they were less likely to be homeless and report sexual risk behaviors. Subjects initiating BUP/NX (N = 295) were significantly more likely to initiate or remain on ART and improve CD4 counts over time compared with baseline; however, these improvements were not significantly improved by longer retention on BUP/NX. Retention on BUP/NX for three or more quarters was, however, significantly associated with increased likelihood of initiating ART (β = 1.34 [1.18, 1.53]) and achieve viral suppression (β = 1.25 [1.10, 1.42]) for the 64 of 119 (54%) subjects not on ART at baseline compared with the 55 subjects not retained on BUP/NX. In longitudinal analyses, being on ART was positively associated with increasing time of observation from baseline and higher mental health quality of life scores (β = 1.25 [1.06, 1.46]) and negatively associated with being homo- or bisexual (β = 0.55 [0.35, 0.97]), homeless (β = 0.58 [0.34, 0.98]), and increasing levels of alcohol addiction severity (β = 0.17 [0.03, 0.88]). The strongest correlate of achieving viral suppression was being on ART (β = 10.27 [5.79, 18.23]). Female gender (β = 1.91 [1.07, 3.41]), Hispanic ethnicity (β = 2.82 [1.44, 5.49]), and increased general health quality of life (β = 1.02 [1.00,1.04]) were also independently correlated with viral suppression. Improvements in CD4 lymphocyte count were significantly associated with being on ART and increased over time. Conclusions:Initiating BUP/NX in HIV clinical care settings is feasible and correlated with initiation of ART and improved CD4 lymphocyte counts. Longer retention on BPN/NX was not associated with improved prescription of ART, viral suppression, or CD4 lymphocyte counts for the overall sample in which the majority was already prescribed ART at baseline. Among those retained on BUP/NX, HIV treatment outcomes did not worsen and were sustained. Increasing time on BUP/NX, however, was especially important for improving HIV treatment outcomes for those not on ART at baseline, the group at highest risk for clinical deterioration. Retaining subjects on BUP/NX is an important goal for sustaining HIV treatment outcomes for those on ART and improving them for those who are not. Comorbid substance use disorders (especially alcohol), mental health problems, and quality-of-life indicators independently contributed to HIV treatment outcomes among HIV-infected persons with opioid dependence, suggesting the need for multidisciplinary treatment strategies for this population.

Association of Opioid Agonist Therapy With Lower Incidence of Hepatitis C Virus Infection in Young Adult Injection Drug Users

IMPORTANCE Injection drug use is the primary mode of transmission for hepatitis C virus (HCV) infection. Prior studies suggest opioid agonist therapy may reduce the incidence of HCV infection among injection drug users; however, little is known about the effects of this therapy in younger users. OBJECTIVE To evaluate whether opioid agonist therapy was associated with a lower incidence of HCV infection in a cohort of young adult injection drug users. DESIGN, SETTING, AND PARTICIPANTS Observational cohort study conducted from January 3, 2000, through August 21, 2013, with quarterly interviews and blood sampling. We recruited young adult (younger than 30 years) injection drug users who were negative for anti-HCV antibody and/or HCV RNA. EXPOSURES Substance use treatment within the past 3 months, including non-opioid agonist forms of treatment, opioid agonist (methadone hydrochloride or buprenorphine hydrochloride) detoxification or maintenance therapy, or no treatment. MAIN OUTCOMES AND MEASURES Incident HCV infection documented with a new positive result for HCV RNA and/or HCV antibodies. Cumulative incidence rates (95% CI) of HCV infection were calculated assuming a Poisson distribution. Cox proportional hazards regression models were fit adjusting for age, sex, race, years of injection drug use, homelessness, and incarceration. RESULTS Baseline characteristics of the sample (n = 552) included median age of 23 (interquartile range, 20-26) years; 31.9% female; 73.1% white; 39.7% who did not graduate from high school; and 69.2% who were homeless. During the observation period of 680 person-years, 171 incident cases of HCV infection occurred (incidence rate, 25.1 [95% CI, 21.6-29.2] per 100 person-years). The rate ratio was significantly lower for participants who reported recent maintenance opioid agonist therapy (0.31 [95% CI, 0.14-0.65]; P = .001) but not for those who reported recent non-opioid agonist forms of treatment (0.63 [95% CI, 0.37-1.08]; P = .09) or opioid agonist detoxification (1.45 [95% CI, 0.80-2.69]; P = .23). After adjustment for other covariates, maintenance opioid agonist therapy was associated with lower relative hazards for acquiring HCV infection over time (adjusted hazard ratio, 0.39 [95% CI, 0.18-0.87]; P = .02). CONCLUSIONS AND RELEVANCE In this cohort of young adult injection drug users, recent maintenance opioid agonist therapy was associated with a lower incidence of HCV infection. Maintenance treatment with methadone or buprenorphine for opioid use disorders may be an important strategy to prevent the spread of HCV infection among young injection drug users.

Predictors of injection drug use cessation and relapse in a prospective cohort of young injection drug users in San Francisco, CA (UFO Study)

BACKGROUND Studies of injection drug use cessation have largely sampled adults in drug treatment settings. Little is known about injection cessation and relapse among young injection drug users (IDU) in the community. METHODS A total of 365 HCV-negative IDU under age 30 years were recruited by street outreach and interviewed quarterly for a prospective cohort between January 2000 and February 2008. Participants were followed for a total of 638 person-years and 1996 visits. We used survival analysis techniques to identify correlates of injection cessation (> or =3 months) and relapse to injection. RESULTS 67% of subjects were male, median age was 22 years (interquartile range (IQR) 20-26) and median years injecting was 3.6 (IQR 1.3-6.5). 28.8% ceased injecting during the follow-up period. Among those that ceased injecting, nearly one-half resumed drug injection on subsequent visits, one-quarter maintained injecting cessation, and one-quarter were lost to follow-up. Participating in a drug treatment program in the last 3 months and injecting less than 30 times per month were associated with injection cessation. Injecting heroin or heroin mixed with other drugs, injecting the residue from previously used drug preparation equipment, drinking alcohol, and using benzodiazepines were negatively associated with cessation. Younger age was associated with relapse to injection. CONCLUSION These results suggest that factors associated with stopping injecting involve multiple areas of intervention, including access to drug treatment and behavioral approaches to reduce injection and sustain cessation. The higher incidence of relapse in the younger subjects in this cohort underscores the need for earlier detection and treatment programs targeted to adolescents and transition-age youth.

Hepatitis B Virus Immunization Among Young Injection Drug Users in San Francisco, Calif: The UFO Study

Hepatitis B virus (HBV) infection is common (44%–80%) in injection drug users (IDUs),1–8 and younger IDUs are at high risk.9–11 Although a safe and effective vaccine is available, high vaccine completion rates in IDUs (70%–86%) have been achieved primarily in drug treatment settings.12–15 Among street-recruited young injectors in San Francisco, Calif, only 13% had serological evidence of prior immunization, and 28% had been infected with HBV.16 We combined cash incentives and street outreach with flexible immunization schedules to improve HBV vaccine completion in young injectors in San Francisco. We examined factors associated with vaccine completion and observed postvaccination antibody responses in completers.

Commercial sex work and risk of HIV infection among young drug-injecting men who have sex with men in San Francisco.

Objective: The objective of this study was to investigate the relationship between sex work and HIV infection among young injection drug-using men who have sex with men (MSM-IDU). Study Design: This study was a cross-sectional analysis of behavioral and serologic data collected from 227 street-recruited MSM-IDU in San Francisco, California, between January 2000 and November 2001. Results: Sixty-eight percent of participants reported being paid by another man for sex. HIV prevalence was 12% (95% confidence interval, 8–16%); 42% of seropositive participants were unaware of their infection. HIV was independently associated with higher number of paying male partners and history of gonorrhea and inversely associated with number of female partners, education, and syringe-sharing. Consistent condom use overall was 41%, but varied significantly by type of partner. Conclusions: Among MSM-IDU in San Francisco, sex work with men is strongly associated with HIV infection and the prevalence of condom use is low. HIV prevention among MSM-IDU must be tailored to address the excess risk associated with sex work.

Investigation of a secondary syringe exchange program for homeless young adult injection drug users in San Francisco, California, U.S.A.

This study investigated an HIV prevention program for homeless young adult injection drug users (IDUs) that combined a secondary syringe exchange program (SEP) with community‐level activities. Homeless young IDUs were recruited from street‐based settings in San Francisco, and a structured questionnaire was administered. The secondary SEP operated in a circumscribed geographic area, and for analytic purposes respondents were assigned to the intervention site group if they primarily spent time in this area (n = 67), or the comparison site group if they primarily spent time elsewhere (n = 55). Almost all (96%) intervention site youth had used the secondary SEP in the past 30 days and were significantly more likely to regularly use SEP. In bivariate analysis, comparison site IDUs were more likely to share syringes, reuse syringes, share the cotton used to filter drugs, and use condoms with casual sex partners only inconsistently. In multivariate analysis, comparison site remained positively associated with sharing syringes (adjusted odds ratio [AOR], 3.748; 95% confidence interval [CI], 1.406‐9.988), reusing syringes (AOR, 2.769; 95% CI, 1.120‐6.847), and inconsistent condom use with casual sex partners (AOR, 4.825; 95% CI, 1.392‐ 16.721). This suggests that the intervention was effective in delivering SEP services to homeless young adult IDUs, and that IDUs who frequented the intervention site had a lower HIV risk than comparison group IDUs.

Prevalence and correlates of HIV infection among young injection drug users in San Francisco.

Objective: We assessed the prevalence of HIV infection and associated risk behaviors among street‐recruited young injection drug users (IDUs) in San Francisco. Methods: In a cross‐sectional study, 304 young (age <30 years) IDUs with a history of injecting in the previous 30 days were interviewed and tested for antibodies to HIV. Analyses assessing independent associations with HIV infection were limited to males only, due to the low number of infections in women. Results: The prevalence of HIV infection was 5.3% overall but was highly stratified by gender and sexual preference (15.6% among homosexual/bisexual men vs. heterosexual men) and recruitment neighborhood (18% in the Polk Street area). Of 16 HIV infections, 14 (88%) were in males. Factors independently associated with HIV infection in males included sexual preference (homosexual/bisexual vs. heterosexual: adjusted odds ratio [AOR], 7.5; 95% confidence interval [CI], 1.5‐36.6), recruitment neighborhood (Polk Street neighborhood vs. other neighborhoods: AOR, 4.8; 95% CI, 1.4‐16.7), and duration of residence in San Francisco (≥1 year vs. <1 year: AOR, 11.8; 95% CI, 1.4‐95.8). Conclusions: The prevalence of HIV infection was highest among male IDUs who have sex with men. The strong associations between HIV infection and sexual orientation and HIV infection and recruitment locale suggest that risk may be attributable largely to sexual risk. In addition to successful prevention efforts aimed at reducing needle‐associated risk, current intervention models aimed at young IDUs should target high‐risk neighborhoods and emphasize sexual risk reduction measures, in particular among men who have sex with men.