Concurrent Hepatitis C and B Virus and Human Immunodeficiency Virus Infections Are Associated With Higher Mortality Risk Illustrating the Impact of Syndemics on Health Outcomes

Background

Hepatitis C virus (HCV), hepatitis B virus (HBV), and human immunodeficiency virus (HIV) infections are associated with significant mortality globally and in North America. However, data on impact of concurrent multiple infections on mortality risk are limited. We evaluated the effect of HCV, HBV, and HIV infections and coinfections and associated factors on all-cause mortality in British Columbia (BC), Canada.

Methods

The BC Hepatitis Testers Cohort includes ~1.7 million individuals tested for HCV or HIV, or reported as a case of HCV, HIV, or HBV from 1990 to 2015, linked to administrative databases. We followed people with HCV, HBV, or HIV monoinfection, coinfections, and triple infections from their negative status to date of death or December 31, 2016. Extended Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for factors associated with all-cause mortality.

Results

Of 658 704 individuals tested for HCV, HBV, and HIV, there were 33 804 (5.13%) deaths. In multivariable Cox regression analysis, individuals with HCV/HBV/HIV (HR, 8.9; 95% CI, 8.2–9.7) infections had the highest risk of mortality followed by HCV/HIV (HR, 4.8; 95% CI, 4.4–5.1), HBV/HIV (HR, 4.1; 95% CI, 3.5–4.8), HCV/HBV (HR, 3.9; 95% CI, 3.7–4.2), HCV (HR, 2.6; 95% CI, 2.6–2.7), HBV (HR, 2.2; 95% CI, 2.0–2.3), and HIV (HR, 1.6; 95% CI, 1.5–1.7). Additional factors associated with mortality included injection drug use, problematic alcohol use, material deprivation, diabetes, chronic kidney disease, heart failure, and hypertension.

Conclusions

Concurrent multiple infections are associated with high mortality risk. Substance use, comorbidities, and material disadvantage were significantly associated with mortality independent of coinfection. Preventive interventions, including harm reduction combined with coinfection treatments, can significantly reduce mortality.

Hepatitis C virus reinfection after successful treatment with direct-acting antiviral therapy in a large population-based cohort

BACKGROUND & AIMS

Direct-acting antiviral therapies (DAA) are an important tool for hepatitis C virus (HCV) elimination. However, reinfection among people who inject drugs (PWID) may hamper elimination targets. Therefore, we estimated HCV reinfection rates among DAA-treated individuals, including PWID.

METHODS

We analyzed data from the British Columbia Hepatitis Testers Cohort which included ∼1.7 million individuals screened for HCV in British Columbia, Canada. We followed HCV-infected individuals treated with DAAs who achieved a sustained virologic response (SVR) and had ≥1 subsequent HCV RNA measurement to April 22nd, 2018. Reinfection was defined as a positive RNA measurement after SVR. PWID were identified using a validated algorithm and classified based on recent (<3 years) or former (≥3 years before SVR) use. Crude reinfection rates per 100 person-years (PYs) were calculated. Poisson regression was used to model adjusted incidence rate ratios (IRRs) and 95% CIs.

RESULTS

Of 4,114 individuals who met the inclusion criteria, most were male (n = 2,692, 65%), born before 1965 (n = 3,411, 83%) and were either recent (n = 875, 21%) or former PWID (n = 1,793, 44%). Opioid-agonist therapy (OAT) was received by 19% of PWID. We identified 40 reinfections during 2,767 PYs. Reinfection rates were higher among recent (3.1/100 PYs; IRR 6.7; 95% CI 1.9-23.5) and former PWID (1.4/100 PYs; IRR 3.7; 95% CI 1.1-12.9) than non-PWID (0.3/100 PYs). Among recent PWID, reinfection rates were higher among individuals born after 1975 (10.2/100 PYs) and those co-infected with HIV (5.7/100 PYs). Only one PWID receiving daily OAT developed reinfection.

CONCLUSIONS

Population-level reinfection rates remain elevated after DAA therapy among PWID because of ongoing exposure risk. Engagement of PWID in harm-reduction and support services is needed to prevent reinfections.

LAY SUMMARY

Direct-acting antivirals are an effective tool for the treatment of hepatitis C virus, enabling the elimination of the virus. However, some patients who have been successfully treated with direct-acting antivirals are at risk of reinfection. Our findings showed that the risk of reinfection was highest among people with recent injection drug use. Among people who inject drugs, daily use of opioid-agonist therapy was associated with a lower risk of reinfection.

Syndemic Characterization of HCV, HBV, and HIV Co-infections in a Large Population Based Cohort Study

BACKGROUND

Limited data are available on HBV, HCV, and HIV co-infections and triple infection. We characterized co-occurrence of HIV, HBV, and HCV infections at the population level in British Columbia (BC) to identify patterns of predisposing factors unique to co-infection subgroups.

METHODS

We analyzed data from the BC Hepatitis Testers Cohort, which includes all individuals tested for HCV or HIV in BC between 1992 and 2013, or included in provincial public health registries of HIV, HCV, HBV, and active tuberculosis. Individuals were classified as negative, mono-, and co-infection groups based on HIV, HBV, and HCV status. We evaluated associations between risk factors (injection drug use, sexual orientation etc.) and co-infection groups using multivariate multinomial logistic regression.

FINDINGS

Of a total of 1,376,989 individuals included in the analysis, 1,276,290 were negative and 100,699 were positive for HIV, HBV, and/or HCV. Most cases (91,399, 90.8%) were mono-infected, while 3991 (4.0%) had HBV/HCV, 670 HBV/HIV (0.7%), 3459 HCV/HIV (3.4%), and 1180 HBV/HCV/HIV (1.2%) co-infection. Risk factor and demographic distribution varied across co-infection categories. MSM classification was associated with higher odds of all HIV co-infection groups, particularly HBV/HIV (OR 6.8; 95% CI: 5.6, 8.27), while injection drug use was most strongly associated with triple infection (OR 64.19; 95% CI: 55.11, 74.77) and HIV/HCV (OR 23.23; 95% CI: 21.32, 25.31).

INTERPRETATION

Syndemics of substance use, sexual practices, mental illness, socioeconomic marginalization, and co-infections differ among population groups, highlighting avenues for optimal composition and context for health services to meet each population's unique needs.

FUNDING

BC Centre for Disease Control and Canadian Institutes of Health Research.

Effect of opioid-substitution therapy and mental health counseling on HIV risk among hepatitis C-infected individuals

Background

Understanding differences in HIV incidence among people living with hepatitis C virus (HCV) can help inform strategies to prevent HIV infection. We estimated the time to HIV diagnosis among HCV-positive individuals and evaluated factors that could affect HIV-infection risk in this population.

Patients and methods

The British Columbia Hepatitis Testers Cohort includes all BC residents (~1.5 million: about a third of all residents) tested for HCV and HIV from 1990 to 2013 and is linked to administrative health care and mortality data. All HCV-positive and HIV-negative individuals were followed to measure time to HIV acquisition (positive test) and identify factors associated with HIV acquisition. Adjusted HRs (aHRs) were estimated using Cox proportional-hazard regression.

Results

Of 36,077 HCV-positive individuals, 2,169 (6%) acquired HIV over 266,883 years of follow-up (overall incidence of 8.1 per 1,000 person years). Overall median (IQR) time to HIV infection was 3.87 (6.06) years. In Cox regression, injection-drug use (aHR 1.47, 95% CI 1.33–1.63), HBV infection (aHR 1.34, 95% CI 1.16–1.55), and being a man who has sex with men (aHR 2.78, 95% CI 2.14–3.61) were associated with higher risk of HIV infection. Opioid-substitution therapy (OST) (aHR 0.59, 95% CI 0.52–0.67) and mental health counseling (aHR 0.48, 95% CI 0.43–0.53) were associated with lower risk of HIV infection.

Conclusion

Injection-drug use, HBV coinfection, and being a man who has sex with men were associated with increased HIV risk and engagement in OST and mental health counseling were associated with reduced HIV risk among HCV-positive individuals. Improving access to OST and mental health services could prevent transmission of HIV and other blood-borne infections, especially in settings where access is limited.

A syndemic approach to assess the effect of substance use and social disparities on the evolution of HIV/HCV infections in British Columbia

BACKGROUND

Co-occurrence of social conditions and infections may affect HIV/HCV disease risk and progression. We examined the changes in relationship of these social conditions and infections on HIV and hepatitis C virus (HCV) infections over time in British Columbia during 1990-2013.

METHODS

The BC Hepatitis Testers Cohort (BC-HTC) includes ~1.5 million individuals tested for HIV or HCV, or reported as a case of HCV, HIV, HBV, or tuberculosis linked to administrative healthcare databases. We classified HCV and HIV infection status into five combinations: HIV-/HCV-, HIV+monoinfected, HIV-/HCV+seroconverters, HIV-/HCV+prevalent, and HIV+/HCV+.

RESULTS

Of 1.37 million eligible individuals, 4.1% were HIV-/HCV+prevalent, 0.5% HIV+monoinfected, 0.3% HIV+/HCV+ co-infected and 0.5% HIV-/HCV+seroconverters. Overall, HIV+monoinfected individuals lived in urban areas (92%), had low injection drug use (IDU) (4%), problematic alcohol use (4%) and were materially more privileged than other groups. HIV+/HCV+ co-infected and HIV-/HCV+seroconverters were materially most deprived (37%, 32%), had higher IDU (28%, 49%), problematic alcohol use (14%, 17%) and major mental illnesses (12%, 21%). IDU, opioid substitution therapy, and material deprivation increased in HIV-/HCV+seroconverters over time. In multivariable multinomial regression models, over time, the odds of IDU declined among HIV-/HCV+prevalent and HIV+monoinfected individuals but not in HIV-/HCV+seroconverters. Declines in odds of problematic alcohol use were observed in HIV-/HCV+seroconverters and coinfected individuals over time.

CONCLUSIONS

These results highlight need for designing prevention, care and support services for HIV and HCV infected populations based on the evolving syndemics of infections and social conditions which vary across groups.

Role of primary T-cell immunodeficiency and hepatitis B coinfection on spontaneous clearance of hepatitis C: The BC Hepatitis Testers Cohort

T-cell host immune response against hepatitis C virus (HCV) has been suggested to play an important role in determining HCV infection outcome. However, data from human studies are not available. This study examined the effect of primary T-cell deficiency along with other factors on the spontaneous clearance of HCV in a large population-based cohort in British Columbia, Canada. The BC Hepatitis Testers Cohort includes all individuals tested for HCV in BC in 1990-2013 linked with data on their medical visits, hospitalizations and prescription drugs. HCV-positive individuals with at least one valid HCV PCR test on/after HCV diagnosis (n=46 783) were included in this study. To examine factors associated with the spontaneous clearance of HCV, multivariable logistic regression was fitted on the full sample, and Cox proportional hazards model on the HCV seroconverters. Spontaneous clearance was observed in 25.1% (n=11 737) of those tested for HCV. After adjusting for potential confounders, the odds of spontaneous clearance of HCV was lower in people with primary T-cell immunodeficiency (adjusted odds ratio [aOR]: 0.55, 95% CI: 0.32-0.94), and higher in females (aOR: 1.61, 95% CI: 1.54-1.68) and in those coinfected with HBV (aOR: 2.31, 95% CI: 1.93-2.77). Similar results were observed in HCV seroconverters except HBV coinfection was not significant. In conclusion, primary T-cell immunodeficiency is associated with a lower spontaneous clearance of HCV while female sex and coinfection with HBV are associated with a higher spontaneous clearance.

Responding to an Explosive HIV Epidemic Driven by Frequent Cocaine Injection: Is There a Role for Safe Injecting Facilities?

Although there have been repeated calls for the establishment of safe injection facilities (SIFs) in Vancouver since the early 1990s, questions remain concerning the feasibility of SIFs due to the high prevalence of injection cocaine and the concomitant problems cocaine use presents. Therefore, we determined the prevalence of willingness to attend SIFs among cocaine injectors in Vancouver and explored the factors associated with this willingness, using data from the Vancouver Injection Drug Users Study. After considering the results derived from this analysis, additional qualitative methods were employed to explore further willingness to use SIFs, barriers and facilitators of SIF utilization, and methods of maximizing use among selected subpopulations of cocaine injectors. The results suggest that a high proportion of cocaine injectors, including some of those most at risk, would attend an SIF if one were available. However, in order to better accommodate cocaine injectors, several modifications could be made to conventional SIF service design and delivery. The vast majority of these modifications relate to ensuring effective responses to cocaine toxicity. Given the acceptability of SIFs among cocaine injectors, it appears that an SIF pilot could result in significant and immediate benefits in terms of public health and community safety.

Twin epidemics of new and prevalent hepatitis C infections in Canada: BC Hepatitis Testers Cohort

Background

We characterized the twin epidemics of new and prevalent hepatitis C virus (HCV) infections in British Columbia, Canada to inform prevention, care and treatment programs.

Methods

The BC Hepatitis Testers Cohort (BC-HTC) includes individuals tested for HCV, HIV or reported as a case of HBV, HCV, HIV or active TB between 1990–2013 linked with data on their medical visits, hospitalizations, cancers, prescription drugs and mortality. Prevalent infection was defined as being anti-HCV positive at first test. Those with a negative test followed by a positive test were considered seroconverters or new infections.

Results

Of 1,132,855 individuals tested for HCV, 64,634 (5.8 %) were positive and an additional 3092 cases tested positive elsewhere for a total of 67,726. Of 55,781 HCV positive individuals alive at the end of 2013, 7064 were seroconverters while 48,717 had prevalent infection at diagnosis. The HCV positivity rate (11.2 %) was highest in birth cohort 1945–1964 which declined over time. New infections were more likely to be male, 15–34 years of age (born 1965-1984), HIV- or HBV-coinfected, socioeconomically disadvantaged, have problematic drug and alcohol use and a mental health illness. The profile was similar for individuals with prevalent infection, except for lower odds of HBV-coinfection, major mental health diagnoses and birth cohort >1975.

Conclusions

The HCV positivity rate is highest in birth cohort 1945–1964 which represents most prevalent infections. New infections occur in younger birth cohorts who are commonly coinfected with HIV and/or HBV, socioeconomically marginalized, and living with mental illness and addictions.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1683-z) contains supplementary material, which is available to authorized users.

Nonadherence to antiretroviral therapy among a community with endemic rates of injection drug use

Highly active antiretroviral therapy (HAART) has resulted in major reductions in HIV-related morbidity and mortality. However, long-term use of HAART is challenging, and substantial numbers of patients discontinue their medications prematurely. The purpose of this analysis is to describe HAART adherence rates among a large urban cohort and examine factors associated with adherence (based on refill compliance). Of the 184 eligible participants, 129 (70%) were less than 95% adherent. Variables independently associated with nonadherence included frequent heroin injection (adjusted odds ratio [AOR] = 2.6, 95% confidence interval [CI], 1.6-4.0), baseline CD4 count less than 200 cells/mm(3) (AOR = 2.5; 95% CI, 1.9-3.2), and poor treatment by health care professionals (AOR = 1.7; 95% CI, 1.2-3.0). Variables inversely associated with HAART nonadherence included attaining viral load suppression (AOR = 0.3; 95% CI, 0.2-0.5) and methadone maintenance therapy (AOR = 0.5; 95% CI, 0.4-0.9). Innovative strategies that address the social barriers facing marginalized populations are needed to support the long-term continuation of HAART.

Assessing Hepatitis C Burden and Treatment Effectiveness through the British Columbia Hepatitis Testers Cohort (BC-HTC): Design and Characteristics of Linked and Unlinked Participants

Background

The British Columbia (BC) Hepatitis Testers Cohort (BC-HTC) was established to assess and monitor hepatitis C (HCV) epidemiology, cost of illness and treatment effectiveness in BC, Canada. In this paper, we describe the cohort construction, data linkage process, linkage yields, and comparison of the characteristics of linked and unlinked individuals.

Methods

The BC-HTC includes all individuals tested for HCV and/or HIV or reported as a case of HCV, hepatitis B (HBV), HIV or active tuberculosis (TB) in BC linked with the provincial health insurance client roster, medical visits, hospitalizations, drug prescriptions, the cancer registry and mortality data using unique personal health numbers. The cohort includes data since inception (1990/1992) of each database until 2012/2013 with plans for annual updates. We computed linkage rates by year and compared the characteristics of linked and unlinked individuals.

Results

Of 2,656,323 unique individuals available in the laboratory and surveillance data, 1,427,917(54%) were included in the final linked cohort, including about 1.15 million tested for HCV and about 1.02 million tested for HIV. The linkage rate was 86% for HCV tests, 89% for HCV cases, 95% for active TB cases, 48% for HIV tests and 36% for HIV cases. Linkage rates increased from 40% for HCV negatives and 70% for HCV positives in 1992 to ~90% after 2005. Linkage rates were lower for males, younger age at testing, and those with unknown residence location. Linkage rates for HCV testers co-infected with HIV, HBV or TB were very high (90–100%).

Conclusion

Linkage rates increased over time related to improvements in completeness of identifiers in laboratory, surveillance, and registry databases. Linkage rates were higher for HCV than HIV testers, those testing positive, older individuals, and females. Data from the cohort provide essential information to support the development of prevention, care and treatment initiatives for those infected with HCV.

Cannabis vaping and public health--some comments on relevance and implications

Cannabis-vaping entails relevant but probably varied effects for public health: it may reduce certain cannabis use-related health risks, but entice cannabis-naive individuals into use due to "cleaner" imagery. Improved evidence is needed to guide informed and differentiated policies for cannabis-vaping, which emphasizes the urgent need for public health-based cannabis regulation.

Planning for the Next Global Pandemic

In order to mitigate human and financial losses as a result of future global pandemics, we must plan now. As the Ebola virus pandemic declines, we must reflect on how we have mismanaged this recent international crisis and how we can better prepare for the next global pandemic. Of great concern is the increasing frequency of pandemics occurring over the last few decades. Clearly, the window of opportunity to act is closing. This editorial discusses many issues including priority emerging and re-emerging infectious diseases; the challenges of meeting international health regulations; the strengthening of global health systems; global pandemic funding; and the One Health approach to future pandemic planning. We recommend that the global health community unites to urgently address these issues in order to avoid the next humanitarian crisis.

Individual and jurisdictional factors associated with voluntary HIV testing in Canada: Results of a national survey, 2011

OBJECTIVE

HIV testing remains a central strategy for HIV prevention for its ability to link those who test positive to treatment and support. In Canada, national guidelines have recently changed as part of standard primary care to recommend voluntary HIV testing for those aged 16-64 years. Using results from a nationally representative survey, we examined individual and jurisdictional factors associated with voluntary testing.

METHODS

A total of 2,139 participants were sampled using a regionally stratified, two-stage recruitment process. English or French interviews (by phone or online) were conducted during May 2011. Voluntary testing was defined as testing at least once for reasons other than blood donation, insurance purposes, immigration screening or research participation. Weighted logistic regression analysis (including socio-demographic, sexual activity, HIV/AIDS knowledge and jurisdictional factors of HIV prevalence and anonymous testing availability) were conducted for the overall sample, and stratified by sex.

RESULTS

Twenty-nine percent (29%) of survey participants reported at least one lifetime voluntary HIV test. For the full-sample model, the following were associated with increased odds of testing: age &lt;60 years, female sex, sexual minority status, perceived HIV knowledge, casual sex partner in previous year, and living in a higher-prevalence jurisdiction. For men, the strongest factor related to testing was sexual minority status (OR = 5.15, p &lt; 0.001); for women, it was having a casual sex partner in the previous year (OR = 2.57, p = 0.001). For both men and women, residing in a jurisdiction with lower HIV prevalence decreased odds of testing.

DISCUSSION

Sex differences should be considered when designing interventions to increase testing uptake. Jurisdictional factors, including HIV prevalence and testing modality, should be investigated further.

Establishing a community-based participatory research partnership among people who use drugs in Ottawa: the PROUD cohort study

Background

Grounded in a community-based participatory research (CBPR) framework, the PROUD (Participatory Research in Ottawa: Understanding Drugs) Study aims to better understand HIV risk and prevalence among people who use drugs in Ottawa, Ontario. The purpose of this paper is to describe the establishment of the PROUD research partnership.

Methods

PROUD relies on peers’ expertise stemming from their lived experience with drug use to guide all aspects of this CBPR project. A Community Advisory Committee (CAC), comprised of eight people with lived experience, three allies and three ex-officio members, has been meeting since May 2012 to oversee all aspects of the project. Eleven medical students from the University of Ottawa were recruited to work alongside the committee. Training was provided on CBPR; HIV and harm reduction; and administering HIV point-of-care (POC) tests so that the CAC can play a key role in research design, data collection, analysis, and knowledge translation activities.

Results

From March-December 2013, the study enrolled 858 participants who use drugs (defined as anyone who has injected or smoked drugs other than marijuana in the last 12 months) into a prospective cohort study. Participants completed a one-time questionnaire administered by a trained peer or medical student, who then administered an HIV POC test. Recruitment, interviews and testing occurred in both the fixed research site and various community settings across Ottawa. With consent, prospective follow-up will occur through linkages to health care records available through the Institute for Clinical and Evaluation Sciences.

Conclusion

The PROUD Study meaningfully engaged the communities of people who use drugs in Ottawa through the formation of the CAC, the training of peers as community-based researchers, and integrated KTE throughout the research project. This project successfully supported skill development across the team and empowered people with drug use experience to take on leadership roles, ensuring that this research process will promote change at the local level. The CBPR methods developed in this study provide important insights for future research projects with people who use drugs in other settings.

Continued low uptake of treatment for hepatitis C virus infection in a large community-based cohort of inner city residents

BACKGROUND & AIMS

Despite advances in HCV treatment, recent data on treatment uptake is sparse. HCV treatment uptake and associated factors were evaluated in a community-based cohort in Vancouver, Canada.

METHODS

The CHASE study is a cohort of inner city residents recruited from January 2003-June 2004. HCV status and treatment were retrospectively and prospectively determined through data linkages with provincial virology and pharmacy databases. Logistic regression analyses were used to identify factors associated with HCV treatment uptake.

RESULTS

Among 2913, HCV antibody testing was performed in 2405, 64% were HCV antibody-positive (n = 1533). Individuals with spontaneous clearance (18%, n = 276) were excluded. Among the remaining 1257 HCV antibody-positive participants (mean age 42, 71% male), 29% were Aboriginal. At enrolment, the majority reported recent injecting (60%) and non-injecting drug use (87%). Between January 1998 and March 2010, 6% (77 of 1257) initiated HCV treatment. In adjusted analyses, Aboriginal ethnicity [adjusted odds ratio (AOR) 0.23; 95% CI 0.10, 0.51] and crack cocaine use (AOR 0.61; 95% CI 0.37, 0.99) were associated with a decreased odds of receiving HCV treatment, while methamphetamine injecting (AOR 0.16; 95% CI 0.02, 1.18) trended towards a lower odds of receiving treatment. HCV treatment uptake ranged from 0.2 (95% CI 0.0, 0.7) per 100 person-years (PYs) in 2003 to 1.6 (95% CI 0.9, 2.6) per 100 PYs in 2009.

CONCLUSION

HCV treatment uptake remains low in this large community-based cohort of inner city residents with a high HCV prevalence and access to universal healthcare.

Impact of supervised injection facilities on community HIV levels: a public health perspective

The health and social consequences of intravenous drug use pose major challenges to cities across North America. Preventable drug-related harms including accidental overdose, serious bacterial infections, injuries of violence and more recently, the emergence of HIV and hepatitis C, have major impacts on community health. Among the various interventions designed to reduce the harms associated with injection drug use, the establishment of a supervised injection facility is perhaps the most controversial. This review will focus on the potential impact of supervised injection facilities on HIV transmission in conjunction with current HIV prevention initiatives. This will include a review of the health and social consequences associated with illicit drugs use, the limitations of drug enforcement, and the potential impact of supervised injection facilities on reducing the harms associated with injection drug use.

Mortality in a large community-based cohort of inner-city residents in Vancouver, Canada

BACKGROUND

The Downtown Eastside is a robust and densely populated neighbourhood in Vancouver, Canada, that is characterized by low-income housing and drug use and a high prevalence of HIV infection. We evaluated mortality and excess mortality among the broader community of individuals living in this neighbourhood.

METHODS

The Community Health and Safety Evaluation is a community-based study of inner-city residents in the Downtown Eastside who were recruited in 2003 and 2004. Participants' data were linked with data in provincial virology and mortality databases retrospectively and prospectively for the period 1991-2009. Mortality and standardized mortality ratios (SMRs) were calculated for the period 2003-2009 to compare death rates in the study population with rates in the population of Vancouver.

RESULTS

Among 2913 participants, 374 deaths occurred, for an all-cause mortality of 223 per 10 000 person-years (95% confidence interval [CI] 201-247 per 10 000 person-years). Compared with the population of Vancouver, significant excess mortality was observed in the study population (SMR 7.1, 95% CI 6.4-7.9). Excess mortality was higher among women (SMR 15.4, 95% CI 12.8-18.5) than among men (SMR 5.8, 95% CI 5.1-6.6). Although crude mortality increased with age, excess mortality was greatest among participants less than 35 years old (SMR 13.2, 95% CI 9.4-18.5) and those 35-39 years old (SMR 13.3, 95% CI 10.3-17.1). Excess risk was also elevated among participants with hepatitis C virus (HCV), HIV and HCV/HIV infection, with SMRs of 5.9 (95% CI 4.9-7.1), 19.2 (95% CI 12.8-28.9) and 23.0 (95% CI 19.3-27.4), respectively.

INTERPRETATION

Our study showed high mortality in this inner-city population, particularly when compared with the general population of Vancouver. Excess mortality was highest among women, younger participants and those infected with either HCV or HIV or both.

The role of diet in predicting iron deficiency anemia in HIV-positive women

PURPOSE

The association between medical, social, and nutritional factors and iron deficiency anemia was examined in adult women who had tested positive for human immunodeficiency virus (HIV) and were living in the Greater Vancouver Area.

METHODS

This was a cross-sectional observational study of 102 HIV-positive women, aged 19 or older, who were patients of one of three chosen community health clinics in Vancouver, British Columbia. Information on usual dietary intake and other nutrition-related factors was collected with a short diet survey, while medical information and laboratory data were obtained from each participant's medical chart.

RESULTS

Of the predictors studied, a CD4 cell count below 200 cells/µL, a regular menstrual pattern, and African ethnicity were associated with an increased risk of iron deficiency anemia. Dietary intake was not independently associated with iron status.

CONCLUSIONS

Iron deficiency anemia in HIV-positive women has multifactorial and complicated causation, but is strongly associated with poorer immune status and greater menstrual losses. Health disparities in Aboriginal and African women may lead to a higher risk for iron deficiency anemia. Routine screening and ongoing nutrition education are necessary for the prevention and management of iron deficiency anemia. Further research into factors associated with iron deficiency anemia is essential to improve prevention and management efforts.

Occupational stigma as a primary barrier to health care for street-based sex workers in Canada

Individuals working in the sex industry continue to experience many negative health outcomes. As such, disentangling the factors shaping poor health access remains a critical public health priority. Within a quasi-criminalised prostitution environment, this study aimed to evaluate the prevalence of occupational stigma associated with sex work and its relationship to barriers to accessing health services. Analyses draw on baseline questionnaire data from a community-based cohort of women in street-based sex work in Vancouver, Canada (2006-2008). Of a total of 252 women, 141 (55.9%) reported occupational sex work stigma (defined as hiding occupational sex work status from family, friends and/or home community), while 125 (49.6%) reported barriers to accessing health services in the previous six months. In multivariable analysis, adjusting for sociodemographic, interpersonal and work environment risks, occupational sex work stigma remained independently associated with an elevated likelihood of experiencing barriers to health access. Study findings indicate the critical need for policy and societal shifts in views of sex work as a legitimate occupation, combined with improved access to innovative, accessible and non-judgmental health care delivery models for street-based sex workers that include the direct involvement of sex workers in development and implementation.

A dose-response relationship between exposure to a large-scale HIV preventive intervention and consistent condom use with different sexual partners of female sex workers in southern India

Background

The Avahan Initiative, a large-scale HIV preventive intervention targeted to high-risk populations including female sex workers (FSWs), was initiated in 2003 in six high-prevalence states in India, including Karnataka. This study assessed if intervention exposure was associated with condom use with FSWs’ sexual partners, including a dose-response relationship.

Methods

Data were from a cross-sectional study (2006-07) of 775 FSWs in three districts in Karnataka. Survey methods accounted for the complex cluster sampling design. Bivariate and multivariable logistic regression was used to separately model the relationships between each of five intervention exposure variables and five outcomes for consistent condom use (CCU= always versus frequently/sometimes/never) with different sex partners, including with: all clients; occasional clients; most recent repeat client; most recent non-paying partner; and the husband or cohabiting partner. Linear tests for trends were conducted for three continuous intervention exposure variables.

Results

FSWs reported highest CCU with all clients (81.7%); CCU was lowest with FSWs’ husband or cohabiting partner (9.6%). In multivariable analysis, the odds of CCU with all clients and with occasional clients were 6.3-fold [95% confidence intervals, CIs: 2.8-14.5] and 2.3-fold [95% CIs: 1.4-4.1] higher among FSWs contacted by intervention staff and 4.9-fold [95% CIs: 2.6-9.3] and 2.3-fold [95% CIs: 1.3-4.1] higher among those who ever observed a condom demonstration by staff, respectively, compared to those who had not. A significant dose-response relationship existed between each of these CCU outcomes and increased duration since first contacted by staff (P=0.001; P=0.006) and numbers of condom demonstrations witnessed (P=0.004; P=0.026); a dose-response relationship was also observed between condom use with all clients and number of times contacted by staff (P=0.047). Intervention exposure was not associated with higher odds of CCU with the most recent repeat client, most recent non-paying partner or with the husband or cohabiting partner.

Conclusion

Study findings suggest that exposure to a large-scale HIV intervention for FSWs was associated with increased CCU with commercial clients. Moreover, there were dose-response relationships between CCU with clients and increased duration since first contacted by staff, times contacted by staff and number of condom demonstrations. Additional program effort is required to increase condom use with non-commercial partners.

The street cost of drugs and drug use patterns: relationships with sex work income in an urban Canadian setting

BACKGROUND

This study investigated the relationship between drug use and sex work patterns and sex work income earned among street-based female sex workers (FSWs) in Vancouver, Canada.

METHODS

We used data from a sample of 129 FSWs who used drugs in a prospective cohort (2007-2008), for a total of 210 observations. Bivariate and multivariable linear regression using generalized estimating equations was used to model the relationship between explanatory factors and sex work income. Sex work income was log-transformed to account for skewed data.

RESULTS

The median age of the sample at first visit was 37 years (interquartile range[IQR]: 30-43), with 46.5% identifying as Caucasian, 48.1% as Aboriginal and 5.4% as another visible minority. The median weekly sex work income and amount spent on drugs was $300 (IQR=$100-$560) and $400 (IQR=$150-$780), respectively. In multivariable analysis, for a 10% increase in money spent on drugs, sex work income increased by 1.9% (coeff: 0.20, 95% CIs: 0.04-0.36). FSWs who injected heroin, FSWs with higher numbers of clients and youth compared to older women (<25 versus 25+ years) also had significantly higher sex work income.

CONCLUSIONS

This study highlights the important role that drug use plays in contributing to increased dependency on sex work for income among street-based FSWs in an urban Canadian setting, including a positive dose-response relationship between money spent on drugs and sex work income. These findings indicate a crucial need to scale up access and availability of evidence-based harm reduction and treatment approaches, including policy reforms, improved social support and economic choice for vulnerable women.

Individual and structural vulnerability among female youth who exchange sex for survival

PURPOSE

Because of growing concerns regarding the heightened vulnerabilities and risk of human immunodeficiency virus infection among youth who exchange sex for survival, we investigated individual risk patterns and structural barriers among young (≤24 years) female sex workers (FSWs) in Vancouver, Canada.

METHODS

Between 2005 and 2008, a total of 255 street-based FSWs (≥14 years) were enrolled into a community-based prospective cohort, and were asked to participate in baseline and biannual questionnaires administered through interviews and human immunodeficiency virus screening. We used contingency table analysis to compare individual and structural barrier results obtained at baseline for younger (≤24 years) FSWs with those of the older (>25 years) FSWs. For longitudinal data, we used generalized estimating equations throughout the follow-up period to determine factors associated with being a young FSW in the past 6 months.

RESULTS

In comparison with older FSWs (n = 199), youth (n = 56) were more likely to spend fewer years engaging in sex exchange (median: 6.4 [interquartile range: 4.6-9.1] vs. 19.9 [interquartile range: 10.0-26.8]; p ≤ .001), belong to an aboriginal ancestry (59% vs. 44%; p = .052), and be homeless (68% vs. 36%; p ≤ .001). In the multivariate generalized estimating equations analysis, youth reported a significantly elevated proportional odds of being homeless (odds ratio [OR]: 1.26 [confidence interval {CI}: 1.08-1.48]), servicing clients in public places (OR: 1.28 [CI: 1.04-1.57]), injecting heroin on a daily basis (OR: 1.35 [CI: 1.06-1.74]), and a significantly reduced odds of accessing methadone maintenance therapy (OR: .76 [CI: .62-.93]).

CONCLUSIONS

This study demonstrates significant displacement of youth who engage in sex exchange to marginalized working and living spaces. The findings of this study bring to attention the critical need for targeted structural interventions including access to youth and gender-specific social housing, safe working spaces, reduction in the amount of harm caused to them, and addiction treatment services for youth engaged in survival sex work.

Crystal methamphetamine use among female street-based sex workers: Moving beyond individual-focused interventions

Given growing concern of the sexual risks associated with crystal methamphetamine use and the dearth of research characterizing the use of methamphetamine among street-based sex workers (FSWs), this study aimed to characterize the prevalence and individual, social, and structural contexts of crystal methamphetamine use among FSWs in a Canadian setting. Drawing on data from a prospective cohort, we constructed multivariate logistic models to examine independent correlates of crystal methamphetamine among FSWs over a two-year follow-up period using generalized estimating equations. Of a total of 255 street-based FSWs, 78 (32%) reported lifetime crystal methamphetamine use and 24% used crystal methamphetamine during the two-year follow-up period, with no significant associations between methamphetamine use and sexual risk patterns. In a final multivariate GEE model, FSWs who used crystal methamphetamine had a higher proportional odds of dual heroin injection (adjOR=2.98, 95%CI: 1.35-5.22), having a primary male sex partner who procures drugs for them (adjOR=1.79, 95%CI: 1.02-3.14), and working (adjOR=1.62, 95%CI: 1.04-2.65) and living (adjOR=1.41, 95%CI: 1.07-1.99) in marginalized public spaces. The findings highlight the crucial need to move beyond the individual to gender-focused safer environment interventions that mediate the physical and social risk environment of crystal methamphetamine use among FSWs.

Impact of hepatitis C virus infection on all-cause and liver-related mortality in a large community-based cohort of inner city residents

The aim of this study was to measure the impact of hepatitis C virus (HCV) infection on mortality in a cohort of inner city residents. The Community Health and Safety Evaluation is a community-based study of inner city residents followed retrospectively and prospectively through linkages with provincial virology and mortality databases. We identified participants having received HCV antibody testing, evaluated cause-specific mortality rates and factors associated with all-cause and liver-related mortality using Cox Proportional Hazards models. Overall, 2332 participants received HCV antibody testing (recent non-injection drug use - 81%). The prevalence of HCV and HIV was 64% (1495 of 2332) and 21% (485 of 2332), respectively. Between January 2003 and December 2007, there were 180 deaths (192 per 10.000 person-years; 95% CI: 165, 222), with 21% HIV-related, 20% drug-related and 7% liver-related. Mortality was associated with age >50 [adjusted hazard ratio (AHR) 2.80 vs < 40 years (referent group); 95% CI 1.93, 4.07, P < 0.001] and HIV infection (AHR 3.81; 95% CI 2.72, 5.34, P < 0.001), but not positive HCV antibody status (AHR 1.19; 95% CI 0.83, 1.72, P = 0.35). Liver-related mortality was associated with age >50 [AHR 18.49 vs < 40 years (referent group); 95% CI 2.27, 150.41, P < 0.001] and positive HCV antibody status (AHR 7.69; 95% CI 0.99, 59.98, P = 0.052). This study demonstrates a high rate of mortality in this population, particularly those with HIV. HCV-infected inner city residents >50 years of age were at significant risk of liver-related mortality. Continued surveillance of this population infected with HCV in the 1970s and 1980s is important.

A peer-led mobile outreach program and increased utilization of detoxification and residential drug treatment among female sex workers who use drugs in a Canadian setting

BACKGROUND

The objectives of this study were to examine the determinants of using a peer-led mobile outreach program (the Mobile Access Project [MAP]) among a sample of street-based female sex workers (FSWs) who use drugs in an urban Canadian setting and evaluate the relationship between program exposure and utilizing addiction treatment services.

METHODS

A detailed questionnaire was administered at baseline and bi-annual follow-up visits over 18 months (2006-2008) to 242 FSWs in Vancouver, Canada. We used bivariate and multivariate logistic regression with generalized estimating equations for both objectives, reporting unadjusted and adjusted odds ratios (AOR) with 95% confidence intervals (CIs).

RESULTS

Over 18 months, 42.2% (202) reports of peer-led mobile outreach program use were made. High-risk women, including those servicing a higher weekly client volume (10+ compared to <10; AOR: 1.7, 95%CIs: 1.1-2.6) and those soliciting clients in deserted, isolated settings (AOR: 1.7, 95%CIs: 1.1-2.7) were more likely to use the program. In total, 9.4% (45) reports of using inpatient addiction treatment services were made (7.5% detoxification; 4.0% residential drug treatment), and 33.6% (161) using outpatient treatment (28.8% methadone; 9.6% alcohol/drug counsellor). Women who used the peer-led mobile outreach were more likely to use inpatient addiction treatment (AOR: 4.2, 95%CIs: 2.1-8.1), even after adjusting for drug use, environmental-structural factors, and outpatient drug treatment.

DISCUSSION

Our findings demonstrate that FSWs at higher risk for sexually transmitted infections and violence are more likely to access this peer-led mobile outreach program and suggest that the program plays a critical role in facilitating utilization of detoxification and residential drug treatment.

Regional patterns of risk for sexually transmitted infections in British Columbia

BACKGROUND

Although rates of sexually transmitted infection (STI) tend to be higher in urban Canada, the province of British Columbia has recently seen above-average rates in the northern health regions.

DATA AND METHODS

Data from the 2005 Canadian Community Health Survey were used to examine sexual behaviour risks by geography and age in British Columbia. Two outcomes were investigated: ever diagnosed with an STI, and did not use a condom during last sexual intercourse. Region was categorized as metropolitan and non-metropolitan (Northern, representing more rural and remote communities, and Southern). Multivariate logistic regression was used to determine associations between the two outcomes and region, age, and other socio-demographic variables. Normalized weights accounted for sampling design.

RESULTS

In adjusted analysis, older age (25 to 49) and being female were significantly associated with previously having an STI and not using a condom during last sex. Being a non-drinker was inversely associated with the former outcome, and being an occasional drinker was inversely associated with both outcomes, compared with being a regular drinker. When stratified by region, the relationship between older age and not using a condom was particularly strong in Northern non-metropolitan regions.

INTERPRETATION

The results highlight the importance of considering older individuals in the design of STI preventive interventions, particularly in non-metropolitan and rural and remote regions, where access to testing and treatment may be limited.

Challenges in initiating antiretroviral therapy in 2010

Many clinical trials have shown that initiating antiretroviral therapy (ART) at higher rather than lower CD4 T cell-positive counts results in survival benefit. Early treatment can help prevent end-organ damage associated with HIV replication and can decrease infectivity. The mainstay of treatment is either a non-nucleoside reverse transcriptase inhibitor or a ritonavir-boosted protease inhibitor in combination with two nucleoside reverse transcriptase inhibitors. While effective at combating HIV, ART can produce adverse alterations of lipid parameters, with some studies suggesting a relationship between some anti-retroviral agents and cardiovascular disease. As the HIV-positive population ages, issues such as hypertension and diabetes must be taken into account when initiating ART. Adhering to ART can be difficult; however, nonoptimal adherence to ART can result in the development of resistance; thus, drug characteristics and the patient's preparedness to begin therapy must be considered. Reducing the pill burden through the use of fixed-dose antiretroviral drug combinations can facilitate adherence.

Conducting HIV/AIDS research with indoor commercial sex workers: reaching a hidden population

BACKGROUND

Although comprising up to 80% of the commercial sex industry in Canada, indoor female sex workers (FSW) are generally not represented in research because they are a hidden population and difficult to access.

OBJECTIVES

This paper describes a community-academic partnership model that was established to gain access to, deliver outreach services to, and conduct community-based research with the indoor commercial sex industry in four cities in British Columbia.

METHODS

The project employed an ongoing community consultation, peer-delivered approach to reaching this overlooked segment of the commercial sex industry. Peers (former and current FSW) were hired, trained, and supported as outreach workers and participated in the development, implementation, and evaluation of the project. Outreach teams visited sex establishments to deliver harm reduction materials and provide education, support, and referrals. The teams developed rapport with establishment managers and staff to facilitate research recruitment and data collection. The community team leader met with managers in targeted business to describe the study and elicit permission to recruit workers. The team leader conducted in-person interviews with consenting FSW.

OBSERVATIONS

During the first 2 years of the project, more than 50 sex establishments were visited by outreach teams and 37 allowed repeat visits. Research interviews have been conducted with 49 FSW in seven establishments from four cities.

CONCLUSIONS

Although the high cost in terms of time and resources must be recognized, this project represents a successful research and outreach model that permits access to the hidden commercial sex industry.

Determinants of hospitalization for a cutaneous injection-related infection among injection drug users: a cohort study

Astract

Survival sex work involvement as a primary risk factor for hepatitis C virus acquisition in drug-using youths in a canadian setting

OBJECTIVE

To examine whether there were differential rates of hepatitis C virus (HCV) incidence in injecting drug-using youths who did and did not report involvement in survival sex work.

DESIGN

Data were derived from 2 prospective cohort studies of injecting drug users (May 1, 1996, to July 31, 2007). Analyses were restricted to HCV antibody-negative youths who completed baseline and at least 1 follow-up assessment.

SETTING

Vancouver, British Columbia, Canada.

PARTICIPANTS

Of 3074 injecting drug users, 364 (11.8%) were youths (aged 14-24 years) with a median age of 21.3 years and a duration of injecting drug use of 3 years. Main Exposure Survival sex work involvement.

MAIN OUTCOME MEASURE

The Kaplan-Meier method and Cox proportional hazards regression were used to compare HCV incidence among youths who did and did not report survival sex work.

RESULTS

Baseline HCV prevalence was 51%, with youths involved in survival sex work significantly more likely to be HCV antibody positive (60% vs 44%; P = .002). In baseline HCV antibody-negative youths, the cumulative HCV incidence at 36 months was significantly higher in those involved in survival sex work (68.4% vs 38.8%; P < .001). The HCV incidence density was 36.8 (95% confidence interval [CI], 24.2-53.5) per 100 person-years in youths reporting survival sex work involvement at baseline compared with 14.1 (9.4-20.3) per 100 person-years in youths not reporting survival sex work. In multivariate Cox proportional hazards analyses, survival sex work was the strongest predictor of elevated HCV incidence (adjusted relative hazard, 2.30; 95% CI, 1.27-4.15).

CONCLUSION

This study calls attention to the critical need for evidence-based social and structural HCV prevention efforts that target youths engaged in survival sex work.

Prevalence and structural correlates of gender based violence among a prospective cohort of female sex workers

OBJECTIVE

To examine the prevalence and structural correlates of gender based violence against female sex workers in an environment of criminalised prostitution.

DESIGN

Prospective observational study.

SETTING

Vancouver, Canada during 2006-8.

PARTICIPANTS

Female sex workers 14 years of age or older (inclusive of transgender women) who used illicit drugs (excluding marijuana) and engaged in street level sex work.

MAIN OUTCOME MEASURE

Self reported gender based violence.

RESULTS

Of 267 female sex workers invited to participate, 251 women returned to the study office and consented to participate (response rate of 94%). Analyses were based on 237 female sex workers who completed a baseline visit and at least one follow-up visit. Of these 237 female sex workers, 57% experienced gender based violence over an 18 month follow-up period. In multivariate models adjusted for individual and interpersonal risk practices, the following structural factors were independently correlated with violence against female sex workers: homelessness (adjusted odds ratio for physical violence (aOR(physicalviolence)) 2.14, 95% confidence interval 1.34 to 3.43; adjusted odds ratio for rape (aOR(rape)) 1.73, 1.09 to 3.12); inability to access drug treatment (adjusted odds ratio for client violence (aOR(clientviolence)) 2.13, 1.26 to 3.62; aOR(physicalviolence) 1.96, 1.03 to 3.43); servicing clients in cars or public spaces (aOR(clientviolence) 1.50, 1.08 to 2.57); prior assault by police (aOR(clientviolence) 3.45, 1.98 to 6.02; aOR(rape) 2.61, 1.32 to 5.16); confiscation of drug use paraphernalia by police without arrest (aOR(physicalviolence) 1.50, 1.02 to 2.41); and moving working areas away from main streets owing to policing (aOR(clientviolence) 2.13, 1.26 to 3.62).

CONCLUSIONS

Our results demonstrate an alarming prevalence of gender based violence against female sex workers. The structural factors of criminalisation, homelessness, and poor availability of drug treatment independently correlated with gender based violence against street based female sex workers. Socio-legal policy reforms, improved access to housing and drug treatment, and scale up of violence prevention efforts, including police-sex worker partnerships, will be crucial to stemming violence against female sex workers.

Piloting a peer-driven intervention model to increase access and adherence to antiretroviral therapy and HIV care among street-entrenched HIV-positive women in Vancouver

A peer-driven intervention (PDI) was developed to support uptake and adherence to highly active antiretroviral therapy (HAART) among women sex workers who use illicit substances in Vancouver, because uptake and adherence continues to be suboptimal. Trends of adherence were examined among women in this program by (1) exposure to the intervention and (2) risk behaviors including drug use and unstable housing. Between January 2007 and January 2008, 20 HIV-positive women were enrolled into the PDI on a rolling basis. PDI participation included weekly peer support meetings, a health advocate (buddy) system, peer outreach service, and onsite nursing care. Adherence was measured directly with pharmacy records (PR) and indirectly with self-report and viral load (VL) outcomes. Participants attended an average of 50 (21-70) PDI meetings. Overall self-reported adherence was high (92%) and most women (11) reported increased adherence from the first to the last 13 PDI meetings attended (average increase = 18%). The number of viral load tests <or=50 copies/mL increased by 40% from the pre-PDI period (1 year before enrollment), to the PDI period (duration enrolled). PR adherence and improvements in VL outcomes were higher among participants with greater housing instability and frequency of injecting/smoking drugs. Despite a very difficult environment to provide HIV care, there is evidence to suggest that the PDI may have had a positive impact on adherence outcomes. Although this would not predict long-term treatment success, the PDI approach to HIV treatment support is a promising program for women who might otherwise be excluded from treatment altogether.

Unstable housing and hepatitis C incidence among injection drug users in a Canadian setting

Background

There has emerged growing recognition of the link between housing and health. Since Vancouver, Canada has had increasing concerns with homelessness brought about by urban renewal in the lead-up to the 2010 Winter Olympic Games, we evaluated hepatitis C virus (HCV) incidence among injection drug users (IDU) with and without stable housing.

Methods

Data were derived from a collaboration between two prospective cohort studies of IDU in Vancouver, Canada. Using Cox Proportional Hazards regression, we compared HCV incidence among participants with and without stable housing, and determined independent predictors of HCV incidence.

Results

Overall, 3074 individuals were recruited between May 1996 and July 2007, among whom 2541 (82.7%) were baseline HCV-infected. Among the 533 (17.3%) individuals who were not HCV-infected at baseline, 147 tested HCV antibody-positive during follow-up, for an incidence density of 16.89 (95% confidence interval: 14.76 – 19.32) per 100 person-years. In a multivariate Cox regression model, unstable housing remained independently associated with HCV infection (relative hazard = 1.47 (1.02 – 2.13).

Conclusion

HCV prevalence and incidence are high in this setting and were associated with unstable housing. Efforts to protect existing low-income housing and improve access to housing may help to reduce HCV incidence.

Factors Associated with Public Injecting Among Users of Vancouver's Supervised Injection Facility

BACKGROUND

We evaluated factors associated with public drug injection among a cohort of injection drug users (SEOSI) originally recruited from within Vancouver's supervised injecting facility (SIF).

METHODS

We used univariate statistics and logistic regression to examine factors associated with public drug injection among SEOSI participants.

FINDINGS

Between June 2004 and July 2005, 714 IDU were followed up as part of SEOSI. In multivariate analyses, factors associated with public drug injection included homelessness (adjusted odds ratio (aOR) = 3.10; p < .001), syringe lending (aOR = 5.39; p < .001), requiring help injecting (aOR = 1.60; p = .05), and reporting that wait times affected frequency of SIF use (aOR = 3.26; p < .001).

INTERPRETATION

Persistent public injection was independently associated with elevated HIV risk behaviors, as well as programmatic factors that limit SIF use. SIF program expansion may further help to reduce persistent risk behaviors and the community concerns related to public injection drug use.

Low uptake of treatment for hepatitis C virus infection in a large community-based study of inner city residents

Despite the availability of effective therapy for hepatitis C virus (HCV) infection, there are little data on the uptake of treatment. We evaluated factors associated with HCV infection and the uptake of HCV treatment in a large community-based inner city cohort in Vancouver, Canada. The Community Health and Safety Evaluation is a cohort study of inner city residents recruited from January 2003 to June 2004. HIV and HCV status and information on prescriptions for HCV treatment were determined through linkage with provincial databases. HCV prevalence was calculated and factors associated with HCV infection were identified. HCV treatment uptake and incidence of HCV infection from January 2000 to December 2004 were expressed in terms of person-years of observation. Among 2913 individuals, HCV antibody testing was performed in 2118 and the HCV seroprevalence was 64.2% (1360 of 2118). In total, 1.1% of HCV antibody-positive individuals (15 of 1360) initiated treatment for HCV infection from January 2000 to December 2004 [0.28 cases per 100 person-years (95% CI, 0.15-0.46)]. Three of 15 (20.0%) treated individuals achieved a sustained virological response. During the same period, the incidence of HCV infection was 7.26 cases (95% CI, 5.72-8.80) per 100 person-years. Overall, the rate of new HCV seroconversions in this cohort in the study period was about 25 times the rate of HCV treatment uptake. There are extremely low rates of HCV treatment initiation and very limited effectiveness, despite a high prevalence of HCV infection in this large community-based cohort of inner city residents with access to universal healthcare.

Determinants of cutaneous injection-related infection care at a supervised injecting facility

PURPOSE

To evaluate the factors associated with receiving cutaneous injection-related infection (CIRI) care among a representative cohort of supervised injecting facility (SIF) users.

METHODS

Data were collected biannually as part of a prospective cohort, the Scientific Evaluation of Supervised Injection study. Kaplan-Meier methods and Cox proportional hazards regression with recurrent events were used to examine incidence and factors associated with CIRI care, respectively.

RESULTS

One thousand eighty individuals were recruited between December 1, 2003 and January 31, 2008. The incidence density of participants receiving CIRI care was 22.0 per 100 person-years (95% confidence interval [CI]: 19.6-24.6). In the adjusted Cox proportional hazard model, female sex (adjusted hazard ratio [AHR]=1.87 [95% CI: 1.32-2.64]), unstable housing (AHR=1.39 [95% CI: 1.02-1.88]), and daily heroin injection (AHR=1.52 [95% CI: 1.13-2.04]) were independently associated with receiving CIRI care at the SIF.

CONCLUSIONS

These results describe who is more likely to receive CIRI care, which is of use to those engaged with policy and practice of treatment regimens involving this population.

Structural and environmental barriers to condom use negotiation with clients among female sex workers: implications for HIV-prevention strategies and policy

OBJECTIVES

We investigated the relationship between environmental-structural factors and condom-use negotiation with clients among female sex workers.

METHODS

We used baseline data from a 2006 Vancouver, British Columbia, community-based cohort of female sex workers, to map the clustering of "hot spots" for being pressured into unprotected sexual intercourse by a client and assess sexual HIV risk. We used multivariate logistic modeling to estimate the relationship between environmental-structural factors and being pressured by a client into unprotected sexual intercourse.

RESULTS

In multivariate analyses, being pressured into having unprotected sexual intercourse was independently associated with having an individual zoning restriction (odds ratio [OR] = 3.39; 95% confidence interval [CI] = 1.00, 9.36), working away from main streets because of policing (OR = 3.01; 95% CI = 1.39, 7.44), borrowing a used crack pipe (OR = 2.51; 95% CI = 1.06, 2.49), client-perpetrated violence (OR = 2.08; 95% CI = 1.06, 4.49), and servicing clients in cars or in public spaces (OR = 2.00; 95% CI = 1.65, 5.73).

CONCLUSIONS

Given growing global concern surrounding the failings of prohibitive sex-work legislation on sex workers' health and safety, there is urgent need for environmental-structural HIV-prevention efforts that facilitate sex workers' ability to negotiate condom use in safer sex-work environments and criminalize abuse by clients and third parties.

HIV/AIDS in Vancouver, British Columbia: a growing epidemic

The prevalence of HIV in Vancouver, British Columbia was subject to two distinct periods of rapid increase. The first occurred in the 1980s due to high incidence among men who have sex with men (MSM), and the second occurred in the 1990s due to high incidence among injection drug users (IDU). The purpose of this study was to estimate and model the trends in HIV prevalence in Vancouver from 1980 to 2006. HIV prevalence data were entered into the UNAIDS/WHO Estimation and Projection Package (EPP) where prevalence trends were estimated by fitting an epidemiological model to the data. Epidemic curves were fit for IDU, MSM, street-based female sex trade workers (FSW), and the general population. Using EPP, these curves were then aggregated to produce a model of Vancouver's overall HIV prevalence. Of the 505 000 people over the age of 15 that reside in Vancouver, 6108 (ranging from 4979 to 7237) were living with HIV in the year 2006, giving an overall prevalence of 1.21 percent (ranging from 0.99 to 1.43 percent). The subgroups of IDU and MSM account for the greatest proportion of HIV infections. Our model estimates that the prevalence of HIV in Vancouver is greater than one percent, roughly 6 times higher than Canada's national prevalence. These results suggest that HIV infection is having a relatively large impact in Vancouver and that evidence-based prevention and harm reduction strategies should be expanded.

Sexual and drug-related vulnerabilities for HIV infection among women engaged in survival sex work in Vancouver, Canada

BACKGROUND

Women engaged in survival sex work face multiple sexual and drug-related harms that directly enhance their vulnerability to HIV infection. Although research on injection-drug-using women has explored predictors of sex work and HIV infection, little information currently exists on the complex vulnerabilities to HIV transmission faced by survival sex workers in this setting. This analysis aimed to determine HIV prevalence among women engaged in survival sex work, and explore sexual and drug-related vulnerabilities associated with baseline infection.

METHODS

Descriptive and univariate analysis were used to explore associations with baseline HIV infection. Variables found to be associated with baseline infection at the univariate level (p<0.05) were entered into a fixed logistic regression model, adjusted for age.

RESULTS

Of a total of 198 women, baseline HIV prevalence was 26%. In multivariate logistic regression, baseline HIV infection was associated with early age of sex work initiation (<18 years) (aOR=1.8, 95% CI: 1.3-2.2), Aboriginal ethnicity (aOR=2.1, 95% CI: 1.4-3.8), daily cocaine injection (aOR=2.2, 95% CI: 1.3-3.5), intensive, daily crack smoking (aOR=2.7, 95% CI: 2.1-3.9), and unprotected sex with an intimate partner (aOR=2.8, 95% CI: 1.9-3.6).

INTERPRETATION

Innovative and evidence-based strategies are urgently needed that address the sexual and drug-related vulnerabilities to HIV infection among survival sex workers and in particular, interventions targeting the precursors to early initiation into sex work.

Risk factors for developing a cutaneous injection-related infection among injection drug users: a cohort study

Background

Cutaneous injection-related infections (CIRI), such as abscesses and cellulitis, are common and preventable among injection drug users (IDU). However, risk factors for CIRI have not been well described in the literature. We sought to characterize the risk factors for current CIRI among individuals who use North America's first supervised injection facility (SIF).

Methods

A longitudinal analysis of factors associated with developing a CIRI among participants enrolled in the Scientific Evaluation of Supervised Injecting (SEOSI) cohort between January 1, 2004 and December 31, 2005 was conducted using generalized linear mixed-effects modelling.

Results

In total, 1065 participants were eligible for this study. The proportion of participants with a CIRI remained under 10% during the study period. In a multivariate generalized linear mixed-effects model, female sex (Adjusted Odds Ratio (AOR) = 1.68 [95% Confidence Interval (CI): 1.16–2.43]), unstable housing (AOR = 1.49 [95% CI: 1.10–2.03]), borrowing a used syringe (AOR = 1.60 [95% CI: 1.03–2.48]), requiring help injecting (AOR = 1.42 [95% CI: 1.03–1.94]), and injecting cocaine daily (AOR = 1.41 [95% CI: 1.02–1.95]) were associated with an increased risk of having a CIRI.

Conclusion

CIRI were common among a subset of IDU in this study, including females, those injecting cocaine daily, living in unstable housing, requiring help injecting or borrowing syringes. In order to reduce the burden of morbidity associated with CIRI, targeted interventions that address a range of factors, including social and environmental conditions, are needed.

Preliminary development of a scale to measure stigma relating to sexually transmitted infections among women in a high risk neighbourhood

Background

As stigma is a socially constructed concept, it would follow that stigma related to sexual behaviours and sexually transmitted infections would carry with it many of the gender-based morals that are entrenched in social constructs of sexuality. In many societies, women tend to be judged more harshly with respect to sexual morals, and would therefore have a different experience of stigma related to sexual behaviours as compared to men. While a variety of stigma scales exist for sexually transmitted infections (STIs) in general; none incorporate these female-specific aspects. The objective of this study was to develop a scale to measure the unique experience of STI-related stigma among women.

Methods

A pool of items was identified from qualitative and quantitative literature on sexual behaviour and STIs among women. Women attending a social evening program at a local community health clinic in a low-income neighbourhood with high prevalence of substance use were passively recruited to take part in a cross-sectional structured interview, including questions on sexual behaviour, sexual health and STI-related stigma. Exploratory factor analysis was used to identify stigma scales, and descriptive statistics were used to assess the associations of demographics, sexual and drug-related risk behaviours with the emerging scales.

Results

Three scales emerged from exploratory factor analysis – female-specific moral stigma, social stigma (judgement by others) and internal stigma (self-judgement) – with alpha co-efficients of 0.737, 0.705 and 0.729, respectively. In this population of women, internal stigma and social stigma carried higher scores than female-specific moral stigma. Aboriginal ethnicity was associated with higher internal and female-specific moral stigma scores, while older age (>30 years) was associated with higher female-specific moral stigma scores.

Conclusion

Descriptive statistics indicated an important influence of culture and age on specific types of stigma. Quantitative researchers examining STI-stigma should consider incorporating these female-specific factors in order to tailor scales for women.

Condom use among injection drug users accessing a supervised injecting facility

OBJECTIVES

Although supervised injecting facility (SIF) use has been associated with reductions in injection-related risk behaviours, the impact of SIFs on the sexual behaviour of injection drug users (IDUs) has not been thoroughly investigated. Therefore, we examined the patterns and predictors of condom use among SIF users in Vancouver, Canada.

METHODS

We performed a longitudinal analysis of the factors associated with consistent condom use among IDUs recruited from within a SIF.

RESULTS

Among 1090 individuals, 650 (59.6%) reported a sexual partner in the past 6 months at baseline. Consistent condom use was reported by 108 (25.3%) and 205 (61.6%) individuals reporting regular or casual partners, respectively. After 2 years of observation, these proportions increased to 32.9% and 69.8%, respectively. In multivariate analysis, predictors of consistent condom use with regular partners included HIV positivity (adjusted odds ratio (AOR) 2.23; 95% CI 1.51 to 3.31), injecting with a sex partner (AOR 0.50; 95% CI 0.37 to 0.68), enrollment in addiction treatment (AOR 0.68, 95% CI 0.52 to 0.89) and time since recruitment (AOR 1.29; 95% CI 1.06 to 1.55 per year). Predictors of consistent condom use with casual partners included HIV positivity (AOR 1.70; 95% CI 1.03 to 2.81), syringe borrowing (AOR 0.54; 95% CI 0.32 to 0.91) and syringe lending (AOR 0.52; 95% CI 0.32 to 0.84).

CONCLUSIONS

Our results demonstrate that among SIF users, consistent condom use was more frequent among casual sex partners and among HIV positive individuals. Importantly, while the prevalence of consistent condom use was low at baseline, it increased over time. Our findings suggest a possible beneficial effect of the SIF on safer sexual practices.

Drug sharing with clients as a risk marker for increased violence and sexual and drug-related harms among survival sex workers

Previous studies have described links between violence, decreased condom use and drug sharing among intimate partners, though limited information exists about the predictors of drug sharing among female sex workers and their clients. The following analysis explored the association between sharing illicit drugs with clients and sexual and drug-related harms among survival sex workers. A total of 198 women participated in interview-administered questionnaires and confidential HIV testing. Of the total, 117 (59%) reported sharing drugs with clients/johns in the last six months and crack cocaine was the primary drug shared (n=108). In logistic regression analysis, sharing drugs with clients/johns was associated with borrowing a used crack pipe (AOR=5.63; 95%CI: 2.71-9.44; p<0.001), intensive/daily crack cocaine smoking (AOR=3.78; 95%CI:1.60-8.92; p<0.002), inconsistent condom use by a client/john (AOR=3.17; 95%CI:1.48-6.77; p<0.003) and having a recent bad date (verbal harassment, physical and/or sexual assault) (AOR=2.71; 95%CI:1.17-6.32; p=0.021). Sharing illicit drugs with clients/johns may be a crucial risk marker for increased violence and sexual and drug-related harms among survival sex workers. HIV prevention and harm reduction initiatives targeting both women and clients/johns are urgently needed, including enhanced support for community and peer-driven sex work initiatives, to address some of the structural facilitators for HIV transmission.

Validity of Self-Reported Adherence Among Injection Drug Users

Background: In Vancouver, the availability of prescription refill data for all HIV-infected individuals plus a prospective cohort of injection drug users (IDUs) permitted an examination of the validity of self-reported highly active antiretroviral therapy (HAART) adherence among IDUs. Methods: Self-reported HAART adherence among Vancouver Injection Drug Users Study participants was compared with pharmacy refill rates from the British Columbia Drug Treatment Program database. Pearson's correlation coefficient and Pearson's χ2 test were used to assess associations between adherence as measured by self-report and pharmacy refill data. Results: Among 88 HIV-infected IDUs, 48 (55%) had an adherence rate of ≥75% as measured by pharmacy refill adherence, whereas 81 (92%) had an adherence rate of ≥75% as measured by self-report. Self-reported adherence was not statistically associated with pharmacy refill adherence ( P > .1). Conclusion: These findings suggest that the validity of self-report measures may be limited when applied to community-recruited IDUs.

Dermatologic Manifestations of Underlying Infectious Disease among Illicit Injection-Drug Users

Background:

Drug use patterns and serious bloodborne infections commonly have dermatologic manifestations among illicit injection-drug users (IDUs).

Objective:

To assess how self-reported skin conditions of IDUs may correlate with underlying infectious diseases after adjustment for drug use patterns.

Methods:

Prospective analysis of factors associated with self-reports of skin rashes, cellulitis, oral lesions, and lymphadenopathy obtained from 1,065 IDUs enrolled in a large cohort study. Variables potentially associated with each outcome were evaluated using multivariate generalized estimating equations.

Results:

In multivariate analyses, drug use patterns were associated with cellulitis, whereas human immunodeficiency virus (HIV) infection and hepatitis C (HCV) were not. HCV infection was independently associated with skin rashes (odds ratio [OR] 1.85; 95% Cl 1.17–2.94). HIV infection was independently associated with lymphadenopathy (OR 2.00; 95% CI 1.52–2.63), skin rash (OR 2.12; 95% CI 1.57–2.86), and oral lesions (OR 14.95; 95% CI 9.41–23.76).

Conclusions:

Self-reports of IDUs, which could easily be obtained as part of a functional inquiry in a clinical setting, correlate with specific drug use patterns and underlying bloodborne infections.

Burden of HIV infection among aboriginal injection drug users in Vancouver, British Columbia

OBJECTIVES

We sought to examine whether there were differential rates of HIV incidence among Aboriginal and non-Aboriginal injection drug users in a Canadian setting.

METHODS

Data were derived from 2 prospective cohort studies of injection drug users in Vancouver, British Columbia. Using the Kaplan-Meier method and Cox proportional hazards regression, we compared HIV incidence among Aboriginal and non-Aboriginal participants.

RESULTS

Overall, 2496 individuals were recruited between May 1996 and December 2005. Compared with that of non-Aboriginal persons, the baseline HIV prevalence was higher among Aboriginal persons (16.0% vs 25.1%; P<.001). Among participants who were HIV negative at baseline, the cumulative HIV incidence at 48 months was higher among Aboriginal persons (18.5% vs 9.5%; P<.001). In multivariate analyses, Aboriginal ethnicity was independently associated with elevated HIV incidence (relative hazard=1.59; 95% confidence interval=1.12, 2.26; P=.009).

CONCLUSIONS

Aboriginal persons in Vancouver had a significantly elevated burden of HIV infection, which calls for a culturally sensitive and evidence-based response. Policymakers in other settings with at-risk Aboriginal populations should seek to avert similar public health emergencies by being proactive with evidence-based HIV-prevention programs.

Mapping violence and policing as an environmental-structural barrier to health service and syringe availability among substance-using women in street-level sex work

BACKGROUND

Within street-based sex work and substance-using populations, there is growing evidence to support the role of place, both physical setting and social meanings attached to place, in mediating the effectiveness and reach of health and harm reduction services.

METHODS

Social mapping was used to explore how health service and syringe availability may be impacted at the geographic level by avoidance of physical settings due to violence and policing among women in street-level sex work. Through a community-based research partnership and extensive peer-led outreach over a 6-month period, women were invited to participate in interview-questionnaires and mapping of their community, working conditions, and access to resources. Results were compiled used ArcGIS software and GIS street maps. In secondary analysis, logistic regression was used to model the geographic association (using likelihood ratio and significance at p<0.05) and stratified models were run to assess differential patterns of avoidance based on age, ethnicity and drug use.

RESULTS

The findings reveal a significant geographic relationship between a heavily concentrated core area of health and syringe availability and avoidance of physical settings due to violence and policing by 198 women in street-level sex work in Vancouver, Canada. Of particular concern, this correlation is significantly elevated among younger and Aboriginal women, active injection drug users, and daily crack cocaine smokers, suggesting significant environmental-structural barriers to interventions among these vulnerable populations.

CONCLUSIONS

The resultant displacement of sex work to primarily industrial settings and side streets pushes women further from health and social supports and reduces access to safer injection and drug use paraphernalia. This study offers important evidence for environmental-structural level prevention and safer environment interventions, supported by legal reforms, that facilitate safer sex work environments, including spatial programming, peer-based prevention, outreach and mobile resources, and peer-supervised safer sex work settings.