Direct comparison of time to AIDS and infectious disease death between HIV seroconverter injection drug users in Italy and the United States: results from the ALIVE and ISS studies. AIDS Link to Intravenous Experiences. Italian Seroconversion Study

Evaluation of Possible Effects of Continued Drug Use on HIV Progression among Women

Data from a prospective, multi-centred study of HIV infection in women (HIV Epidemiology Research Study [HERS)) was analysed to investigate the effect of continued injection drug use behaviours on progression to AIDS. All women enrolled in the HERS had at enrolment and at six-month intervals, a face-to-face interview which included specific injection drug use, a physical exam, and specimen collection that included T-cell subset analysis and HIV plasma RNA detection. Six hundred and thirty-nine HIV-infected women contributed 3021 person years of observation during 7.25 years of follow-up, and 299 of these women progressed to AIDS (46.8%). In multivariable analysis, there was no significantly increased risk of progression to AIDS for women reporting pre-baseline injection drug use [hazard ratio (HR)=1.07 (0.78, 1.47)] or reported injection drug use during follow-up [HR=0.89 (0.66, 1.21)] compared with never injecting. In a separate multivariable-model, comparing women who reported no injection in past six months to active injection drug users, the frequency of injection during the previous six months measured by daily injection [HR=0.97 (0.61, 1.55)] or less than daily injection [HR=O.84 (0.54, 1.33)] was not associated with progression to AIDS. Being in drug treatment was independently associated with a slower progression to AIDS [HR=0.41 (0.28,0.59)]. Neither injection drug use, nor frequency of injection drug use was associated with progression to AIDS among HIV infected women. Initiation of antiretroviral therapy among drug users should be based on readiness for treatment rather than concern about faster progression.

Are there differences in disease progression and mortality among male and female HIV patients on antiretroviral therapy? A meta-analysis of observational cohorts

Studies examining the sex differences in morbidity and mortality among HIV/AIDS patients have yielded inconsistent results. We conducted a meta-analysis of sex differences in disease progression and mortality among HIV/AIDS patients. Medical literature databases from inception to August 2014 were searched for published observational studies assessing sex differences in immunologic and virologic response, disease progression and mortality among HIV-infected patients. Random effects meta-analyses of 115 eligible studies were conducted to obtain pooled estimates of outcomes and heterogeneity was explored in sub-group analyses. Pooled estimates showed an increased risk of progression to AIDS (relative risk [RR]=1.11,95% CI=1.02-1.21) and all-cause mortality (RR=1.23, 95% CI=1.17-1.29) among males compared to females. All-cause mortality differed by sex only in low and middle income countries. The risk of AIDS-related mortality (RR=1.03, 95% CI=0.82-1.30), immunologic failure (RR=1.19,95% CI: 0.97-1.47), virologic suppression (RR=0.98, 95% CI=0.84-1.14), virologic failure (RR=1.26, 95% CI=0.99-1.61) and the change in CD4 cell count (Weighted mean difference [WMD] = -5.15, 95% CI= -13.57 to 3.28) did not differ by sex. These findings were modified by disease severity, adherence and use of highly active antiretroviral therapy. We conclude that HIV-related disease progression and survival outcomes are poorer in males.

Impact of cocaine abuse on HIV pathogenesis

Over 1.2 million people in the United States are infected with the human immunodeficiency virus type 1 (HIV-1). Tremendous progress has been made over the past three decades on many fronts in the prevention and treatment of HIV-1 disease. However, HIV-1 infection is incurable and antiretroviral drugs continue to remain the only effective treatment option for HIV infected patients. Unfortunately, only three out of ten HIV-1 infected individuals in the US have the virus under control. Thus, majority of HIV-1 infected individuals in the US are either unaware of their infection status or not connected/retained to care or are non-adherent to antiretroviral therapy (ART). This national public health crisis, as well as the ongoing global HIV/AIDS pandemic, is further exacerbated by substance abuse, which serves as a powerful cofactor at every stage of HIV/AIDS including transmission, diagnosis, pathogenesis, and treatment. Clinical studies indicate that substance abuse may increase viral load, accelerate disease progression and worsen AIDS-related mortality even among ART-adherent patients. However, confirming a direct causal link between substance abuse and HIV/AIDS in human patients remains a highly challenging endeavor. In this review we will discuss the recent and past developments in clinical and basic science research on the effects of cocaine abuse on HIV-1 pathogenesis.

Accounting for dropout reason in longitudinal studies with nonignorable dropout

Dropout is a common problem in longitudinal cohort studies and clinical trials, often raising concerns of nonignorable dropout. Selection, frailty, and mixture models have been proposed to account for potentially nonignorable missingness by relating the longitudinal outcome to time of dropout. In addition, many longitudinal studies encounter multiple types of missing data or reasons for dropout, such as loss to follow-up, disease progression, treatment modifications and death. When clinically distinct dropout reasons are present, it may be preferable to control for both dropout reason and time to gain additional clinical insights. This may be especially interesting when the dropout reason and dropout times differ by the primary exposure variable. We extend a semi-parametric varying-coefficient method for nonignorable dropout to accommodate dropout reason. We apply our method to untreated HIV-infected subjects recruited to the Acute Infection and Early Disease Research Program HIV cohort and compare longitudinal CD4⁺ T cell count in injection drug users to nonusers with two dropout reasons: anti-retroviral treatment initiation and loss to follow-up.

Cocaine modulates HIV-1 integration in primary CD4+ T cells: implications in HIV-1 pathogenesis in drug-abusing patients

Epidemiologic studies suggest that cocaine abuse worsens HIV-1 disease progression. Increased viral load has been suggested to play a key role for the accelerated HIV disease among cocaine-abusing patients. The goal of this study was to investigate whether cocaine enhances proviral DNA integration as a mechanism to increase viral load. We infected CD4(+) T cells that are the primary targets of HIV-1 in vivo and treated the cells with physiologically relevant concentrations of cocaine (1 µM-100 µM). Proviral DNA integration in the host genome was measured by nested qPCR. Our results illustrated that cocaine from 1 µM through 50 µM increased HIV-1 integration in CD4(+) T cells in a dose-dependent manner. As integration can be modulated by several early postentry steps of HIV-1 infection, we examined the direct effects of cocaine on viral integration by in vitro integration assays by use of HIV-1 PICs. Our data illustrated that cocaine directly increases viral DNA integration. Furthermore, our MS analysis showed that cocaine is able to enter CD4(+) T cells and localize to the nucleus-. In summary, our data provide strong evidence that cocaine can increase HIV-1 integration in CD4(+) T cells. Therefore, we hypothesize that increased HIV-1 integration is a novel mechanism by which cocaine enhances viral load and worsens disease progression in drug-abusing HIV-1 patients.

Influence of noninjecting and injecting drug use on mortality, retention in the cohort, and antiretroviral therapy, in participants in the Swiss HIV Cohort Study

OBJECTIVES

We studied the influence of noninjecting and injecting drug use on mortality, dropout rate, and the course of antiretroviral therapy (ART), in the Swiss HIV Cohort Study (SHCS).

METHODS

Cohort participants, registered prior to April 2007 and with at least one drug use questionnaire completed until May 2013, were categorized according to their self-reported drug use behaviour. The probabilities of death and dropout were separately analysed using multivariable competing risks proportional hazards regression models with mutual correction for the other endpoint. Furthermore, we describe the influence of drug use on the course of ART.

RESULTS

A total of 6529 participants (including 31% women) were followed during 31 215 person-years; 5.1% participants died; 10.5% were lost to follow-up. Among persons with homosexual or heterosexual HIV transmission, noninjecting drug use was associated with higher all-cause mortality [subhazard rate (SHR) 1.73; 95% confidence interval (CI) 1.07-2.83], compared with no drug use. Also, mortality was increased among former injecting drug users (IDUs) who reported noninjecting drug use (SHR 2.34; 95% CI 1.49-3.69). Noninjecting drug use was associated with higher dropout rates. The mean proportion of time with suppressed viral replication was 82.2% in all participants, irrespective of ART status, and 91.2% in those on ART. Drug use lowered adherence, and increased rates of ART change and ART interruptions. Virological failure on ART was more frequent in participants who reported concomitant drug injections while on opiate substitution, and in current IDUs, but not among noninjecting drug users.

CONCLUSIONS

Noninjecting drug use and injecting drug use are modifiable risks for death, and they lower retention in a cohort and complicate ART.

Cocaine enhances HIV-1-induced CD4(+) T-cell apoptosis: implications in disease progression in cocaine-abusing HIV-1 patients

Substance abuse is a major barrier in eradication of the HIV epidemic because it serves as a powerful cofactor for viral transmission, disease progression, and AIDS-related mortality. Cocaine, one of the commonly abused drugs among HIV-1 patients, has been suggested to accelerate HIV disease progression. However, the underlying mechanism remains largely unknown. Therefore, we tested whether cocaine augments HIV-1-associated CD4(+) T-cell decline, a predictor of HIV disease progression. We examined apoptosis of resting CD4(+) T cells from HIV-1-negative and HIV-1-positive donors in our study, because decline of uninfected cells plays a major role in HIV-1 disease progression. Treatment of resting CD4(+) T cells with cocaine (up to 100 μmol/L concentrations) did not induce apoptosis, but 200 to 1000 μmol/L cocaine induced apoptosis in a dose-dependent manner. Notably, treatment of CD4(+) T cells isolated from healthy donors with both HIV-1 virions and cocaine significantly increased apoptosis compared with the apoptosis induced by cocaine or virions alone. Most important, our biochemical data suggest that cocaine induces CD4(+) T-cell apoptosis by increasing intracellular reactive oxygen species levels and inducing mitochondrial depolarization. Collectively, our results provide evidence of a synergy between cocaine and HIV-1 on CD4(+) T-cell apoptosis that may, in part, explain the accelerated disease observed in HIV-1-infected drug abusers.

HIV transmission from drug injectors to partners who do not inject, and beyond: modelling the potential for a generalized heterosexual epidemic in St. Petersburg, Russia

BACKGROUND

HIV infection is prevalent among drug injectors in St. Petersburg and their non-injecting heterosexual partners (PIDUs). There are fears that sexual transmission of HIV from IDUs to PIDUs may portend a self-sustaining, heterosexual epidemic in Russia.

METHODS

Our model combines a network model of sexual partnerships of IDUs and non-IDUs to represent sexual transmission of HIV and a deterministic model for parenteral transmission among IDUs. Behavioural parameters were obtained from a survey of St. Petersburg IDUs and their sexual partners. We based our model fits on two scenarios for PIDU prevalence in 2006 (5.6% and 15.1%, calculated excluding and including HCV co-infected PIDUs respectively) and compared predictions for the general population HIV prevalence.

RESULTS

Results indicate that sexual transmission could sustain a non-IDU HIV epidemic. The model indicates that general population prevalence may be greater than current estimates imply. Parenteral transmission drives the epidemic and the PIDU bridge population plays a crucial role transferring infection to non-IDUs. The model indicates that the high PIDU prevalence is improbable because of the high risk behaviour this implies; the lower prevalence is possible.

CONCLUSION

The model implies that transmission through PIDUs will sustain a heterosexual epidemic, if prevalence among IDUs and PIDUs is as high as survey data suggest. We postulate that current estimates of population prevalence underestimate the extent of the HIV epidemic because they are based on the number of registered cases only. Curtailing transmission among injectors and PIDUs will be vital in controlling heterosexual transmission.

Trends in the population prevalence of people who inject drugs in US metropolitan areas 1992-2007

BACKGROUND

People who inject drugs (PWID) have increased risk of morbidity and mortality. We update and present estimates and trends of the prevalence of current PWID and PWID subpopulations in 96 US metropolitan statistical areas (MSAs) for 1992-2007. Current estimates of PWID and PWID subpopulations will help target services and help to understand long-term health trends among PWID populations.

METHODOLOGY

We calculated the number of PWID in the US annually from 1992-2007 and apportioned estimates to MSAs using multiplier methods. We used four types of data indicating drug injection to allocate national annual totals to MSAs, creating four distinct series of component estimates of PWID in each MSA and year. The four component estimates are averaged to create the best estimate of PWID for each MSA and year. We estimated PWID prevalence rates for three subpopulations defined by gender, age, and race/ethnicity. We evaluated trends using multi-level polynomial models.

RESULTS

PWID per 10,000 persons aged 15-64 years varied across MSAs from 31 to 345 in 1992 (median 104.4) to 34 to 324 in 2007 (median 91.5). Trend analysis indicates that this rate declined during the early period and then was relatively stable in 2002-2007. Overall prevalence rates for non-Hispanic black PWID increased in 2005 as compared to other racial/ethnic groups. Hispanic prevalence, in contrast, declined across time. Importantly, results show a worrisome trend in young PWID prevalence since HAART was initiated--the mean prevalence was 90 to 100 per 10,000 youth in 1992-1996, but increased to >120 PWID per 10,000 youth in 2006-2007.

CONCLUSIONS

Overall, PWID rates remained constant since 2002, but increased for two subpopulations: non-Hispanic black PWID and young PWID. Estimates of PWID are important for planning and evaluating public health programs to reduce harm among PWID and for understanding related trends in social and health outcomes.

Social and structural factors associated with HIV disease progression among illicit drug users: a systematic review

OBJECTIVE

To systematically review factors associated with HIV disease progression among illicit drug users, focusing on exposures exogenous to individuals that likely shape access and adherence to HIV treatment.

DESIGN

A systematic review of peer-reviewed English-language studies among HIV-seropositive illicit drug users with at least one of these endpoint of interest: a diagnosis of AIDS; death; changes/differences in CD4 cell counts; or changes/differences in plasma HIV-1 RNA levels.

METHODS

Articles were included if they reported factors associated with an outcome of interest among a group of illicit drug users. Studies were identified, screened and selected using systematic methods.

RESULTS

Of 2668 studies matching the search criteria, 58 (2%) met the inclusion criteria, all but one from North America or western Europe. Overall, 41 (71%) studies contained significant individual-level clinical characteristics or behaviors (e.g. illicit drug use) associated with disease progression. Fifteen studies (26%) identified significant social, physical, economic or policy-level exposures, including incarceration, housing status or lack of legal income.

CONCLUSION

Although past studies demonstrate important environmental exposures that appear to shape access to care and subsequent disease progression, the limited literature to examine these factors demonstrates the need for future research to consider risk environment characteristics and the role they may play in shaping health outcomes from HIV infection among drug users through determining access and adherence to evidence-based care.

Immunosuppressive effects of opioids--clinical relevance

Opioid-induced immunosuppression has been demonstrated in cell culture experiments and in animal models. This is in striking contrast to the paucity of confirmatory studies in humans. This review describes the basic pharmacokinetics and -dynamics of opioid use in patients. It summarizes the major findings on opioid use and infectious complications in intensive care unit (ICU) patients, in patients with acute or chronic non-malignant pain, and in intravenous drug users (IDU). The limitations of studies in each area are discussed. For example, ethical concerns may complicate randomized placebo-controlled trials (RCT) in acute postoperative pain and for a large part of ICU patients. Importantly, most studies in patients with chronic (non-malignant) pain only inadequately report infectious complications in relation to opioid use since their incidence is usually not considered to be drug related. Infectious complications in IDUs are very frequent but cannot easily be distinguished from risk behavior or risk environment. In summary, convincing clinical evidence is lacking that opioids per se increase the rate of infectious complications in most patient categories. From a clinical standpoint, important unresolved issues are i) selection of relevant animal models, ii) opioid selection and discontinuation, and iii) the role of coexisting diseases and concomitant other medications.

Rapid dissemination of SIV follows multisite entry after rectal inoculation

Receptive ano-rectal intercourse is a major cause of HIV infection in men having sex with men and in heterosexuals. Current knowledge of the mechanisms of entry and dissemination during HIV rectal transmission is scarce and does not allow the development of preventive strategies. We investigated the early steps of rectal infection in rhesus macaques inoculated with the pathogenic isolate SIVmac251 and necropsied four hours to nine days later. All macaques were positive for SIV. Control macaques inoculated with heat-inactivated virus were consistently negative for SIV. SIV DNA was detected in the rectum as early as four hours post infection by nested PCR for gag in many laser-microdissected samples of lymphoid aggregates and lamina propria but never in follicle-associated epithelium. Scarce SIV antigen positive cells were observed by immunohistofluorescence in the rectum, among intraepithelial and lamina propria cells as well as in clusters in lymphoid aggregates, four hours post infection and onwards. These cells were T cells and non-T cells that were not epithelial cells, CD68⁺ macrophages, DC-SIGN⁺ cells or fascin⁺ dendritic cells. DC-SIGN⁺ cells carried infectious virus. Detection of Env singly spliced mRNA in the mucosa by nested RT-PCR indicated ongoing viral replication. Strikingly, four hours post infection colic lymph nodes were also infected in all macaques as either SIV DNA or infectious virus was recovered. Rapid SIV entry and dissemination is consistent with trans-epithelial transport. Virions appear to cross the follicle-associated epithelium, and also the digestive epithelium. Viral replication could however be more efficient in lymphoid aggregates. The initial sequence of events differs from both vaginal and oral infections, which implies that prevention strategies for rectal transmission will have to be specific. Microbicides will need to protect both digestive and follicle-associated epithelia. Vaccines will need to induce immunity in lymph nodes as well as in the rectum.

Non-injection drug use and HIV disease progression in the era of combination antiretroviral therapy

Little is known about the effects of non-injection drug use (NIDU) on HIV antiretroviral treatment outcomes. We conducted a systematic literature search and identified nine publications from prospective cohort studies investigating the relationship between NIDU and clinical HIV disease progression. Hazard ratios from studies estimating the effect of drug use on time to AIDS-related mortality ranged from 0.89 to 3.61, and only two of these were statistically significant. Hazard ratios from studies assessing time to an AIDS-defining event ranged from 1.19 to 2.51, with 8 of the 14 estimates falling between 1.55 and 1.65 regardless of drug use definition and measurement of use or frequency. It is suggested that NIDU may have a moderate effect of increasing the risk of progression to AIDS, but its impact on AIDS-related mortality is uncertain. NIDU may affect HIV antiretroviral treatment outcomes primarily through interaction with antiretroviral therapy and, to a lesser extent, through immune modulation and deterioration of general health. The limitations about published studies are discussed, and future perspectives on research on this topic are provided.

Associations between use of crack cocaine and HIV-1 disease progression: research findings and implications for mother-to-infant transmission

Recent in vitro and in vivo research has suggested that cocaine has a direct effect on the pathogenesis of AIDS. These findings are confirmed by epidemiological studies linking the use of injected, inhaled, and smoked (crack) cocaine and indicators of HIV disease progression, even among adherent users of highly active antiretroviral therapy. Recent studies of vertical HIV transmission suggest that cocaine use may play a role in mother-to-child infection via alteration of maternal immune responses, enhanced viral replication in maternal immune cells, or alterations in the immune systems of neonates or infants. The purpose of this article is to review research conducted over the past several decades on associations between use of cocaine and HIV disease progression, especially among HIV+ women, and to explore its potential relevance for understanding mother-to-infant transmission of HIV.

Excess mortality among HIV-infected patients diagnosed with substance use dependence or abuse receiving care in a fully integrated medical care program

BACKGROUND

We examined the association between substance use (SU) disorder and mortality among HIV-infected patients in a large, private medical care program.

METHODS

In a retrospective cohort design, HIV-infected patients (≥14 years old) from a large health plan (Northern California) were studied to examine mortality associated with diagnosis of SU dependence or abuse over an 11-year period.

RESULTS

At study entry or during follow-up, 2,279 (25%) of 9,178 HIV-infected patients had received a diagnosis of SU disorder. Diagnoses were categorized as alcohol dependence/abuse only, illicit drugs only, or both. Cause of death differed by the category of SU diagnosis. Mortality rates ranged from 35.5 deaths per 1,000 person-years in patients with an SU disorder to 17.5 deaths among patients without an SU disorder. Regression results indicated mortality risk was significantly higher in all categories of SU disorder compared to no SU diagnosis (hazard ratios ranging from 1.65 to 1.67) after adjustment for SU treatment and confounders.

CONCLUSIONS

A diagnosis of SU dependence/abuse is associated with higher mortality among HIV-infected patients for whom access to medical services is not a significant factor.

HIV-2 CRF01_AB: first circulating recombinant form of HIV-2

BACKGROUND

Five HIV-2-seropositive cases were recently identified in Japan, outside the HIV-2 endemic area of West Africa. To clarify the molecular epidemiology of HIV-2 in Japan, we analyzed sequences of these cases in detail.

METHODS

HIV-2 genetic groups were determined by gag and env sequences. For suspected recombinant isolates, the genetic structure was determined by full-length genomic analyses. To understand the history and evolution of HIV-2 recombinant isolates, we estimated the time of most recent common ancestor by Bayesian Markov chain Monte Carlo method.

RESULTS

Three isolates were determined as recombinants of groups A and B, and their mosaic genome structures were identical with that of 7312A, a recombinant isolate reported in 1990 from Côte d'Ivoire. Our 3 isolates and 7312A fulfilled the criteria for determining a circulating recombinant form (CRF). These isolates were verified by the Los Alamos HIV sequence database as the first CRF of HIV-2, HIV-2 CRF01_AB. The mean time of most recent common ancestor of CRF01_AB was estimated as between 1964 and 1973, several decades after the estimated emergence of HIV-2.

CONCLUSIONS

We recently identified HIV-2 CRF01_AB cases in Japan. This ectopic observation of the virus outside its original endemic area suggests an ongoing global spread of HIV-2 CRF01_AB.

Rhesus macaque model of chronic opiate dependence and neuro-AIDS: longitudinal assessment of auditory brainstem responses and visual evoked potentials

Our work characterizes the effects of opiate (morphine) dependence on auditory brainstem and visual evoked responses in a rhesus macaque model of neuro-AIDS utilizing a chronic continuous drug delivery paradigm. The goal of this study was to clarify whether morphine is protective, or if it exacerbates simian immunodeficiency virus (SIV)-related systemic and neurological disease. Our model employs a macrophage tropic CD4/CCR5 coreceptor virus, SIV(mac)239 (R71/E17), which crosses the blood-brain barrier shortly after inoculation and closely mimics the natural disease course of human immunodeficiency virus infection. The cohort was divided into three groups: morphine only, SIV only, and SIV + morphine. Evoked potential (EP) abnormalities in subclinically infected macaques were evident as early as 8 weeks postinoculation. Prolongations in EP latencies were observed in SIV-infected macaques across all modalities. Animals with the highest cerebrospinal fluid viral loads and clinical disease showed more abnormalities than those with subclinical disease, confirming our previous work (Raymond et al., J Neurovirol 4:512-520, 1998; J Neurovirol 5:217-231, 1999; AIDS Res Hum Retroviruses 16:1163-1173, 2000). Although some differences were observed in auditory and visual evoked potentials in morphine-treated compared to morphine-untreated SIV-infected animals, the effects were relatively small and not consistent across evoked potential type. However, morphine-treated animals with subclinical disease had a clear tendency toward higher virus loads in peripheral and central nervous system tissues (Marcario et al., J Neuroimmune Pharmacol 3:12-25, 2008) suggesting that if had been possible to follow all animals to end-stage disease, a clearer pattern of evoked potential abnormality might have emerged.

Gender differences in HIV progression to AIDS and death in industrialized countries: slower disease progression following HIV seroconversion in women

To evaluate sex differences in human immunodeficiency virus (HIV) disease progression before (pre-1997) and after (1997-2006) introduction of highly active antiretroviral therapy, the authors used data from a collaboration of 23 HIV seroconverter cohort studies from Europe, Australia, and Canada restricted to the 6,923 seroconverters infected through injecting drug use and sex between men and women. Within a competing risk framework, they used Cox proportional hazards models allowing for late entry to evaluate sex differences in time from HIV seroconversion to death, to acquired immunodeficiency syndrome (AIDS), and to each first AIDS-defining disease and death without AIDS. While no significant sex differences were found before 1997, from 1997 onward, women had a lower risk of AIDS (adjusted cumulative relative risk (aCRR) = 0.76, 95% confidence interval (CI): 0.63, 0.90) and death (adjusted hazard ratio = 0.68, 95% CI: 0.56, 0.82) than men did. Compared with men, women also had lower risks of AIDS dementia complex (aCRR = 0.23, 95% CI: 0.07, 0.74), tuberculosis (aCRR = 0.60, 95% CI: 0.39, 0.92), Kaposi's sarcoma (aCRR = 0.27, 95% CI: 0.07, 0.99), lymphomas (aCRR = 0.47, 95% CI: 0.23, 0.96), and death without AIDS (aCRR = 0.74, 95% CI: 0.56, 0.98). Sex differences in HIV disease progression have become larger and statistically significant in the era of highly active antiretroviral therapy, supporting a stronger impact of health interventions among women.

Crack cocaine, disease progression, and mortality in a multicenter cohort of HIV-1 positive women

BACKGROUND

Longitudinal associations between patterns of crack cocaine use and progression of HIV-1 disease are poorly understood, especially among women. This study explores relationships between crack use and HIV-1 disease outcomes in a multicenter cohort of infected women.

METHODS

Subjects were 1686 HIV-seropositive women enrolled at six US research centers in the Women's Interagency HIV Study. Approximately 80% were non-white and 29% used crack during the study period. Cox survival and random regression analysis examined biannual observations made April 1996 through September 2004. Outcome measures included death due to AIDS-related causes, CD4 cell count, HIV-1 RNA level, and newly acquired AIDS-defining illnesses.

RESULTS

Persistent crack users were over three times as likely as non-users to die from AIDS-related causes, controlling for use of HAART self-reported at 95% or higher adherence, problem drinking, age, race, income, education, illness duration, study site, and baseline virologic and immunologic indicators. Persistent crack users and intermittent users in active and abstinent phases showed greater CD4 cell loss and higher HIV-1 RNA levels controlling for the same covariates. Persistent and intermittent crack users were more likely than non-users to develop new AIDS-defining illnesses controlling for identical confounds. These results persisted when controlling for heroin use, tobacco smoking, depressive symptoms, hepatitis C virus coinfection, and injection drug use.

CONCLUSION

Use of crack cocaine independently predicts AIDS-related mortality, immunologic and virologic markers of HIV-1 disease progression, and development of AIDS-defining illnesses among women.

Community coverage and HIV prevention: assessing metrics for estimating HIV incidence through syringe exchange

BACKGROUND

Evaluations of syringe-exchange programme effectiveness that attempt to measure "coverage" by determining the percentage of the at-risk population reached by a programme are insufficient since programmes must provide syringes on a continual basis. Determining the relationship between the extent of programme coverage and its impact (i.e., reductions in disease risk or incidence) is complicated by the lack of controlled trials with cohorts of drug users and instead has to be estimated by imputation, mathematical modelling, or ecological data analysis. This report offers an approach to determine community-wide impact and discusses the limitations of that approach.

METHODS

Easily created programme tracking data were maintained by exchanges in New Haven, CT, USA and Chicago, IL, USA. Data compiled by month quantified the number of unique participants visiting syringe-exchange programmes and the number of syringes distributed. "Coverage", defined either as the percentage of individuals reached or percentage of community syringe need met, was estimated by incorporating measures of the size of the injector population or injection frequency. These measures of coverage are placed in the context of changing programme operations to estimate the effect of these changes on coverage. Finally, data on AIDS cases from New Haven and Chicago were used to estimate the community-wide impact of syringe exchange.

RESULTS

Two mobile syringe-exchange programmes operated with very different exchange policies. Programme data revealed that coverage of individuals rarely exceeded 10% and was higher in New Haven than in Chicago. On the other hand, coverage measured as the percentage of syringe need met was higher at the Chicago exchange that employed the less restrictive policy. The impact of syringe exchange in the two cities was measured by comparing subsequent AIDS cases. The relative reduction in injection-related AIDS cases as a function of all new AIDS diagnoses was 21.7% in New Haven and 41.4% in Chicago.

CONCLUSIONS

A modest investment in the collection of programme data can yield reliable and interpretable information on the extent of programme reach and retention. Limitations to the approach result from the ecological nature of the data and from the need to use data from outside the programme that may be less reliable. For the cases presented here, coverage rates will vary as a function of the programme policies; however, even modest coverage rates - well below those recommended by UNAIDS - can have significant impacts on HIV epidemics. Restrictive policies appeared to increase the coverage if measured only by the proportion of monthly participants and not by the proportion of syringe need met by a programme. More generally, programmes can collect programmatic data and some rapid assessment data (estimates of IDU population and injection frequency) to estimate of the impact of their programmes.

Estimating the total mortality among problem drug users

This paper's objective is to develop a method to estimate the total mortality among problem drug users. The total mortality is given by a base rate of mortality not related to drugs and the deaths that are directly and indirectly related to drugs. A fatal poisoning by drugs (overdose) is directly related to drugs, whereas a casualty due to a drug-related disease or a drug-related accident is indirectly related to drugs. As an example of a method to estimate the total mortality, the results from a cohort study among methadone patients in Amsterdam were projected on the whole population of problem drug users in The Netherlands. Due to differences between the problem drug users in Amsterdam and the rest of the country, adjustments were required. It was found that an initial estimation did not require adjustment for injection behavior and gender but did require adjustment for age and the percentage of HIV infection. In a first unadjusted estimation, the total number of deaths among problem drug users in The Netherlands in 2001 was estimated at 606 deaths. After adjustment for age, the estimated mortality decreased to 573 deaths, and after adjustment for HIV infection, this estimation again decreased to 479 deaths. From the ultimately estimated mortality, 11% was considered to be not related to drugs, 23% was attributed directly to drugs, and 66% was attributed indirectly to drugs. The number of direct deaths, as estimated by this method, falls in the same order of magnitude as the number extracted from the Causes of Death Statistics, when selecting cases according to the Drug-Related Deaths Standard as established by the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA). Further cross-validation with other measures will be needed to assess the accuracy of the method, the limitations of which are discussed with respect to stipulating directions for future research.

The spread of HIV-1 subtypes B and CRF01_AE among injecting drug users in Bangkok, Thailand

The HIV epidemic among injecting drug users (IDUs) in Bangkok was initially dominated by HIV subtype B and later by the recombinant CRF01_AE. The present study investigates the distribution of the 2 variants in time and how it is affected by changes in injecting risk behavior and treatment. A mathematic model describing the spread of HIV subtype B and CRF01_AE among IDUs was developed, and data from the AIDSVAX B/E cohort of IDUs in Bangkok were used. From the model, it was calculated that during 1999 to 2003, the annual incidence of HIV was around 0.6 and 2.7 to 3.9 infections per 100 person-years for subtype B and CRF01_AE, respectively. Of the new infections, 18% and 72% are first infections with subtype B and CRF01_AE, respectively, and 9% are superinfections. With increases in risk behavior, the fraction of superinfections rises. If treatment reduces the infectivity of CRF01_AE more than that of subtype B, the fraction of subtype B infections should increase. Subtype B should remain prevalent in a small but considerable fraction of the population for a long time. Changes in risk behavior and the introduction of treatment may alter the distribution of subtypes, but CRF01_AE should remain dominant.

Evaluation of change in CD4+ cell counts in AIDS clinical trials

To evaluate the antiretroviral activity of antiretroviral agents and to compare the effects of two different antiretroviral agents, we propose a non-parametric mixed-effects model to investigate change of CD4+ counts. The proposed model and methods are applied to analyse the data from PACTG345 study. Population and individual patterns of change of CD4+ counts and a reference band are obtained. Our results indicate that treatment with high-dose ritonavir is significantly superior compared with low-dose ritonavir.

Case study: accessible primary health care--a foundation to improve health outcomes for people who inject drugs

ISSUE

Injecting drug users (IDUs) represent a large part of the population with HIV globally, however, IDUs continue to have less access to HIV treatment than non-IDUs. While IDUs with HIV potentially fare as well on anti-retroviral therapy (ART) as non-IDUs in terms of HIV disease progression, ART adherence is critical. Opioid dependent IDUs may experience lifestyle instability affecting ART adherence. IDUs often have a range of complex health and social welfare needs beyond HIV.

THE APPROACH

Opioid agonist pharmacotherapies such as methadone maintenance treatment, improve overall health and psychosocial stability among opioid-dependent IDUs. The integration of pharmacotherapies into primary health care settings also allows the direct observation of the concomitant administration of HIV treatments. This dual treatment approach maximises HIV treatment adherence and enables the timely management of other clinical issues. Where relevant, sexual and reproductive, infant and maternal health services should also be incorporated alongside HIV and hepatitis B and C prevention services. Services should be anonymous and confidential, and be provided by a multidisciplinary team in a non-judgemental way. Involvement of IDUs in service planning should also be promoted to ensure the acceptability of the model to the target population.

A CASE STUDY

The Kirketon Road Centre (KRC) in Kings Cross, Australia, is an example of a community-based primary health care service delivery model that comprehensively addresses a range of complex health and social welfare needs IDUs may have. Established in 1987 to prevent HIV/AIDS and other transmissible infections among "at risk" young people, IDUs and commercial sex workers, the KRC model has also proven versatile in upscaling to meet hepatitis C and other emerging health needs of IDUs in a timely way.

CONCLUSION

Integrated primary health care models should be promoted more widely as a foundation to improve the health outcomes of IDUs.

Model Projections on the Required Coverage of Syringe Distribution to Prevent HIV Epidemics Among Injecting Drug Users

BACKGROUND

Although syringe distribution is effective in preventing HIV transmission among injecting drug users (IDUs), there is little evidence on the required coverage to substantially reduce HIV transmission.

METHODS

A mathematical model is developed to explore the relationship between the endemic HIV prevalence among IDUs and the coverage of syringe distribution. Data from IDU populations in the United Kingdom and Belarus are used to explore the implications of increasing coverage and the effect of changes in other behaviors.

RESULTS

Projections suggest that there is a coverage threshold, which, if reached, could lead to substantial decreases in HIV prevalence. The threshold largely depends on the frequency that IDUs inject and (safely) reuse their syringes, and corresponds to less than 4 syringe-sharing events per IDU per month. Other factors, such as the injecting cessation rate and efficacy of syringe cleaning, only have substantial impact near threshold coverage levels.

CONCLUSIONS

Our results support a policy of increasing the coverage of syringe distribution but highlight the difficulty in producing a universal coverage target. Great public health benefit could be conferred by encouraging the safe reuse of an IDU's own syringes and small stable injecting groups. Policies that discourage this will negate the impact of syringe distribution interventions.

Access to highly active antiretroviral therapy for injection drug users: adherence, resistance, and death

Injection drug users (IDUs) continue to comprise a major risk group for HIV infection throughout the world and represent the focal population for HIV epidemics in Asia and Eastern Europe/Russia. HIV prevention programs have ranged from HIV testing and counseling, education, behavioral and network interventions, drug abuse treatment, bleach disinfection of needles, needle exchange and expanded syringe access, as well as reducing transition to injection and primary substance abuse prevention. With the advent of highly active antiretroviral therapy (HAART) in 1996, dramatic clinical improvements have been seen. In addition, the treatment's impact on reducing HIV viral load (and therefore transmission by all routes) provides a stronger rationale for an expansion of the focus on prevention to emphasize early identification and treatment of HIV infected individuals. However, treatment of IDUs has many challenges including adherence, resistance and relapse to high risk behaviors, all of which impact issues of access and ultimately effectiveness of potent antiretroviral treatment. A major current challenge in addressing the HIV epidemic revolves around an appropriate approach to HIV treatment for IDUs.

The role of substance abuse in HIV disease progression: reconciling differences from laboratory and epidemiologic investigations

From the onset of the HIV/AIDS epidemic, the use of licit and illicit drugs has been investigated for its potential impact on HIV disease progression. Findings from a large number of laboratory-based studies indicate that drug abuse may exacerbate HIV disease progression; however, epidemiological studies have shown mixed results. This article presents a review of findings from both laboratory-based and epidemiologic investigations. In addition, we provide a careful evaluation of methodological strengths and limitations inherent to both study designs in order to provide a more nuanced understanding of how these findings may complement one another.

The relationship between non-injection drug use behaviors on progression to AIDS and death in a cohort of HIV seropositive women in the era of highly active antiretroviral therapy use

AIMS

To evaluate the effects of longitudinal patterns and types of non-injection drug use (NIDU) on HIV progression in the highly active antiretroviral therapy (HAART) era.

DESIGN

Women's Interagency HIV Study (WIHS), a prospective cohort study conducted at six US sites.

METHODS

Data were collected semi-annually from 1994 to 2002 on 1046 HIV(+) women. Multivariate Cox proportional hazards modeling was used to estimate relative hazards for developing AIDS and for death by pattern and type of NIDU.

FINDINGS

During follow-up, 285 AIDS events and 287 deaths, of which 177 were AIDS-related, were reported. At baseline, consistent and former NIDU was associated with CD4(+) counts of < 200 cells/microl (43% and 46%, respectively) and viral load > 40,000 copies/ml (53% and 55%, respectively). Consistent NIDU reported less HAART use (53%) compared with other NIDU patterns. Stimulant use was associated with CD4(+) cell counts of < 200 cells/microl (53%) and lower HAART initiation (63%) compared with other NIDU types. In multivariate analyses, progression to AIDS was significantly higher among consistent (RH = 2.52), inconsistent (RH = 1.63) and former (RH = 1.56) users compared with never users; and for stimulant (RH = 2.04) and polydrug (RH = 1.65) users compared with non-users. Progression to all-cause death was higher only among former users (RH = 1.48) compared with never users in multivariate analysis. NIDU behaviors were not associated with progression to AIDS-related death.

CONCLUSIONS

In this study, pattern and type of NIDU were associated with HIV progression to AIDS and all-cause mortality. These differences were associated with lower HAART utilization among consistent NIDU and use of stimulants, and poor baseline immunological and virological status among former users.

Potential cost-effectiveness of a preventive hepatitis C vaccine in high risk and average risk populations in Canada

Hepatitis C virus (HCV) vaccine development remains at an early stage. We explored the economic and health consequences of potential HCV vaccines by comparing universal vaccination with a hepatitis C vaccine to no vaccination in two groups: (1) injecting drug users (IDU); (2) all 12 year olds, using a Markov cohort simulation. Among IDUs, vaccination would avert 248 cases of HCV infection and 89 HCV-related deaths per 1000 individuals, and reduce costs. In average risk cohorts, vaccination did not reduce costs but was reasonably cost effective. These results provide encouragement to vaccine developers that a vaccine that is moderately effective and reasonably priced should not face economic barriers to implementation and will be attractive to third party payers.

Sex and the course of HIV infection in the pre- and highly active antiretroviral therapy eras

We reviewed the available literature on the potential effects of sex on the course of HIV infection and found that there is little evidence for sex differences in the rate of disease progression in the pre-highly active antiretroviral therapy (HAART) and HAART era. Compared to men, women appeared to have lower HIV RNA levels and higher CD4 cell counts shortly after infection with HIV, but studies were inconclusive regarding whether these differences diminish over time. Differences in viral load or CD4+ cell count might cause women to delay initiation of HAART. Nonetheless, we found no substantial sex difference in the benefit of antiretroviral therapy. The studies we reviewed failed to find any harmful effect of pregnancy on HIV disease progression. With the availability of effective antiretroviral agents, HIV-infected women have increasingly decided to have children. Conflicting results exist on the effect of HAART on regression of cervical intra-epithelial neoplasia (CIN). Unlike CIN, invasive cervical cancer has not been found to be much higher in HIV-infected women than in HIV-uninfected women. Although publication bias cannot be ruled out, published studies suggest higher rates of adverse events among HIV-infected women on therapy as compared to men. As more pharmacological agents are developed, it is especially important that potential sex differences in pharmacodynamics are assessed. The relationship between metabolic abnormalities, changes in body habitus, and endocrine perturbations has not been extensively studied. Whether sex differences are due to unalterable genetic factors or social and environmental conditions, it is imperative that all HIV-infected individuals have equal access to interventions that can slow disease progression.

Interaction between HIV and intravenous heroin abuse?

In this article I will review the findings of the potential interactive effects of HIV infection and heroin use as observed in both clinical and laboratory studies. Some of the findings are discrepant and I will endeavour to propose models that could accommodate these variant results as well as suggest factors that could be considered in analysing future investigations in order to resolve these apparent discrepancies.

Retinoids and drugs of abuse: implications for neurological disease risk in human immunodeficiency virus type 1 infection

Among injection drug users, human immunodeficiency virus (HIV) type 1 infection may be associated with an increased risk of nervous system disease. For HIV-infected drug users with vitamin A deficiency, the overall risk of HIV-related morbidity and mortality may also be higher. In previous studies, levels of retinol, retinol-binding protein, and transthyretin in samples from such individuals were examined and found to be lower than such levels in seronegative control subjects. Also, in studies using an activated mononuclear cell line, all-trans retinoic acid and 9-cis retinoic acid suppressed production of the tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma. However, simultaneous exposure of the cells to morphine at a concentration similar to that to which drug users are exposed resulted in increased production of these cytokines. Therefore, morphine may alter the immunomodulatory effects of retinoids, thereby potentially affecting the clinical outcome of studies involving retinoid administration to HIV-infected drug users and increasing the risk for the development of HIV-related complications, including neurological disease.

Clinical and immunologic progression in HIV-infected US women before and after the introduction of highly active antiretroviral therapy

OBJECTIVE

To examine factors associated with clinical and immunologic HIV disease progression in a cohort of US women.

DESIGN

Analysis of data from a prospective, longitudinal, case-control study of HIV-infected women followed every 6 months for 7 years.

SETTING

Four urban clinical centers in the United States.

PARTICIPANTS

648 HIV-infected women who did not have AIDS at time of entry into the study.

MEASUREMENTS

Structured clinical and behavioral interviews; protocol-directed physical examinations; CD4 lymphocyte counts; plasma HIV RNA; infectious pathogen serologies. RESULTS With 2304 women-years of follow-up, 46.1% of the women developed AIDS; however, 93.3% of the diagnoses were based on CD4 counts dropping to <200 cells/mm(3). Only 10.6% of the women with CD4 counts <200 cells/mm(3) developed an opportunistic infection. Baseline CD4 count was the strongest predictor of subsequent clinical progression. Illicit substance use, multiple pregnancies, demographic variables, and other infections were not associated with progression. Among women with CD4 counts >500 cells/mm(3) at baseline, those who were anemic or had hepatitis C were more likely to progress to AIDS. By the end of the study, only 52% of the participants were on highly active antiretroviral therapy (HAART).

CONCLUSIONS

Despite underutilization of HAART in this multicenter cohort of urban women, opportunistic infections were uncommon, despite CD4 declines.

Assessing limiting factors to the acceptance of antiretroviral therapy in a large cohort of injecting drug users

OBJECTIVE

A comprehensive questionnaire was designed to assess the knowledge and understanding of injecting drug users (IDUs) regarding their HIV disease, and to determine any factors that may increase the acceptance of antiretroviral therapy (ART) by this group.

RESULTS

Twenty percent of the total IDU cohort attending the GUIDE (GenitoUrinary Medicine and Infectious Diseases) clinic participated in the study. Fifty-two percent had been homeless in the past 5 years and 84% are unemployed. Seventy-two percent of patients did not complete second level education and 10% were illiterate. Fifty-one percent had siblings or parents with a history of injection drug misuse, and 25% had at least one sibling also HIV positive. Forty-seven percent started using drugs before the age of 13 years, and the most common initial drug was heroin (44%). Ninety-five percent had attended for methadone maintenance therapy (MMT), with 39% currently attending for daily therapy. The majority of patients were unable to simply explain or interpret CD4 cell counts (54%) and 'viral loads' (65%). Fifty-seven percent of patients were receiving highly active antiretroviral therapy (HAART). There was a statistically significant association between patients receiving HAART and both attendance at a primary care physician for methadone maintenance therapy (P = 0.005), and weekly take-outs of methadone (P = 0.005). There was also an association between adherence to HAART and attendance at a methadone maintenance clinic (P = 0.04).

CONCLUSIONS

This study highlights the chaotic lifestyle and complex social background of the IDU. Such factors were not, however, associated with acceptance of HAART. The primary factor associated with both the acceptance of and adherence to HAART was regular and stable attendance for methadone therapy.

HIV-1 infection in injection drug users

Injection drug use is an efficient and ongoing means of HIV transmission and is the principal mode of transmission in some parts of the world. In the United States, approximately 10,000 injection drug users are believed to acquire HIV each year. The US Public Health Service hopes to decrease all HIV transmission in the United States by 50% in the next 5 years, by promoting care and prevention services to infected persons. Subtle differences in the virology and immunopathogenesis of HIV between injection drug users and other groups at risk are still being investigated. So far such differences have no practical implication. Comparison of progression rates and survival with HIV across risk groups has been difficult because of the many competing causes of death unrelated to HIV among injection drug users, but overall HIV disease progression rates are similar across risk groups, after adjusting for age. Some AIDS-related opportunistic infections are more common (such as tuberculosis) or less common (such as Kaposi's sarcoma) among injection drug users, based on rates of exposure and latent infection. Other comorbidities, including chronic psychiatric disorders and hepatitis C disease, are more common among injection drug users than among others with HIV infection. Highly active antiretroviral treatment seems to be as effective in persons with a history of injected drug use as in others. Increasing the numbers of HIV-infected injection drug users who know their diagnosis, increasing their access to care and prevention services, and increasing their adherence to a therapeutic regimen are the current challenges in confronting the HIV-epidemic among injection drug users. To overcome these obstacles, clinicians must have both technical knowledge and skill in assisting patients with behavior change.

Factors influencing HIV progression in a seroconverter cohort in Madrid from 1985 to 1999

OBJECTIVE

To study HIV progression from seroconversion over a 15 year period and measure the population effectiveness of highly active antiretroviral therapy (HAART).

METHODS

A cohort study of people with well documented dates of seroconversion. Cumulative risk of AIDS and death were calculated by extended Kaplan-Meier allowing for late entry. Cox proportional hazards models were used to study variables associated with HIV progression. To assess the impact of HAART, calendar time was divided in three periods; before 1992, 1992-6, and 1997-9.

RESULTS

From January 1985 to May 2000, 226 seroconverters were identified. The median seroconversion interval was 11 months, median seroconversion date was March 1993. 202 (89%) were men, 76% of whom were homo/bisexual. A 66% reduction in progression to AIDS was observed in 1997-9 compared to 1992-96 (HR 0.34 95% CI: 0.16 to 0.70). People with primary education appeared to have faster progression to AIDS compared to those with university studies (HR 2.69 95%CI: 1.17 to 6.16). An 82% reduction in mortality from HIV seroconversion was observed in 1997-9 (HR 0.18 95% CI: 0.05 to 0.68) compared to 1992-6. Progression to death for people with primary education was twice as fast as for those with university education (p 0.0007). People without confirmation of an HIV negative test had faster progression (HR 4.47 95% CI: 1.18 to 16.92).

CONCLUSIONS

The reduction in progression to AIDS and death from seroconversion from 1992-6 to 1997-9 in Madrid is likely to be attributable to HAART. HIV progression was faster in subjects with primary education; better educational level may be associated with better adherence to medication.

Improved methods and assumptions for estimation of the HIV/AIDS epidemic and its impact: Recommendations of the UNAIDS Reference Group on Estimates, Modelling and Projections

UNAIDS and WHO produce biannual country-specific estimates of HIV/AIDS and its impact. These estimates are based on methods and assumptions that reflect the best understanding of HIV epidemiology and demography at the time. Where significant advances are made in epidemiological and demographic research, the methods and assumptions must evolve to match these advances. UNAIDS established an Epidemiology Reference Group in 1999 to advise them and other organisations on HIV epidemiology and methods for making estimates and projections of HIV/AIDS. During the meeting of the reference group in 2001, four priority areas were identified where methods and assumptions should be reviewed and perhaps modified: a) models of the HIV epidemic, b) survival of adults with HIV-1 in low and middle income countries, c) survival of children with HIV-1 in low and middle income countries, and d) methods to estimate numbers of AIDS orphans. Research and literature reviews were carried out by Reference Group members and invited specialists, prior to meetings held during 2001-2. Recommendations reflecting the consensus of the meeting participants on the four priority areas were determined at each meeting. These recommendations were followed in UNAIDS and WHO development of country-specific estimates of HIV/AIDS and its impact for end of 2001.

HIV-1 infection in rural Africa: is there a difference in median time to AIDS and survival compared with that in industrialized countries?

OBJECTIVES

To describe the progression times of HIV-1 infection from seroconversion to AIDS and to death, and time from first developing AIDS to death in rural Uganda. Also, to describe the proportion of individuals within the cohort dying with AIDS and the CD4 lymphocyte count before death.

DESIGN

A prospective, longitudinal, population-based cohort.

METHODS

Since 1990, 107 HIV-prevalent cases, 168 incident cases and 235 HIV-seronegative controls have been recruited into a cohort in rural Uganda. Participants are recruited from the general population and they are reviewed routinely every 3 months and at other times when ill.

RESULTS

The median time from seroconversion to death was 9.8 years. Age over 40 years at seroconversion was associated with more rapid progression (P < 0.001, log rank test). For the first 4 years of the study, HIV contributed little to the death rates in the HIV incident cases, but after 5 years, the contribution of HIV became greater and was particularly marked in the oldest age group. Survival rates in the cohort were similar to those in the general population. The median time from seroconversion to AIDS was 9.4 years and from AIDS to death was 9.2 months. Of those infected with HIV-1, 80% died with AIDS and 20% had a CD4 count < 10 x 106 cells/l.

CONCLUSIONS

Survival with HIV-1 infection is similar in Africa to industrialized countries before the use of antiretroviral therapy; when they do die, many of those in Africa are severely immunosuppressed and most have clinical features of AIDS.

Factors related to virologic failure among HIV-positive injecting drug users treated with combination antiretroviral therapy including two nucleoside reverse transcriptase inhibitors and nevirapine

Treatment strategies in human immunodeficiency virus (HIV)-positive active injecting drug users (IDUs) must take into account their lifestyles, that often result in low adherence to therapy. The nonnucleoside reverse transcriptase inhibitors (NNRTI) offer simpler treatment regimens, but the appearance of drug resistance during treatment failure may cause high levels of cross-resistance to all NNRTIs. We adopted a combination therapy of two NRTIs and nevirapine (NVP) for treatment of IDU patients to evaluate its feasibility in such patients. From October 1998 to December 1999, demographic, clinical, and laboratory data from 80 IDUs on this regimen were collected. Fisher's exact test, Kaplan Meier method, and Cox model were used for statistical analysis. Overall, 20 IDUs discontinued the treatment because of side effects and 20 IDUs experienced treatment failure. Considering the treatment failure as an end point, 55.6% (95% confidence interval [CI]: 37.9%-72.6%) of patients was still undergoing treatment after 12 months compared to 44.6% (31.8%-58.6%) when discontinuation was also taken into account. An increasing trend over time was observed in the CD4+ lymphocyte count, among failing and nonfailing IDUs. By multivariate analysis, baseline HIV-RNA, treatment breaks and low adherence and active injecting drug use turned out to be significantly associated with treatment failure. Our results show that continuing injecting drug use and treatment breaks are the main factors that can lead to treatment failure in IDUs and easily to NNRTI class resistance.

Initial plasma HIV-1 RNA levels and progression to AIDS in women and men

BACKGROUND

It is unclear whether there are differences between men and women with human immunodeficiency virus type 1 (HIV-1) infection in the plasma level of viral RNA (the viral load). In men, the initial viral load after seroconversion predicts the likelihood of progression to the acquired immunodeficiency syndrome (AIDS), but the relation between the two has not been assessed in women. Currently, the guidelines for initiating antiretroviral therapy are applied uniformly to women and men.

METHODS

From 1988 through 1998, the viral load and the CD4+ lymphocyte count were measured approximately every six months in 156 male and 46 female injection-drug users who were followed prospectively after HIV-1 seroconversion.

RESULTS

The median initial viral load was 50,766 copies of HIV-1 RNA per milliliter in the men but only 15,103 copies per milliliter in the women (P<0.001). The median initial CD4+ count did not differ significantly according to sex (659 and 672 cells per cubic millimeter, respectively). HIV-1 infection progressed to AIDS in 29 men and 15 women, and the risk of progression did not differ significantly according to sex. For each increase of 1 log in the viral load (on a base 10 scale), the hazard ratio for progression to AIDS was 1.55 (95 percent confidence interval, 0.97 to 2.47) among the men and 1.43 (95 percent confidence interval, 0.76 to 2.69) among the women. The median initial viral load was 77,822 HIV-1 RNA copies per milliliter in the men in whom AIDS developed and 40,634 copies per milliliter in the men in whom it did not; the corresponding values in the women were 17,149 and 12,043 copies per milliliter. Given the recommendation that treatment should be initiated when the viral load reaches 20,000 copies per milliliter, 74 percent of the men but only 37 percent of the women in our study would have been eligible for therapy at the first visit after seroconversion (P<0.001).

CONCLUSIONS

Although the initial level of HIV-1 RNA was lower in women than in men, the rates of progression to AIDS were similar. Treatment guidelines that are based on the viral load, rather than the CD4+ lymphocyte count, will lead to differences in eligibility for antiretroviral treatment according to sex.