Longitudinal community plasma HIV-1 RNA concentrations and incidence of HIV-1 among injecting drug users: prospective cohort study

Burden of HIV and tuberculosis co-infection in Montreal, Quebec

OBJECTIVE

Define the burden of HIV-TB co-infection and predictors of HIV screening among incident TB cases.

METHODS

Analysis of surveillance data on TB incident cases reported to Montreal's Public Health Department from 2004 to 2009. Among all reported TB cases, proportions of cases with HIV testing and HIV infection were calculated by patient characteristics. A test for linear trends was performed on the annual proportions of HIV-tested and HIV-positive cases. Adjusted odds ratios (AOR) for HIV testing at time of TB diagnosis were computed.

RESULTS

A total of 778 incident TB cases were included in the analysis. HIV testing was reported for 50.8% (n=395) of cases. The proportion of HIV-tested cases increased significantly from 43% in 2004 to 70% in 2009. HIV-TB co-infection was found in 9.3% of patients with reported HIV status or in 4.2% of the overall cohort. HIV prevalence was high in men, individuals aged 40-59, those originating from Sub-Saharan Africa and the Caribbean, and the homeless. Multivariate analysis revealed that HIV testing at time of TB diagnosis was performed mainly for subjects born in the Caribbean, Central or South America, or Sub-Saharan Africa, those with pulmonary disease, and injection drug users.

CONCLUSIONS

Although reporting of HIV testing among incident TB patients increased, targeted HIV testing still occurs. HIV prevalence in TB cases remained stable during the study period; however, it may be underestimated due to missed opportunities for HIV testing and under-reporting.

Cohort profile: Seek and treat for the optimal prevention of HIV/AIDS in British Columbia (STOP HIV/AIDS BC)

The Seek and Treat for Optimal Prevention of HIV/AIDS (STOP HIV/AIDS) cohort is a census of all identified HIV-positive individuals in the province of British Columbia. It was formed through the linkage of nine provincial treatment, surveillance and administrative databases. This open cohort allows for bidirectional analyses from 1996 onward and is refreshed annually. Extensive data collection for cohort members includes demographic information, detailed clinical and laboratory data, complete prescription drug use including antiretroviral agents, and information on health service utilization encompassing inpatient and outpatient care, addictions treatment and palliative care. This cohort provides an unprecedented opportunity to evaluate, over an extended time period, patterns and determinants of key outcomes including engagement in the cascade of HIV care from diagnosis to treatment to viral suppression as well as monitoring trends in medical costs, health outcomes and other key healthcare delivery indicators at a population level with wide-ranging, high-quality data. The overall purpose of these activities is to enable the development and implementation of strategically targeted interventions to improve access to testing, care and treatment for all HIV-positive individuals living in British Columbia.

Changes in HIV incidence among people who inject drugs in Taiwan following introduction of a harm reduction program: a study of two cohorts

BACKGROUND

Harm reduction strategies for combating HIV epidemics among people who inject drugs (PWID) have been implemented in several countries. However, large-scale studies using sensitive measurements of HIV incidence and intervention exposures in defined cohorts are rare. The aim of this study was to determine the association between harm reduction programs and HIV incidence among PWID.

METHODS AND FINDINGS

The study included two populations. For 3,851 PWID who entered prison between 2004 and 2010 and tested HIV positive upon incarceration, we tested their sera using a BED HIV-1 capture enzyme immunoassay to estimate HIV incidence. Also, we enrolled in a prospective study a cohort of 4,357 individuals who were released from prison via an amnesty on July 16, 2007. We followed them with interviews at intervals of 6-12 mo and by linking several databases. A total of 2,473 participants who were HIV negative in January 2006 had interviews between then and 2010 to evaluate the association between use of harm reduction programs and HIV incidence. We used survival methods with attendance at methadone clinics as a time-varying covariate to measure the association with HIV incidence. We used a Poisson regression model and calculated the HIV incidence rate to evaluate the association between needle/syringe program use and HIV incidence. Among the population of PWID who were imprisoned, the implementation of comprehensive harm reduction programs and a lower mean community HIV viral load were associated with a reduced HIV incidence among PWID. The HIV incidence in this population of PWID decreased from 18.2% in 2005 to 0.3% in 2010. In an individual-level analysis of the amnesty cohort, attendance at methadone clinics was associated with a significantly lower HIV incidence (adjusted hazard ratio: 0.20, 95% CI: 0.06-0.67), and frequent users of needle/syringe program services had lower HIV incidence (0% in high NSP users, 0.5% in non NSP users). In addition, no HIV seroconversions were detected among prison inmates.

CONCLUSIONS

Although our data are affected by participation bias, they strongly suggest that comprehensive harm- reduction services and free treatment were associated with reversal of a rapidly emerging epidemic of HIV among PWID. Please see later in the article for the Editors' Summary.

How does population viral load vary with the evolution of a large HIV epidemic in sub-Saharan Africa?

Using mathematical modelling, we describe the temporal evolution of population HIV-1 viral load in Tanzania throughout the epidemic. Population log₁₀ viral load was found to be stable and not sensitive to epidemic dynamics. However, even modest increases in antiretroviral therapy (ART) coverage were reflected as appreciable reductions in population log₁₀ viral load. As ART coverage expands in sub-Saharan Africa, population log₁₀ viral load will increasingly become a powerful proxy for monitoring ART implementation and HIV incidence trends.

Trends in plasma HIV-RNA suppression and antiretroviral resistance in British Columbia, 1997-2010

OBJECTIVES

To examine temporal trends in plasma viral load (pVL) suppression and antiretroviral resistance from 1997 to 2010 in British Columbia (BC), Canada, and determine characteristics, pVL ranges, and resistance profiles of HIV-positive individuals with unsuppressed pVL in 2010.

METHODS

HIV-positive individuals ≥19 years old in the provincial database at the BC Centre for Excellence in HIV/AIDS were included. Virological suppression was defined as 2 consecutive pVL <500 copies per milliliter within each calendar year. Temporal trends were evaluated using the Cochran-Armitage test. Persons with suppressed vs. unsuppressed pVL in 2010 were compared using the Pearson χ² or Fisher exact test (categorical variables) and the Wilcoxon rank-sum test (quantitative variables), including unsuppressed individuals only if they were on antiretroviral therapy (ART) in 2010 or their baseline CD4 count was <350 cells per cubic millimeter or <500 cells per cubic millimeter, in separate analyses.

RESULTS

The proportion of individuals with suppressed pVL increased from 24% to 80% (P < 0.001). In comparative analyses, individuals with unsuppressed pVL (877 of 6142) were more likely to be female (30% vs. 16%), younger (median, 43 vs. 48 years), have injection drug use history (38% vs. 30%), report Aboriginal ancestry (30% vs. 16%), and have hepatitis C coinfection (57% vs. 34%) (all P < 0.001). Similar patterns were observed using the <500 cells per cubic millimeter CD4 cutoff. The median pVL of all unsuppressed individuals in 2010 was 12,896 copies per milliliter (interquartile range, 1495-47,763).

CONCLUSIONS

The proportion of individuals achieving pVL suppression in BC has increased markedly since 1997; however, further efforts are needed to maximize the individual and societal benefits of modern antiretroviral therapy.

Antiretrovirals for HIV prevention: when should they be recommended?

Since the introduction of the first antiretroviral agent for HIV treatment, information on antiretroviral therapy (ART) effectiveness has grown continuously. In recent years, there has also been a growth of interest in use of ART for the prevention of HIV transmission, either by reducing the infectivity of the infected person or by protecting the uninfected individuals from HIV acquisition. The purpose of this review is to summarize the body of evidence available for treatment as prevention and pre-exposure prophylaxis and their effectiveness in prevention of infection. In addition, our aim is to discuss the operational aspects of both prevention strategies and to provide commentary for future HIV prevention programs.

Improving antiretroviral therapy scale-up and effectiveness through service integration and decentralization

BACKGROUND

Current service delivery systems do not reach all people in need of antiretroviral therapy (ART). In order to inform the operational and service delivery section of the WHO 2013 consolidated antiretroviral guidelines, our objective was to summarize systematic reviews on integrating ART delivery into maternal, newborn, and child health (MNCH) care settings in countries with generalized epidemics, tuberculosis (TB) treatment settings in which the burden of HIV and TB is high, and settings providing opiate substitution therapy (OST); and decentralizing ART into primary health facilities and communities.

DESIGN

A summary of systematic reviews.

METHODS

The reviewers searched PubMed, Embase, PsycINFO, Web of Science, CENTRAL, and the WHO Index Medicus databases. Randomized controlled trials and observational cohort studies were included if they compared ART coverage, retention in HIV care, and/or mortality in MNCH, TB, or OST facilities providing ART with MNCH, TB, or OST facilities providing ART services separately; or primary health facilities or communities providing ART with hospitals providing ART.

RESULTS

The reviewers identified 28 studies on integration and decentralization. Antiretroviral therapy integration into MNCH facilities improved ART coverage (relative risk [RR] 1.37, 95% confidence interval [CI] 1.05-1.79) and led to comparable retention in care. ART integration into TB treatment settings improved ART coverage (RR 1.83, 95% CI 1.48-2.23) and led to a nonsignificant reduction in mortality (RR 0.55, 95% CI 0.29-1.05). The limited data on ART integration into OST services indicated comparable rates of ART coverage, retention, and mortality. Partial decentralization into primary health facilities improved retention (RR 1.05, 95% CI 1.01-1.09) and reduced mortality (RR 0.34, 95% CI 0.13-0.87). Full decentralization improved retention (RR 1.12, 95% CI 1.08-1.17) and led to comparable mortality. Community-based ART led to comparable rates of retention and mortality.

CONCLUSION

Integrating ART into MNCH, TB, and OST services was often associated with improvements in ART coverage, and decentralization of ART into primary health facilities and communities was often associated with improved retention. Neither integration nor decentralization was associated with adverse outcomes. These data contributed to recommendations in the WHO 2013 consolidated antiretroviral guidelines to integrate ART delivery into MNCH, TB, and OST services and to decentralize ART.

Expansion of HAART coverage is associated with sustained decreases in HIV/AIDS morbidity, mortality and HIV transmission: the "HIV Treatment as Prevention" experience in a Canadian setting

Background

There has been renewed call for the global expansion of highly active antiretroviral therapy (HAART) under the framework of HIV treatment as prevention (TasP). However, population-level sustainability of this strategy has not been characterized.

Methods

We used population-level longitudinal data from province-wide registries including plasma viral load, CD4 count, drug resistance, HAART use, HIV diagnoses, AIDS incidence, and HIV-related mortality. We fitted two Poisson regression models over the study period, to relate estimated HIV incidence and the number of individuals on HAART and the percentage of virologically suppressed individuals.

Results

HAART coverage, median pre-HAART CD4 count, and HAART adherence increased over time and were associated with increasing virological suppression and decreasing drug resistance. AIDS incidence decreased from 6.9 to 1.4 per 100,000 population (80% decrease, p = 0.0330) and HIV-related mortality decreased from 6.5 to 1.3 per 100,000 population (80% decrease, p = 0.0115). New HIV diagnoses declined from 702 to 238 cases (66% decrease; p = 0.0004) with a consequent estimated decline in HIV incident cases from 632 to 368 cases per year (42% decrease; p = 0.0003). Finally, our models suggested that for each increase of 100 individuals on HAART, the estimated HIV incidence decreased 1.2% and for every 1% increase in the number of individuals suppressed on HAART, the estimated HIV incidence also decreased by 1%.

Conclusions

Our results show that HAART expansion between 1996 and 2012 in BC was associated with a sustained and profound population-level decrease in morbidity, mortality and HIV transmission. Our findings support the long-term effectiveness and sustainability of HIV treatment as prevention within an adequately resourced environment with no financial barriers to diagnosis, medical care or antiretroviral drugs. The 2013 Consolidated World Health Organization Antiretroviral Therapy Guidelines offer a unique opportunity to further evaluate TasP in other settings, particularly within generalized epidemics, and resource-limited setting, as advocated by UNAIDS.

A multicenter study of initiation of antiretroviral therapy and transmitted drug resistance in antiretroviral-naive adolescents and young adults with HIV in New York City

BACKGROUND

In December 2009, the Department of Health and Human Services guidelines for initiation of antiretroviral therapy (ART) changed to include patients with CD4 counts between 350 and 500 cells/µL. The aims of this study were to assess uptake of this recommendation in ART-naive youth with human immunodeficiency virus (HIV) and to describe the epidemiology of transmitted genotypic drug resistance mutations (DRMs) in this population.

METHODS

A multicenter, retrospective cohort study of ART initiation in ART-naive youth was performed. Eligible subjects were 13-25 years of age, were diagnosed with HIV within 1 year of presentation to care at the study sites, and presented to care from January 2007 to June 2011.

RESULTS

Of 685 potential subjects identified, 331 (49%) fulfilled inclusion criteria. Mean CD4 count at presentation to care was 452 cells/µL. Overall, 191 (58%) subjects started ART. The mean CD4 count at ART initiation was 261 cells/µL before and 363 cells/µL after the 2009 guideline change (P < .0001). Of 212 (64%) subjects with resistance testing available prior to ART initiation, 38 (18%) subjects had a major DRM and an increased proportion of resistance was seen in later study years.

CONCLUSIONS

Our study demonstrated an uptake in recently changed guideline recommendations to treat HIV-infected individuals at higher CD4 counts and reinforces the importance of performing resistance testing at entry into care, as 18% of our population had major DRMs prior to initiation of ART.

Community HIV-1 drug resistance is associated with transmitted drug resistance

OBJECTIVES

As community viral load (CVL) measurements are associated with the incidence of new HIV-1 infections in a population, we hypothesized that similarly measured community drug resistance (CDR) could predict the prevalence of transmitted drug resistance (TDR).

METHODS

Between 2001 and 2011, the prevalences of HIV-1 drug resistance for patients with established infection receiving HIV care (i.e. CDR) and TDR in recently infected patients were determined in San Diego. At each position in HIV-1 reverse transcriptase (RT) and protease (pro), drug resistance was evaluated both as the overall prevalence of resistance-associated mutations and by weighting each resistance position to the concurrent viral load of the patient and its proportion to the total viral load of the clinic (CVL). The weighting was the proportion of the CVL associated with patients identified with resistance at each residue. Spearman ranked correlation coefficients were used to determine associations between CDR and TDR.

RESULTS

We analysed 1088 resistance tests for 971 clinic patients and baseline resistance tests for 542 recently infected patients. CDR at positions 30, 46, and 88 in pro was associated with TDR between 2001 and 2011. When CDR was weighted by the viral load of patients, CDR was associated with TDR at position 103 in RT. Each of these associations was corroborated at least once using shorter measurement intervals.

CONCLUSIONS

Despite evaluation of a limited percentage of chronically infected patients in San Diego, CDR correlated with TDR at key resistance positions and therefore may be a useful tool with which to predict the prevalence of TDR.

Monitored viral load: a measure of HIV treatment outcomes in an outpatient setting in Rhode Island

Community viral load measurements have been postulated to be a population-based biomarker of HIV disease. We propose the use of the monitored community viral load (mCVL) as an aggregate measure of viral load among persons receiving HIV care with available HIV-1 plasma viral loads and applied it to our clinic population from 2003-2010. We demonstrated a reduction in mCVL from 16,589 copies/ml to 11,992 copies/ml that correlated with a rising rate of antiretroviral use and HIV viral suppression; however, differences among risk populations were observed. The mCVL is a useful measure of HIV burden among patients in-care; it may reflect the HIV transmission risk in the community and help target preventive interventions.

Integration of health services improves multiple healthcare outcomes among HIV-infected people who inject drugs in Ukraine

BACKGROUND

People who inject drugs (PWID) experience poor outcomes and fuel HIV epidemics in middle-income countries in Eastern Europe and Central Asia. We assess integrated/co-located (ICL) healthcare for HIV-infected PWID, which despite international recommendations, is neither widely available nor empirically examined.

METHODS

A 2010 cross-sectional study randomly sampled 296 HIV-infected opioid-dependent PWID from two representative HIV-endemic regions in Ukraine where ICL, non-co-located (NCL) and harm reduction/outreach (HRO) settings are available. ICL settings provide onsite HIV, addiction, and tuberculosis services, NCLs only treat addiction, and HROs provide counseling, needles/syringes, and referrals, but no opioid substitution therapy (OST). The primary outcome was receipt of quality healthcare, measured using a quality healthcare indicator (QHI) composite score representing percentage of eight guidelines-based recommended indicators met for HIV, addiction and tuberculosis treatment. The secondary outcomes were individual QHIs and health-related quality-of-life (HRQoL).

RESULTS

On average, ICL-participants had significantly higher QHI composite scores compared to NCL- and HRO-participants (71.9% versus 54.8% versus 37.0%, p<0.001) even after controlling for potential confounders. Compared to NCL-participants, ICL-participants were significantly more likely to receive antiretroviral therapy (49.5% versus 19.2%, p<0.001), especially if CD4 ≤ 200 (93.8% versus 62.5% p<0.05); guideline-recommended OST dosage (57.3% versus 41.4%, p<0.05); and isoniazid preventive therapy (42.3% versus 11.2%, p<0.001). Subjects receiving OST had significantly higher HRQoL than those not receiving it (p<0.001); however, HRQoL did not differ significantly between ICL- and NCL-participants.

CONCLUSIONS

These findings suggest that OST alone improves quality-of-life, while receiving care in integrated settings collectively and individually improves healthcare quality indicators for PWID.

Late presentation for human immunodeficiency virus HIV diagnosis results of a Belgian single centre

BACKGROUND

Antiretroviral therapy reduces mortality and morbidity in HIVinfected individuals, most markedly when initiated early, before advanced immunodeficiency has developed. Although the international guidelines recommend starting antiretroviral therapy ART with a high CD4 cell count level, in the practice, this is particularly challenging to achieve, especially in late presentation of HIV diagnosis. The aim of this study was to determine the frequency and the demographic features associated with late presentation for HIV diagnosis in our Centre.

METHODS

All newly diagnosed patients with HIV between January 2007 and December 2011 in our AIDS Reference Centre, were included. Late presenter patient was defined as patient with CD4 count 350/mm(3) at the time of diagnosis. Demographic age, sex, ethnicity, migration and clinical characteristics transmission mode, CD4 cell count, viral load were collected. We also collected data on outcome median day of hospitalization, mortality, virological response to ART and lost to followup LTFU. LTFU was defined as patient without any medical contact and viral load measurements during two consecutive years in our centre.

RESULTS

From 2007 to 2011, 154 429 out of 359 patients newly diagnosed with HIV were late presenters. According to univariate analysis, age 50, female gender, migrant from subSaharan Africa and heterosexual contact were associated with late presentation for HIV diagnosis. In the multivariate analysis, age 50, heterosexual contact and migrant status particularly women were the only independent risk factors for late presentation. Late presenters tend to have a worse outcome than nonlate presenters.

CONCLUSION

A considerable proportion of patients continue to be diagnosed with advanced HIV disease, despite the fact that risk factors for late presentation have been clearly identified. Despite high testing rate for HIV in Belgium, highrisk population like migrant, heterosexual contact, remain under tested. In order to be able to detect and treat all patients with high CD4 cell count as recommended by all international guidelines, we recommend developing testing policies specifically focused on these categories at high risk for late presentation.

Safety, tolerability, and immunogenicity of repeated doses of dermavir, a candidate therapeutic HIV vaccine, in HIV-infected patients receiving combination antiretroviral therapy: results of the ACTG 5176 trial

BACKGROUND

HIV-specific cellular immune responses are associated with control of viremia and delayed disease progression. An effective therapeutic vaccine could mimic these effects and reduce the need for continued antiretroviral therapy. DermaVir, a topically administered plasmid DNA-nanomedicine expressing HIV (CladeB) virus-like particles consisting of 15 antigens, induces predominantly central memory T-cell responses.

METHODS

Treated HIV-infected adults (HIV RNA <50 and CD4 >350) were randomized to placebo or escalating DermaVir doses (0.1 or 0.4 mg of plasmid DNA at weeks 1, 7, and 13 in the low- and intermediate-dose groups and 0.8 mg at weeks 0, 1, 6, 7, 12, and 13 in the high-dose group), n = 5-6 evaluable subjects per group. Immunogenicity was assessed by a 12-day cultured interferon-γ enzyme-linked immunosorbent spot assay at baseline and at weeks 9, 17, and 37 using 1 Tat/Rev and 3 overlapping Gag peptide pools (p17, p24, and p15).

RESULTS

Groups were comparable at baseline. The study intervention was well tolerated, without dose-limiting toxicities. Most responses were highest at week 17 (4 weeks after last vaccination) when Gag p24 responses were significantly greater among intermediate-dose group compared with control subjects [median (IQR): 67,600 (5633-74,368) versus 1194 (9-1667)] net spot-forming units per million cells, P = 0.032. In the intermediate-dose group, there was also a marginal Gag p15 response increase from baseline to week 17 [2859 (1867-56,933), P = 0.06], and this change was significantly greater than in the placebo group [0 (-713 to 297), P = 0.016].

CONCLUSIONS

DermaVir administration was associated with a trend toward greater HIV-specific, predominantly central memory T-cell responses. The intermediate DermaVir dose tended to show the greatest immunogenicity, consistent with previous studies in different HIV-infected patient populations.

Closing the gap: increases in life expectancy among treated HIV-positive individuals in the United States and Canada

BACKGROUND

Combination antiretroviral therapy (ART) has significantly increased survival among HIV-positive adults in the United States (U.S.) and Canada, but gains in life expectancy for this region have not been well characterized. We aim to estimate temporal changes in life expectancy among HIV-positive adults on ART from 2000-2007 in the U.S. and Canada.

METHODS

Participants were from the North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD), aged ≥20 years and on ART. Mortality rates were calculated using participants' person-time from January 1, 2000 or ART initiation until death, loss to follow-up, or administrative censoring December 31, 2007. Life expectancy at age 20, defined as the average number of additional years that a person of a specific age will live, provided the current age-specific mortality rates remain constant, was estimated using abridged life tables.

RESULTS

The crude mortality rate was 19.8/1,000 person-years, among 22,937 individuals contributing 82,022 person-years and 1,622 deaths. Life expectancy increased from 36.1 [standard error (SE) 0.5] to 51.4 [SE 0.5] years from 2000-2002 to 2006-2007. Men and women had comparable life expectancies in all periods except the last (2006-2007). Life expectancy was lower for individuals with a history of injection drug use, non-whites, and in patients with baseline CD4 counts <350 cells/mm(3).

CONCLUSIONS

A 20-year-old HIV-positive adult on ART in the U.S. or Canada is expected to live into their early 70 s, a life expectancy approaching that of the general population. Differences by sex, race, HIV transmission risk group, and CD4 count remain.

Potential impact of the US President's Emergency Plan for AIDS relief on the tuberculosis/HIV coepidemic in selected Sub-Saharan African countries

BACKGROUND

There are limited data measuring the impact of expanded human immunodeficiency virus (HIV) prevention activities on the tuberculosis epidemic at the country level. Here, we characterized the potential impact of the US President's Emergency Plan for AIDS Relief (PEPFAR) on the tuberculosis epidemic in sub-Saharan Africa.

METHODS

We selected 12 focus countries (countries receiving the greatest US government investments) and 29 nonfocus countries (controls). We used tuberculosis incidence and mortality rates and relative risks to compare time periods before and after PEPFAR's inception, and a tuberculosis/HIV indicator to calculate the rate of change in tuberculosis incidence relative to the HIV prevalence.

RESULTS

Comparing the periods before and after PEPFAR's implementation, both tuberculosis incidence and mortality rates have diminished significantly and to a higher degree in focus countries. The relative risk for developing tuberculosis, comparing those with and without HIV, was 22.5 for control and 20.0 for focus countries. In most focus countries, the tuberculosis epidemic is slowing down despite some regions still experiencing an increase in HIV prevalence.

CONCLUSIONS

This ecological study showed that PEPFAR had a more consistent and substantial effect on HIV and tuberculosis in focus countries, highlighting the likely link between high levels of HIV investment and broader effects on related diseases such as tuberculosis.

Factors Associated with Late Initiation of Highly Active Antiretroviral Therapy among Young HIV-Positive Men and Women Aged 18 to 29 Years in Canada

Initiating highly active antiretroviral therapy (HAART) with low CD4 counts or AIDS-defining illnesses (ADIs) increases risk of treatment failure and death. We examined factors associated with late initiation among 18- to 29-year-olds within the Canadian Observational Cohort (CANOC) collaboration, a multi-site study of HIV-positive persons who initiated HAART after 2000. Late initiation was defined as beginning HAART with a CD4 count <200 cells/mm3 and/or having a baseline ADI. Multivariable logistic regression was used to identify independent correlates of late initiation. In total, 1026 individuals (422 from British Columbia, 400 from Ontario, and 204 from Quebec) met our age criteria. At HAART initiation, median age was 27 years (interquartile range, 24, 28 years). A total of 412 individuals (40%) identified as late initiators. Late initiation was associated with female gender, age >25 years at initiation, initiating treatment in earlier years, and having higher baseline viral load. The high number of young adults in our cohort starting HAART late indicates important target populations for specialized services, increased testing, and linkages to care.

Antiretroviral treatment interruption and loss to follow-up in two HIV cohorts in Australia and Asia: implications for 'test and treat' prevention strategy

Both antiretroviral treatment interruption (TI) and cessation have been strongly discouraged since 2006. We describe the incidence, duration, and risk factors for TI and loss-to-follow-up (LTFU) rates across 13 countries. All 4689 adults (76% men) in two large HIV cohorts in Australia and Asia commencing combination antiretroviral therapy (ART) to March 2010 were included. TI was defined by ART cessation >30 days, then recommencement, and loss to follow-up (LTFU) by no visit since 31 March 2009 and no record of death. Survival analysis and Poisson regression methods were used. With median follow-up of 4.4 years [interquartile range (IQR):2.1-6.5], TI incidence was 6.7 per 100 person years (PY) (95% CI:6.1-7.3) pre-2006, falling to 2.0 (95% CI:1.7-2.2) from 2006 (p<0.01). LTFU incidence was 3.5 per 100 PY (95% CI:3.1-3.9) pre-2006, and 4.1 (95% CI:3.5-4.9) from 2006 (p=0.22). TIs accounted for 6.4% of potential time on ART pre-2006 and 1.2% from 2006 (p<0.01), and LTFU 4.7% of potential time on ART pre-2006 and 6.6% from 2006 (p<0.01). Median TI duration was 163 (IQR: 75-391) days pre-2006 and 118 (IQR: 67-270) days from 2006 (p<0.01). Independent risk factors for the first TI were: Australia HIV Observational Database participation; ART initiation pre-2006; ART regimens including stavudine and didanosine; three nucleoside analogue reverse transcriptase inhibitors; ≥7 pills per day; and ART with food restrictions (fasting or with food). In conclusion, since 2006, 7.8% of patients had significant time off treatment, which has the potential to compromise any 'test and treat' policy as during the interruption viral load will rebound and increase the risk of transmission.

Incarceration is associated with used syringe lending among active injection drug users with detectable plasma HIV-1 RNA: a longitudinal analysis

Background

Informed by recent studies demonstrating the central role of plasma HIV-1 RNA viral load (VL) on HIV transmission, interventions to employ HIV antiretroviral treatment as prevention (TasP) are underway. To optimize these efforts, evidence is needed to identify factors associated with both non-suppressed VL and HIV risk behaviours. Thus, we sought to assess the possible role played by exposure to correctional facilities on VL non-suppression and used syringe lending among HIV-seropositive people who use injection drugs (PWID).

Methods

We used data from the ACCESS study, a community-recruited prospective cohort. We used longitudinal multivariate mixed-effects analyses to estimate the relationship between incarceration and plasma HIV-1 RNA > 500 copies/mL among antiretroviral therapy (ART)-exposed active PWID and, during periods of non-suppression, the relationship between incarceration and used syringe lending.

Results

Between May 1996 and March 2012, 657 ART-exposed PWID were recruited. Incarceration was independently associated with higher odds of VL non-suppression (Adjusted Odds Ratio [AOR] = 1.54, 95% Confidence Interval [95% CI]: 1.10, 2.16). In a separate multivariate model restricted to periods of VL non-suppression, incarceration was independently associated with lending used syringes (AOR = 1.81, 95% CI: 1.03, 3.18).

Conclusions

The current findings demonstrate that incarceration is associated with used syringe lending among active PWID with detectable plasma HIV-1 RNA. Our results provide a possible pathway for the commonly observed association between incarceration and increased risk of HIV transmission. Our results suggest that alternatives to incarceration of non-violent PWID and evidence-based combination HIV prevention interventions for PWID within correctional facilities are urgently needed.

HIV treatment as prevention: the key to an AIDS-free generation

The presence of elevated HIV viral load within blood and genital secretions is a critical driver of transmission events. Long-term suppression of viral load to undetectable levels through the use of antiretroviral therapy is now standard practice for clinical management of HIV. Antiretroviral therapy therefore can play a key role as a means to curb HIV transmission. Results of a randomized clinical trial, in conjunction with several observational studies, have now confirmed that antiretroviral therapy markedly decreases HIV transmission risk. Mathematical models and population-based ecologic studies suggest that further expansion of antiretroviral coverage within current guidelines can play a major role in controlling the spread of HIV. Expansion of so-called "Treatment as Prevention" initiatives relies upon maximal uptake of the HIV continuum-of-care cascade to allow for successful identification of those not yet known to be HIV-infected, engagement of patients in appropriate care, and subsequently achieving sustained virologic suppression in patients with the use of antiretroviral therapy. Since 2010, the Joint United Nations AIDS (UNAIDS) program has called for the inclusion of antiretroviral treatment as a key pillar in the global strategy to control the spread of HIV infection. This has now been invigorated by the release of the World Health Organization's 2013 Consolidated Antiretroviral Therapy Guidelines, recommending treatment to be offered to all HIV-infected individuals with CD4 cell counts below 500/mm³, and, regardless of CD4 cell count, to serodiscordant couples, TB and HBV co-infected individuals, pregnant women, and children below the age of 5 years.

BRIEF - SYNOPSIS OF THE CURRENT EVIDENCE ON THE RISK OF HIV TRANSMISSION

BACKGROUND

Knowledge of the risk of HIV transmission has evolved over the past decade as evidence on the impact of biological and behavioural co-factors, such as viral load, has come to light. We undertook a comprehensive review of the evidence on the risk of HIV transmission.

METHODS

A search was conducted for literature published between January 2001 and May 2012. The search focused on systematic, meta-analytic, and narrative reviews. For topics where no reviews existed, primary research studies were included.

RESULTS

The risk estimates for the sexual transmission of HIV, per sex act, ranged from 0.5% to 3.38% (with mid-range estimates of 1.4% to 1.69%) for receptive anal intercourse; 0.06% to 0.16% for insertive anal intercourse; 0.08% to 0.19% for receptive vaginal intercourse; and approximately 0.05% to 0.1% for insertive vaginal intercourse. For people who inject drugs, the risk of transmission from a contaminated needle, per injection, was estimated to be between 0.7% and 0.8%. A number of factors impact the risk, including viral load, the presence of other sexually transmitted infections (STIs), and male circumcision.

CONCLUSIONS

Within each route of transmission, estimates of the risk of transmission varied widely, likely due to the role of behavioural and biological co-factors. Viral load appears to be an important predictor of transmission, regardless of the route of transmission. However, the evidence indicates that viral load is not the only determinant and that certain co-factors play a role in increasing (e.g., STIs) or decreasing (e.g., male circumcision) the risk of transmission.

The effect of churn on "community viral load" in a well-defined regional population

BACKGROUND

The concept of community viral load (CVL) was introduced to quantify the pool of transmissible HIV within a community and to monitor the potential impact of highly active antiretroviral therapy (HAART) on reducing new infections. The implications of churn (patient movement in/out of care in a community) on CVL have not been studied.

METHODS

The annual CVL was determined in the entire geographic HIV population receiving care in southern Alberta from 2001 to 2010; the CVL for specific subpopulations was analyzed for 2009. CVL was determined for patients under continuous care, newly diagnosed, new to the region, moved away, returned, and lost to follow-up (LTFU). Viral loads (VLs) <50 or <200 copies per milliliter were deemed undetectable and suppressed, respectively. The mean VL per patient and total VL were used to determine CVL.

RESULTS

From 2001 to 2010, the HAART uptake for all patients increased from 62% to 81%, undetectability from 32% to 66%, and suppression from 49% to 72%. The annual total CVL however did not vary significantly after 2003. Incidence rates for new locally diagnosed infections increased from 4.4 to 5.8/100,000 per year. In 2009, newly diagnosed HIV patients (6.6%) contributed 37.5% to the CVL, whereas patients transferring in/out of the region or lost to follow-up contributed 33% to the CVL. Patients in continuous care (79% of all patients) contributed 29.5% to the total CVL.

CONCLUSIONS

Increasing HAART coverage did not reduce the CVL or reduce new HIV diagnoses in our population. The effect of churn significantly limited CVL use as a measure for evaluating the impact of HAART in reducing HIV transmissions in our population.

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

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

CONCLUSION

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

Understanding the disparity: predictors of virologic failure in women using highly active antiretroviral therapy vary by race and/or ethnicity

BACKGROUND

Stark racial/ethnic disparities in health outcomes exist among those living with HIV in the United States. One of 3 primary goals of the National HIV/AIDS Strategy is to reduce HIV-related disparities and health inequities.

METHODS

Using data from HIV-infected women participating in the Women's Interagency HIV Study from April 2006 to March 2011, we measured virologic failure (HIV RNA >200 copies/mL) after suppression (HIV RNA < 80 copies/mL) on highly active antiretroviral therapy. We identified predictors of virologic failure using discrete time survival analysis and calculated racial/ethnic-specific population-attributable fractions (PAFs).

RESULTS

Of 887 eligible women, 408 (46%) experienced virologic failure during the study period. Hispanic and white women had significantly lower hazards of virologic failure than African American women [Hispanic hazard ratio, (HR) = 0.8, 95% confidence interval: (0.6 to 0.9); white HR = 0.7 (0.5 to 0.9)]. The PAF of virologic failure associated with low income was higher in Hispanic [adjusted hazard ratios (aHR) = 2.2 (0.7 to 6.5), PAF = 49%] and African American women [aHR = 1.8 (1.1 to 3.2), PAF = 38%] than among white women [aHR = 1.4 (0.6 to 3.4), PAF = 16%]. Lack of health insurance compared with public health insurance was associated with virologic failure only among Hispanic [aHR = 2.0 (0.9 to 4.6), PAF = 22%] and white women [aHR = 1.9 (0.7 to 5.1), PAF = 13%]. By contrast, depressive symptoms were associated with virologic failure only among African-American women [aHR = 1.6 (1.2 to 2.2), PAF = 17%].

CONCLUSIONS

In this population of treated HIV-infected women, virologic failure was common, and correlates of virologic failure varied by race/ethnicity. Strategies to reduce disparities in HIV treatment outcomes by race/ethnicity should address racial/ethnic-specific barriers including depression and low income to sustain virologic suppression.

Antiretroviral therapy for prevention of HIV transmission: potential role for people who inject drugs in Central Asia

Interest in the use of antiretroviral therapy (ART) for prevention stems from mounting evidence from research studies demonstrating that ART is associated with a decrease in sexual HIV transmission among serodiscordant couples and, perhaps, in other populations at risk. There is paucity of data on the efficacy of ART for prevention in key populations, including persons who inject drugs (PWID). In this paper, we examine the current status of HIV services for PWID in Central Asia, the use of ART by this population and explore ART for prevention for PWID in this context. We also discuss research and implementation questions with relevance to such a strategy in the region.

Longitudinal changes in engagement in care and viral suppression for HIV-infected injection drug users

OBJECTIVE

To examine temporal trends and predictors of linkage to HIV care, longitudinal retention in care and viral suppression among injection drug users (IDUs) infected with HIV.

DESIGN

Community-based, prospective cohort study.

METHODS

We prospectively studied 790 HIV-infected IDUs participating in the AIDS Linked to the Intravenous Experience (ALIVE) study from 1998 through 2011. IDUs were considered linked to care if they attended any HIV care visit during follow-up and retained in care if they reported HIV clinic attendance at every semi-annual study visit. We used logistic regression to identify predictors of poor retention in care and failure to achieve sustained viral suppression in response to ART.

RESULTS

Of 790 HIV-infected IDUs studied, 740 (93.6%) were ever linked to care. The majority of IDUs (76.7%) received ART at some point during observation and of these, most (85.4%) achieved viral suppression. However, over a median of 8.7 years of follow-up, only 241 (30.5%) IDUs were continuously retained with no 6-month lapses in HIV care and only 63 (10.2%) had sustained viral suppression at every study visit after first receiving ART. Suboptimal engagement in care was associated with poor access to medical care, active drug use, and incarceration.

CONCLUSION

Compared with national estimates of retention in care and virologic suppression in the United States, IDUs are substantially less likely to remain fully engaged in HIV care. Strategies to optimize HIV care should acknowledge the elevated risk of poor engagement in care among IDUs.

The cascade of HIV care in British Columbia, Canada, 1996-2011: a population-based retrospective cohort study

BACKGROUND

The cascade of HIV care has become a focal point for implementation efforts to maximise the individual and public health benefits of antiretroviral therapy. We aimed to characterise longitudinal changes in engagement with the cascade of HIV care in British Columbia, Canada, from 1996 to 2011.

METHODS

We used estimates of provincial HIV prevalence from the Public Health Agency of Canada and linked provincial population-level data to define, longitudinally, the numbers of individuals in each of the eight stages of the cascade of HIV care (HIV infected, diagnosed, linked to HIV care, retained in HIV care, highly active antiretroviral therapy (HAART) indicated, on HAART, adherent to HAART, and virologically suppressed) in British Columbia from 1996 to 2011. We used sensitivity analyses to determine the sensitivity of cascade-stage counts to variations in their definitions.

FINDINGS

13,140 people were classified as diagnosed with HIV/AIDS in British Columbia during the study period. We noted substantial improvements over time in the proportions of individuals at each stage of the cascade of care. Based on prevalence estimates, the proportion of unidentified HIV-positive individuals decreased from 49·0% (estimated range 36·2-57·5%) in 1996 to 29·0% (11·6-40·7%) in 2011, and the proportion of HIV-positive people with viral suppression reached 34·6% (29·0-43·1%) in 2011.

INTERPRETATION

Careful mapping of the cascade of care is crucial to understanding what further efforts are needed to maximise the beneficial effects of available interventions and so inform efforts to contain the spread of HIV/AIDS.

FUNDING

British Columbia Ministry of Health, US National Institute on Drug Abuse (National Institutes of Health).

Disparities in community viral load among HIV-infected persons in New York City

OBJECTIVE

HIV infection is a major problem in New York City (NYC), with more than 100,000 living HIV-infected persons. Novel public health approaches are needed to control the epidemic. The NYC Department of Health and Mental Hygiene (DOHMH) analysed community viral load (CVL) for a baseline to monitor the population-level impact of HIV control interventions.

DESIGN

A cross-sectional study using routinely collected surveillance data.

METHODS

All HIV-infected persons reported to the NYC HIV Registry who were at least 13 years of age, with at least one viral load test result in 2008, and alive at the end of 31 December 2008 were included. CVL was defined as the mean of individual viral load means reported between January and December 2008. Detectable viral load was defined as an individual mean of more than 400 copies/ml. Differences in CVL and proportion undetectable were computed by socio-demographic characteristics and summary measures were mapped.

RESULTS

New York City CVL was 21,318 copies/ml overall (N=62,550) and 44,749 copies/ml (N=28,366) among persons with detectable mean viral loads. CVL varied by demographic and clinical characteristics, with statistically significant differences (P<0.001) in all groups except race/ethnicity (P=0.16). Men, persons aged 20-49 years, MSM, persons with AIDS, those with a CD4 cell count of 200 cells/μl or less and persons diagnosed after 2006 had higher mean viral load. Overall, 54.7% of HIV-infected persons had a suppressed mean viral load, with individual and neighbourhood variations (P<0.0001).

CONCLUSION

This analysis showed strong disparities in reported CVL by individual characteristics and neighbourhoods. CVL patterns can be utilized to target interventions and track their impact.

Availability of HIV prevention and treatment services for people who inject drugs: findings from 21 countries

BACKGROUND

About a third of the global HIV infections outside sub-Saharan Africa are related to injecting drug use (IDU), and this accounts for a growing proportion of persons living with HIV. This paper is a response to the need to monitor the state of the HIV epidemic as it relates to IDU and the availability of HIV treatment and harm reduction services in 21 high epidemic countries.

METHODS

A data collection form was designed to cover questions on rates of IDU, prevalence and incidence of HIV and information on HIV treatment and harm reduction services available to people who inject drugs (PWID). National and regional data on HIV infection, IDU in the form of reports and journal articles were sought from key informants in conjunction with a systematic search of the literature.

RESULTS

Completed data collection forms were received for 11 countries. Additional country-specific information was sourced via the literature search. The overall proportion of HIV positive PWID in the selected countries ranged from 3% in Kazakhstan to 58% in Vietnam. While IDU is relatively rare in sub-Saharan Africa, it is the main driver of HIV in Mauritius and Kenya, with roughly 47% and 36% of PWID respectively being HIV positive. All countries had antiretroviral treatment (ART) available to PWID, but data on service coverage were mainly missing. By the end of 2010, uptake of needle and syringe programmes (NSP) in Bangladesh, India and Slovakia reached the internationally recommended target of 200 syringes per person, while uptake in Kazakhstan, Vietnam and Tajikistan reached between 100-200 syringes per person. The proportion of PWID receiving opioid substitution therapy (OST) ranged from 0.1% in Kazakhstan to 32.8% in Mauritius, with coverage of less than 3% for most countries.

CONCLUSIONS

In order to be able to monitor the impact of HIV treatment and harm reduction services for PWID on the epidemic, epidemiological data on IDU and harm reduction service provision to PWID needs to be regularly collected using standardised indicators.

The potential impact of expanding antiretroviral therapy and combination prevention in Vietnam: towards elimination of HIV transmission

BACKGROUND

Few studies have assessed the effects of antiretroviral therapy (ART) to prevent HIV transmission in Asian HIV epidemics. Vietnam has a concentrated HIV epidemic with the highest prevalence among people who inject drugs. We investigated the impact of expanded HIV testing and counseling (HTC) and early ART, combined with other prevention interventions on HIV transmission.

METHODS

A deterministic mathematical model was developed using HIV prevalence trends in Can Tho province, Vietnam. Scenarios included offering periodic HTC and immediate ART with and without targeting subpopulations and examining combined strategies with methadone maintenance therapy and condom use.

RESULTS

From 2011 to 2050, maintaining current interventions will incur an estimated 18,115 new HIV infections and will cost US $22.1 million (reference scenario). Annual HTC and immediate treatment, if offered to all adults, will reduce new HIV infections by 14,513 (80%) and will cost US $76.9 million. Annual HTC and immediate treatment offered only to people who inject drugs will reduce new infections by 13,578 (75%) and will cost only US $23.6 million. Annual HTC and immediate treatment for key populations, combined with scale-up of methadone maintenance therapy and condom use, will reduce new infections by 14,723 (81%) with similar costs (US $22.7 million). This combination prevention scenario will reduce the incidence to less than 1 per 100,000 in 14 years and will result in a relative cost saving after 19 years.

CONCLUSIONS

Targeted periodic HTC and immediate ART combined with other interventions is cost-effective and could lead to potential elimination of HIV in Can Tho.

The validity of clinic-based samples in approximating out-of-care HIV-infected populations

Tremendous strides have been made in the diagnosis and treatment of human immunodeficiency virus (HIV); perhaps now the largest barrier to controlling HIV is retaining those diagnosed in care. Data on out-of-care populations are needed to develop effective retention methods, yet obtaining these remains methodologically challenging due to inherent difficulties in sampling. The purpose of this study was to evaluate whether individuals identified by two sampling methods commonly used to approximate out-of-care populations were significantly different from a sample of newly identified out-of-care persons. We compared medical records of 345 out-of-care persons identified by a novel population-based health information exchange who had not received CD4 or viral load monitoring in >1 year with: medical records from a randomly selected, time-matched sample of 488 HIV-infected persons with at least one HIV care visit in the past 5 years, and interviews with 382 participants from a time-matched clinic-based convenience sample. Newly identified out-of-care persons were significantly different from both proxies with respect to demographic, clinical, and utilization characteristics, suggesting that samples of in-care proxy persons are inadequate to describe those not engaged in care. Novel approaches to sampling out-of care populations are urgently needed in order to better understand these populations and ways to improve retention and slow the HIV/AIDS epidemic.

Community viral load and CD4 count distribution among people living with HIV in a South African Township: implications for treatment as prevention

INTRODUCTION

The goals of scale-up of antiretroviral therapy (ART) have expanded from prevention of morbidity and death to include prevention of transmission. Morbidity and mortality risk are associated with CD4 count; transmission risk depends on plasma viral load (VL). This study aimed to describe CD4 count and VL distributions among HIV-infected individuals in a South African township to gain insights into the potential impact of ART scale-up on community HIV transmission risk.

METHODS

A random sample of 10% of the adult population was invited to attend an HIV testing service. Study procedures included a questionnaire, HIV testing, CD4 count, and VL testing.

RESULTS

One thousand one hundred forty-four (88.0%) of 1300 randomly selected individuals participated in the study. Two hundred sixty tested positive, giving an HIV prevalence of 22.7% [95% confidence interval (CI): 20.3 to 25.3]. A third of all HIV-infected individuals (33.5%, 95% CI: 27.8 to 39.6) reported taking ART. The median CD4 count was 417 cells per microliter (interquartile range, 285-627); 33 (12.7%, 95% CI: 8.9 to 17.4) had a CD4 count of ≤200 cells per microliter. VL measurements were available for 219 individuals (84.2%) and were undetectable in 72 (33.9%), >1500 copies per milliliter in 127 (58.0%) and >10,000 copies per milliliter in 96 (43.8%). Of those reporting they were receiving ART, 30.4% had a VL >1500 copies per milliliter compared with 58.0% of those reporting they were not receiving ART.

CONCLUSIONS

A small proportion of those living with HIV in this community had a CD4 count of <200 cells per microliter; more than half had a VL high enough to be associated with considerable transmission risk. A substantial proportion of HIV-infected individuals remained at risk of transmitting HIV even after starting ART.

Treatment as prevention: toward an AIDS-free generation

In British Columbia, Canada, intensive efforts have been made to implement and maintain a treatment-as-prevention strategy among the HIV-infected population. Acceleration of antiretroviral therapy coverage has resulted in a substantial increase in the median CD4+ cell count at which treatment is initiated and a dramatic decline in community plasma HIV RNA levels. This has resulted in a reduction in diagnoses of new cases of HIV infection, including among injection drug users. Proportions of individuals with viral suppression have steadily increased and the expansion of antiretroviral therapy coverage has not been associated with increased levels of HIV resistance. Further, adoption of routine HIV testing in acute care settings has been very well accepted and has captured new cases at a rate of 5 per 1000 tests outside of high-risk populations, offering an additional strategy for identifying and linking at least some individuals with undiagnosed HIV infection to care. Deriving optimal individual and social health outcomes in HIV infection requires improvement in every element of the cascade of care. This article summarizes a presentation by Julio S. G. Montaner, MD, at the IAS-USA continuing education program held in San Francisco, California, in March 2013.

Disparities in engagement in care and viral suppression among persons with HIV

BACKGROUND

Engagement across the spectrum of HIV care can improve health outcomes and prevent HIV transmission. We used HIV surveillance data to examine these outcomes.

METHODS

San Francisco residents who were diagnosed with HIV between 2009 and 2010 were included. We measured the characteristics and proportion of persons linked to care within 6 months of diagnosis, retained in care for second and third visits, and virally suppressed within 12 months of diagnosis.

RESULTS

Of 862 persons included, 750 (87%) entered care within 6 months of diagnosis; of these, 72% had a second visit in the following 3-6 months; and of these, 80% had a third visit in the following 3-6 months. Viral suppression was achieved in 50% of the total population and in 76% of those retained for 3 visits. Lack of health insurance and unknown housing status were associated with not entering care (P < 0.01). Persons with unknown insurance status were less likely to be retained for a second visit; those younger than 30 years were less likely to be retained for a third visit. Independent predictors of failed viral suppression included age <40 years, homelessness, unknown housing status, and having a single or 2 medical visits compared with 3 visits.

CONCLUSIONS

Socioeconomic resources and age, not race or gender, are associated with disparities in engagement in HIV care in San Francisco.

Overview of the current state of the epidemic

At the end of 2011, about half of the 34.0 million [31.4-35.9 million] people living with HIV infection knew their HIV status. With large regional variations, an estimated 0.8% of all adults aged 15 to 49 years have HIV infection and HIV subtype diversity is increasing. Although HIV incidence has declined in 39 countries, it is stable or increasing in others. HIV prevalence continues to rise as antiretroviral treatment scale-up results in fewer HIV-related deaths while new infections continue to occur. Increased treatment uptake is likely reducing HIV transmission in countries with large mortality declines. Key populations, including sex workers, men who have sex with men, transgender people, people who inject drugs and young women in high prevalence settings require effective prevention programs urgently. Correcting mismatches in resource allocation and reducing community viral load will accelerate incidence declines and affect future epidemic trends, if concerted action is taken now.

Controlling the HIV Epidemic with Antiretrovirals

In the context of emerging evidence related to preexposure prophylaxis and HIV treatment as prevention, an evidence summit was held in mid-2012 to discuss the current state of the science and to provide a platform for consensus building around whether and how these prevention strategies might be implemented globally. Health care providers, researchers, policy makers, people living with HIV/AIDS, and representatives of government authorities, donor agencies, pharmaceutical companies, advocacy organizations, and professional associations attended from 52 countries. An international advisory committee was convened to identify key messages and recommendations based upon the data presented and discussed at the summit. The advisory committee further worked to develop this consensus statement meant to assist relevant stakeholders in taking stock and mapping out a route forward to enhance the HIV prevention armamentarium.

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

Background

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

Analysis

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

Conclusions

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

Linking and retaining HIV patients in care: the importance of provider attitudes and behaviors

Retention in HIV treatment may reduce morbidity and mortality, as well as slow the epidemic. Myriad barriers to retention include stigma, homophobia, structural barriers, transportation, and insurance. The purpose of this study was to evaluate patient perceptions of provider attitudes among HIV-infected persons within a state-wide public hospital system in Louisiana. A convenience sample of patients attending HIV clinics throughout the state participated in an anonymous interview. Factors associated with negative perceptions of care were evaluated in conjunction with a validated stigma measure. Factors associated with having a delayed entry into or break in care were evaluated in conjunction with perceived stigma. Between 2/1/09 and 7/31/11, 479 participants were interviewed and had sufficient data available, of whom 53.4% were male, 79.3% were African American, and 29.4% reported a break or delayed entry into HIV care of >1 year. A break in care was associated with perceiving that the doctor or health professionals do not listen carefully most or all of the time (p<0.01), having an elevated stigma score (p<0.05), and indicating that providers dislike caring for HIV-infected people (p<0.01). Women were more likely to have an elevated stigma score than men (p<0.01), as were participants over 30 (p<0.01); those with a gay/bisexual orientation (p<0.05) were less likely to have an elevated stigma score. Those with a break in care were less likely to have Medicaid (p<0.05). Providers play a key role in the retention of HIV-infected persons in care and are critical to improving outcomes and slowing the epidemic. Development of novel approaches to reduce stigma are imperative in improving retention.

Antiretroviral therapy for prevention of HIV transmission in HIV-discordant couples

BACKGROUND

Antiretroviral drugs have been shown to reduce risk of mother-to-child transmission of human immunodeficiency virus (HIV) and are also widely used for post-exposure prophylaxis for parenteral and sexual exposures. Sexual transmission may be lower in couples in which one partner is infected with HIV and the other is not and the infected partner is on antiretroviral therapy (ART).

OBJECTIVES

To determine if ART use in an HIV-infected member of an HIV-discordant couple is associated with lower risk of HIV transmission to the uninfected partner compared to untreated discordant couples.

SEARCH METHODS

We used standard Cochrane methods to search electronic databases and conference proceedings with relevant search terms without limits to language.

SELECTION CRITERIA

Randomised controlled trials (RCT), cohort studies and case-control studies of HIV-discordant couples in which the HIV-infected member of the couple was being treated or not treated with ART DATA COLLECTION AND ANALYSIS: Abstracts of all trials identified by electronic or bibliographic scanning were examined independently by two authors. We initially identified 3,833 references and examined 87 in detail for study eligibility. Data were abstracted independently using a standardised abstraction form.

MAIN RESULTS

One RCT and nine observational studies were included in the review. These ten studies identified 2,112 episodes of HIV transmission, 1,016 among treated couples and 1,096 among untreated couples. The rate ratio for the single randomised controlled trial was 0.04 [95% CI 0.00, 0.27]. All index partners in this study had CD4 cell counts at baseline of 350-550 cells/µL. Similarly, the summary rate ratio for the nine observational studies was 0.58 [95% CI 0.35, 0.96], with substantial heterogeneity (I(2)=64%). After excluding two studies with inadequate person-time data, we estimated a summary rate ratio of 0.36 [95% CI 0.17, 0.75] with substantial heterogeneity (I(2)=62%). We also performed subgroup analyses among the observational studies to see if the effect of ART on prevention of HIV differed by the index partner's CD4 cell count. Among couples in which the infected partner had ≥350 CD4 cells/µL, we estimated a rate ratio of 0.12 [95% CI 0.01, 1.99]. In this subgroup, there were 247 transmissions in untreated couples and 30 in treated couples.

AUTHORS' CONCLUSIONS

ART is a potent intervention for prevention of HIV in discordant couples in which the index partner has ≤550 CD4 cells/µL. A recent multicentre RCT confirms the suspected benefit seen in earlier observational studies and reported in more recent ones. Questions remain about durability of protection, the balance of benefits and adverse events associated with earlier therapy, long-term adherence and transmission of ART-resistant strains to partners. Resource limitations and implementation challenges must also be addressed.Counselling, support, and follow up, as well as mutual disclosure, may have a role in supporting adherence, so programmes should be designed with these components. In addition to ART provision, the operational aspects of delivering such programmes must be considered.

Fifteen million people on antiretroviral treatment by 2015: treatment as prevention

PURPOSE OF REVIEW

The declaration of the United Nations High Level meeting on AIDS in June 2011 includes 10 concrete targets, including to ensure that there are 15 million people living with human immunodeficiency virus (HIV) on antiretroviral treatment (ART) by 2015. This review examines the potential, opportunities and challenges of treatment as prevention of HIV and tuberculosis (TB) in reaching this target.

RECENT FINDINGS

Although around 8 million people are on treatment, everyone living with HIV will eventually need ART to stay alive. As many as 24  million people living with HIV today are not on treatment, the majority not even being aware of their HIV infection. Expansion of a comprehensive prevention strategy including providing ART to 15 million or more people would significantly reduce HIV and TB morbidity, mortality and transmission. The challenges include ensuring human rights protections, steady drug supply, early diagnosis and linkage to care, task shifting, adherence, retention, and monitoring and evaluation. Expansion could also lead to the control and possible elimination of HIV in many places.

SUMMARY

Achieving an 'AIDS-free generation' whereby deaths related to HIV are drastically reduced, people living with HIV are AIDS-free on ART, and HIV transmission is decreased, is both scientifically sound and practically feasible. The global community could reach 15 million people on ART by 2015 while expanding our vision and efforts to include diagnosis and treatment for all the 32  million people living with HIV in the future.

Examining the evidence on the causal effect of HAART on transmission of HIV using the Bradford Hill criteria

In recent years, evidence has accumulated regarding the ability of HAART to prevent HIV transmission. Early supportive evidence was derived from observational, ecological and population-based studies. More recently, a randomized clinical trial showed that immediate use of HAART led to a 96% decrease in HIV transmission events within HIV serodiscordant heterosexual couples. However, the generalizability of the effect of HAART, and the population-level impact on HIV transmission continues to generate substantial debate. We, therefore, conducted a review of the evidence regarding the preventive effect of HAART on HIV transmission within the context of the Bradford Hill criteria for causality. Taken together, we find the accumulated evidence supporting HIV treatment as prevention meets each of the Bradford Hill criteria for causality. We conclude that the opportunity cost of inaction while waiting for additional evidence on the generalizability of effect in other risk groups is too high. Efforts should be redoubled to mobilize the financial capital and political will to optimize implementation of HIV Treatment as Prevention strategies on a wide scale.

Housing status and the health of people living with HIV/AIDS

Individuals who are homeless or living in marginal conditions have an elevated burden of infection with HIV. Existing research suggests the HIV/AIDS pandemic in resource-rich settings is increasingly concentrated among members of vulnerable and marginalized populations, including homeless/marginally-housed individuals, who have yet to benefit fully from recent advances in highly-active antiretroviral therapy (HAART). We reviewed the scientific evidence investigating the relationships between inferior housing and the health status, HAART access and adherence and HIV treatment outcomes of people living with HIV/AIDS (PLWHA.) Studies indicate being homeless/marginally-housed is common among PLWHA and associated with poorer levels of HAART access and sub-optimal treatment outcomes. Among homeless/marginally-housed PLWHA, determinants of poorer HAART access/adherence or treatment outcomes include depression, illicit drug use, and medication insurance status. Future research should consider possible social- and structural-level determinants of HAART access and HV treatment outcomes that have been shown to increase vulnerability to HIV infection among homeless/marginally-housed individuals. As evidence indicates homeless/marginally-housed PLWHA with adequate levels of adherence can benefit from HAART at similar rates to housed PLWHA, and given the individual and community benefits of expanding HAART use, interventions to identify HIV-seropositive homeless/marginally-housed individuals, and engage them in HIV care including comprehensive support for HAART adherence are urgently needed.

Community viral load as a measure for assessment of HIV treatment as prevention

Community viral load, defined as an aggregation of individual viral loads of people infected with HIV in a specific community, has been proposed as a useful measure to monitor HIV treatment uptake and quantify its effect on transmission. The first reports of community viral load were published in 2009, and the measure was subsequently incorporated into the US National HIV/AIDS Strategy. Although intuitively an appealing strategy, measurement of community viral load has several theoretical limitations and biases that need further assessment, which can be grouped into four categories: issues of selection and measurement, the importance of HIV prevalence in determining the potential for ongoing HIV transmission, interpretation of community viral load and its effect on ongoing HIV transmission in a community, and the ecological fallacy (ie, ecological bias). These issues need careful assessment as community viral load is being considered as a public health measurement to assess the effect of HIV care on prevention.

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

Background and Aims

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

Methods

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

Results

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

Conclusions

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

High coverage of ART associated with decline in risk of HIV acquisition in rural KwaZulu-Natal, South Africa

The landmark HIV Prevention Trials Network (HPTN) 052 trial in HIV-discordant couples demonstrated unequivocally that treatment with antiretroviral therapy (ART) substantially lowers the probability of HIV transmission to the HIV-uninfected partner. However, it has been vigorously debated whether substantial population-level reductions in the rate of new HIV infections could be achieved in "real-world" sub-Saharan African settings where stable, cohabiting couples are often not the norm and where considerable operational challenges exist to the successful and sustainable delivery of treatment and care to large numbers of patients. We used data from one of Africa's largest population-based prospective cohort studies (in rural KwaZulu-Natal, South Africa) to follow up a total of 16,667 individuals who were HIV-uninfected at baseline, observing individual HIV seroconversions over the period 2004 to 2011. Holding other key HIV risk factors constant, individual HIV acquisition risk declined significantly with increasing ART coverage in the surrounding local community. For example, an HIV-uninfected individual living in a community with high ART coverage (30 to 40% of all HIV-infected individuals on ART) was 38% less likely to acquire HIV than someone living in a community where ART coverage was low (<10% of all HIV-infected individuals on ART).