Highly active antiretroviral therapy (HAART) among HIV-infected drug users: a prospective cohort study of sexual risk and injecting behaviour

HIV and hepatitis C treatment uptake among people who use drugs participating in the Amsterdam Cohort Studies, 1985-2015

BACKGROUND

HIV-positive people who use drugs (PWUD) start antiretroviral therapy (ART) later than other risk groups, and among HCV-positive PWUD, HCV treatment uptake is low. Nowadays, HCV direct-acting antivirals (DAAs) are available and reimbursed in the Netherlands (since 2014). The Amsterdam Cohort Studies (ACS), initiated in 1985, provides us the opportunity to describe temporal trends in ART and HCV-treatment uptake among PWUD through 2015.

METHODS

We analyzed data from PWUD participating in the ACS between 1985 and 2015. ART and HCV-treatment data were obtained from ACS questionnaires and medical records. Treatment uptake was defined by: treatment initiation (the proportion initiating any kind of ART/HCV treatment when treatment-naïve) and coverage (the proportion ever treated for HIV/HCV) among all HIV-/HCV-RNA-positive PWUD. Each was calculated per calendar year. We estimated the cumulative probability of ART uptake in the pre-cART (<1996) and cART era (January 1, 1996) among HIV seroconverters, with all-cause mortality as a competing risk.

RESULTS

Of 1305 PWUD, 263 (20.2%) were HIV-antibody positive and 810 (62.1%) were HCV-antibody positive, at study entry. ART coverage increased over time, from 5.7% in 1990 and 42.2% in 1996 to 91.7% in 2015. The proportion initiating ART ranged from 4.8% in 1990 to 33.3% in 2011. At 8 years after HIV seroconversion, cumulative probability of ART uptake was 42.5% in the pre-cART era and 61.5% in the cART era. HCV treatment initiation peaked in 2006 (9.7%). HCV-treatment coverage was 43.9% in 2015 but lower among HIV-coinfected (23.5%) than HCV-monoinfected PWUD (52.5%). In 2015, 3.0% initiated HCV treatment with DAAs.

CONCLUSION

We observed an increase in ART and HCV-treatment coverage among PWUD over time. As expected, ART uptake was higher in the cART era than the pre-cART era. Although in 2015 HCV treatment coverage was relatively high, DAA uptake was still low.

Temporal trends in mortality among people who use drugs compared with the general Dutch population differ by hepatitis C virus and HIV infection status

OBJECTIVES

We aimed to identify temporal trends in all-cause and cause-specific mortality rates among people who use drugs (PWUD) compared with the general Dutch population and to determine whether mortality trends differed by hepatitis C virus (HCV)/HIV (co) infection status.

DESIGN

Longitudinal cohort study.

METHODS

Using data from the Amsterdam Cohort Studies among 1254 PWUD (1985-2012), all-cause and cause-specific standardized mortality ratios (SMRs) were calculated; SMRs were stratified by serological group (HCV/HIV-uninfected, HCV-monoinfected, and HCV/HIV-coinfected) and calendar period. Temporal trends were estimated using Poisson regression.

RESULTS

The overall all-cause SMR was 13.9 (95% confidence interval 12.6-15.3). The SMR significantly declined after 1996, especially due to a decline among women (P < 0.001). The highest SMR was observed among HCV/HIV-coinfected individuals during 1990-1996 (SMR 61.9, 95% confidence interval 50.4-76.0), which significantly declined after this period among women (P = 0.001). In contrast, SMR for HCV-monoinfected, and HCV/HIV-uninfected PWUD did not significantly change over time. The SMR for non-natural deaths significantly declined (P = 0.007), whereas the SMR for HIV-related deaths was the highest during all calendar periods.

CONCLUSIONS

We found evidence for declining all-cause mortality among PWUD compared with the general population rates. Those with HCV/HIV-coinfection showed the highest SMR. The decline in the SMR seems to be attributable to the decline in mortality among women. Mortality rates due to non-natural deaths came closer to those of the general population over time. However, HIV-related deaths remain an important cause of mortality among PWUD when compared with the general Dutch population. This study reinforces the importance of harm-reduction interventions and HCV/HIV treatment to reduce mortality among PWUD.

Effects of HIV antiretroviral therapy on sexual and injecting risk-taking behavior: a systematic review and meta-analysis

BACKGROUND

Increased global access and use of antiretroviral therapy (ART) for human immunodeficiency virus (HIV) has been postulated to undermine HIV prevention efforts by changing individual risk-taking behavior. This review aims to determine whether ART use is associated with changes in sexual or injecting risk-taking behavior or diagnosis of sexually transmitted infections (STIs).

METHODS

A systematic review and meta-analysis was conducted of HIV-seropositive participants receiving ART compared with no ART use in experimental or observational studies. Primary outcomes included (1) any unprotected sexual intercourse, (2) STI diagnoses, and (3) any unsafe injecting behavior.

RESULTS

Fifty-eight studies met the selection criteria. Fifty-six studies containing 32 857 participants reported unprotected sex; 11 studies containing 16 138 participants reported STI diagnoses; and 4 studies containing 1600 participants reported unsafe injecting behavior. All included studies were observational. Unprotected sex was lower in participants receiving ART than in those not receiving ART (odds ratio [OR], 0.73; 95% confidence interval [CI], .64-.83; P < .001; heterogeneity I(2) = 79%) in both high-income (n = 38) and low-/middle-income country (n = 18) settings, without any evidence of publication bias. STI diagnoses were also lower among individuals on ART (OR, 0.58; 95% CI, .33-1.01; P = .053; I(2) = 92%); however, there was no difference in injecting risk-taking behavior with antiretroviral use (OR, 0.90; 95% CI, .60-1.35; P = .6; I(2) = 0%).

CONCLUSIONS

Despite concerns that use of ART might increase sexual or injecting risk-taking, available research suggests that unprotected sex is reduced among HIV-infected individuals on treatment. The reasons for this are not yet clear, although self-selection and mutually reinforcing effects of HIV treatment and prevention messages among people on ART are likely.

Treatment as prevention among injecting drug users; extrapolating from the Amsterdam cohort study

OBJECTIVE

To determine the potential of treatment as prevention for reducing HIV incidence among injecting drug users (IDU).

METHODS

Transmission dynamics of HIV as influenced by cART uptake and demographic changes were studied using an individual-based model. Parameters were based on data of the Amsterdam Cohort Study, and counterfactual treatment scenarios were examined for this city. Demography of the modeled population was also varied to allow for more general conclusions.

RESULTS

We estimated that over the complete HIV epidemic among IDU in Amsterdam the historic use of cART has led to only 2% less incidence. As individuals were treated from low CD4 cell counts, their decreased infectiousness was offset by increased infectious lifetime. Large reduction in incidence could result from a test and immediate treat strategy, with elimination of HIV occurring when the average time from infection to starting treatment was less than 2 months. However, substantial proportions of new infections were prevented only if the test and treat intervention was implemented within the first few years after HIV-epidemic onset, especially for a declining IDU population. Ignoring heterogeneity in risk-behavior led to overly optimistic expectations of the prevention effects of treatment. In general, treatment led to much greater reduction in incidence compared with stopping HIV-infected IDU from lending out syringes.

CONCLUSION

A test and immediate treat strategy for HIV among IDU could lead to great reductions in incidence. To fully eliminate the spread of HIV, treatment as prevention should be combined with other interventions, with behavioral intervention directed at those not yet HIV infected.

Association between knowledge of HIV-positive status or use of antiretroviral therapy and high-risk transmission behaviors: systematic review

To systematically review the evidence on the association between knowledge of HIV-positive status or use of antiretroviral therapy (ART) and high-risk transmission behaviors, we searched Ovid MEDLINE from 2004 to February 2012 and the Cochrane Library Database through the first quarter of 2012. Four observational studies meeting inclusion criteria addressed HIV-positive status and seven addressed the use of ART and effects on behavior. Studies including both average and high-risk populations were conducted in developed countries and were rated at least fair quality. Overall, knowledge of HIV-positive status was associated with less engagement in high-risk transmission behaviors, and the use of ART was not found to increase participation in high-risk transmission behaviors by HIV-positive individuals.

Changing risk behaviours and the HIV epidemic: a mathematical analysis in the context of treatment as prevention

Background

Expanding access to highly active antiretroviral therapy (HAART) has become an important approach to HIV prevention in recent years. Previous studies suggest that concomitant changes in risk behaviours may either help or hinder programs that use a Treatment as Prevention strategy.

Analysis

We consider HIV-related risk behaviour as a social contagion in a deterministic compartmental model, which treats risk behaviour and HIV infection as linked processes, where acquiring risk behaviour is a prerequisite for contracting HIV. The equilibrium behaviour of the model is analysed to determine epidemic outcomes under conditions of expanding HAART coverage along with risk behaviours that change with HAART coverage. We determined the potential impact of changes in risk behaviour on the outcomes of Treatment as Prevention strategies. Model results show that HIV incidence and prevalence decline only above threshold levels of HAART coverage, which depends strongly on risk behaviour parameter values. Expanding HAART coverage with simultaneous reduction in risk behaviour act synergistically to accelerate the drop in HIV incidence and prevalence. Above the thresholds, additional HAART coverage is always sufficient to reverse the impact of HAART optimism on incidence and prevalence. Applying the model to an HIV epidemic in Vancouver, Canada, showed no evidence of HAART optimism in that setting.

Conclusions

Our results suggest that Treatment as Prevention has significant potential for controlling the HIV epidemic once HAART coverage reaches a threshold. Furthermore, expanding HAART coverage combined with interventions targeting risk behaviours amplify the preventive impact, potentially driving the HIV epidemic to elimination.

Drug users in Amsterdam: are they still at risk for HIV?

Background and Aims

To examine whether drug users (DU) in the Amsterdam Cohort Study (ACS) are still at risk for HIV, we studied trends in HIV incidence and injecting and sexual risk behaviour from 1986 to 2011.

Methods

The ACS is an open, prospective cohort study on HIV. Calendar time trends in HIV incidence were modelled using Poisson regression. Trends in risk behaviour were modelled via generalized estimating equations. In 2010, a screening for STI (chlamydia, gonorrhoea and syphilis) was performed. Determinants of unprotected sex were studied using logistic regression analysis.

Results

The HIV incidence among 1298 participants of the ACS with a total follow-up of 12,921 person-years (PY) declined from 6.0/100 PY (95% confidence interval [CI] 3.2–11.1) in 1986 to less than 1/100 PY from 1997 onwards. Both injection and sexual risk behaviour declined significantly over time. Out of 197 participants screened for STI in 2010–2011, median age 49 years (IQR 43–59), only 5 (2.5%) were diagnosed with an STI. In multivariable analysis, having a steady partner (aOR 4.1, 95% CI 1.6–10.5) was associated with unprotected sex. HIV-infected participants were less likely to report unprotected sex (aOR 0.07, 95% CI 0.02–0.37).

Conclusions

HIV incidence and injection risk behaviour declined from 1986 onwards. STI prevalence is low; unprotected sex is associated with steady partners and is less common among HIV-infected participants. These findings indicate a low transmission risk of HIV and STI, which suggests that DU do not play a significant role in the current spread of HIV in Amsterdam.

Transmission of risk-group specific HIV-1 strains among Dutch drug users for more than 20 years and their replacement by nonspecific strains after switching to low-harm drug practices

OBJECTIVES

To characterize HIV-1 epidemiological networks of men having sex with men (MSM) and drug users (DUs) in the Netherlands for >30 years.

DESIGN AND METHODS

Previously, we demonstrated different origin of the HIV-1 epidemics in Dutch MSM and DUs. To achieve the study objectives, risk group-specific genetic markers in the pol gene were examined in 315 participants of the Amsterdam Cohort Studies on HIV/AIDS who were registered as HIV-1 infected in 1981-2011.

RESULTS

Phylogenetic analysis demonstrated circulation of distinct virus strains in the 2 networks, with 98% of viruses of MSM clustering together and apart from strains of 73% DUs. Nine genetic markers that significantly distinguished virus strains specific for DUs were identified, of which 3 were ≥90% conserved. Over the total observation period, only 6% of viruses (4 of MSM and 14 of DUs) clustered with those of the other risk group. Among these sequences, the 3 most conserved genetic markers of that other risk group were 87% conserved.All 4 cases of DU-specific viruses among MSM occurred in 1980s-early 1990s. Viruses nonspecific for DUs were causing new infections among DUs at the rate of 20% till 2002 and replaced DU-specific strains among new infections thereafter, coinciding with switching of DUs to low-harm drug practices.

CONCLUSIONS

Dutch MSM and DUs have remained separate epidemiological networks for decades, despite their geographical and behavioral overlap. Switching to low-harm drug practices among DUs resulted in new infections caused by HIV-1 strains originating from other risk groups.

Changes in sexual and drug-related risk behavior following antiretroviral therapy initiation among HIV-infected injection drug users

OBJECTIVE

To evaluate whether HAART is associated with subsequent sexual and drug-related risk behavior compensation among injection drug users (IDUs).

DESIGN

A community-based cohort study of 362 HIV-infected IDUs initiating HAART in Baltimore, Maryland.

METHODS

HAART use and risk behavior was assessed at 8316 biannual study visits (median 23). Using logistic regression with generalized estimating equations (GEE), we examined the effect of HAART initiation on changes in risk behavior while adjusting for sociodemographics, alcohol use, CD4 cell count, year of initiation and consistency of HAART use.

RESULTS

At HAART initiation, participants were a median of 44.4 years old, 71.3% men and 95.3% African-American. In multivariable analysis, HAART initiation was associated with a 75% reduction in the likelihood of unprotected sex [adjusted odds ratio (aOR) 0.25; 95% confidence interval (CI), 0.19-0.32] despite no change in overall sexual activity (aOR 0.95; 0.80-1.12). Odds of any injecting decreased by 38% (aOR 0.62; 0.51-0.75) after HAART initiation. Among the subset of persistent injectors, needle-sharing increased nearly two-fold (aOR 1.99; 1.57-2.52). Behavioral changes were sustained for more than 5 years after HAART initiation and did not differ by consistency of HAART use. Reporting specific high-risk behaviors in the year prior to initiation was a robust predictor of engaging in those behaviors subsequent to HAART.

CONCLUSION

Overall, substantial declines in sexual risk-taking and active injecting argue against significant behavioral compensation among IDUs following HAART initiation. These data also provide evidence to support identifying persons with risky pre-HAART behavior for targeted behavioral intervention.

Competing risks and the clinical community: irrelevance or ignorance?

Life expectancy has dramatically increased in industrialized nations over the last 200 hundred years. The aging of populations carries over to clinical research and leads to an increasing representation of elderly and multimorbid individuals in study populations. Clinical research in these populations is complicated by the fact that individuals are likely to experience several potential disease endpoints that prevent some disease-specific endpoint of interest from occurrence. Large developments in competing risks methodology have been achieved over the last decades, but we assume that recognition of competing risks in the clinical community is still marginal. It is the aim of this article to address translational aspects of competing risks to the clinical community. We describe clinical populations where competing risks issues may arise. We then discuss the importance of agreement between the competing risks methodology and the study aim, in particular the distinction between etiologic and prognostic research questions. In a review of 50 clinical studies performed in individuals susceptible to competing risks published in high-impact clinical journals, we found competing risks issues in 70% of all articles. Better recognition of issues related to competing risks and of statistical methods that deal with competing risks in accordance with the aim of the study is needed. Copyright © 2011 John Wiley & Sons, Ltd.

Hepatitis C testing and treatment among active drug users in Amsterdam: results from the DUTCH-C project

BACKGROUND

Although hepatitis C virus (HCV) treatment has shown to be effective, uptake of treatment among active drug users is still low. The Drug Users Treatment for Chronic Hepatitis-C project aims to offer active drug users in Amsterdam HCV testing and treatment using a multidisciplinary approach.

METHODS

The study population comprises drug users participating in the Amsterdam Cohort Studies and drug users referred to the Drug Users Treatment for Chronic Hepatitis-C unit. Drug users were offered HCV testing and, if chronically infected, medical and psychiatric screening and HCV treatment. Various specialists collaborated to provide optimal care. We assessed test-uptake and treatment-uptake and outcomes.

RESULTS

Four hundred and ninety-seven Amsterdam Cohort Studies drug users were offered HCV testing: 449 out of 497 (90%) accepted. HCV antibodies were found in 267 out of 449 (60%): 183 out of 267 (69%) were HCV-viremic and 49 out of 183 (27%) were HIV-co-infected. Of the 134 HCV-monoinfected patients, 102 (76%) initiated additional medical screening and 44 started treatment by 1 July 2009. Sixty-two drug users referred from methadone clinics were also HCV-monoinfected, of whom 14 started treatment by 1 July 2009. In total 58 persons were treated: 16 (27%) with genotype 1 or 4, 42 (72%) with genotype 2 or 3. Eighty-four percent used methadone, 97% used drugs (heroin, cocaine or amphetamine) at least once in the 6 months before treatment, 19% were active injectors. Sixty-two percent used alcohol, 41% had psychiatric disease other than substance abuse. Of the 57 individuals with sufficient follow-up, 37 (65%) achieved sustained virological response.

CONCLUSION

In a multidisciplinary setting, HIV-negative drug users with chronic HCV infection can be treated successfully despite active drug or alcohol use and psychiatric diseases. Therefore, access to HCV therapy using an integrated approach should be increased for this population.

Treatment and care for injecting drug users with HIV infection: a review of barriers and ways forward

We review evidence for effectiveness, cost-effectiveness, and coverage of antiretroviral therapy (ART) for injecting drug users (IDUs) infected with HIV, with particular attention to low-income and middle-income countries. In these countries, nearly half (47%) of all IDUs infected with HIV are in five nations--China, Vietnam, Russia, Ukraine, and Malaysia. In all five countries, IDU access to ART is disproportionately low, and systemic and structural obstacles restrict treatment access. IDUs are 67% of cumulative HIV cases in these countries, but only 25% of those receiving ART. Integration of ART with opioid substitution and tuberculosis treatment, increased peer engagement in treatment delivery, and reform of harmful policies--including police use of drug-user registries, detention of drug users in centres offering no evidence-based treatment, and imprisonment for possession of drugs for personal use--are needed to improve ART coverage of IDUs.

Attitudes toward needle-sharing and HIV transmission risk behavior among HIV+ injection drug users in clinical care

Risky behavior related to injection drug use accounts for a considerable proportion of incident HIV infection in the United States. Large numbers of injection drug users (IDUs) currently receive antiretroviral therapy in clinical settings and are accessible for risk-reduction interventions to reduce transmission of drug-resistant HIV and spread of HIV to uninfected others. The current study examined attitudes toward needle- or equipment-sharing among 123 HIV-positive IDUs in clinical care in an effort to understand the dynamics of such behavior and to create a basis for clinic-based risk-reduction interventions. Results indicate that at baseline, participants who reported extremely negative attitudes toward needle-sharing were less likely to have shared during the past month than those with less-extreme negative attitudes. Demographic, behavioral, and attitudinal variables were entered into a logistic regression model to examine needle-sharing group membership among HIV-positive IDUs. Being female and having less-extreme negative attitudes toward sharing were independent and significant correlates of sharing behavior. Interventions targeting needle-sharing attitudes deployed within the clinical care setting may be well-positioned to reduce HIV transmission among HIV-positive IDUs.

Risk of hepatitis-related mortality increased among hepatitis C virus/HIV-coinfected drug users compared with drug users infected only with hepatitis C virus: a 20-year prospective study

BACKGROUND

Progression of liver-related disease is accelerated in individuals coinfected with HIV and hepatitis C virus (HCV). Because the life expectancy of HIV-infected drug users (DUs) improved after the widespread use of highly active antiretroviral therapy (HAART), HCV-related death is likely to become more important. To disentangle the effects of HCV and HIV, we compared the overall and cause-specific mortality between HCV/HIV-infected DUs and HCV-infected DUs and DUs without HCV or HIV, followed up between 1985 and 2006.

METHODS

A total of 1295 participants in the Amsterdam Cohort Study were included. Cause-specific hazard ratios (CHRs) were estimated for the eras before (<1997) and since HAART (> or =1997) within and among serologic groups.

RESULTS

The risk of dying decreased for most causes of death > or =1997; this decrease was not the same for the different serologic groups. Among HCV/HIV-coinfected DUs, the risk of hepatitis/liver-related death did not substantially change over time (CHR = 0.87, 95% confidence interval [CI]: 0.21 to 3.58), whereas the risk of AIDS-related mortality decreased. Compared with DUs solely infected with HCV, HCV/HIV-coinfected DUs were at increased risk of dying from hepatitis/liver-related disease (CHR = 7.15, 95% CI: 1.98 to 25.8), other natural causes (CHR = 3.09, 95% CI: 1.41 to 6.79), and nonnatural causes (CHR = 2.30, 95% CI: 1.07 to 4.95) in the HAART era.

CONCLUSIONS

HCV/HIV-coinfected DUs remain at increased risk of dying from hepatitis/liver-related death in the HAART era compared with HCV-monoinfected DUs. This risk did not change in HCV/HIV-coinfected DUs after HAART was introduced, suggesting that in the HAART era, HIV continues to accelerate HCV disease progression. Efforts should be made to establish effective treatment for HCV infection in HCV/HIV-coinfected individuals.

Decline in HIV incidence and injecting, but not in sexual risk behaviour, seen in drug users in Amsterdam: a 19-year prospective cohort study

OBJECTIVE

To study temporal changes in HIV incidence, HIV transmission routes, and both injecting and sexual risk behaviour in the open Amsterdam Cohort Study (ACS) among drug users. Initiated in 1985, the ACS enables us to study changes in trends since HAART became widespread in 1996.

METHODS

Person-time techniques were used to study the trend in HIV incidence among HIV-negative drug users. HIV transmission routes were determined using detailed standardised questionnaires. Trends in injecting and sexual risk behaviours were evaluated with a logistic regression model adjusted for correlations between visits of the same individual.

RESULTS

The 1315 HIV-negative individuals, of whom 93 seroconverted for HIV, yielded 6970 HIV-negative person-years of follow-up. The HIV incidence was seven per 100 person-years in 1986 and varied between 0 and 0.5 per 100 person-years after 1999. The odds ratio was 15.6 (95% confidence interval, 2.6-94.6) for HIV transmission through unprotected heterosexual contact versus injecting after 1996 compared with the period before. Reports of both injecting and borrowing needles significantly declined over the period 1985-2004. Reports of sexual risk behaviour and sexually transmitted infections at follow-up visits decreased before 1996, but not after 1996.

CONCLUSION

The HIV incidence among drug users in the ACS has declined since 1985. Accompanied by a reduction in injecting drug use and needle sharing, this decline occurred despite continued sexual risk behaviour. At present, new HIV seroconversions are related mainly to unprotected heterosexual contacts. Therefore, HIV prevention programmes for drug users should pay specific attention to the importance of safe sex practices.