Using HIV viral load to guide treatment-for-prevention interventions

Effects of Behavioral Intervention Components for African American/Black and Latino Persons Living with HIV with Non-suppressed Viral Load Levels: Results of an Optimization Trial

There is an urgent need for efficient behavioral interventions to increase rates of HIV viral suppression for populations with serious barriers to engagement along the HIV care continuum. We carried out an optimization trial to test the effects of five behavioral intervention components designed to address barriers to HIV care continuum engagement for African American/Black and Latino persons living with HIV (PLWH) with non-suppressed HIV viral load levels: motivational interviewing sessions (MI), focused support groups (SG), peer mentorship (PM), pre-adherence skill building (SB), and navigation with two levels, short (NS) and long (NL). The primary outcome was HIV viral suppression (VS) and absolute viral load (VL) and health-related quality of life were secondary outcomes. Participants were 512 African American/Black and Latino PLWH poorly engaged in HIV care and with detectable HIV viral load levels in New York City, recruited mainly through peer referral. Overall, VS increased to 37%, or 45% in a sensitivity analysis. MI and SG seemed to have antagonistic effects on VS (z = - 1.90; p = 0.057); the probability of VS was highest when either MI or SG was assigned, but not both. MI (Mean Difference = 0.030; 95% CI 0.007-0.053; t(440) = 2.60; p = 0.010) and SB (Mean Difference = 0.030; 95% CI 0.007-0.053; t(439) = 2.54; p = 0.012) improved health-related quality of life. This is the first optimization trial in the field of HIV treatment. The study yields a number of insights into approaches to improve HIV viral suppression in PLWH with serious barriers to engagement along the HIV care continuum, including chronic poverty, and underscores challenges inherent in doing so.

Genome-wide association study reveals genetic variants associated with HIV-1C infection in a Botswana study population

Although there have been many studies of gene variant association with different stages of HIV/AIDS progression in United States and European cohorts, few gene-association studies have assessed genic determinants in sub-Saharan African populations, which have the highest density of HIV infections worldwide. We carried out genome-wide association studies on 766 study participants at risk for HIV-1 subtype C (HIV-1C) infection in Botswana. Three gene associations (AP3B1, PTPRA, and NEO1) were shown to have significant association with HIV-1C acquisition. Each gene association was replicated within Botswana or in the United States-African American or United States-European American AIDS cohorts or in both. Each associated gene has a prior reported influence on HIV/AIDS pathogenesis. Thirteen previously discovered AIDS restriction genes were further replicated in the Botswana cohorts, extending our confidence in these prior AIDS restriction gene reports. This work presents an early step toward the identification of genetic variants associated with and affecting HIV acquisition or AIDS progression in the understudied HIV-1C afflicted Botswana population.

Reaching 90-90-90 in Botswana

PURPOSE OF REVIEW

Botswana, a small country in southern Africa, has had a very high prevalence of HIV since about 1995. It seems important to analyze the response of this country to help us understand how it became one of the first nations to achieve the 90-90-90 targets.

RECENT FINDINGS

Botswana began a national program for treatment of HIV/AIDS with ARVs in 2002. Initially established in the four largest population centers, it expanded to more than 30 sites throughout the country by 2004. Also in 2004, an 'opt out' system for HIV testing was introduced. The government-sponsored ARV regimen for initiation was ZDV/3TC/EFV until 2008, then TDF/FTC/EFV until 2016, when it became TDF/FTC/DTG along with the introduction of treatment for all. Levels of both acquired and transmitted drug resistance have been low. In late 2013, we began the Ya Tsie or Botswana Combination Prevention Project (BCCP), a cluster randomized trial for 100 000 exurban and rural adults in 30 villages that included enhanced testing, linkage to care, and ARV treatment for 15 intervention villages, one in each pair. A 20% baseline survey in 2013-2015 revealed 29% prevalence and values that were already close to 90-90-90. With 83.3% of HIV-positive adults knowing they were infected, 87.4% of those knowing they were infected already on ARV, and 96.5% of those on ARV in complete viral suppression, this represented a combined value of 70.2% toward the target of 73%. By best estimates, incidence fell by about 30% over the 29-month period of the trial, which is compatible with Botswana reaching a 90% reduction in incidence in 10 years as proposed by the UNAIDS model. On the basis of an end-of-study survey in three intervention villages, we estimate that Botswana could reach 95-95-95 by 2019.

SUMMARY

These results illustrate that it is possible to reach 90-90-90 in countries with very high HIV prevalence.

Intimate partner violence against HIV-positive Cameroonian women: Prevalence, associated factors and relationship with antiretroviral therapy discontinuity-results from the ANRS-12288 EVOLCam survey

Background:

Intimate partner violence in its various forms increases HIV exposure in female victims and potentially jeopardizes the HIV treatment cascade, for instance, by impeding engagement in and adherence to care. Elevated rates of HIV and intimate partner violence are reported in Central Africa. Evidence on the effect of intimate partner violence on antiviral therapy interruption is lacking in Cameroon, where only 330,000 women live with HIV and only 19% of HIV-positive people are virally suppressed. This study aimed to assess the prevalence and factors of intimate partner violence against HIV-positive women and its relationship with antiretroviral therapy interruption ⩾1 month.

Methods:

The EVOLCam cross-sectional survey was conducted in 19 hospitals in the Center and Littoral regions. The study sample comprised antiviral therapy–treated women declaring at least one sexual partner in the previous year. Scores of recent emotional, physical, extreme physical and sexual intimate partner violence were built using principal component analysis and categorized under no, occasional or frequent intimate partner violence. Multivariate logistic analyses were performed to investigate the relationship between intimate partner violence and recent antiretroviral therapy interruption ⩾1 month, and associated factors.

Results:

Among the 894 analyzed women, the prevalence of intimate partner violence was 29% (emotional), 22% (physical), 13% (extreme physical) and 18% (sexual). Frequent physical intimate partner violence was a significant risk factor of antiretroviral therapy interruption ⩾1 month (adjusted odds ratio = 2.42 (95% confidence interval = 1.00; 5.87)). It was also associated with HIV-related stigma (2.53 (1.58; 4.02)), living with a main partner (2.03 (1.20; 3.44) and non-defensive violence against this partner (5.75 (3.53; 9.36)).

Conclusion:

Intimate partner violence is a potential barrier to antiviral therapy continuity and aggravates vulnerability of Cameroonian HIV-positive women. The prevention and detection of intimate partner violence by HIV services might help to reach the last “90” of the 90-90-90 targets.

Diagnosis of Human Immunodeficiency Virus Infection

HIV diagnostics have played a central role in the remarkable progress in identifying, staging, initiating, and monitoring infected individuals on life-saving antiretroviral therapy. They are also useful in surveillance and outbreak responses, allowing for assessment of disease burden and identification of vulnerable populations and transmission "hot spots," thus enabling planning, appropriate interventions, and allocation of appropriate funding. HIV diagnostics are critical in achieving epidemic control and require a hybrid of conventional laboratory-based diagnostic tests and new technologies, including point-of-care (POC) testing, to expand coverage, increase access, and positively impact patient management. In this review, we provide (i) a historical perspective on the evolution of HIV diagnostics (serologic and molecular) and their interplay with WHO normative guidelines, (ii) a description of the role of conventional and POC testing within the tiered laboratory diagnostic network, (iii) information on the evaluations and selection of appropriate diagnostics, (iv) a description of the quality management systems needed to ensure reliability of testing, and (v) strategies to increase access while reducing the time to return results to patients. Maintaining the central role of HIV diagnostics in programs requires periodic monitoring and optimization with quality assurance in order to inform adjustments or alignment to achieve epidemic control.

High HIV-1 RNA Among Newly Diagnosed People in Botswana

HIV-1 RNA level is strongly associated with HIV transmission risk. We sought to determine whether HIV-1 RNA level was associated with prior knowledge of HIV status among treatment-naive HIV-infected individuals in Botswana, a country with high rates of antiretroviral treatment (ART) coverage. This information may be helpful in targeting HIV diagnosis and treatment efforts in similar high HIV prevalence settings in a population-based survey. HIV-infected individuals were identified during a household survey performed in 30 communities across Botswana. ART-naive persons with detectable HIV-1 RNA (>400 copies/mL) were divided into two groups, newly diagnosed and individuals tested in the past who knew about their HIV infection at the time of household visit, but had not taken ART. Levels of HIV-1 RNA were compared between groups, overall and by age and gender. Among 815 HIV-infected ART-naive persons with detectable virus, newly diagnosed individuals had higher levels of HIV-1 RNA (n = 490, median HIV-1 RNA 4.35, interquartile range (IQR) 3.79-4.91 log₁₀ copies/mL) than those who knew about their HIV-positive status (n = 325, median HIV-1 RNA 4.10, IQR 3.55-4.68 log₁₀ copies/mL; p values <.001, but p value = .011 after adjusting for age and gender). A nonsignificant trend for higher HIV-1 RNA was found among newly diagnosed men 30 years of age or older (median HIV-1 RNA 4.58, IQR 4.07-5.02 log₁₀ copies/mL vs. 4.17, 3.61-4.71 log₁₀ copies/mL). Newly diagnosed individuals have elevated levels of HIV-1 RNA. This study highlights the need for early diagnosis and treatment of HIV infection for purposes of HIV epidemic control, even in a setting with high ART coverage.

Do Less Harm: Evaluating HIV Programmatic Alternatives in Response to Cutbacks in Foreign Aid

BACKGROUND

Resource-limited nations must consider their response to potential contractions in international support for HIV programs.

OBJECTIVE

To evaluate the clinical, epidemiologic, and budgetary consequences of alternative HIV program scale-back strategies in 2 recipient nations, the Republic of South Africa (RSA) and Côte d'Ivoire (CI).

DESIGN

Model-based comparison between current standard (CD4 count at presentation of 0.260 × 109 cells/L, universal antiretroviral therapy [ART] eligibility, and 5-year retention rate of 84%) and scale-back alternatives, including reduced HIV detection, no ART or delayed initiation (when CD4 count is <0.350 × 109 cells/L), reduced investment in retention, and no viral load monitoring or second-line ART.

DATA SOURCES

Published RSA- and CI-specific estimates of the HIV care continuum, ART efficacy, and HIV-related costs.

TARGET POPULATION

HIV-infected persons, including future incident cases.

TIME HORIZON

5 and 10 years.

PERSPECTIVE

Modified societal perspective, excluding time and productivity costs.

OUTCOME MEASURES

HIV transmissions and deaths, years of life, and budgetary outlays (2015 U.S. dollars).

RESULTS OF BASE-CASE ANALYSIS

At 10 years, scale-back strategies increase projected HIV transmissions by 0.5% to 19.4% and deaths by 0.6% to 39.1%. Strategies can produce budgetary savings of up to 30% but no more. Compared with the current standard, nearly every scale-back strategy produces proportionally more HIV deaths (and transmissions, in RSA) than savings. When the least harmful and most efficient alternatives for achieving budget cuts of 10% to 20% are applied, every year of life lost will save roughly $900 in HIV-related outlays in RSA and $600 to $900 in CI.

RESULTS OF SENSITIVITY ANALYSIS

Scale-back programs, when combined, may result in clinical and budgetary synergies and offsets.

LIMITATION

The magnitude and details of budget cuts are not yet known, nor is the degree to which other international partners might step in to restore budget shortfalls.

CONCLUSION

Scaling back international aid to HIV programs will have severe adverse clinical consequences; for similar economic savings, certain programmatic scale-back choices result in less harm than others.

PRIMARY FUNDING SOURCE

National Institutes of Health and Steve and Deborah Gorlin MGH Research Scholars Award.

Psychosocial and Behavioral Characteristics of High-Risk Men Who Have Sex with Men (MSM) of Unknown HIV Positive Serostatus in Bangkok, Thailand

HIV prevalence remains high in men who have sex with men (MSM) in Bangkok. Even though resources for HIV testing and treatment are available for all, a large proportion of MSM still do not get HIV tested. We studied high risk MSM who are unaware of their HIV status to help maximize effectiveness of our resources. Convenience sampling was conducted among MSM who came for HIV testing at the Thai Red Cross Anonymous Clinic and two popular drop-in centers in Bangkok. Inclusion criteria were MSM aged >18 years, have not been tested positive for HIV, who reported ≥1 of the following in the previous 6 months: condomless sex with a male, being a sex worker, or having a sexual transmitted infection diagnosis. Audio-Computer-Assisted Self-Interview was used to assess psychosocial profile, sexual risks, and HIV testing patterns prior to being informed of their HIV positive status. Among 499 high-risk MSM enrolled, the median age was 24.8 years and 112 (22 %) tested HIV-positive. Among the HIV-positive participants, 92 % self-identified as gay (versus bisexual), 39 % attained a bachelors degree or higher, 65 % had monthly income 10,000-29,999 baht ($280-830 USD), 10 % had vaginal or anal sex with a woman in the past 12 months, 39 % had condomless receptive sex with men and 21 % went to Lat Phrao to find a sexual partner. Compared to HIV negative MSM, HIV-positive MSM had less HIV testing: 31 % had ever been tested for HIV, 12 % had been tested in the past 6 months; but were more likely to guess correctly their positive status (31 %). Regarding psychosocial variables among HIV-positive MSM, 7 % had regular methamphetamine use in the past 3 months, 10 % had >2 sources of discrimination, and 8 % had >2 sources of discrimination due to being MSM. In multivariable model, age<30 year old, self-identified as gay, had monthly income <50,000 baht ($1400 USD), had anal sex with men in past 12 months, had >2 sources of discrimination because of being MSM, did not get HIV test in past 6 months, and guess of positive HIV were significantly associated with HIV positive status. Young MSM with lower socioeconomic status (SES) should be prioritized for innovative approaches to promoting awareness and uptake of HIV testing. Societal stigmatization of MSM should be addressed as a potential barrier to uptake of voluntary HIV testing. Resilience factors among these marginalized MSM who still test frequently and remain HIV-negative despite residing in a context with community viral loads and discrimination should also be studied in order to curb the HIV epidemic in Bangkok.

The Anticipated Clinical and Economic Effects of 90-90-90 in South Africa

BACKGROUND

The Joint United Nations Programme on HIV/AIDS (UNAIDS) 90-90-90 global treatment target aims to achieve 73% virologic suppression among HIV-infected persons worldwide by 2020.

OBJECTIVE

To estimate the clinical and economic value of reaching this ambitious goal in South Africa, by using a microsimulation model of HIV detection, disease, and treatment.

DESIGN

Modeling of the "current pace" strategy, which simulates existing scale-up efforts and gradual increases in overall virologic suppression from 24% to 36% in 5 years, and the UNAIDS target strategy, which simulates 73% virologic suppression in 5 years.

DATA SOURCES

Published estimates and South African survey data on HIV transmission rates (0.16 to 9.03 per 100 person-years), HIV-specific age-stratified fertility rates (1.0 to 9.1 per 100 person-years), and costs of care ($11 to $31 per month for antiretroviral therapy and $20 to $157 per month for routine care).

TARGET POPULATION

South African HIV-infected population, including incident infections over the next 10 years.

PERSPECTIVE

Modified societal perspective, excluding time and productivity costs.

TIME HORIZON

5 and 10 years.

INTERVENTION

Aggressive HIV case detection, efficient linkage to care, rapid treatment scale-up, and adherence and retention interventions toward the UNAIDS target strategy.

OUTCOME MEASURES

HIV transmissions, deaths, years of life saved, maternal orphans, costs (2014 U.S. dollars), and cost-effectiveness.

RESULTS OF BASE-CASE ANALYSIS

Compared with the current pace strategy, over 5 years the UNAIDS target strategy would avert 873 000 HIV transmissions, 1 174 000 deaths, and 726 000 maternal orphans while saving 3 002 000 life-years; over 10 years, it would avert 2 051 000 HIV transmissions, 2 478 000 deaths, and 1 689 000 maternal orphans while saving 13 340 000 life-years. The additional budget required for the UNAIDS target strategy would be $7.965 billion over 5 years and $15.979 billion over 10 years, yielding an incremental cost-effectiveness ratio of $2720 and $1260 per year of life saved, respectively.

RESULTS OF SENSITIVITY ANALYSIS

Outcomes generally varied less than 20% from base-case outcomes when key input parameters were varied within plausible ranges.

LIMITATION

Several pathways may lead to 73% overall virologic suppression; these were examined in sensitivity analyses.

CONCLUSION

Reaching the 90-90-90 HIV suppression target would be costly but very effective and cost-effective in South Africa. Global health policymakers should mobilize the political and economic support to realize this target.

PRIMARY FUNDING SOURCE

National Institutes of Health and the Steve and Deborah Gorlin MGH Research Scholars Award.

Psychiatric Distress, Drug Use, and HIV Viral Load Suppression in Russia

To explore the influence of psychiatric distress and substance use on viral load suppression in HIV-infected patients taking ART we analyzed socio-demographic characteristics, CD4+ cells count and viral loads, the Symptom Check List-90 and the Addiction Severity Index of 75 patients who had taken ART for at least 6 month. Using viral load data as the marker of ART success, we divided the sample into two groups. Comparison of the groups showed that education, marriage, and female gender are predictors of optimal viral load suppression. Overall results failed to demonstrate substance use and psychiatric distress as predictors of viral load suppression.

Changing Antiretroviral Eligibility Criteria: Impact on the Number and Proportion of Adults Requiring Treatment in Swaziland

OBJECTIVE

Early initiation of antiretroviral treatment (ART) at CD4 cell count ≥ 500 cells per microliter reduces morbidity and mortality in HIV-infected adults. We determined the proportion of HIV-infected people with high viral load (VL) for whom transmission prevention would be an additional benefit of early treatment.

DESIGN

A randomly selected subset of a nationally representative sample of HIV-infected adults in Swaziland in 2012.

METHODS

Eight to 12 months after a national survey to determine adult HIV prevalence, 1067 of 5802 individuals identified as HIV-infected were asked to participate in a follow-up cross-sectional assessment. CD4 cell enumeration, VL measurements, and ART status were obtained to estimate the proportion of currently untreated adults and of the entire HIV-infected population with high VL (≥ 1000 copies/mL) whose treatment under a test-and-treat or VL threshold eligibility strategy would reduce HIV transmission.

RESULTS

Of the 927 (87% of 1067) participants enrolled, 466 (50%) reported no ART use. Among them, 424 (91%) had VL ≥ 1000 copies per milliliter; of these, 148 (35%) were eligible for ART at the then existing CD4 count threshold of <350 cells per microliter; an additional 107 (25%) were eligible with expanded CD4 criterion of <500 cells per microliter; and 169 (40%) remained ART ineligible. Thus, 36% of the 466 currently untreated and 18% of the total 927 had high VL yet remained ART ineligible under a CD4 criterion of <500 cells per microliter.

CONCLUSIONS

A test-and-treat or VL threshold for treatment eligibility is necessary to maximize the HIV transmission prevention benefits of ART.

Estimation of the Overall Treatment Effect in the Presence of Interference in Cluster-Randomized Trials of Infectious Disease Prevention

An issue that remains challenging in the field of causal inference is how to relax the assumption of no interference between units. Interference occurs when the treatment of one unit can affect the outcome of another, a situation which is likely to arise with outcomes that may depend on social interactions, such as occurrence of infectious disease. Existing methods to accommodate interference largely depend upon an assumption of “partial interference” – interference only within identifiable groups but not among them. There remains a considerable need for development of methods that allow further relaxation of the no-interference assumption. This paper focuses on an estimand that is the difference in the outcome that one would observe if the treatment were provided to all clusters compared to that outcome if treatment were provided to none – referred as the overall treatment effect. In trials of infectious disease prevention, the randomized treatment effect estimate will be attenuated relative to this overall treatment effect if a fraction of the exposures in the treatment clusters come from individuals who are outside these clusters. This source of interference – contacts sufficient for transmission that are with treated clusters – is potentially measurable. In this manuscript, we leverage epidemic models to infer the way in which a given level of interference affects the incidence of infection in clusters. This leads naturally to an estimator of the overall treatment effect that is easily implemented using existing software.

HIV viral load: a concept analysis and critique

In this article, we examine the concept of HIV viral load and how it has evolved over time (1995-2013) in the field of HIV/AIDS. Although the term viral load is used extensively in this field, few efforts have been directed toward the conceptualization of HIV viral load, which is often left unquestioned, undertheorized, and portrayed as a neutral and objective laboratory value that has remained relatively stable over time--with the exception of progressive advancements in technology, techniques, and sensitivity. The purpose of this article is to apply the evolutionary concept analysis method developed by Rodgers (1989, 2000a) to the concept of HIV viral load. To set the stage, we establish the need for a concept analysis of HIV viral load and provide an overview of the evolutionary view. Then, drawing on the steps proposed by Rodgers (2000a), we outline the process of data collection, management, and analysis. We then offer an in-depth discussion of the findings (attributes, antecedents, and consequences) informed by Wuest's (2000) critical approach to concept analysis. We conclude by highlighting the implications of this analysis for clinical practice, research, and theory.

Depression, substance use, viral load, and CD4+ count among patients who continued or left antiretroviral therapy for HIV in St. Petersburg, Russian Federation

Antiretroviral therapy (ART) became more widely available in the Russian Federation in 2006 when the Global Fund made a contribution to purchase ART with a mandate to increase numbers of patients receiving it. Funds were distributed to AIDS Centers and selected hospitals, and numbers quickly increased. Though ART is highly effective for adherent patients, dropout has been a problem; thus understanding characteristics of patients who remain on ART vs. those who leave treatment may provide information to facilitate engagement. We retrospectively assessed depression, hopelessness, substance use, viral load, and CD4+ counts of 120 patients who dropped out of ART for ≥12 months (Lost-to-Care, LTCs) and 120 who continued for ≥12 months (Engaged-in-Care, EICs). As expected, LTCs had higher viral loads and depression, lower CD4+ counts, more alcohol, heroin, and injection drug use in the past 30 days. A binary logistic regression with Center for Epidemiologic Studies Depression score, Beck Hopelessness score, whether drugs/alcohol had ever prevented them from taking ART, and past 30 days' alcohol use [χ(2)(4) = 64.27, p = .0.000] correctly classified 74.5% of participants as LTC or EIC, suggesting that integrated treatment for substance use, psychiatric, and HIV could reduce dropout and improve outcomes.

Sample size considerations in the design of cluster randomized trials of combination HIV prevention

Background Cluster randomized trials have been utilized to evaluate the effectiveness of HIV prevention strategies on reducing incidence. Design of such studies must take into account possible correlation of outcomes within randomized units. Purpose To discuss power and sample size considerations for cluster randomized trials of combination HIV prevention, using an HIV prevention study in Botswana as an illustration. Methods We introduce a new agent-based model to simulate the community-level impact of a combination prevention strategy and investigate how correlation structure within a community affects the coefficient of variation - an essential parameter in designing a cluster randomized trial. Results We construct collections of sexual networks and then propagate HIV on them to simulate the disease epidemic. Increasing level of sexual mixing between intervention and standard-of-care (SOC) communities reduces the difference in cumulative incidence in the two sets of communities. Fifteen clusters per arm and 500 incidence cohort members per community provide 95% power to detect the projected difference in cumulative HIV incidence between SOC and intervention communities (3.93% and 2.34%) at the end of the third study year, using a coefficient of variation 0.25. Although available formulas for calculating sample size for cluster randomized trials can be derived by assuming an exchangeable correlation structure within clusters, we show that deviations from this assumption do not generally affect the validity of such formulas. Limitations We construct sexual networks based on data from Likoma Island, Malawi, and base disease progression on longitudinal estimates from an incidence cohort in Botswana and in Durban as well as a household survey in Mochudi, Botswana. Network data from Botswana and larger sample sizes to estimate rates of disease progression would be useful in assessing the robustness of our model results. Conclusion Epidemic modeling plays a critical role in planning and evaluating interventions for prevention. Simulation studies allow us to take into consideration available information on sexual network characteristics, such as mixing within and between communities as well as coverage levels for different prevention modalities in the combination prevention package.

Impact of viral load and the duration of primary infection on HIV transmission: systematic review and meta-analysis

OBJECTIVES

HIV 'treatment as prevention' (TasP) describes early treatment of HIV-infected patients intended to reduce viral load and transmission. Crucial assumptions for estimating TasP's effectiveness are the underlying estimates of transmission risk. We aimed to determine transmission risk during primary infection, and describe the relation of HIV transmission risk to viral load.

DESIGN

A systematic review and meta-analysis.

METHODS

We searched PubMed and Embase databases for studies that established a relationship between viral load and transmission risk, or primary infection and transmission risk, in serodiscordant couples. We analysed assumptions about the relationship between viral load and transmission risk, and between duration of primary infection and transmission risk.

RESULTS

We found 36 eligible articles, based on six different study populations. Studies consistently found that higher viral loads lead to higher HIV transmission rates, but assumptions about the shape of this increase varied from exponential increase to saturation. The assumed duration of primary infection ranged from 1.5 to 12 months; for each additional month, the log10 transmission rate ratio between primary and asymptomatic infection decreased by 0.40.

CONCLUSION

Assumptions and estimates of the relationship between viral load and transmission risk, and the relationship between primary infection and transmission risk, vary substantially and predictions of TasP's effectiveness should take this uncertainty into account.

Methadone maintenance therapy decreases the rate of antiretroviral therapy discontinuation among HIV-positive illicit drug users

We sought to examine whether methadone maintenance therapy (MMT) decreased rates of antiretroviral therapy (ART) discontinuation and was associated with plasma HIV RNA responses among a cohort of illicit drug users. Cumulative ART discontinuation rates were estimated using Kaplan-Meier methods and factors independently associated with ART discontinuation were identified using Cox proportional hazards regression. Engagement in MMT was negatively and independently associated with ART discontinuation [Adjusted Relative Hazard = 0.67 (95 % CI 0.54-0.83); p < 0.001]. Among participants receiving ART and MMT, 81.6 % of plasma HIV-1 RNA assessments were <500 copies/mL, while 65.81 % of HIV-1 RNA assessments among those prescribed ART without MMT were <500 copies/mL (p < 0.001). These results demonstrate that engagement in MMT conferred a protective benefit against ART discontinuation and was associated with a significant increase in plasma HIV RNA suppression among HIV-infected opioid-dependent drug users.

Finding those at risk: acute HIV infection in Newark, NJ

BACKGROUND

A screening strategy combining rapid HIV-1/2 (HIV) antibody testing with pooled HIV-1 RNA testing increases identification of HIV infections, but may have other limitations that restrict its usefulness to all but the highest incidence populations.

OBJECTIVE

By combining rapid antibody detection and pooled nucleic acid amplification testing (NAAT) testing, we sought to improve detection of early HIV-1 infections in an urban Newark, NJ hospital setting.

STUDY DESIGN

Pooled NAAT HIV-1 RNA testing was offered to emergency department patients and outpatients being screened for HIV antibodies by fingerstick-rapid HIV testing. For those negative by rapid HIV and agreeing to NAAT testing, pooled plasma samples were prepared and sent to the University of Washington where real-time reverse transcription-polymerase chain reaction (RT-PCR) amplification was performed.

RESULTS

Of 13,226 individuals screened, 6381 had rapid antibody testing alone, and 6845 agreed to add NAAT HIV screening. Rapid testing identified 115 antibody positive individuals. Pooled NAAT increased HIV-1 case detection by 7.0% identifying 8 additional cases. Overall, acute HIV infection yield was 0.12%. While males represent only 48.1% of those tested by NAAT, all samples that screened positive for HIV-1 RNA were obtained from men.

CONCLUSION

HIV-1 RNA testing of pooled, HIV antibody-negative specimens permits identification of recent infections. In Newark, pooled NAAT increased HIV-1 case detection and provided an opportunity to focus on treatment and prevention messages for those most at risk of transmitting infection. Although constrained by client willingness to participate in testing associated with a need to return to receive further results, use of pooled NAAT improved early infection sensitivity.

The importance of extended high viremics in models of HIV spread in South Africa

Recent studies found a substantial fraction of 'extended high viremics' among HIV-1 subtype C, the most common subtype in southern Africa. Extended high viremics are HIV infected individuals who maintain a high viral load for a longer time period than usual after the initial infection. They are more infectious during this period, and their infection progresses to full-blown AIDS and death much faster than usual. This study investigates the impact of extended high viremics on the spread of the HIV epidemic in South Africa. We develop a simple deterministic compartmental model for HIV infection that includes extended high viremics. As the available data on extended high viremics are limited, we parameterize this model using only the fraction of extended high viremics among new infections and the reduced life-span of extended high viremics. We find that without extended high viremics, the HIV prevalence in South Africa would have remained close to its 1990 level, instead of increasing to the current epidemic levels. We also find that the greater the fraction of extended high viremics among susceptibles, the greater the steady-state HIV prevalence and the more sensitive the steady-state prevalence is to the HIV transmission probability. These results suggest that extended high viremics have an impact on the HIV epidemic in South Africa; justify the need for comprehensive epidemiological studies since the current data is limited; and suggest that future models of HIV for southern Africa should explicitly model extended high viremics.

Preclinical pharmacokinetics and tissue distribution of long-acting nanoformulated antiretroviral therapy

Long-acting injectable nanoformulated antiretroviral therapy (nanoART) was developed with the explicit goal of improving medicine compliance and for drug targeting of viral tissue reservoirs. Prior nanoART studies completed in humanized virus-infected mice demonstrated sustained antiretroviral responses. However, the pharmacokinetics (PK) and tissue distribution of nanoART were not characterized. To this end, the PK and tissue distribution of nanoformulated atazanavir (ATV) and ritonavir (RTV) injected subcutaneously or intramuscularly in mice and monkeys were evaluated. Fourteen days after injection, ATV and RTV levels were up to 13-, 41-, and 4,500-fold higher than those resulting from native-drug administration in plasma, tissues, and at the site of injection, respectively. At nanoART doses of 10, 50, 100, and 250 mg/kg of body weight, relationships of more- and less-than-proportional increases in plasma and tissue levels with dose increases were demonstrated with ATV and RTV. Multiple-dose regimens showed serum and tissue concentrations up to 270-fold higher than native-drug concentrations throughout 8 weeks of study. Importantly, nanoART was localized in nonlysosomal compartments in tissue macrophages, creating intracellular depot sites. Reflective data were obtained in representative rhesus macaque studies. We conclude that nanoART demonstrates blood and tissue antiretroviral drug levels that are enhanced compared to those of native drugs. The sustained and enhanced PK profile of nanoART is, at least in part, the result of the sustained release of ATV and RTV from tissue macrophases and at the site of injection.

Socio-economic, clinical and biological risk factors for mother - to - child transmission of HIV-1 in Muhima health centre (Rwanda): a prospective cohort study

BACKGROUND

Three decades since the first HIV-1 infected patients in Rwanda were identified in 1983; the Acquired Immunodeficiency Syndrome epidemic has had a devastating history and is still a major public health challenge in the country. This study was aimed at assessing socioeconomic, clinical and biological risk factors for mother - to - child transmission of HIV- in Muhima health centre (Kigali/Rwanda).

METHODS

The prospective cohort study was conducted at Muhima Health centre (Kigali/Rwanda).During the study period (May 2007 - April 2010), of 8,669 pregnant women who attended antenatal visits and screened for HIV-1, 736 tested HIV-1 positive and among them 700 were eligible study participants. Hemoglobin, CD4 count and viral load tests were performed for participant mothers and HIV-1 testing using DNA PCR technique for infants.Follow up data for eligible mother-infant pairs were obtained from women themselves and log books in Muhima health centre and maternity, using a structured questionnaire.Predictors of mother-to-child transmission of HIV-1 were assessed by multivariable logistic regression analysis.

RESULTS

Among the 679 exposed and followed-up infants, HIV-1 status was significantly associated with disclosure of HIV status to partner both at 6 weeks of age (non-disclosure of HIV status, adjusted odds ratio [AOR] 4.68, CI 1.39 to 15.77, p < 0.05; compared to disclosure) and at 6 months of age (non-disclosure of HIV status, AOR, 3.41, CI 1.09 to 10.65, p < 0.05, compared to disclosure).A significant association between mother's viral load (HIV-1 RNA) and infant HIV-1 status was found both at 6 weeks of age (> = 1000 copies/ml, AOR 7.30, CI 2.65 to 20.08, p < 0.01, compared to <1000 copies/ml) and at 6 months of age (> = 1000 copies/ml, AOR 4.60, CI 1.84 to 11.49, p < 0.01, compared to <1000 copies/ml).

CONCLUSION

In this study, the most relevant factors independently associated with increased risk of mother - to - child transmission of HIV-1 included non-disclosure of HIV status to partner and high HIV-1 RNA. Members of this cohort also showed socioeconomic inequalities, with unmarried status carrying higher risk of undisclosed HIV status. The monitoring of maternal HIV-1 RNA level might be considered as a routinely used test to assess the risk of transmission with the goal of achieving viral suppression as critical for elimination of pediatric HIV, particularly in breastfeeding populations.

CD34+ hematopoietic stem cells support entry and replication of poliovirus: a potential new gene introduction route

Pluripotent hematopoietic stem cells (HSC) are critical in sustaining and constantly renewing the blood and immune system. The ability to alter biological characteristics of HSC by introducing and expressing genes would have enormous therapeutic possibilities. Previous unpublished work suggested that human HSC co-express CD34 (cluster of differentiation 34; an HSC marker) and CD155 (poliovirus receptor; also called Necl-5/Tage4/PVR/CD155). In the present study, we demonstrate the co-expression of CD34 and CD155 in primary human HSC. In addition, we demonstrate that poliovirus infects and replicates in human hematopoietic progenitor cell lines. Finally, we show that poliovirus replicates in CD34+ enriched primary HSC. CD34+ enriched HSC co-express CD155 and support poliovirus replication. These data may help further understanding of poliovirus spread in vivo and also demonstrate that human HSC may be amenable for gene therapy via poliovirus-capsid-based vectors. They may also help elucidate the normal function of Necl-5/Tage4/PVR/CD155.

Mapping HIV community viral load: space, power and the government of bodies

HIV plasma viral load testing has become more than just a clinical tool to monitor treatment response at the individual level. Increasingly, individual HIV plasma viral load testing is being reported to public health agencies and is used to inform epidemiological surveillance and monitor the presence of the virus collectively using techniques to measure 'community viral load'. This article seeks to formulate a critique and propose a novel way of theorizing community viral load. Based on the salient work of Michel Foucault, especially the governmentality literature, this article critically examines the use of community viral load as a new strategy of government. Drawing also on the work of Miller and Rose, this article explores the deployment of 'community' through the re-configuration of space, the problematization of viral concentrations in specific microlocales, and the government (in the Foucauldian sense) of specific bodies which are seen as 'risky', dangerous and therefore, in need of attention. It also examines community viral load as a necessary precondition - forming the 'conditions of possibility' - for the recent shift to high impact prevention tactics that are being scaled up across North America.

May viral (antigen) load be the real crucial tool leading to anergy in a "micro-evolutionary" model of host/virus interaction?

HYPOTHESIS

The hypothesis in the present work is that in host/virus/tumor (antigens) interactions, leading to anergy of the immune system, the Viral (antigen) load plays a crucial and central role, which all interactions turn around.

BACKGROUND

Notwithstanding apparent strong favorable evidences, the still prevailing concept of "active virus strategies to escape" may be misleading, since it might hide the cited pivotal role in a wide number of researches. This concept could be easily substituted by a microevolutionary model explaining many unresolved questions and allowing to emerge the role of antigen load conditioned reactions of the host's immune system as motivated choices. EVIDENCES: An anergy induced condition can be detected not only in HCV, but also in the course of persistent viral (e.g. HBV, HIV) and non viral parasitic infections (e.g. Leishmania and Helminths) which share the same host's reactions leading to anergy, independently on the infecting agents. The starting point of those reactions is always time elapsing from the primary infection after a short early (often undetected) period of high viral(antigen) load in the lack of clearance. This latter seems then the only conceivable link between such so different infections determining, as far as HBV and HCV are concerned, also Hepatocarcinoma under indirect facilitating conditions. In a wide majority of studies it seems clearly evident that viral load exerts a main role which contributes to determine host chosen reactions aimed at avoiding dangerous outcomes while controlling viral load. Strong clinical (i.e. both HIV infected patients treated with HAART, and helminths infected people with deworming drugs acting directly on viral and parasitic loads) and experimental studies (i.e. chimpanzees (the only animal model of HCV infection) infected with HBV inocula of different size) are here reported or cited to highlight the crucial role of antigen load also on HIV infection transmission, seroconversion, disease progression, treatment initiation and efficacy.

CONCLUDING SUGGESTIONS

The new era for antiviral drugs like protease and polymerase inhibitors that seem to be more efficacious and less toxic than Ribavirin, may open the possibility to verify, when administered during the early phase of HCV infection (eventually helped by an immune-stimulant cytokine as IL-2), whether a precocious significant reduction of viral load (threshold) may allow the host to sustain his strong reactions and clear the virus within the due time, confirming the hypothesis about the crucial role of this tool which may be extended to all the cited infections.

Behavioral factors in assessing impact of HIV treatment as prevention

The recent NIH HPTN 052 study of using HIV treatment to prevent HIV transmission in serostatus discordant heterosexual partnerships has garnered much attention. In subsequent discussions, however, the topic of HIV-related risk behavior has been nearly absent. Here, we identify the critical roles that HIV-related risk behavior plays in determining the unmet needs, optimal targeting, and ultimate impact of treatment as prevention. We describe the size of the population at risk of HIV and three subgroups of persons living with HIV (PLWH) based on awareness of serostatus and risk behavior, and the corresponding HIV transmission rates to seronegative partners. For each of the subgroups of PLWH, we identify which approach is most relevant ("testing and linkage to care," "treatment as prevention," and/or "treatment as clinical care"). We observe that the impact of "treatment as prevention" on HIV incidence will depend heavily on which subgroup of PLWH is targeted for services.