Epidemiologic links between drug use and HIV epidemics: an international perspective

Suppression of HIV-TAT and cocaine-induced neurotoxicity and inflammation by cell penetrable itaconate esters

HIV-associated neurological disorder (HAND) is a serious complication of HIV infection marked by neurotoxicity induced by viral proteins like Tat. Substance abuse exacerbates neurocognitive impairment in people living with HIV. There is an urgent need for therapeutic strategies to combat HAND comorbid with Cocaine Use Disorder (CUD). Our analysis of HIV and cocaine-induced transcriptomes in primary cortical cultures revealed significant overexpression of the macrophage-specific gene aconitate decarboxylase 1 (Acod1). The ACOD1 protein converts the tricarboxylic acid intermediate cis-aconitate into itaconate during the activation of inflammation. Itaconate then facilitates cytokine production and activates anti-inflammatory transcription factors, shielding macrophages from infection-induced cell death. However, the immunometabolic function of itaconate was unexplored in HIV and cocaine-exposed microglia. We assessed the potential of 4-octyl-itaconate (4OI), a cell-penetrable ester form of itaconate known for its anti-inflammatory properties. When primary cortical cultures exposed to Tat and cocaine were treated with 4OI, microglial cell number increased and the morphological altercations induced by Tat and cocaine were reversed. Microglial cells also appeared more ramified, resembling the quiescent microglia. 4OI treatment inhibited secretion of the proinflammatory cytokines IL-1α, IL-1β, IL-6, and MIP1-α induced by Tat and cocaine. Transcriptome profiling determined that Nrf2 target genes were significantly activated in Tat and 4OI treated cultures relative to Tat alone. Further, genes associated with cytoskeleton dynamics in inflammatory microglia were downregulated by 4OI treatment. Together, the results strongly suggest 4-octyl-itaconate holds promise as a potential candidate for therapeutic development to treat HAND coupled with CUD comorbidities.

Suppression of HIV and cocaine-induced neurotoxicity and inflammation by cell penetrable itaconate esters

HIV-associated neurological disorder (HAND) is a serious complication of HIV infection, marked by neurotoxicity induced by viral proteins like Tat. Substance abuse exacerbates neurocognitive impairment in people living with HIV. There is an urgent need for effective therapeutic strategies to combat HAND comorbid with Cocaine Use Disorder (CUD). Our analysis of the HIV and cocaine-induced transcriptomes in primary cortical cultures revealed a significant overexpression of the macrophage-specific gene, aconitate decarboxylase 1 (Acod1), caused by the combined insults of HIV and cocaine. ACOD1 protein converts the tricarboxylic acid intermediate cis-aconitate into itaconate during the activation of inflammation. The itaconate produced facilitates cytokine production and subsequently activates anti-inflammatory transcription factors, shielding macrophages from infection-induced cell death. While the role of itaconate' in limiting inflammation has been studied in peripheral macrophages, its immunometabolic function remains unexplored in HIV and cocaine-exposed microglia. We assessed in this model system the potential of 4-octyl-itaconate (4OI), a cell-penetrable esterified form of itaconate known for its potent anti-inflammatory properties and potential therapeutic applications. We administered 4OI to primary cortical cultures exposed to Tat and cocaine. 4OI treatment increased the number of microglial cells in both untreated and Tat±Cocaine-treated cultures and also reversed the morphological altercations induced by Tat and cocaine. In the presence of 4OI, microglial cells also appeared more ramified, resembling the quiescent microglia. Consistent with these results, 4OI treatment inhibited the secretion of the proinflammatory cytokines IL-1α, IL-1β, IL-6, and MIP1-α induced by Tat and cocaine. Transcriptome profiling further determined that Nrf2 target genes such as NAD(P)H quinone oxidoreductase 1 (Nqo1), Glutathione S-transferase Pi (Gstp1), and glutamate cysteine ligase catalytic (Gclc), were most significantly activated in Tat-4OI treated cultures, relative to Tat alone. Further, genes associated with cytoskeleton dynamics in inflammatory microglia were downregulated by 4OI treatment. Together, the results strongly suggest 4-octyl-itaconate holds promise as a potential candidate for therapeutic development aimed at addressing HAND coupled with CUD comorbidities.

HIV Education, Empathy, and Empowerment (HIVE3): A Peer Support Intervention for Reducing Intersectional Stigma as a Barrier to HIV Testing among Men Who Have Sex with Men in Ghana

Men who have sex with men (MSM) in Ghana remain at heightened risk of HIV infection, and face challenges in accessing HIV prevention and care services. Previous research in Ghana shows that MSM face intersectional stigma across ecological levels (family, peers, healthcare settings, and community level) and the criminalization of same-gender sexual behaviors in the country. To protect their wellbeing from exposure to stigma, many MSM avoid interactions with healthcare systems and services, which inadvertently inhibits their opportunities for early detection and treatment of HIV. Consequently, MSM in Ghana carry a disproportionate burden of HIV prevalence (18%) compared to the general population (2%), highlighting the need for culturally relevant processes in HIV/STI prevention, and care communication to optimize sexual health and wellness among MSM in Ghana. To this effect, we collaborated with community partners to use the Assessment, Decision, Adaptation, Production, Topical Experts, Training, Testing (ADAPT-ITT) model to modify a theory-driven smartphone-based peer support intervention to enhance its focus on intersectional stigma reduction, and improve HIV health-seeking behaviors among MSM, including HIV testing and linkage to care. We used the Dennis Peer Support Model to develop the peer support components (emotional, informational, and appraisal support) to increase peer social support, decrease social isolation, and minimize intersectional stigma effects on HIV-related healthcare-seeking behaviors. This paper shows the preliminary acceptability and effectiveness of employing culturally relevant techniques and communication strategies to provide secure peer support to improve HIV prevention and care among key populations in highly stigmatized environments.

Hepatitis C Virus Infection in Persons Who Inject Drugs in the Middle East and North Africa: Intervention Strategies

There is a high incidence and prevalence of hepatitis C viral infection in persons with or without substance use disorders (SUDs) in the Middle East and North Africa (MENA) region, but only a small number receive comprehensive care. Highly effective direct-acting antiviral (DAA) medications are available at substantially lower costs; however, complete elimination of the hepatitis C virus (HCV) can only be achieved if integrated care strategies target those at highest risk for HCV infection and transmission and improve access to care. Due to the high prevalence of SUD in the MENA region, strategies to eliminate HCV must focus on integrated healthcare across multiple subspecialties, including addiction medicine, psychiatry, infectious diseases, hepatology, and social work. In this invited manuscript, we review the epidemiology of HCV in the MENA region and highlight intervention strategies to attain the WHO's goal of HCV eradication by 2030.

Epidemiological features of HIV/AIDS in the Middle East and North Africa from 1990 to 2017

The growing trend of HIV/AIDS is a major concern in the Middle East and North Africa (MENA) regions, as its incidence in the region has increased by 31% in the last decade. The study population in the countries of the MENA region included 21 countries with a population of approximately 400 million. The Global Burden of Disease database was used to calculate the number of HIV/AIDS cases. Modeling for each country is based on the availability and quality of data. The highest incidence rates of HIV/AIDS were in Sudan, United Arab Emirates (UAE), Tunisia, and Iran, respectively, and the highest mortality rates were in Sudan, UAE, Oman, and Morocco, respectively. The incidence, prevalence and mortality rates, as well as the disability adjusted life years (DALYs) rate declined in 2017 compared to 1990. The highest percentage of changes in DALY rates was reported for Turkey, the United Arab Emirates (UAE), and Sudan, respectively, and the lowest for Qatar, Kuwait, and Bahrain. In general, unsafe sex had the highest impact on the DALY index in all countries in the region except Iran and Bahrain. Policymakers should therefore be encouraged to develop harm reduction programs for people living with HIV, and invest globally in reducing HIV prevalence rates in commercial sex workers, people who inject drugs, and men who have sex with men in the region, as well as eliminating mother-to-child HIV transmission.

Violence and hepatitis C transmission in prison-A modified social ecological model

BACKGROUND

Transmission of hepatitis C virus (HCV) among the prisoner population is most frequently associated with sharing of non-sterile injecting equipment. Other blood-to-blood contacts such as tattooing and physical violence are also common in the prison environment, and have been associated with HCV transmission. The context of such non-injecting risk behaviours, particularly violence, is poorly studied. The modified social-ecological model (MSEM) was used to examine HCV transmission risk and violence in the prison setting considering individual, network, community and policy factors.

METHODS

The Australian Hepatitis C Incidence and Transmission Study in prisons (HITS-p) cohort enrolled HCV uninfected prisoners with injecting and non-injecting risk behaviours, who were followed up for HCV infection from 2004-2014. Qualitative interviews were conducted within 23 participants; of whom 13 had become HCV infected. Deductive analysis was undertaken to identify violence as risk within prisons among individual, network, community, and public policy levels.

RESULTS

The risk context for violence and HCV exposure varied across the MSEM. At the individual level, participants were concerned about blood contact during fights, given limited scope to use gloves to prevent blood contamination. At the network level, drug debt and informing on others to correctional authorities, were risk factors for violence and potential HCV transmission. At the community level, racial influence, social groupings, and socially maligned crimes like sexual assault of children were identified as possible triggers for violence. At the policy level, rules and regulations by prison authority influenced the concerns and occurrence of violence and potential HCV transmission.

CONCLUSION

Contextual concerns regarding violence and HCV transmission were evident at each level of the MSEM. Further evidence-based interventions targeted across the MSEM may reduce prison violence, provide opportunities for HCV prevention when violence occurs and subsequent HCV exposure.

Inhibition of the Dead Box RNA Helicase 3 Prevents HIV-1 Tat and Cocaine-Induced Neurotoxicity by Targeting Microglia Activation

HIV-1 Associated Neurocognitive Disorder (HAND) is a common and clinically detrimental complication of HIV infection. Viral proteins, including Tat, released from infected cells, cause neuronal toxicity. Substance abuse in HIV-infected patients greatly influences the severity of neuronal damage. To repurpose small molecule inhibitors for anti-HAND therapy, we employed MOLIERE, an AI-based literature mining system that we developed. All human genes were analyzed and prioritized by MOLIERE to find previously unknown targets connected to HAND. From the identified high priority genes, we narrowed the list to those with known small molecule ligands developed for other applications and lacking systemic toxicity in animal models. To validate the AI-based process, the selective small molecule inhibitor of DDX3 helicase activity, RK-33, was chosen and tested for neuroprotective activity. The compound, previously developed for cancer treatment, was tested for the prevention of combined neurotoxicity of HIV Tat and cocaine. Rodent cortical cultures were treated with 6 or 60 ng/ml of HIV Tat and 10 or 25 μM of cocaine, which caused substantial toxicity. RK-33 at doses as low as 1 μM greatly reduced the neurotoxicity of Tat and cocaine. Transcriptome analysis showed that most Tat-activated transcripts are microglia-specific genes and that RK-33 blocks their activation. Treatment with RK-33 inhibits the Tat and cocaine-dependent increase in the number and size of microglia and the proinflammatory cytokines IL-6, TNF-α, MCP-1/CCL2, MIP-2, IL-1α and IL-1β. These findings reveal that inhibition of DDX3 may have the potential to treat not only HAND but other neurodegenerative diseases. Graphical Abstract RK-33, selective inhibitor of Dead Box RNA helicase 3 (DDX3) protects neurons from combined Tat and cocaine neurotoxicity by inhibition of microglia activation and production of proinflammatory cytokines.

Large-Scale Validation of Hypothesis Generation Systems via Candidate Ranking

The first step of many research projects is to define and rank a short list of candidates for study. In the modern rapidity of scientific progress, some turn to automated hypothesis generation (HG) systems to aid this process. These systems can identify implicit or overlooked connections within a large scientific corpus, and while their importance grows alongside the pace of science, they lack thorough validation. Without any standard numerical evaluation method, many validate general-purpose HG systems by rediscovering a handful of historical findings, and some wishing to be more thorough may run laboratory experiments based on automatic suggestions. These methods are expensive, time consuming, and cannot scale. Thus, we present a numerical evaluation framework for the purpose of validating HG systems that leverages thousands of validation hypotheses. This method evaluates a HG system by its ability to rank hypotheses by plausibility; a process reminiscent of human candidate selection. Because HG systems do not produce a ranking criteria, specifically those that produce topic models, we additionally present novel metrics to quantify the plausibility of hypotheses given topic model system output. Finally, we demonstrate that our proposed validation method aligns with real-world research goals by deploying our method within MOLIERE, our recent topic-driven HG system, in order to automatically generate a set of candidate genes related to HIV-associated neurodegenerative disease (HAND). By performing laboratory experiments based on this candidate set, we discover a new connection between HAND and Dead Box RNA Helicase 3 (DDX3).

REPRODUCIBILITY

code, validation data, and results can be found at sybrandt.com/2018/validation.

The role of catecholamines in HIV neuropathogenesis

The success of anti-retroviral therapy has improved the quality of life and lifespan of HIV + individuals, transforming HIV infection into a chronic condition. These improvements have come with a cost, as chronic HIV infection and long-term therapy have resulted in the emergence of a number of new pathologies. This includes a variety of the neuropathological and neurocognitive effects collectively known as HIVassociated neurocognitive disorders (HAND) or NeuroHIV. These effects persist even in the absence of viral replication, suggesting that they are mediated the long-term changes in the CNS induced by HIV infection rather than by active replication. Among these effects are significant changes in catecholaminergic neurotransmission, especially in dopaminergic brain regions. In HIV-infected individuals not treated with ARV show prominent neuropathology is common in dopamine-rich brain regions and altered autonomic nervous system activity. Even infected individuals on therapy, there is significant dopaminergic neuropathology, and elevated stress and norepinephrine levels correlate with a decreased effectiveness of antiretroviral drugs. As catecholamines function as immunomodulatory factors, the resultant dysregulation of catecholaminergic tone could substantially alter the development of HIVassociated neuroinflammation and neuropathology. In this review, we discuss the role of catecholamines in the etiology of HIV neuropathogenesis. Providing a comprehensive examination of what is known about these molecules in the context of HIV-associated disease demonstrates the importance of further studies in this area, and may open the door to new therapeutic strategies that specifically ameliorate the effects of catecholaminergic dysregulation on NeuroHIV.

Association of age and time of disease with HIV-associated neurocognitive disorders: a Japanese nationwide multicenter study

There is no detailed information on the association between age, time of disease, and HIV-associated neurocognitive disorders (HAND). In this prospective study involving 17 medical facilities across Japan, we recruited HIV-infected patients to complete a 14-test neuropsychological battery that assess eight neurocognitive domains. HAND were diagnosed by the Frascati criteria. Of 1399 recruited patients, 728 were enrolled. The prevalence of HAND was 25.3% [13.5% asymptomatic neurocognitive impairment, 10.6% mild neurocognitive disorder (MND), and 1.2% HIV-associated dementia (HAD)]. Tests that assess executive and visuospatial functions showed better diagnostic accuracy than other tests for HAND. Multivariate analysis identified age (≥ 50 years) and incomplete virological suppression as risk factors for MND and HAD and current ART as a protective factor. The prevalence of MND and HAD was low in the early stage of infection (6.3% in ≥ 2 to < 6 years), then increased in the later stage [17.3% in ≥ 11 years, p = 0.001 (vs. ≥ 2 to < 6 years)], independent of age or treatment. Older patients were more likely to show MND or HAD in the early stage of HIV infection (26.7 vs. 8.7% for < 2 years and 17.4 vs. 3.1% for ≥ 2 to < 6 years, p = 0.040 and 0.004, respectively) compared to younger ones. In conclusion, MND and HAD were more commonly found in later years since diagnosis of HIV infection and older patients are at risk of neurocognitive impairment at the early stage of HIV infection. Tests for executive and visuospatial functions seem more sensitive than other tests for diagnosing HAND.

HIV, Tat and dopamine transmission

Human Immunodeficiency Virus (HIV) is a progressive infection that targets the immune system, affecting more than 37 million people around the world. While combinatorial antiretroviral therapy (cART) has lowered mortality rates and improved quality of life in infected individuals, the prevalence of HIV associated neurocognitive disorders is increasing and HIV associated cognitive decline remains prevalent. Recent research has suggested that HIV accessory proteins may be involved in this decline, and several studies have indicated that the HIV protein transactivator of transcription (Tat) can disrupt normal neuronal and glial function. Specifically, data indicate that Tat may directly impact dopaminergic neurotransmission, by modulating the function of the dopamine transporter and specifically damaging dopamine-rich regions of the CNS. HIV infection of the CNS has long been associated with dopaminergic dysfunction, but the mechanisms remain undefined. The specific effect(s) of Tat on dopaminergic neurotransmission may be, at least partially, a mechanism by which HIV infection directly or indirectly induces dopaminergic dysfunction. Therefore, precisely defining the specific effects of Tat on the dopaminergic system will help to elucidate the mechanisms by which HIV infection of the CNS induces neuropsychiatric, neurocognitive and neurological disorders that involve dopaminergic neurotransmission. Further, this will provide a discussion of the experiments needed to further these investigations, and may help to identify or develop new therapeutic approaches for the prevention or treatment of these disorders in HIV-infected individuals.

Seroprevalence of HCV and HIV infection among clients of the nation's longest-standing statewide syringe exchange program: A cross-sectional study of Community Health Outreach Work to Prevent AIDS (CHOW)

BACKGROUND

The Community Health Outreach Work to Prevent AIDS (CHOW) Project is the first and longest-standing statewide integrated and funded needle and syringe exchange program (SEP) in the US. Initiated on O'ahu in 1990, CHOW expanded statewide in 1993. The purpose of this study is to estimate the prevalences of hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infection, and to characterize risk behaviors associated with infection among clients of a long-standing SEP through the analysis of the 2012 CHOW evaluation data.

METHODS

A cross-sectional sample of 130 CHOW Project clients was selected from January 1, 2012 through December 31, 2012. Questionnaires captured self-reported exposure information. HIV and HCV antibodies were detected via rapid, point-of-care FDA-approved tests. Log-binomial regressions were used to estimate prevalence proportion ratios (PPRs). A piecewise linear log-binomial regression model containing 1 spline knot was used to fit the age-HCV relationship.

RESULTS

The estimated seroprevalence of HCV was 67.7% (95% confidence interval [CI]=59.5-75.8%). HIV seroprevalence was 2.3% (95% CI=0-4.9%). Anti-HCV prevalence demonstrated age-specific patterns, ranging from 31.6% through 90.9% in people who inject drugs (PWID) <30 to ≥60 years respectively. Age (continuous/year) prior to spline knot at 51.5 years (adjusted PPR [APPR]=1.03; 95% CI=1.02-1.05) and months exchanging syringes (quartiles) (APPR=1.92; 95% CI=1.3-3.29) were independently associated with anti-HCV prevalence.

CONCLUSION

In Hawai'i, HCV prevalence among PWID is hyperendemic demonstrating age- and SEP duration-specific trends. Relatively low HIV prevalence compared with HCV prevalence reflects differences in transmissibility of these 2 blood-borne pathogens and suggests much greater efficacy of SEP for HIV prevention.

Examining the Efficacy of HIV Risk-Reduction Counseling on the Sexual Risk Behaviors of a National Sample of Drug Abuse Treatment Clients: Analysis of Subgroups

HIV counseling with testing has been part of HIV prevention in the U.S. since the 1980s. Despite the long-standing history of HIV testing with prevention counseling, the CDC released HIV testing recommendations for health care settings contesting benefits of prevention counseling with testing in reducing sexual risk behaviors among HIV-negatives in 2006. Efficacy of brief HIV risk-reduction counseling (RRC) in decreasing sexual risk among subgroups of substance use treatment clients was examined using multi-site RCT data. Interaction tests between RRC and subgroups were performed; multivariable regression evaluated the relationship between RRC (with rapid testing) and sex risk. Subgroups were defined by demographics, risk type and level, attitudes/perceptions, and behavioral history. There was an effect (p < .0028) of counseling on number of sex partners among some subgroups. Certain subgroups may benefit from HIV RRC; this should be examined in studies with larger sample sizes, designed to assess the specific subgroup(s).

Effects of combination approach on harm reduction programs: the Taiwan experience

BACKGROUND

In 2003, a major epidemic of human immunodeficiency virus emerged among injection drug users in Taiwan. In response to the twin epidemics of HIV and intravenous drug addiction, the government implemented comprehensive harm reduction programs beginning in 2005. Collected data from relevant agencies were used to explore the impact of the harm reduction programs on HIV and illicit drug use.

METHODS

This study divided 2002-2015 into three intervention phases and used the surveillance data and statistics on the HIV epidemic, drug abuse, and the intervention from relevant agencies to explore the correlations between different variables in different intervention periods and the combination effects of interventions on the HIV epidemic.

RESULTS

In the pre-intervention phase, the growth of the HIV epidemic followed the rapidly increasing number of heroin users, reaching a peak in 2005. After the initiation of harm reduction programs, the HIV epidemic ceased growing, even rapidly declining with the expansion of needle and syringe exchange programs and opioid substitution therapy; however, the number of heroin users remained high. When the implementation of the needle and syringe exchange programs and the opioid substitution therapy program reached the plateau level in the consolidation phase, the number of heroin users also decreased rapidly. The combination effects of the harm reduction programs in this period also pushed levels of HIV infection below those before this outbreak.

CONCLUSIONS

The HIV epidemic among injection drug users incorporates the dual problems of drug addiction and needle-sharing behaviors, so the use of a single intervention will not resolve all of the problems. Facing a severe HIV epidemic among injection drug users, quickly scaling up and promoting comprehensive harm reduction programs is a good strategy that can be used to simultaneously reverse the HIV epidemic and to resolve the illicit drug use problems. More research is needed to find out the reasons behind why there were cases that declined opioid substitution therapy, so that efforts can be undertaken to avoid the epidemic rebounding.

Status of HIV and hepatitis C virus infections among prisoners in the Middle East and North Africa: review and synthesis

INTRODUCTION

The status of HIV and hepatitis C virus (HCV) infections among incarcerated populations in the Middle East and North Africa (MENA) and the links between prisons and the HIV epidemic are poorly understood. This review synthesized available HIV and HCV data in prisons in MENA and highlighted opportunities for action.

METHODS

The review was based on data generated through the systematic searches of the MENA HIV/AIDS Epidemiology Synthesis Project (2003 to December 15, 2015) and the MENA HCV Epidemiology Synthesis Project (2011 to December 15, 2015). Sources of data included peer-reviewed publications and country-level reports and databases.

RESULTS AND DISCUSSION

We estimated a population of 496,000 prisoners in MENA, with drug-related offences being a major cause for incarceration. Twenty countries had data on HIV among incarcerated populations with a median prevalence of 0.6% in Afghanistan, 6.1% in Djibouti, 0.01% in Egypt, 2.5% in Iran, 0% in Iraq, 0.1% in Jordan, 0.05% in Kuwait, 0.7% in Lebanon, 18.0% in Libya, 0.7% in Morocco, 0.3% in Oman, 1.1% in Pakistan, 0% in Palestine, 1.2% in Saudi Arabia, 0% in Somalia, 5.3% in Sudan and South Sudan, 0.04% in Syria, 0.05% in Tunisia, and 3.5% in Yemen. Seven countries had data on HCV, with a median prevalence of 1.7% in Afghanistan, 23.6% in Egypt, 28.1% in Lebanon, 15.6% in Pakistan, and 37.8% in Iran. Syria and Libya had only one HCV prevalence measure each at 1.5% and 23.7%, respectively. There was strong evidence for injecting drug use and the use of non-sterile injecting-equipment in prisons. Incarceration and injecting drugs, use of non-sterile injecting-equipment, and tattooing in prisons were found to be independent risk factors for HIV or HCV infections. High levels of sexual risk behaviour, tattooing and use of non-sterile razors among prisoners were documented.

CONCLUSIONS

Prisons play an important role in HIV and HCV dynamics in MENA and have facilitated the emergence of large HIV epidemics in at least two countries, Iran and Pakistan. There is evidence for substantial but variable HIV and HCV prevalence, as well as risk behaviour including injecting drug use and unprotected sex among prisoners across countries. These findings highlight the need for comprehensive harm-reduction strategies in prisons.

Hepatitis C and HIV incidence and harm reduction program use in a conflict setting: an observational cohort of injecting drug users in Kabul, Afghanistan

Background

Armed conflict may increase the risk of HIV and other pathogens among injecting drug users (IDUs); however, there are few prospective studies. This study aimed to measure incidence and potential predictors, including environmental events and needle and syringe distribution and collection program (NSP) use, of hepatitis C virus (HCV) and HIV among IDUs in Kabul, Afghanistan.

Methods

Consenting adult IDUs completed interviews quarterly in year 1 and semi-annually in year 2 and HCV and HIV antibody testing semi-annually through the cohort period (November 2007–December 2009). Interviews detailed injecting and sexual risk behaviors, NSP service use, and conflict-associated displacement. Quarters with peak conflict or local displacement were identified based on literature review, and key events, including insurgent attacks and deaths, were reported with simple counts. Incidence and predictors of HCV and HIV were measured with Cox proportional hazards models.

Results

Of 483 IDUs enrolled, 385 completed one or more follow-up visits (483.8 person-years (p-y)). All participants were male with a median age of 28 years and a median duration of injecting of 2 years. Reported NSP use among the participants ranged from 59.9 to 70.5 % in the first year and was 48.4 and 55.4 % at 18 and 24 months, respectively. There were 41 confirmed deaths, with a crude death rate of 93.4/1000 p-y (95 % confidence interval (CI) 67.9–125) and overdose as the most common cause. HCV and HIV incidence were 35.6/100 p-y (95 % CI 28.3–44.6) and 1.5/100 p-y (95 % CI 0.6–3.3), respectively. Changing from injecting to smoking was protective for HCV acquisition (adjusted hazard ratio (AHR) = 0.53, 95 % CI 0.31–0.92), while duration of injecting (AHR = 1.09, 95 % CI 1.01–1.18/year) and sharing syringes (AHR = 10.09, 95 % CI 1.01–100.3) independently predicted HIV infection.

Conclusion

There is high HCV incidence and high numbers of reported deaths among male Kabul IDUs despite relatively consistent levels of harm reduction program use; peak violence periods did not independently predict HCV and HIV risk. Programming should increase awareness of HCV transmission and overdose risks, prepare clients for harm reduction needs during conflict or other causes of displacement, and continue efforts to engage community and police force support.

Cross-sectional assessments of participants' characteristics and loss to follow-up in the first Opioid Substitution Therapy Pilot Program in Kabul, Afghanistan

Background

Kabul has over 12,000 people who inject drugs (PWID), most of them heroin users, and opioid substitution therapy has recently been introduced as an effective method to reduce opioid use. We aimed to evaluate a pilot Opioid Substitution Therapy Pilot Program (OSTPP) in Kabul, Afghanistan, particularly to (1) describe characteristics of the participants enrolled in the program and (2) identify factors associated with client retention in the OSTPP.

Findings

Two cross-sectional surveys evaluated participants attending the OSTPP at baseline (n = 83) and 18 months after (n = 57). Questionnaires assessed socio-demographic, drug use behavior, and general and mental health factors. After 18 months, 57 participants remained in the OSTPP. Participants lost to follow-up were younger (p < 0.01) and married (p < 0.01) and had no family contact (p < 0.01). Participants at 18 months reported no criminal activity in the last month and only two (3.5 %) reported heroin use in the last month, constituting significant decreases from baseline.

Conclusions

While preliminary results are promising, further evaluation is needed to determine the feasibility of implementing OSTPP in this setting and effectiveness in reducing injection risk behaviors in Afghanistan.

Migrant Workers in Kazakhstan: Gender Differences in HIV Knowledge and Sexual Risk Behaviors

This study compares sexual risk behaviors among male and female migrant market vendors in Almaty, Kazakhstan. From the Barakholka Market, 209 male and 213 female market vendors were randomly recruited. Self-reported data were collected through standardized face-to-face interviews. Dry blood spot was used as specimen for syphilis testing. Propensity score stratification was used to estimate adjusted prevalence or rate ratios by gender. Compared to male migrant workers, females had lower HIV knowledge and were less likely to have multiple sexual partners. There was no evidence of a gender difference for prevalence of syphilis, condom use with unsteady partners, and safe sex communication between couples. Associations between mobility patterns and engagement in multiple sexual partnerships were stronger among women than men. Efforts should be made to mitigate the gender differential in HIV knowledge among migrants, especially women. Such efforts need to be implemented in both home and host countries.

Chronic inflammation and the role for cofactors (hepatitis C, drug abuse, antiretroviral drug toxicity, aging) in HAND persistence

HIV-associated neurocognitive disorders (HAND) is a group of syndromes of varying degrees of cognitive impairment affecting up to 50 % of HIV-infected individuals. The neuropathogenesis of HAND is thought to be driven by HIV invasion and productive replication within brain perivascular macrophages and endogenous microglia, and to some degree by restricted infection of astrocytes. The persistence of HAND in individuals experiencing suppression of systemic HIV viral load with antiretroviral therapy (ART) is incompletely explained, and suggested factors include chronic inflammation, persistent HIV replication in brain macrophages, effects of aging on brain vulnerability, and co-morbid conditions including hepatitis C (HCV) co-infection, substance abuse, and CNS toxicity of ART, among other factors. This review discusses several of these conditions: chronic inflammation, co-infection with HCV, drugs of abuse, aging, and antiretroviral drug effects. Effectively managing these co-morbid conditions in individuals with and without HAND is critical for improving neurocognitive outcomes and decreasing HIV-associated morbidity.

Dopamine increases CD14+CD16+ monocyte migration and adhesion in the context of substance abuse and HIV neuropathogenesis

Drug abuse is a major comorbidity of HIV infection and cognitive disorders are often more severe in the drug abusing HIV infected population. CD14⁺CD16⁺ monocytes, a mature subpopulation of peripheral blood monocytes, are key mediators of HIV neuropathogenesis. Infected CD14⁺CD16⁺ monocyte transmigration across the blood brain barrier mediates HIV entry into the brain and establishes a viral reservoir within the CNS. Despite successful antiretroviral therapy, continued influx of CD14⁺CD16⁺ monocytes, both infected and uninfected, contributes to chronic neuroinflammation and the development of HIV associated neurocognitive disorders (HAND). Drug abuse increases extracellular dopamine in the CNS. Once in the brain, CD14⁺CD16⁺ monocytes can be exposed to extracellular dopamine due to drug abuse. The direct effects of dopamine on CD14⁺CD16⁺ monocytes and their contribution to HIV neuropathogenesis are not known. In this study, we showed that CD14⁺CD16⁺ monocytes express mRNA for all five dopamine receptors by qRT-PCR and D1R, D5R and D4R surface protein by flow cytometry. Dopamine and the D1-like dopamine receptor agonist, SKF38393, increased CD14⁺CD16⁺ monocyte migration that was characterized as chemokinesis. To determine whether dopamine affected cell motility and adhesion, live cell imaging was used to monitor the accumulation of CD14⁺CD16⁺ monocytes on the surface of a tissue culture dish. Dopamine increased the number and the rate at which CD14⁺CD16⁺ monocytes in suspension settled to the dish surface. In a spreading assay, dopamine increased the area of CD14⁺CD16⁺ monocytes during the early stages of cell adhesion. In addition, adhesion assays showed that the overall total number of adherent CD14⁺CD16⁺ monocytes increased in the presence of dopamine. These data suggest that elevated extracellular dopamine in the CNS of HIV infected drug abusers contributes to HIV neuropathogenesis by increasing the accumulation of CD14⁺CD16⁺ monocytes in dopamine rich brain regions.

Risky behavior and correlates of HIV and Hepatitis C Virus infection among people who inject drugs in three cities in Afghanistan

BACKGROUND

Injecting drug use is the primary mode of HIV transmission and acquisition in Afghanistan. People who inject drugs (PWID) in the country have been characterized by high risk injecting behavior and a high burden of HCV infection. We aimed to estimate the burden of HIV, HCV, and other infectious diseases and to identify the correlates of HIV and HCV infection among PWID living in three major Afghan cities in 2009.

METHODS

Epidemiologic data was collected among PWID for the integrated biological and behavioral surveillance (IBBS) survey between May and August, 2009 in three Afghan cities. Data were collected using a structured questionnaire and biologic specimens to screen for HIV, HBV, HCV, syphilis, and HSV-2 using rapid testing kits. Multiple logistic regression models were constructed to identify correlates of infection.

RESULTS

Among 548 participants, pooled HIV prevalence was 7.1% (Mazar-i-Sharif: 1.0%, Kabul: 3.1%, Herat: 18.4%) and HCV prevalence was 40.3%. Almost all participants with HIV infection were co-infected with HCV (94.9%). Pooled prevalence estimates for other diseases included 7.1% for HBV, 5.5% for syphilis; and 9.3% for HSV-2. Living in Herat, ever in prison and time injecting were independently associated with HIV infection. Living in Kabul, Herat and time injecting were independently associated with HCV infection.

CONCLUSIONS

There is a high and heterogeneous burden of HIV and HCV among PWID in Afghan cities. Provision of comprehensive harm reduction services to PWID in Afghanistan is warranted to reduce exposures associated with HIV and HCV infection, especially in the city of Herat.

Dopamine receptor activation increases HIV entry into primary human macrophages

Macrophages are the primary cell type infected with HIV in the central nervous system, and infection of these cells is a major component in the development of neuropathogenesis and HIV-associated neurocognitive disorders. Within the brains of drug abusers, macrophages are exposed to increased levels of dopamine, a neurotransmitter that mediates the addictive and reinforcing effects of drugs of abuse such as cocaine and methamphetamine. In this study we examined the effects of dopamine on HIV entry into primary human macrophages. Exposure to dopamine during infection increased the entry of R5 tropic HIV into macrophages, irrespective of the concentration of the viral inoculum. The entry pathway affected was CCR5 dependent, as antagonizing CCR5 with the small molecule inhibitor TAK779 completely blocked entry. The effect was dose-dependent and had a steep threshold, only occurring above 108 M dopamine. The dopamine-mediated increase in entry required dopamine receptor activation, as it was abrogated by the pan-dopamine receptor antagonist flupenthixol, and could be mediated through both subtypes of dopamine receptors. These findings indicate that the effects of dopamine on macrophages may have a significant impact on HIV pathogenesis. They also suggest that drug-induced increases in CNS dopamine may be a common mechanism by which drugs of abuse with distinct modes of action exacerbate neuroinflammation and contribute to HIV-associated neurocognitive disorders in infected drug abusers.

HIV among people who inject drugs in the Middle East and North Africa: systematic review and data synthesis

BACKGROUND

It is perceived that little is known about the epidemiology of HIV infection among people who inject drugs (PWID) in the Middle East and North Africa (MENA). The primary objective of this study was to assess the status of the HIV epidemic among PWID in MENA by describing HIV prevalence and incidence. Secondary objectives were to describe the risk behavior environment and the HIV epidemic potential among PWID, and to estimate the prevalence of injecting drug use in MENA.

METHODS AND FINDINGS

This was a systematic review following the PRISMA guidelines and covering 23 MENA countries. PubMed, Embase, regional and international databases, as well as country-level reports were searched up to December 16, 2013. Primary studies reporting (1) the prevalence/incidence of HIV, other sexually transmitted infections, or hepatitis C virus (HCV) among PWIDs; or (2) the prevalence of injecting or sexual risk behaviors, or HIV knowledge among PWID; or (3) the number/proportion of PWID in MENA countries, were eligible for inclusion. The quality, quantity, and geographic coverage of the data were assessed at country level. Risk of bias in predefined quality domains was described to assess the quality of available HIV prevalence measures. After multiple level screening, 192 eligible reports were included in the review. There were 197 HIV prevalence measures on a total of 58,241 PWID extracted from reports, and an additional 226 HIV prevalence measures extracted from the databases. We estimated that there are 626,000 PWID in MENA (range: 335,000-1,635,000, prevalence of 0.24 per 100 adults). We found evidence of HIV epidemics among PWID in at least one-third of MENA countries, most of which are emerging concentrated epidemics and with HIV prevalence overall in the range of 10%-15%. Some of the epidemics have however already reached considerable levels including some of the highest HIV prevalence among PWID globally (87.1% in Tripoli, Libya). The relatively high prevalence of sharing needles/syringes (18%-28% in the last injection), the low levels of condom use (20%-54% ever condom use), the high levels of having sex with sex workers and of men having sex with men (15%-30% and 2%-10% in the last year, respectively), and of selling sex (5%-29% in the last year), indicate a high injecting and sexual risk environment. The prevalence of HCV (31%-64%) and of sexually transmitted infections suggest high levels of risk behavior indicative of the potential for more and larger HIV epidemics.

CONCLUSIONS

Our study identified a large volume of HIV-related biological and behavioral data among PWID in the MENA region. The coverage and quality of the data varied between countries. There is robust evidence for HIV epidemics among PWID in multiple countries, most of which have emerged within the last decade and continue to grow. The lack of sufficient evidence in some MENA countries does not preclude the possibility of hidden epidemics among PWID in these settings. With the HIV epidemic among PWID in overall a relatively early phase, there is a window of opportunity for prevention that should not be missed through the provision of comprehensive programs, including scale-up of harm reduction services and expansion of surveillance systems.

Human immunodeficiency virus and hepatitis C virus coinfection in Nepal

OBJECTIVES

The study aimed at finding prevalence, mode of transmission, and pattern of CD4 cell count among hepatitis C virus (HCV) coinfected human immunodeficiency virus (HIV)-positive individuals in Nepal.

METHODS

This was a descriptive cross-sectional study carried out in three Volunteer Counseling and Testing clinics, one from Dharan and two from Kathmandu, Nepal. Three hundred and thirteen individuals were recruited.

RESULTS

Forty-two percent of HIV-infected persons had HCV coinfection. Significant associations with HIV and HCV coinfection were male gender (p <0.001) and injection drug use (IDU) (p <0.001). The mean CD4 cell count was significantly lower in HCV coinfected individuals, compared to those without coinfection, after 1.5 years (p =0.017), 2 years (p =0.0457), 3 years (p =0.011), and 3.5 years (p <0.001) of antiretroviral therapy.

CONCLUSION

HCV coinfection was common in HIV-infected individuals in Nepal and was associated with male gender, IDU, and lower CD4 counts.

Psychometric properties of the World Health Organization Quality Of Life Assessment-Brief in methadone patients: a validation study in northern Taiwan

Background

Quality of life (QOL) is an important outcome measure in the treatment of heroin addiction. The Taiwan version of the World Health Organization Quality of Life assessment (WHOQOL-BREF [TW]) has been developed and studied in various groups, but not specifically in a population of injection drug users. The aim of this study was to analyze the psychometric properties of the WHOQOL-BREF (TW) in a sample of injection drug users undergoing methadone maintenance treatment.

Methods

A total of 553 participants were interviewed and completed the instrument. Item-response distributions, internal consistency, corrected item-domain correlation, criterion-related validity, and construct validity through confirmatory factor analysis were evaluated.

Results

The frequency distribution of the 4 domains of the WHOQOL-BREF (TW) showed no floor or ceiling effects. The instrument demonstrated adequate internal consistency (Cronbach’s alpha coefficients were higher than 0.7 across the 4 domains) and all items had acceptable correlation with the corresponding domain scores (r = 0.32-0.73). Correlations (p < 0.01) of the 4 domains with the 2 benchmark items assessing overall QOL and general health were supportive of criterion-related validity. Confirmatory factor analysis yielded marginal goodness-of-fit between the 4-domain model and the sample data.

Conclusions

The hypothesized WHOQOL-BREF measurement model was appropriate for the injection drug users after some adjustments. Despite different patterns found in the confirmatory factor analysis, the findings overall suggest that the WHOQOL-BREF (TW) is a reliable and valid measure of QOL among injection drug users and can be utilized in future treatment outcome studies. The factor structure provided by the study also helps to understand the QOL characteristics of the injection drug users in Taiwan. However, more research is needed to examine its test-retest reliability and sensitivity to changes due to treatment.

Beyond early infant diagnosis: case finding strategies for identification of HIV-infected infants and children

There are 3.4 million children infected with HIV worldwide, with up to 2.6 million eligible for treatment under current guidelines. However, roughly 70% of infected children are not receiving live-saving HIV care and treatment. Strengthening case finding through improved diagnosis strategies, and actively linking identified HIV-infected children to care and treatment is essential to ensuring that these children benefit from the care and treatment available to them. Without attention or advocacy, the majority of these children will remain undiagnosed and die from complications of HIV. In this article, we summarize the challenges of identifying HIV-infected infants and children, review currently available evidence and guidance, describe promising new strategies for case finding, and make recommendations for future research and interventions to improve identification of HIV-infected infants and children.

Modified social ecological model: a tool to guide the assessment of the risks and risk contexts of HIV epidemics

Background

Social and structural factors are now well accepted as determinants of HIV vulnerabilities. These factors are representative of social, economic, organizational and political inequities. Associated with an improved understanding of multiple levels of HIV risk has been the recognition of the need to implement multi-level HIV prevention strategies. Prevention sciences research and programming aiming to decrease HIV incidence requires epidemiologic studies to collect data on multiple levels of risk to inform combination HIV prevention packages.

Discussion

Proximal individual-level risks, such as sharing injection devices and unprotected penile-vaginal or penile-anal sex, are necessary in mediating HIV acquisition and transmission. However, higher order social and structural-level risks can facilitate or reduce HIV transmission on population levels. Data characterizing these risks is often far more actionable than characterizing individual-level risks. We propose a modified social ecological model (MSEM) to help visualize multi-level domains of HIV infection risks and guide the development of epidemiologic HIV studies. Such a model may inform research in epidemiology and prevention sciences, particularly for key populations including men who have sex with men (MSM), people who inject drugs (PID), and sex workers. The MSEM builds on existing frameworks by examining multi-level risk contexts for HIV infection and situating individual HIV infection risks within wider network, community, and public policy contexts as well as epidemic stage. The utility of the MSEM is demonstrated with case studies of HIV risk among PID and MSM.

Summary

The MSEM is a flexible model for guiding epidemiologic studies among key populations at risk for HIV in diverse sociocultural contexts. Successful HIV prevention strategies for key populations require effective integration of evidence-based biomedical, behavioral, and structural interventions. While the focus of epidemiologic studies has traditionally been on describing individual-level risk factors, the future necessitates comprehensive epidemiologic data characterizing multiple levels of HIV risk.

Drug induced increases in CNS dopamine alter monocyte, macrophage and T cell functions: implications for HAND

Central nervous system (CNS) complications resulting from HIV infection remain a major public health problem as individuals live longer due to the success of combined antiretroviral therapy (cART). As many as 70 % of HIV infected people have HIV associated neurocognitive disorders (HAND). Many HIV infected individuals abuse drugs, such as cocaine, heroin or methamphetamine, that may be important cofactors in the development of HIV CNS disease. Despite different mechanisms of action, all drugs of abuse increase extracellular dopamine in the CNS. The effects of dopamine on HIV neuropathogenesis are not well understood, and drug induced increases in CNS dopamine may be a common mechanism by which different types of drugs of abuse impact the development of HAND. Monocytes and macrophages are central to HIV infection of the CNS and to HAND. While T cells have not been shown to be a major factor in HIV-associated neuropathogenesis, studies indicate that T cells may play a larger role in the development of HAND in HIV infected drug abusers. Drug induced increases in CNS dopamine may dysregulate functions of, or increase HIV infection in, monocytes, macrophages and T cells in the brain. Thus, characterizing the effects of dopamine on these cells is important for understanding the mechanisms that mediate the development of HAND in drug abusers.

Combination implementation for HIV prevention: moving from clinical trial evidence to population-level effects

The promise of combination HIV prevention-the application of multiple HIV prevention interventions to maximise population-level effects-has never been greater. However, to succeed in achieving significant reductions in HIV incidence, an additional concept needs to be considered: combination implementation. Combination implementation for HIV prevention is the pragmatic, localised application of evidence-based strategies to enable high sustained uptake and quality of interventions for prevention of HIV. In this Review, we explore diverse implementation strategies including HIV testing and counselling models, task shifting, linkage to and retention in care, antiretroviral therapy support, behaviour change, demand creation, and structural interventions, and discusses how they could be used to complement HIV prevention efforts such as medical male circumcision and treatment as prevention. HIV prevention and treatment have arrived at a pivotal moment when combination efforts might result in substantial enough population-level effects to reverse the epidemic and drive towards elimination of HIV. Only through careful consideration of how to implement and operationalise HIV prevention interventions will the HIV community be able to move from clinical trial evidence to population-level effects.

Opiate use, treatment, and harm reduction in Afghanistan: recent changes and future directions

Afghanistan leads global opium and cannabis production, amidst concerted efforts to improve the country's infrastructure. In this commentary, the evidence base for drivers of increased drug use in the context of deteriorating security is presented, government, donor, and civil society responses to date are described, and key areas for health policy response are summarized. Opiate use in Afghanistan shows disturbing trends: multiple substances are accessible at low cost and frequently used in combination, and injecting use has become more common. Pressures from both donor and governmental sectors have compromised innovations in programming. Further, civil unrest and resultant displacement have created challenges for programme implementation. Afghanistan urgently needs a well-funded, sustainable, comprehensive, and inclusive programme of drug dependency treatment, aftercare, and harm reduction services, as well as realistic, effective, and culturally salient primary prevention programmes. To date, drug dependence is not a prioritised issue, current programmes are under-resourced, and the continuum of care has a narrow scope generally limited to treatment. Unless this issue is addressed, the next generation of Afghans is poised to become a casualty of the opiate industry.

A venue-based approach to reaching MSM, IDUs and the general population with VCT: a three study site in Kenya

A venue-based HIV prevention study which included Voluntary Counseling and Testing (VCT) was conducted in three diverse areas of Kenya-Malindi, Nanyuki and Rachounyo. Aims of the study were to: (1) assess the acceptability of VCT for the general population, men who have sex with men (MSM), and injecting drug users (IDUs) within the context of a venue-based approach; (2) determine if there were differences between those agreeing and not agreeing to testing; and (3) study factors associated with being HIV positive. Approximately 98% of IDUs and 97% of MSM agreed to VCT, providing evidence that populations with little access to services and whose behaviors are stigmatized and often considered illegal in their countries can be reached with needed HIV prevention services. Acceptability of VCT in the general population ranged from 60% in Malindi to 48% in Nanyuki. There were a few significant differences between those accepting and declining testing. Notably in Rachuonyo and Malindi those reporting multiple partners were more likely to accept testing. There was also evidence that riskier sexual behavior was associated with being HIV positive for both men in Rachounyo and women in Malindi. Overall HIV prevalence was higher among the individuals in this study compared to individuals sampled in the 2008-2009 Kenya Demographic and Health Survey, indicating the method is an appropriate means to reach the highest risk individuals including stigmatized populations.

The urgency of providing comprehensive and integrated treatment for substance abusers with HIV

Substance abuse is linked to many new cases of HIV infection. Barriers such as the myth that drug users cannot adhere to HIV/AIDS treatment block progress in curbing the spread of HIV in that population. In this article we explain the need to aggressively seek out high-risk, hard-to-reach substance abusers and to offer them HIV testing, access to treatment, and the necessary support to remain in treatment--both for HIV and for substance abuse. We summarize evidence showing that injection drug users can successfully undergo HIV treatment; that many substance abusers adhere to antiretroviral therapy as well as do people who don't inject drugs; and that injection drug users who undergo substance abuse treatment are more likely to obtain and stay in treatment for their HIV infection. This evidence makes a strong case for integrating substance abuse treatment with HIV treatment programs and providing substance abusers with universal access to HIV treatment. But an integrated strategy will require changes in the health care system to overcome lingering obstacles that inhibit the merging of substance abuse treatment with HIV programs.

Prevalence and correlates of HIV, syphilis, and hepatitis B and C infection and harm reduction program use among male injecting drug users in Kabul, Afghanistan: A cross-sectional assessment

Background

A nascent HIV epidemic and high prevalence of risky drug practices were detected among injecting drug users (IDUs) in Kabul, Afghanistan from 2005-2006. We assessed prevalence of HIV, hepatitis C virus (HCV), hepatitis B surface antigen (HBsAg), syphilis, and needle and syringe program (NSP) use among this population.

Methods

IDUs were recruited between June, 2007 and March, 2009 and completed questionnaires and rapid testing for HIV, HCV, HBsAg, and syphilis; positive samples received confirmatory testing. Logistic regression was used to identify correlates of HIV, HCV, and current NSP use.

Results

Of 483 participants, all were male and median age, age at first injection, and duration of injection were 28, 24, and 2.0 years, respectively. One-fifth (23.0%) had initiated injecting within the last year. Reported risky injecting practices included ever sharing needles/syringes (16.9%) or other injecting equipment (38.4%). Prevalence of HIV, HCV Ab, HBSAg, and syphilis was 2.1% (95% CI: 1.0-3.8), 36.1% (95% CI: 31.8-40.4), 4.6% (95% CI: 2.9-6.9), and 1.2% (95% CI: 0.5-2.7), respectively. HIV and HCV infection were both independently associated with sharing needles/syringes (AOR = 5.96, 95% CI: 1.58 - 22.38 and AOR = 2.33, 95% CI: 1.38 - 3.95, respectively). Approximately half (53.8%) of the participants were using NSP services at time of enrollment and 51.3% reported receiving syringes from NSPs in the last three months. Current NSP use was associated with initiating drug use with injecting (AOR = 2.58, 95% CI: 1.22 - 5.44), sharing injecting equipment in the last three months (AOR = 1.79, 95% CI: 1.16 - 2.77), prior incarceration (AOR = 1.57, 95% CI: 1.06 - 2.32), and greater daily frequency of injecting (AOR = 1.40 injections daily, 95% CI: 1.08 - 1.82).

Conclusions

HIV and HCV prevalence appear stable among Kabul IDUs, though the substantial number having recently initiated injecting raises concern that transmission risk may increase over time. Harm reduction programming appears to be reaching high-risk drug user populations; however, monitoring is warranted to determine efficacy of prevention programming in this dynamic environment.

Current understanding of HIV-associated neurocognitive disorders pathogenesis

PURPOSE OF REVIEW

The present review discusses current concepts of HIV-associated neurocognitive disorders (HAND) in the era of antiretroviral therapy (ART). As the HIV epidemic enters its fourth decade (the second decade of ART), research must address evolving factors in HAND pathogenesis. These include persistent systemic and central nervous system (CNS) inflammation, aging in the HIV-infected brain, HIV subtype (clade) distribution, concomitant use of drugs of abuse, and potential neurotoxicity of ART drugs.

RECENT FINDINGS

Although the severest form of HAND, HIV-associated dementia (HAD), is now rare due to ART, the persistence of milder, functionally important HAND forms persist in up to half of HIV-infected individuals. HAND prevalence may be higher in areas of Africa where different HIV subtypes predominate, and ART regimens that are more effective in suppressing CNS HIV replication can improve neurological outcomes. HAND are correlated with persistent systemic and CNS inflammation, and enhanced neuronal injury due to stimulant abuse (cocaine and methamphetamine), aging, and possibly ART drugs themselves.

SUMMARY

Prevention and treatment of HAND requires strategies aimed at suppressing CNS HIV replication and effects of systemic and CNS inflammation in aging and substance-abusing HIV populations. Use of improved CNS-penetrating ART must be accompanied by evaluation of potential ART neurotoxicity.