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

mHealth Interventions to Promote Anti-Retroviral Adherence in HIV: Narrative Review

Background

Antiretrovirals (ARVs) are key in the management of HIV. Although no cure exists, ARVs help patients live healthy lives and prevent transmission to others. Adherence to complex regimens is paramount to outcomes and in avoiding the emergence of drug-resistant viruses. The goal of therapy is to reach an undetectable viral load. However, adherence is a common problem, stemming from issues such as mental health, chaotic home situations, and busy work schedules. Mobile health (mHealth) represents a new approach in improving medication adherence, and multiple studies have been performed in this area.

Objective

This study aims to review the current implementation of mHealth in the management of HIV among different groups of patients.

Methods

We used PubMed, Academic Search Elite, and 1 journal database with various search terms to review the current implementation of mHealth in HIV care.

Results

Titles and abstracts were screened, and 61 papers were identified and fully reviewed. The literature was divided into lower- and higher-income nations, as defined by the United Nations. A total of 20 studies with quantitative results were identified, with 10 being text- and SMS-based interventions (the majority of these being in lower-income countries) and 8 being smartphone-based apps (primarily in higher-income countries). The majority of these studies determined whether there was an effect on adherence or biochemical parameters (viral load and CD4 count). Various qualitative studies have also been conducted, and many have focused on determining the specific design of interventions that were successful (frequency of messaging, types of messages, etc) as well as priorities for patients with regard to mHealth interventions.

Conclusions

There seems to be a role of mHealth in the management of HIV in lower-income nations; however, the optimal design of an intervention needs to be delineated. In higher-income countries, where the 2 significant risk factors were injection drugs and men who have sex with men, the benefit was less clear, and more research is needed.

Predicting the impact of clustered risk and testing behaviour patterns on the population-level effectiveness of pre-exposure prophylaxis against HIV among gay, bisexual and other men who have sex with men in Greater Vancouver, Canada

Pre-exposure prophylaxis (PrEP) has the potential to greatly reduce transmission of HIV. However, significant questions remain around how behavioural factors may influence its impact within target populations. We used a 2014 sexual behaviour survey to modify and recalibrate a mathematical model of HIV infection dynamics within the population of gay, bisexual and other men who have sex with men (GBMSM) in the Greater Vancouver area of British Columbia, Canada. We performed a clustering analysis on the survey data to divide the population into categories associated with their reported risk of HIV exposure as well as their reported testing habits and attitudes towards PrEP. We found a positive association between reported risk and testing behaviour and level of awareness/interest in PrEP. Using the cluster groups to structure the population, we then estimated the impact of PrEP on HIV transmission in our study population. We found that the association between behaviour and interest in PrEP substantially boosted the population-level effectiveness of PrEP. Within our model, if PrEP adoption was unrelated to risk and testing, an additional 206 (95% credible interval 5-261), new infections representing 15% of total infections are predicted to occur among GBMSM over ten years, compared to where PrEP is adopted by individuals according to their level of interest. Our results underscore the importance of incorporating behavioural data into models when predicting the impact of future public health interventions.

A novel Bayesian approach to predicting reductions in HIV incidence following increased testing interventions among gay, bisexual and other men who have sex with men in Vancouver, Canada

Increasing HIV testing rates among high-risk groups should lead to increased numbers of cases being detected. Coupled with effective treatment and behavioural change among individuals with detected infection, increased testing should also reduce onward incidence of HIV in the population. However, it can be difficult to predict the strengths of these effects and thus the overall impact of testing. We construct a mathematical model of an ongoing HIV epidemic in a population of gay, bisexual and other men who have sex with men. The model incorporates different levels of infection risk, testing habits and awareness of HIV status among members of the population. We introduce a novel Bayesian analysis that is able to incorporate potentially unreliable sexual health survey data along with firm clinical diagnosis data. We parameterize the model using survey and diagnostic data drawn from a population of men in Vancouver, Canada. We predict that increasing testing frequency will yield a small-scale but long-term impact on the epidemic in terms of new infections averted, as well as a large short-term impact on numbers of detected cases. These effects are predicted to occur even when a testing intervention is short-lived. We show that a short-lived but intensive testing campaign can potentially produce many of the same benefits as a campaign that is less intensive but of longer duration.

HIV serology signal-to-cutoff ratio as a rapid method to predict confirmation of HIV infection

Early and rapid detection of patients with HIV is a key to preventing further transmission. The purpose of this study was to assess the ability of signal-to-cutoff (S/CO) ratio from initial screening fourth-generation HIV serology to predict subsequent confirmation of HIV. Patients with a first-time positive HIV serology (S/CO ratio ≥ 1) from 2012 to 2016 were included. Ratios were compared to the results of confirmatory testing. Predictive probabilities (PPs) of a positive confirmatory result were calculated based on a logistic regression model. A total of 45,138 HIV serology tests were performed; 250 patients met inclusion criteria, comprising 84 (34%) HIV negative patients, 136 (54%) chronic infections, and 30 (12%) acute infections. The PP of a confirmed positive result increased with higher S/CO ratios, with a PP of 100% for a S/CO of 55 (95% CI 95-100). This study enables a more informed discussion of the probability of HIV infection, based on HIV serology S/CO thresholds, prior to a confirmatory result.

Factors associated with HIV infection among female sex workers in Brazil

BACKGROUND

Female sex workers (FSWs) are one of the most-at-risk population groups for human immunodeficiency virus (HIV) infection. This paper aims at identifying the main predictors of HIV infection among FSW recruited in the 2nd Biological and Behavioral Surveillance Survey in 12 Brazilian cities in 2016.

METHOD

Data were collected on 4245 FSW recruited by respondent driven sampling (RDS). Weights were inversely proportional to participants' network sizes. To establish the correlates of HIV infection, we used logistic regression models taking into account the dependence of observations resultant from the recruitment chains. The analysis included socio-demographic sex work characteristics, sexual behavior, history of violence, alcohol and drug use, utilization of health services, and occurrence of other sexually transmitted infections (STIs).

RESULTS

HIV prevalence was estimated as 5.3% (4.4%-6.2%). The odds ratio (OR) of an HIV-positive recruiter choosing an HIV-positive participant was 3.9 times higher than that of an HIV-negative recruiter (P < .001). Regarding socio-demographic and sex work characteristics, low educational level, street as the main work venue, low price per sexual encounter, and longer exposure time as a sex worker were found to be associated with HIV infection, even after controlling for the homophily effect. The OR of being HIV infected among FSW who had been exposed to sexual violence at least once in a lifetime (OR = 1.5, P = .028) and the use of illicit drugs at least once a week were highly significant as well, particularly for frequent crack use (OR = 3.6, P < .001). Among the sexual behavior indicators, not using condoms in some circumstances were significantly associated with HIV infection (OR = 1.8, P = .016). Regarding the occurrence of other STI, the odds of being HIV infected was significantly higher among FSW with a reactive treponemal test for syphilis (OR = 4.6, P < .001).

CONCLUSIONS

The main factors associated with HIV infection identified in our study characterize a specific type of street-based sex work in Brazil and provided valuable information for developing interventions. However, there is a further need of addressing social and contextual factors, including illicit drug use, violence, exploitation, as well as stigma and discrimination, which can influence sexual behavior.

A historical review of HIV prevention and care initiatives in British Columbia, Canada: 1996-2015

INTRODUCTION

British Columbia has made significant progress in the treatment and prevention of HIV since 1996, when Highly Active Antiretroviral Therapy (HAART) became available. However, we currently lack a historical summary of HIV prevention and care interventions implemented in the province since the introduction of HAART and how they have shaped the HIV epidemic. Guided by a socio-ecological framework, we present a historical review of biomedical and health services, community and structural interventions implemented in British Columbia from 1996-2015 to prevent HIV transmission or otherwise enhance the cascade of HIV care.

METHODS

We constructed a historical timeline of HIV interventions implemented in BC between 1996 and 2015 by reviewing publicly available reports, guidelines and other documents from provincial health agencies, community organizations and AIDS service organizations, and by conducting searches of peer-reviewed literature through PubMed and Ovid MEDLINE. We collected further programmatic information by administering a data collection form to representatives from BC's regional health authorities and an umbrella agency representing 45 AIDS Service organizations. Using linked population-level health administrative data, we identified key phases of the HIV epidemic in British Columbia, as characterized by distinct changes in HIV incidence, HAART uptake and the provincial HIV response.

RESULTS AND DISCUSSION

In total, we identified 175 HIV prevention and care interventions implemented in BC from 1996 to 2015. We identify and describe four phases in BC's response to HIV/AIDS: the early HAART phase (1996-1999); the harm reduction and health service scale-up phase (2000-2005); the early Treatment as Prevention phase (2006-2009); and the STOP HIV/AIDS phase (2010-present). In doing so, we provide an overview of British Columbia's universal and centralized HIV treatment system and detail the role of community-based and provincial stakeholders in advancing innovative prevention and harm reduction approaches, as well as "seek, test, treat and retain" strategies.

CONCLUSIONS

The review provides valuable insight into British Columbia's HIV response, highlights emerging priorities, and may inform future efforts to evaluate the causal impact of interventions.

Relative effects of antiretroviral therapy and harm reduction initiatives on HIV incidence in British Columbia, Canada, 1996-2013: a modelling study

BACKGROUND

Antiretroviral therapy (ART) and harm reduction services have been cited as key contributors to control of HIV epidemics; however, the specific contribution of ART has been questioned due to uncertainty of its true efficacy on HIV transmission through needle sharing. We aimed to isolate the independent effects of harm reduction services (opioid agonist treatment uptake and needle distribution volumes) and ART on HIV transmission via needle sharing in British Columbia, Canada, from 1996 to 2013.

METHODS

We used comprehensive linked individual health administrative and registry data for the population of diagnosed people living with HIV in British Columbia to populate a dynamic, compartmental transmission model to simulate the HIV/AIDS epidemic in British Columbia from 1996 to 2013. We estimated HIV incidence, mortality, and quality-adjusted life-years (QALYs). We also estimated scenarios designed to isolate the independent effects of harm reduction services and ART, assuming 50% (10-90%) efficacy, in reducing HIV incidence through needle sharing, and we investigated structural and parameter uncertainty.

FINDINGS

We estimate that 3204 (upper bound-lower bound 2402-4589) incident HIV cases were averted between 1996 and 2013 as a result of the combined effect of the expansion of harm reduction services and ART coverage on HIV transmission via needle sharing. In a hypothetical scenario assuming ART had zero effect on transmission through needle sharing, we estimated harm reduction services alone would have accounted for 77% (upper bound-lower bound 62-95%) of averted HIV incidence. In a separate hypothetical scenario where harm reduction services remained at 1996 levels, we estimated ART alone would have accounted for 44% (10-67%) of averted HIV incidence. As a result of high distribution volumes, needle distribution predominantly accounted for incidence reductions attributable to harm reduction but opioid agonist treatment provided substantially greater QALY gains.

INTERPRETATION

If the true efficacy of ART in preventing HIV transmission through needle sharing is closer to its efficacy in sexual transmission, ART's effect on incident cases averted could be greater than that of harm reduction. Nonetheless, harm reduction services had a vital role in reducing HIV incidence in British Columbia, and should be viewed as essential and cost-effective tools in combination implementation strategies to reduce the public health and economic burden of HIV/AIDS.

FUNDING

BC Ministry of Health; National Institutes of Health (R01DA041747); Genome Canada (142HIV).

Navigating identity, territorial stigma, and HIV care services in Vancouver, Canada: A qualitative study

This study examines the influence of territorial stigma on access to HIV care and other support services. Qualitative interviews were conducted with thirty people living with HIV (PLHIV) who use drugs recruited from the Dr. Peter Centre (DPC), an HIV care facility located in Vancouver, Canada's West End neighbourhood that operates under a harm reduction approach. Findings demonstrated that territorial stigma can undermine access to critical support services and resources in spatially stigmatized neighbourhoods among PLHIV who use drugs who have relocated elsewhere. Furthermore, PLHIV moving from spatially stigmatized neighbourhoods - in this case, Vancouver's Downtown Eastside - to access HIV care services experienced tension with different groups at the DPC (e.g., men who have sex with me, people who use drugs), as these groups sought to define who constituted a'normative' client. Collectively, these findings demonstrate the urgent need to consider the siting of HIV care services as the epidemic evolves.

Missed Opportunities for HIV Prophylaxis Among Emergency Department Patients With Occupational and Nonoccupational Body Fluid Exposures

STUDY OBJECTIVE

Exposures to HIV are frequently managed in the emergency department (ED) for assessment and potential initiation of HIV postexposure prophylaxis. Despite established guidelines, it is unclear whether patients with a nonoccupational exposure are managed similarly to patients with an occupational exposure.

METHODS

This retrospective study used an administrative database to identify consecutive patients at a single ED with a discharge diagnosis of "blood or body fluid exposure" without sexual assault from April 1, 2007 to June 30, 2013. Patient exposure details and physician management were ascertained according to predefined guidelines. The primary outcome was the proportion of patients with high-risk exposures who were correctly given HIV prophylaxis; the secondary outcome was the proportion of patients with low-risk exposures who were correctly not given HIV prophylaxis. Other outcomes included the proportion of patients who had a baseline HIV test in the ED, the proportion who followed up with an HIV test within 6 months, and the number of seroconversions in this group. All outcomes were compared between nonoccupational and occupational exposure.

RESULTS

Of 1,972 encounters, 1,358 patients (68.9%) had an occupational exposure and 614 (31.1%) had a nonoccupational exposure. In the occupational exposure group, 190 patients (14.0%) were deemed high risk, with 160 (84.2%; 95% confidence interval [CI] 78.1% to 88.9%) appropriately given prophylaxis. In the nonoccupational exposure group, 287 patients (46.7%) had a high-risk exposure, with 208 (72.5%; 95% CI 66.8% to 77.5%) given prophylaxis, for a difference of 11.7% (95% CI 3.8% to 19.1%). For low-risk exposures, appropriate management of both occupational and nonoccupational exposure was similar (92.4% versus 93.0%). At the index ED visit, 90.5% of occupational exposure patients and 76.7% of nonoccupational exposure patients received HIV testing, for a difference of 13.8% (95% CI 10.1% to 17.7%). At 6 months, 25.4% of patients with an occupational exposure and 35.0% of patients with a nonoccupational exposure had a follow-up test, for a difference of -9.6% (95% CI -14.2% to -5.1%). Of patients who had follow-up testing within 6 months, 4 of 215 (1.9%) in the nonoccupational exposure group tested newly positive for HIV, whereas 0 of 345 (0%) in the occupational exposure group tested positive.

CONCLUSION

For ED patients with blood or body fluid exposures, those with high-risk nonoccupational exposures were not given HIV prophylaxis nearly twice as often as those with high-risk occupational exposure. Although 6-month follow-up testing rates were low, 1.9% of high-risk nonoccupational exposure patients seroconverted.

Increasing awareness about HIV prevention among young people who initiated injection drug use in a Canadian setting, 1988-2014

BACKGROUND

Globally, harm reduction interventions, including needle and syringe programs (NSPs), have been shown to reduce HIV risks among people who inject drugs (PWID). However, little is known about the impact of these efforts on the circumstances of first injection. Therefore, we sought to identify changes in the awareness about HIV prevention and syringe borrowing at the time of first injection drug use in Vancouver, Canada, during a period of NSP expansion.

METHODS

Data were drawn from prospective cohorts of PWID in Vancouver, who initiated injecting between 1988 and 2014. Multivariable regression was used to assess changes in the awareness about HIV and NSPs and syringe borrowing behaviour at first injection against calendar year of first injection.

RESULTS

Among 1044 participants (36.9% female), at the time of first injection 73.9% reported having known syringe sharing was an HIV risk, 54.1% reported having heard of NSPs, and 7.8% reported having borrowed a syringe used by others. In multivariable analyses, calendar year of first injection was independently and positively associated with awareness about HIV (adjusted prevalence ratio [APR]: 1.09; 95% confidence interval [CI]: 1.06, 1.11) and awareness about NSPs (APR: 1.18; 95% CI: 1.13, 1.24). While calendar year of first injection was significantly and negatively associated with syringe borrowing at first injection in bivariable analyses, the association did not remain significant in multivariable analyses (adjusted odds ratio: 0.90; 95% CI: 0.72, 1.14).

CONCLUSIONS

We found that awareness about HIV and NSPs at first injection have increased over time amongst PWID in this setting. However, declining trends in syringe borrowing at first injection were not determined after adjustment for socio-demographic characteristics. This suggests that HIV prevention efforts may have contributed to increased awareness about HIV prevention, but further research is needed to identify sub-populations at heightened risk of HIV at first injection.

Optimizing an HIV testing program using a system dynamics model of the continuum of care

Realizing the full individual and population-wide benefits of antiretroviral therapy for human immunodeficiency virus (HIV) infection requires an efficient mechanism of HIV-related health service delivery. We developed a system dynamics model of the continuum of HIV care in Vancouver, Canada, which reflects key activities and decisions in the delivery of antiretroviral therapy, including HIV testing, linkage to care, and long-term retention in care and treatment. To measure the influence of operational interventions on population health outcomes, we incorporated an HIV transmission component into the model. We determined optimal resource allocations among targeted and routine testing programs to minimize new HIV infections over five years in Vancouver. Simulation scenarios assumed various constraints informed by the local health policy. The project was conducted in close collaboration with the local health care providers, Vancouver Coastal Health Authority and Providence Health Care.

Predictors of liver-related death among people who inject drugs in Vancouver, Canada: a 15-year prospective cohort study

Introduction

While HIV/AIDS remains an important cause of death among people who inject drugs (PWID), the potential mortality burden attributable to hepatitis C virus (HCV) infection among this population is of increasing concern. Therefore, we sought to identify trends in and predictors of liver-related mortality among PWID.

Methods

Data were derived from prospective cohorts of PWID in Vancouver, Canada, between 1996 and 2011. Cohort data were linked to the provincial vital statistics database to ascertain mortality rates and causes of death. Multivariate Cox proportional hazards regression was used to examine the relationship between HCV infection and time to liver-related death. A sub-analysis examined the effect of HIV/HCV co-infection.

Results and discussion

In total, 2,279 PWID participated in this study, with 1,921 (84.3%) having seroconverted to anti-HCV prior to baseline assessments and 124 (5.4%) during follow-up. The liver-related mortality rate was 2.1 (95% confidence interval [CI]: 1.5–3.0) deaths per 1,000 person-years and was stable over time. In multivariate analyses, HCV seropositivity was not significantly associated with liver-related mortality (adjusted relative hazard [ARH]: 0.45; 95% CI: 0.15–1.37), but HIV seropositivity was (ARH: 2.67; 95% CI: 1.27–5.63). In sub-analysis, HIV/HCV co-infection had a 2.53 (95% CI: 1.18–5.46) times hazard of liver-related death compared with HCV mono-infection.

Conclusions

In this study, HCV seropositivity did not predict liver-related mortality while HIV seropositivity did. The findings highlight the critical role of HIV mono- and co-infection rather than HCV infection in contributing to liver-related mortality among PWID in this setting.

The impact of clinical, demographic and risk factors on rates of HIV transmission: a population-based phylogenetic analysis in British Columbia, Canada

BACKGROUND

The diversification of human immunodeficiency virus (HIV) is shaped by its transmission history. We therefore used a population based province wide HIV drug resistance database in British Columbia (BC), Canada, to evaluate the impact of clinical, demographic, and behavioral factors on rates of HIV transmission.

METHODS

We reconstructed molecular phylogenies from 27,296 anonymized bulk HIV pol sequences representing 7747 individuals in BC-about half the estimated HIV prevalence in BC. Infections were grouped into clusters based on phylogenetic distances, as a proxy for variation in transmission rates. Rates of cluster expansion were reconstructed from estimated dates of HIV seroconversion.

RESULTS

Our criteria grouped 4431 individuals into 744 clusters largely separated with respect to risk factors, including large established clusters predominated by injection drug users and more-recently emerging clusters comprising men who have sex with men. The mean log10 viral load of an individual's phylogenetic neighborhood (composed of 5 other individuals with shortest phylogenetic distances) increased their odds of appearing in a cluster by >2-fold per log10 viruses per milliliter.

CONCLUSIONS

Hotspots of ongoing HIV transmission can be characterized in near real time by the secondary analysis of HIV resistance genotypes, providing an important potential resource for targeting public health initiatives for HIV prevention.

Hospitals as a 'risk environment': an ethno-epidemiological study of voluntary and involuntary discharge from hospital against medical advice among people who inject drugs

People who inject drugs (PWID) experience high levels of HIV/AIDS and hepatitis C (HCV) infection that, together with injection-related complications such as non-fatal overdose and injection-related infections, lead to frequent hospitalizations. However, injection drug-using populations are among those most likely to be discharged from hospital against medical advice, which significantly increases their likelihood of hospital readmission, longer overall hospital stays, and death. In spite of this, little research has been undertaken examining how social-structural forces operating within hospital settings shape the experiences of PWID in receiving care in hospitals and contribute to discharges against medical advice. This ethno-epidemiological study was undertaken in Vancouver, Canada to explore how the social-structural dynamics within hospitals function to produce discharges against medical advice among PWID. In-depth interviews were conducted with thirty PWID recruited from among participants in ongoing observational cohort studies of people who inject drugs who reported that they had been discharged from hospital against medical advice within the previous two years. Data were analyzed thematically, and by drawing on the 'risk environment' framework and concepts of social violence. Our findings illustrate how intersecting social and structural factors led to inadequate pain and withdrawal management, which led to continued drug use in hospital settings. In turn, diverse forms of social control operating to regulate and prevent drug use in hospital settings amplified drug-related risks and increased the likelihood of discharge against medical advice. Given the significant morbidity and health care costs associated with discharge against medical advice among drug-using populations, there is an urgent need to reshape the social-structural contexts of hospital care for PWID by shifting emphasis toward evidence-based pain and drug treatment augmented by harm reduction supports, including supervised drug consumption services.

Hepatitis C virus treatment for prevention among people who inject drugs: Modeling treatment scale-up in the age of direct-acting antivirals

Substantial reductions in hepatitis C virus (HCV) prevalence among people who inject drugs (PWID) cannot be achieved by harm reduction interventions such as needle exchange and opiate substitution therapy (OST) alone. Current HCV treatment is arduous and uptake is low, but new highly effective and tolerable interferon-free direct-acting antiviral (DAA) treatments could facilitate increased uptake. We projected the potential impact of DAA treatments on PWID HCV prevalence in three settings. A dynamic HCV transmission model was parameterized to three chronic HCV prevalence settings: Edinburgh, UK (25%); Melbourne, Australia (50%); and Vancouver, Canada (65%). Using realistic scenarios of future DAAs (90% sustained viral response, 12 weeks duration, available 2015), we projected the treatment rates required to reduce chronic HCV prevalence by half or three-quarters within 15 years. Current HCV treatment rates may have a minimal impact on prevalence in Melbourne and Vancouver (<2% relative reductions) but could reduce prevalence by 26% in 15 years in Edinburgh. Prevalence could halve within 15 years with treatment scale-up to 15, 40, or 76 per 1,000 PWID annually in Edinburgh, Melbourne, or Vancouver, respectively (2-, 13-, and 15-fold increases, respectively). Scale-up to 22, 54, or 98 per 1,000 PWID annually could reduce prevalence by three-quarters within 15 years. Less impact occurs with delayed scale-up, higher baseline prevalence, or shorter average injecting duration. Results are insensitive to risk heterogeneity or restricting treatment to PWID on OST. At existing HCV drug costs, halving chronic prevalence would require annual treatment budgets of US $3.2 million in Edinburgh and approximately $50 million in Melbourne and Vancouver.

CONCLUSION

Interferon-free DAAs could enable increased HCV treatment uptake among PWID, which could have a major preventative impact. However, treatment costs may limit scale-up, and should be addressed.

HIV due to female sex work: regional and global estimates

INTRODUCTION

Female sex workers (FSWs) are at high risk of HIV infection. Our objective was to determine the proportion of HIV prevalence in the general female adult population that is attributable to the occupational exposure of female sex work, due to unprotected sexual intercourse.

METHODS

Population attributable fractions of HIV prevalence due to female sex work were estimated for 2011. A systematic search was conducted to retrieve required input data from available sources. Data gaps of HIV prevalence in FSWs for 2011 were filled using multilevel modeling and multivariate linear regression. The fraction of HIV attributable to female sex work was estimated as the excess HIV burden in FSWs deducting the HIV burden in FSWs due to injecting drug use.

RESULTS

An estimated fifteen percent of HIV in the general female adult population is attributable to (unsafe) female sex work. The region with the highest attributable fraction is Sub Saharan Africa, but the burden is also substantial for the Caribbean, Latin America and South and Southeast Asia. We estimate 106,000 deaths from HIV are a result of female sex work globally, 98,000 of which occur in Sub-Saharan Africa. If HIV prevalence in other population groups originating from sexual contact with FSWs had been considered, the overall attributable burden would probably be much larger.

DISCUSSION

Female sex work is an important contributor to HIV transmission and the global HIV burden. Effective HIV prevention measures exist and have been successfully targeted at key populations in many settings. These must be scaled up.

CONCLUSION

FSWs suffer from high HIV burden and are a crucial core population for HIV transmission. Surveillance, prevention and treatment of HIV in FSWs should benefit both this often neglected vulnerable group and the general population.

Mortality among British Columbians testing for hepatitis C antibody

BACKGROUND

Hepatitis C virus (HCV) infection is a major preventable and treatable cause of morbidity and mortality. The ability to link population based centralized laboratory HCV testing data with administrative databases provided a unique opportunity to compare mortality between HCV seronegative and seropositive individuals. Through the use of laboratory testing patterns and results, the objective of this study was to differentiate the viral effects of mortality due to HCV infection from risk behaviours/activities that are associated with acquisition of HCV infection.

METHODS

Serological testing data from the British Columbia (BC) Centre for Disease Control Public Health Microbiology and Reference Laboratory from 1992-2004 were linked to the BC Vital Statistics Agency death registry. Four groups of HCV testers were defined by their HCV antibody (anti-HCV) testing patterns: single non-reactive (SNR); serial multiple tested non-reactive (MNR); reactive at initial testing (REAC); and seroconverter (SERO) (previously seronegative followed by reactive, a marker for incident infection). Standardized mortality ratios (SMRs) were calculated to compare the relative risk of all cause and disease specific mortality to that of the BC population for each serological group. Time dependent Cox proportional hazard regression was used to compare hazard ratios (HRs) among HCV serological groups.

RESULTS

All anti-HCV testers had higher SMRs than the BC population. Referent to the SNR group, the REAC group had higher risks for liver (HR: 9.62; 95% CI=8.55-10.87) and drug related mortality (HR: 13.70; 95% CI=11.76-16.13). Compared to the REAC group, the SERO group had a lower risk for liver (HR: 0.53; 95% CI=0.24-0.99), but a higher risk for drug related mortality (HR: 1.54; 95% CI=1.12-2.05).

CONCLUSIONS

These findings confirm that individuals who test anti-HCV positive have increased mortality related to progressive liver disease, and that a substantial proportion of the mortality is attributable to drug use and risk behaviours/activities associated with HCV acquisition. Mortality reduction in HCV infected individuals will require comprehensive prevention programming to reduce the harms due to behaviours/activities which relate to HCV acquisition, as well as HCV treatment to prevent progression of chronic liver disease.

Social-structural factors associated with supportive service use among a cohort of HIV-positive individuals on antiretroviral therapy

As mortality rates decrease in British Columbia, Canada, supportive services (e.g. housing, food, counseling, addiction treatment) are increasingly conceptualized as critical components of care for people living with HIV/AIDS. Our study investigates social and clinical correlates of supportive service use across differing levels of engagement. Among 915 participants from the Longitudinal Investigations into Supportive and Ancillary health services (LISA) cohort, 742 (81%) reported using supportive services. Participants were nearly twice as likely to engage daily in supportive services if they self-identified as straight (95% confidence interval [CI], adjusted odds ratio [AOR]: 1.69), had not completed high school (95% CI, AOR: 1.97), had an annual income of < $15,000 (95% CI, AOR: 1.81), were unstably housed (95% CI, AOR: 1.89), were currently using illicit drugs (95% CI, AOR: 1.60), or reported poor social capital in terms of perceived neighborhood problems (95% CI, AOR: 1.15) or standard of living (95% CI, AOR: 1.70). Of interest, after adjusting for sociodemographic and socioeconomic variables, no clinical markers remained an independent predictor of use of supportive services. High service use by those demonstrating social and clinical vulnerabilities reaffirms the need for continued expansion of supportive services to facilitate a more equitable distribution of health among persons living with HIV.

Community-Based Research among Marginalized HIV Populations: Issues of Support, Resources, and Empowerment

A research question was posed to us by a local HIV-resource organization interested in exploring the educational and service needs of those unreached. In order to properly address this inquiry, we developed a community-based participatory research by training peer-led volunteers to facilitate focus-group discussions within Aboriginal and refugees participants following an interview guide. We gathered Aboriginal people and refugees separated into three focus groups each, enrolling a total of 41 self-identified HIV-positive, 38 males. The discussions were tape recorded upon consent and lasted between 59 and 118 minutes. We analyzed the thematic information collected interactively through constant comparison. The qualitative data leading to categories, codes, and themes formed the basis for the spatial representation of a conceptual mapping. Both groups shared similar struggles in living with HIV and in properly accessing local nonmedical HIV resources and discussed their concerns towards the need for empowerment and support to take control of their health.

Needle exchange and the HIV epidemic in Vancouver: lessons learned from 15 years of research

During the mid-1990s, Vancouver experienced a well characterized HIV outbreak among injection drug users (IDU) and many questioned how this could occur in the presence of a high volume needle exchange program (NEP). Specific concerns were fuelled by early research demonstrating that frequent needle exchange program attendees were more likely to be HIV positive than those who attended the NEP less frequently. Since then, some have misinterpreted this finding as evidence that NEPs are ineffective or potentially harmful. In light of continuing questions about the Vancouver HIV epidemic, we review 15 years of peer-reviewed research on Vancouver's NEP to describe what has been learned through this work. Our review demonstrates that: (1) NEP attendance is not causally associated with HIV infection, (2) frequent attendees of Vancouver's NEP have higher risk profiles which explain their increased risk of HIV seroconversion, and (3) a number of policy concerns, as well as the high prevalence of cocaine injecting contributed to the failure of the NEP to prevent the outbreak. Additionally, we highlight several improvements to Vancouver's NEP that contributed to declines in syringe sharing and HIV incidence. Vancouver's experience provides a number of important lessons regarding NEP. Keys to success include refocusing the NEP away from an emphasis on public order objectives by separating distribution and collection functions, removing syringe distribution limits and decentralizing and diversifying NEP services. Additionally, our review highlights the importance of context when implementing NEPs, as well as ongoing evaluation to identify factors that constrain or improve access to sterile syringes.

Implications for HIV prevention programs from a serobehavioural survey of men who have sex with men in Vancouver, British Columbia: the ManCount study

BACKGROUND

We examined HIV prevalence, awareness of HIV serostatus and HIV risk behaviour among a sample of men who have sex with men (MSM) in Vancouver.

METHODS

MSM > or = 18 years were recruited from August 2008 to February 2009 through community venues. Participants completed a questionnaire and provided a dried blood spot (DBS) for HIV and other STI testing. We performed descriptive statistics and bivariate analyses of key explanatory variables.

RESULTS

A total of 1,169 participants completed questionnaires; of these, 1,138 (97.3%) provided DBS specimens suitable for testing. The median age was 33 years (IQR 26-44). A total of 206 (18%) were HIV-positive by DBS, of whom 86% were aware they were positive. HIV seropositivity increased from 7.1% in those < 30 years of age to 19% in those 30-44 years and 34% among those > or = 45 years (p < 0.001 for test of trend). Of the 933 who self-reported as HIV-negative or unknown, 28 (3.0%) tested HIV-positive. Among those not tested for HIV in the previous 2 years, the reasons for not testing differed between participants with undiagnosed HIV infection and those who were HIV-negative. A total of 62% of study participants who self-reported as HIV-negative reported using a condom the last time they had anal sex. The use of risk-reduction measures was reported by 91.1% of all study participants (72% if excluding consistent condom use).

CONCLUSION

The majority of MSM in Vancouver have adopted behaviours that reduce their HIV-related risk. However, prevention programs must continue to promote condom use, increase HIV testing, and better inform MSM of the value and limitations of other risk-reduction strategies.

The impact of stressful life events on unprotected anal intercourse among gay and bisexual men

We investigated the hypothesis that gay and bisexual men experiencing stressful life events are more likely to engage in risky sexual behavior. Data were from a cohort study of 155 HIV-positive and 207 HIV-negative men in Ontario, Canada (1998-2007). We quantified the relation between stressful life events and unprotected anal intercourse with a non-regular partner. In the past 6 months, 19% reported unprotected intercourse (HIV+: 28%; HIV-: 13%) and 58% reported one or more stressful life events (HIV+: 64%; HIV-: 55%). Among HIV-negative men, the odds of unprotected intercourse increased by 1.15 for each additional event (95%CI 1.06, 1.24). Among HIV-positive men, those who reported the event "problems due to alcohol or drugs" were 1.80 (95%CI 1.27, 2.56) times more likely to report unprotected intercourse. Interventions to assist men to cope with stress may help to prevent population spread of HIV and improve overall health.

Cohort Profile: Longitudinal Investigations into Supportive and Ancillary health services

The Longitudinal Investigations into Supportive and Ancillary health services (LISA) study is a cohort of people living with HIV/AIDS who have ever accessed anti-retroviral therapy (ART) in British Columbia, Canada. The LISA study was developed to better understand the outcomes of people living with HIV with respect to supportive services use, socio-demographic factors and quality of life. Between July 2007 and January 2010, 1000 participants completed an interviewer-administered questionnaire that included questions concerning medical history, substance use, social and medical support services, food and housing security and other social determinants of health characteristics. Of the 1000 participants, 917 were successfully linked to longitudinal clinical data through the provincial Drug Treatment Program. Within the LISA cohort, 27% of the participants are female, the median age is 39 years and 32% identify as Aboriginal. Knowledge translation activities for LISA include the creation of plain language summaries, internet resources and arts-based engagement activities such as Photovoice.

HIV testing and willingness to get HIV testing at a peer-run drop-in centre for people who inject drugs in Bangkok, Thailand

BACKGROUND

Regular HIV testing among people who inject drugs is an essential component of HIV prevention and treatment efforts. We explored HIV testing behaviour among a community-recruited sample of injection drug users (IDU) in Bangkok, Thailand.

METHODS

Data collected through the Mitsampan Community Research Project were used to examine correlates of HIV testing behaviour among IDU and to explore reasons for not being tested. Multivariate logistic regression was used to examine factors associated with willingness to access HIV testing at the drug-user-run Mitsampan Harm Reduction Centre (MSHRC).

RESULTS

Among the 244 IDU who participated in this study, 186 (76.2%) reported receiving HIV testing in the previous six months. Enrolment in voluntary drug treatment (odds ratio [OR] = 2.34; 95% confidence interval [CI]: 1.18-4.63) and the tenofovir trial (OR = 44.81; 95%CI: 13.44-149.45) were positively associated with having been tested, whereas MSHRC use (OR = 1.78; 95%CI: 0.96-3.29) was marginally associated with having been tested. 56.9% of those who had not been tested reported in engaging in HIV risk behaviour in the past six months. 181 (74.2%) participants were willing to be tested at the MSHRC if testing were offered there. In multivariate analyses, willingness to get HIV testing at the MSHRC was positively associated with ever having been to the MSHRC (adjusted odds ratio [AOR] = 2.42; 95%CI: 1.21-4.85) and, among females, being enrolled in voluntary drug treatment services (AOR = 9.38; 95%CI: 1.14-76.98).

CONCLUSIONS

More than three-quarters of IDU received HIV testing in the previous six months. However, HIV risk behaviour was common among those who had not been tested. Additionally, 74.2% of participants were willing to receive HIV testing at the MSHRC. These findings provide evidence for ongoing HIV prevention education, as well potential benefits of incorporating HIV testing for IDU within peer-led harm reduction programs.

Minimal transmission of HIV despite persistently high transmission of hepatitis C virus in a Swedish needle exchange program

The aim of this study was to examine the prevalence and incidence of HIV and hepatitis B and C (HBV and HCV) among injecting drug users in a Swedish needle exchange programme (NEP) and to identify risk factors for blood-borne transmission. A series of serum samples from NEP participants enrolled from 1997 to 2005 were tested for markers of HIV, HBV and HCV (including retrospective testing for HCV RNA in the last anti-HCV-negative sample from each anti-HCV seroconverter). Prevalence and incidence were correlated with self-reported baseline characteristics. Among 831 participants available for follow-up, one was HIV positive at baseline and two seroconverted to anti-HIV during the follow-up of 2433 HIV-negative person-years [incidence 0.08 per 100 person-years at risk (pyr); compared to 0.0 in a previous assessment of the same NEP covering 1990-1993]. The corresponding values for HBV were 3.4/100 pyr (1990-1993: 11.7) and for HCV 38.3/100 pyr (1990-1993: 27.3). HCV seroconversions occurred mostly during the first year after NEP enrolment. Of the 332 cases testing anti-HCV negative at enrolment, 37 were positive for HCV RNA in the same baseline sample (adjusted HCV incidence 31.5/100 pyr). HCV seroconversion during follow-up was significantly associated with mixed injection use of amphetamine and heroin, and a history of incarceration at baseline. In this NEP setting, HIV prevalence and incidence remained low and HBV incidence declined because of vaccination, but transmission of HCV was persistently high. HCV RNA testing in anti-HCV-negative NEP participants led to more accurate identification of timepoints for transmission.

HIV incidence and prevalence among aboriginal peoples in Canada

We examined incidence, prevalence, and correlates of HIV infection in Aboriginal peoples in Canada and found that among most risk groups both Aboriginal and non-Aboriginal participants showed similar levels of HIV prevalence. Aboriginal peoples who use illicit drugs were found to have higher HIV incidence and prevalence when compared to their non-Aboriginal drug-using peers. Aboriginal street youth and female sex workers were also found to have higher HIV prevalence. Among Aboriginal populations, correlates of HIV-positive sero-status include syringe sharing and frequently injecting drugs, as well as geographic and social factors such as living in Vancouver or having a history of non-consensual sex. This study is relevant to Canada and elsewhere, as Indigenous populations are disproportionately represented in the HIV epidemic worldwide.

Modelling HIV epidemics in the antiretroviral era: the UNAIDS Estimation and Projection package 2009

Objective

The UNAIDS Estimation and Projection Package (EPP) is a tool for country-level estimation and short-term projection of HIV/AIDS epidemics based on fitting observed HIV surveillance data on prevalence. This paper describes the adaptations made in EPP 2009, the latest version of this tool, as new issues have arisen in the global response, in particular the global expansion of antiretroviral therapy (ART).

Results

By December 2008 over 4 million people globally were receiving ART, substantially improving their survival. EPP 2009 required modifications to correctly adjust for the effects of ART on incidence and the resulting increases in HIV prevalence in populations with high ART coverage. Because changing incidence is a better indicator of program impact, the 2009 series of UNAIDS tools also focuses on calculating incidence alongside prevalence. Other changes made in EPP 2009 include: an improved procedure, incremental mixture importance sampling, for efficiently generating more accurate uncertainty estimates; provisions to vary the urban/rural population ratios in generalised epidemics over time; introduction of a modified epidemic model that accommodates behaviour change in low incidence settings; and improved procedures for calibrating models. This paper describes these changes in detail, and discusses anticipated future changes in the next version of EPP.

Is Vancouver Canada's supervised injection facility cost-saving?

OBJECTIVE

To determine whether Vancouver's Insite supervised injection facility and syringe exchange programs are cost-saving--that is, are the savings due to averted HIV-related medical care costs sufficient to offset Insite's operating costs?

METHODS

The analyses examined the impact of Insite's programs for a single year. Mathematical models were used to calculate the number of additional HIV infections that would be expected if Insite were closed. The life-time HIV-related medical costs associated with these additional infections were compared to the annual operating costs of the Insite facility.

RESULTS

If Insite were closed, the annual number of incident HIV infections among Vancouver IDU would be expected to increase from 179.3 to 262.8. These 83.5 preventable infections are associated with $17.6 million (Canadian) in life-time HIV-related medical care costs, greatly exceeding Insite's operating costs, which are approximately $3 million per year.

CONCLUSIONS

Insite's safe injection facility and syringe exchange program substantially reduce the incidence of HIV infection within Vancouver's IDU community. The associated savings in averted HIV-related medical care costs are more than sufficient to offset Insite's operating costs.

Expanding HAART treatment to all currently eligible individuals under the 2008 IAS-USA Guidelines in British Columbia, Canada

Background

In 2008, the IAS-USA published the revised guidelines for the use of HAART in adults substantially increasing the number of individuals eligible for HAART. The epidemic in British Columbia (BC) is mainly among men who have sex with men and those with injection drug use. Here, we explored the potential impact of different HAART coverage scenarios, based on the new guidelines, on the HIV-related incidence, morbidity and mortality in BC, Canada.

Methodology

We built a mathematical transmission model to investigate different HAART coverage scenarios (50%, 60%, 75% and 100%) of those medically eligible to receive HAART under the 2008 IAS guidelines. All new scenarios were compared to the current coverage in BC under the 2006 IAS guidelines (i.e. baseline scenario). In BC, it is estimated that 25–30% of individuals are unaware of their status. Costs were drug-related and reported in Canadian dollars. HIV-related morbidity and mortality were estimated based on the disability-adjusted life years (DALY) methodology.

Principal Findings

Currently, there are 4379 individuals on HAART under the IAS 2006 guidelines and 6781 individuals who qualify for treatment based on the new guidelines. Within 5 years, increasing HAART coverage decreased yearly new infections by at least 44.8%. In the 50% scenario, in 5 years, DALY decreased by 53% corresponding to 4155 averted DALYs, and in 25 years it decreased by 66% corresponding to 5837 averted DALYs. The effect was even stronger if the 75% scenario was chosen instead. Compared to the 100% expansion scenario, we observed an excess in annual direct treatment expenditures at the end of 5 years of approximately 1 million dollars in the 75% scenario, and of approximately 2 million dollars in the 50% scenario.

Conclusions/Significance

The individual and public health benefits of these new guidelines are immense. The results show that by increasing the number of individuals on HAART save lives, it is cost averting, and it positively impacts society by decreasing the number of new HIV infections. Thus, public health community should consider incremental gains when considering guidelines and policy.