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Biomedical subjects

Thomas Kerr

Publications and source records attributed to Thomas Kerr.

At least 37 records · Page 2Linked to original sources

Initiation of opiate addiction in a Canadian prison: a case report.

BACKGROUND: In North America, the harms of illicit drug use have been responded to primarily through law enforcement interventions. This strategy has resulted in record populations of addicted individuals being incarcerated in both Canada and the United States. The incarceration of non-violent drug offenders has become increasingly controversial as studies demonstrate the harms, including elevated HIV risk behavior, of incarcerating injection drug users. Other harms, such as the initiation of illicit drug use by prison inmates who previously did not use drugs, have been less commonly described. CASE PRESENTATION: We report on the case of an individual who initiated non-injection opiate use in a Canadian prison and developed an addiction to the drug. Upon release into the community, the individual continued using opiates and sought treatment at a clinic. The patient feared that he might initiate injection use of opiates if his cravings could not be controlled. The patient was placed on methadone maintenance therapy. CONCLUSION: While anecdotal reports indicate that initiation in prison of the use of addictive illicit substances is frequent, documentation through clinical experience is rare, and the public health implications of this behavior have not been given sufficient attention in the literature. Strategies of incarcerating non-violent drug offenders and attempting to keep illicit drugs out of prisons have not reduced the harms and costs of illicit drug use. Effective, practical alternatives are urgently needed; expanded community diversion programs for non-violent drug offenders deserve particular attention.

Journal Article↗

Elevated rates of HIV infection among young Aboriginal injection drug users in a Canadian setting.

OBJECTIVES: Recent reports have suggested that Aboriginal and American Indian people are at elevated risk of HIV infection. We undertook the present study to compare socio-demographic and risk variables between Aboriginal and non-Aboriginal young (aged 13 - 24 years) injection drug users (IDUs) and characterize the burden of HIV infection among young Aboriginal IDUs. METHODS: We compared socio-demographic and risk variables between Aboriginal and non-Aboriginal young IDUs. Data were collected through the Vancouver Injection Drug Users Study (VIDUS). Semi-annually, participants have completed an interviewer-administered questionnaire and have undergone serologic testing for HIV and Hepatitis C (HCV). RESULTS: To date over 1500 Vancouver IDU have been enrolled and followed, among whom 291 were aged 24 years and younger. Of the 291 young injectors, 80 (27%) were Aboriginal. In comparison to non-Aboriginal youth, Aboriginal youth were more likely to test seropositive for either HIV (20% vs 7%, p=< 0.001) or Hepatitis C virus (HCV) (66% vs 38%, p =< 0.001), be involved in sex work and live in the city's IDU epi-centre at baseline. After 48 months of follow-up, Aboriginal youth experienced significantly higher HIV seroconversion rates than non-Aboriginal youth, 27.8 per ppy (95% CI: 13.4-42.2) vs. 7.0 per ppy (95% CI: 2.3-11.8) respectively (log-rank p = 0.005) and the incidence density over the entire follow-up period was 12.6 per 100 pyrs (CI: 6.49-21.96) and 3.9 per 100 pyrs (CI: 1.8-7.3) respectively. INTERPRETATION: These findings demonstrate that culturally relevant, evidence based prevention programs are urgently required to prevent HIV infection among Aboriginal youth.

Journal Article↗

Impact of HAART and injection drug use on life expectancy of two HIV-positive cohorts in British Columbia.

BACKGROUND: The introduction of HAART has led to consistent improvements in survival among HIV-infected individuals. However, there is evidence that not all populations have benefited equally from HAART and that mortality rates are higher in HIV-infected injection drug users than in non-users. OBJECTIVE: To model life expectancies for HIV-positive individuals subdivided according to history of injection drug use and treatment with HAART. DESIGN: Population-based study of HIV-positive persons in British Columbia's HIV/AIDS treatment program. METHODS: The primary outcome measures in this study were life expectancy at exact age 20 and potential years of life lost. RESULTS: The highest life expectancy (38.9 years) and lowest potential years of life lost were measured for individuals taking HAART and without a history of injection drug use. The lowest life expectancy (19.1 years) and highest potential years of life lost were measured in HIV-positive injection drug users who were not taking HAART. CONCLUSIONS: There are substantial disparities in life expectancy for persons living with HIV in British Columbia. Members of the injection drug community, particularly those who are not taking HAART, experience elevated mortality in comparison with those without a history of drug use.

Adult↗

Impact of a medically supervised safer injection facility on community drug use patterns: a before and after study.

PROBLEM: Illicit use of injected drugs is linked with high rates of HIV infection and fatal overdose, as well as community concerns about public drug use. Supervised injecting facilities have been proposed as a potential solution, but fears have been raised that they might encourage drug use. DESIGN: A before and after study. Participants and setting 871 injecting drug users recruited from the community in Vancouver, Canada. KEY MEASURES FOR IMPROVEMENT: Rates of relapse into injected drug use among former users and of stopping drug use among current users. STRATEGIES FOR CHANGE: Local health authorities established the Vancouver supervised injecting facility to provide injecting drug users with sterile injecting equipment, intervention in the event of overdose, primary health care, and referral to external health and social services. EFFECTS OF CHANGE: Analysis of periods before and after the facility's opening showed no substantial increase in the rate of relapse into injected drug use (17% v 20%) and no substantial decrease in the rate of stopping injected drug use (17% v 15%). LESSONS LEARNT: Recently reported benefits of supervised injecting facilities on drug users' high risk behaviours and on public order do not seem to have been offset by negative community impacts.

Adult↗

Potential community and public health impacts of medically supervised safer smoking facilities for crack cocaine users.

There is growing evidence of the public health and community harms associated with crack cocaine smoking, particularly the risk of blood-borne transmission through non-parenteral routes. In response, community advocates and policy makers in Vancouver, Canada are calling for an exemption from Health Canada to pilot a medically supervised safer smoking facility (SSF) for non-injection drug users (NIDU). Current reluctance on the part of health authorities is likely due to the lack of existing evidence surrounding the extent of related harm and potential uptake of such a facility among NIDUs in this setting. In November 2004, a feasibility study was conducted among 437 crack cocaine smokers. Univariate analyses were conducted to determine associations with willingness to use a SSF and logistic regression was used to adjust for potentially confounding variables (p < 0.05). Variables found to be independently associated with willingness to use a SSF included recent injection drug use (OR = 1.72, 95% CI: 1.09-2.70), having equipment confiscated or broken by police (OR = 1.96, 95% CI: 1.24-2.85), crack bingeing (OR = 2.16, 95% CI: 1.39-3.12), smoking crack in public places (OR = 2.48, 95% CI: 1.65-3.27), borrowing crack pipes (OR = 2.50, 95% CI: 1.86-3.40), and burns/inhaled brillo due to rushing smoke in public places (OR = 4.37, 95% CI: 2.71-8.64). The results suggest a strong potential for a SSF to reduce the health related harms and address concerns of public order and open drug use among crack cocaine smokers should a facility be implemented in this setting.

Journal Article↗

The impact of sex partners' HIV status on HIV seroconversion in a prospective cohort of injection drug users.

OBJECTIVE AND DESIGN: The identification of individuals at highest risk of HIV infection is critical for targeting prevention strategies. We evaluated the HIV status of the sex partners of injection drug users (IDUs) and rates of subsequent HIV seroconversion among a prospective cohort study of IDUs. METHODS: We performed an analysis of the time to HIV infection among baseline HIV-negative IDUs enrolled in the Vancouver Injection Drug Users Study. IDUs were stratified based on whether or not they reported having an HIV-positive sex partner. Kaplan-Meier methods were used to estimate cumulative HIV incidence rates, and Cox regression was used to determine adjusted relative hazards (RHs) for HIV seroconversion. RESULTS: Of 1013 initially HIV-negative IDUs, 4.8% had an HIV-positive partner at baseline. After 18 months, the cumulative HIV incidence rate was significantly elevated among those who reported having an HIV-positive sex partner (23.4% vs. 8.1%; log-rank P < 0.001). In a Cox regression model adjusting for all variables that were associated with the time to HIV infection in univariate analyses, including drug use characteristics, having an HIV-positive sex partner (RH = 2.42 [95% confidence interval: 1.30 to 4.60]; P = 0.005) remained independently associated with time to HIV seroconversion. CONCLUSIONS: Having an HIV-positive sex partner was strongly and independently associated with seroconversion after adjustment for risk factors related to drug use. Our findings may aid public health workers in their efforts to identify IDUs who should be targeted with education and prevention efforts and indicate the need for ongoing development of prevention interventions for IDU sex partners who are HIV discordant.

AIDS Serodiagnosis↗

Factors associated with early adolescent initiation into injection drug use: implications for intervention programs.

This study explores factors associated with early adolescent (aged < or = 16 years) initiation into injection drug use among young (< or = 29 years) injection drug users (IDUs). Data were collected through the Vancouver Injection Drug Users Study (VIDUS). Since 1996, 542 participants aged 29 years and younger have been enrolled and followed. In total, 205 (38%) young participants were initiated at age 16 years or younger. The proportion of young initiators was greater among: females, adjusted odds ratio [AOR]: 1.63 (95% confidence interval [CI]: 1.09-2.44); sex workers, AOR: 1.61 (CI: 1.11-2.31); binge drug users, AOR: 1.45 (CI: 1.01-2.08); and those who have been in juvenile detention or jail, AOR: 1.78 (CI: 1.16-2.66). Early initiates were more likely to be infected with human immunodeficiency virus (HIV), OR: 2.6 (CI: 1.3-5.0) and hepatitis C virus (HCV), OR: 2.6 (CI: 1.3-5.0). Targeted early interventions are required, specifically designed for and in collaboration with girls and young women.

Adolescent↗

Prevalence and correlates of cervical cancer screening among injection drug users.

OBJECTIVE: Access to cervical cancer screening may be lower among lower income and socially disadvantaged populations. However, few studies have specifically examined factors associated with cervical cancer screening among socially marginalized populations, especially in settings with free health care systems. METHODS: The present study was conducted to examine the prevalence and correlates of cervical cancer screening among injection drug users. We examined rates of Papanicolaou (Pap) smear testing among female participants in the Vancouver Injection Drug Users Study (VIDUS). Univariate and logistic regression analyses were used to evaluate factors associated with cervical cancer screening. RESULTS: During the period from December 2004 to May 2005, 297 female injection drug users were seen. In logistic regression analyses, age (adjusted odds ratio [AOR]=0.70; 95% confidence intervals [CI] 0.53, 0.92, P=0.010), HIV infection (AOR=2.46; 95% CI 1.41,4.26, P=0.001), hepatitis C infection (AOR=0.25; 95% CI 0.09,0.71, P=0.010), and having visited a family physician in the prior six months (OR=3.10; 95% CI 1.58, 6.07, P=0.001) were independently associated with recent cervical cancer screening. CONCLUSIONS: After adjustment for regular physician visits, HIV infection was associated with elevated rates of cervical screening. This is reassuring, given the elevated risk of cervical cancer among this population. Interventions may be required to improve uptake of screening among older injection drug users and drug users infected with hepatitis C.

Adult↗

Impact of HIV testing on uptake of HIV therapy among antiretroviral naive HIV-infected injection drug users.

Improving access to antiretroviral therapy among injection drug users remains an urgent public health concern. We examined the time to antiretroviral therapy (ART) use among antiretroviral naive HIV-infected injection drug users who were unaware of their HIV status to examine the impact of receipt of HIV test results on uptake of ART. Time to ART use was examined using Kaplan - Meier methods, and factors associated with the time to ART were evaluated using Cox proportional hazards regression. Between May 1996 and May 2003, 312 HIV-infected individuals were enrolled into the Barriers to Antiretroviral Therapy (BART) cohort, among whom 105 (33.7%) reported not knowing their HIV status at baseline. At 24 months post-baseline, those participants who returned for test results within 8 months initiated ART at a significantly elevated rate [adjusted relative hazard = 1.87 (95% CI: 1.05 - 3.33)]. These findings demonstrate the potential to improve uptake of ART among injection drug users through targeted HIV testing and counselling initiatives that encourage the receipt of HIV test results, and suggest that strategies to improve awareness of HIV infection may improve access to antiretroviral therapy.

Anti-Retroviral Agents↗

Binge drug use independently predicts HIV seroconversion among injection drug users: implications for public health strategies.

Several studies have highlighted risk factors that cause HIV vulnerability among injection drug users (IDUs); these studies in turn have prompted public health officials to take action to minimize these risks. We sought to evaluate the potential association between binge drug use and HIV seroconversion and, subsequently, risk factors associated with binge drug use among a cohort of IDUs. To do this, we performed analyses of (1) associations with HIV seroconversion and (2) associations with binge drug use among participants enrolled in the Vancouver Injection Drug Users Study (VIDUS), a prospective cohort of IDU. Because serial measures for each individual were available, we undertook a time-updated Cox regression analysis to detect associations with HIV incidence and variables potentially associated with binge drug use were evaluated by using generalized estimating equations (GEE). Overall, 1548 IDU were enrolled into the VIDUS cohort between May 1996 and May 2003. There were 1013 individuals who were HIV seronegative at enrollment and had at least one follow-up visit; 125 (12%) became HIV positive during the study period for a cumulative incidence rate of 14% at 64 months after enrollment. In the final multivariate model, binge drug use [Adjusted Hazards Ratio: 1.61 (CI: 1.12, 2.31)] was independently associated with HIV seroconversion. In subanalyses, when we evaluated associations with binge drug use in GEE analyses, borrowing [Odds Ratio (OR): 153 (CI: 1.33-1.76)] and lending [OR: 1.73 (CI: 1.50-1.98)] syringes, sex trade work [OR: 1.14 (CI: 1.01-1.29)], frequent cocaine [OR: 2.34 (CI: 2.11-2.60)] and heroin [OR: 1.29 (CI: 1.17-1.43)] injection were independently associated with binge drug use and methadone [OR: 0.80 (CI: 0.71-0.89)] was protective against binge drug use. Our study identified an independent association between binge drug use and HIV incidence and demonstrated several high-risk drug practices associated with bingeing. Given the unaddressed public health risks associated with bingeing, a public health response protocol must be developed to minimize the personal and public health risks associated with the binge use of drugs.

British Columbia↗

Factors associated with buying and selling syringes among injection drug users in a setting of one of North America's largest syringe exchange programs.

We performed analyses of syringe buying and syringe selling among Vancouver injection drug users, recruited from May 1996 and followed up between November 2002 and August 2003, in the context of one of North America's largest syringe exchange programs (SEPs). An interviewer-administered questionnaire, approximately 45 minutes in duration, was used to collect information regarding risk factors for HIV infection and sources of sterile syringes. Seventy participants (15%) reported syringe selling and 122 (26%) reported syringe buying. Syringe sellers were more likely to be female, reside in unstable housing, need help injecting, and have visited the SEP at least once weekly. Syringe buyers were more likely to need help injecting, have difficulty finding new syringes, have binged on drugs, and have visited the SEP at least once weekly. Syringe buying most frequently occurred when the SEP was closed.

Acquired Immunodeficiency Syndrome↗

Changes in Canadian heroin supply coinciding with the Australian heroin shortage.

AIMS: Previous studies have largely attributed the Australian heroin shortage to increases in local law enforcement efforts. Because western Canada receives heroin from similar source nations, but has not measurably increased enforcement practices or funding levels, we sought to examine trends in Canadian heroin-related indices before and after the Australian heroin shortage, which began in approximately January 2001. METHODS: During periods before and after January 2001, we examined the number of fatal overdoses and ambulance responses to heroin-related overdoses that required the use of naloxone in British Columbia, Canada. As an overall marker of Canadian supply reduction, we also examined the quantity of heroin seized during this period. Lastly, we examined trends in daily heroin use among injection drug users enrolled in the Vancouver Injection Drug Users Study (VIDUS). RESULTS: There was a 35% reduction in overdose deaths, from an annual average of 297 deaths during the years 1998-2000 in comparison to an average of 192 deaths during 2001-03. Similarly, use of naloxone declined 45% in the period coinciding with the Australian heroin shortage. Interestingly, the weight of Canadian heroin seized declined 64% coinciding with the Australian heroin shortage, from an average of 184 kg during 1998-2000 to 67 kg on average during 2001-03. Among 1587 VIDUS participants, the period coinciding with the Australian heroin shortage was associated independently with reduced daily injection of heroin [adjusted odds ratio: 0.55 (95% CI: 0.50-0.61); P < 0.001]. CONCLUSIONS: Massive decreases in three independent markers of heroin use have been observed in western Canada coinciding with the Australian heroin shortage, despite no increases in funding to Canadian enforcement efforts. Markedly reduced Canadian seizure activity also coincided with the Australian heroin shortage. These findings suggest that external global heroin supply forces deserve greater investigation and credence as a potential explanation for the Australian heroin shortage.

Australia↗

Public injecting and the need for 'safer environment interventions' in the reduction of drug-related harm.

BACKGROUND: One key structural dimension in the distribution of drug-related harm associated with injecting drug use is the injecting environment. Epidemiological evidence associates elevated blood-borne viral risk with injecting in 'public' and 'semipublic' environments. Yet the quality of evidence on public injecting and related viral risk is variable, and is lacking in many countries such as the United Kingdom. AIM: This commentary considers the micro-injecting environment as a critical dimension of risk, exploring the need for 'safer injecting environment interventions'. METHODS: We draw upon published research evidence and qualitative case examples. RESULTS: We note the limits in epidemiological evidence on public injecting and emphasize the need for ethnographic research to determine the 'social relations' of how drug users and risk practices interact with injecting environments. We identify three main forms of 'safer environment intervention': purpose-built drug consumption rooms; interventions within existing spatial relations; and spatial programming and urban design. While drug consumption rooms find evidence-based support, they are not a panacea. We emphasize the potential of interventions embedded within existing spatial and social relations. These include low-cost pragmatic interventions enhancing facilities and safety at public and semipublic injecting sites and, primarily, peer-based interventions, including peer-supervised injecting sites. We caution against spatial programming and urban design interventions which can cause the displacement of socially marginalized populations and the redistribution of harm. CONCLUSIONS: Public health interventions in the addictions field have in the past focused upon individual behavioural change at the cost of social interventions and environmental change. We wish to focus greater attention on reducing risks related to public injecting and encourage greater debate on 'safer environment interventions' in harm reduction.

Environment↗

Pharmacokinetic interactions between HIV antiretroviral therapy and drugs used to treat opioid dependence.

Injection drug use is a common risk factor for HIV infection, and opioid use and dependence is the underlying condition that often fuels HIV risk behaviour and subsequent HIV seroconversion among injection drug users (IDUs). Treatment of opioid dependence often requires continued opioid administration in the form of substitution therapy, which means that opioid-using IDUs often continue receiving opioids even after cessation of illicit drug use. The concurrent use of both antiretrovirals and opioids in HIV-positive individuals is thus common. This review was undertaken to summarise current knowledge on the interactions between the opioids and antiretrovirals and to make recommendations on the treatment of HIV-positive opioid-dependent patients.

Animals↗

HIV prevalence among aboriginal British Columbians.

CONTEXT: There is considerable concern about the spread of HIV disease among Aboriginal peoples in British Columbia. OBJECTIVE: To estimate the number of Aboriginal British Columbians infected with HIV. DESIGN AND SETTING: A population-based analysis of Aboriginal men and women in British Columbia, Canada from 1980 to 2001. PARTICIPANTS: Epidemic curves were fit for gay and bisexual men, injection drug users, men and women aged 15 to 49 years and persons over 50 years of age. MAIN OUTCOME MEASURES: HIV prevalence for the total Aboriginal population was modeled using the UNAIDS/WHO Estimation and Projection Package (EPP). Monte Carlo simulation was used to estimate potential number infected for select transmission group in 2001. RESULTS: A total of 170,025 Aboriginals resided in British Columbia in 2001, of whom 69% were 15 years and older. Of these 1,691 (range 1,479-1,955) men and women aged 15 years and over were living with HIV with overall prevalence ranging from 1.26% to 1.66%. The majority of the persons infected were men. Injection drug users (range 1,202-1,744) and gay and bisexual men (range 145, 232) contributed the greatest number of infections. Few persons infected were from low risk populations. CONCLUSION: More than 1 in every 100 Aboriginals aged 15 years and over was living with HIV in 2001. Culturally appropriate approaches are needed to tailor effective HIV interventions to this community.

Journal Article↗

Attendance, drug use patterns, and referrals made from North America's first supervised injection facility.

BACKGROUND: North America's first government sanctioned supervised injection facility (SIF) was opened in Vancouver in response to the serious health and social consequences of injection drug use and the perseverance of committed advocates and drug user groups who demanded change. This analysis was conducted to describe the attendance, demographic characteristics, drug use patterns, and referrals made during the first 18 months of operation. METHODS: As part of the evaluation strategy for the SIF, information is collected through a comprehensive on-site database designed to track attendance and the daily activities within the facility. All users of the SIF must sign a waiver form and are then entered into a database using a unique identifier of their choice. This identifier is used at each subsequent visit to provide a prospective record of attendance, drug use, and interventions. RESULTS: From 10 March 2004 to 30 April 2005 inclusive, there were 4764 unique individuals who registered at the SIF. The facility successfully attracted a range of community injection drug users including women (23%) and members of the Aboriginal community (18%). Although heroin was used in 46% of all injections, cocaine was injected 37% of the time. There were 273 witnessed overdoses with no fatalities. During just 12 months of observation, 2171 individual referrals were made with the majority (37%) being referred for addiction counseling. INTERPRETATION: Vancouver's SIF has successfully been integrated into the community, has attracted a wide cross section of community injection drug users, has intervened in overdoses, and initiated over 2000 referrals to counseling and other support services. These findings should be useful for other settings considering SIF trials.

Acquired Immunodeficiency Syndrome↗