Prevention of HIV-1 infection with early antiretroviral therapy

HIV treatment as prevention: natural experiments highlight limits of antiretroviral treatment as HIV prevention

There is growing enthusiasm for increasing coverage of antiretroviral treatment among HIV-infected people for the purposes of preventing ongoing transmission. Treatment as prevention will face a number of barriers when implemented in real world populations, which will likely lead to the effectiveness of this strategy being lower than proposed by optimistic modelling scenarios or ideal clinical trial settings. Some settings, as part of their prevention and treatment strategies, have already attained rates of HIV testing and use of antiretroviral therapy--with high levels of viral suppression--that many countries would aspire to as targets for a treatment-as-prevention strategy. This review examines a number of these "natural experiments", namely, British Columbia, San Francisco, France, and Australia, to provide commentary on whether treatment as prevention has worked in real world populations. This review suggests that the population-level impact of this strategy is likely to be considerably less than as inferred from ideal conditions.

HIV treatment as prevention: systematic comparison of mathematical models of the potential impact of antiretroviral therapy on HIV incidence in South Africa

BACKGROUND

Many mathematical models have investigated the impact of expanding access to antiretroviral therapy (ART) on new HIV infections. Comparing results and conclusions across models is challenging because models have addressed slightly different questions and have reported different outcome metrics. This study compares the predictions of several mathematical models simulating the same ART intervention programmes to determine the extent to which models agree about the epidemiological impact of expanded ART.

METHODS AND FINDINGS

Twelve independent mathematical models evaluated a set of standardised ART intervention scenarios in South Africa and reported a common set of outputs. Intervention scenarios systematically varied the CD4 count threshold for treatment eligibility, access to treatment, and programme retention. For a scenario in which 80% of HIV-infected individuals start treatment on average 1 y after their CD4 count drops below 350 cells/µl and 85% remain on treatment after 3 y, the models projected that HIV incidence would be 35% to 54% lower 8 y after the introduction of ART, compared to a counterfactual scenario in which there is no ART. More variation existed in the estimated long-term (38 y) reductions in incidence. The impact of optimistic interventions including immediate ART initiation varied widely across models, maintaining substantial uncertainty about the theoretical prospect for elimination of HIV from the population using ART alone over the next four decades. The number of person-years of ART per infection averted over 8 y ranged between 5.8 and 18.7. Considering the actual scale-up of ART in South Africa, seven models estimated that current HIV incidence is 17% to 32% lower than it would have been in the absence of ART. Differences between model assumptions about CD4 decline and HIV transmissibility over the course of infection explained only a modest amount of the variation in model results.

CONCLUSIONS

Mathematical models evaluating the impact of ART vary substantially in structure, complexity, and parameter choices, but all suggest that ART, at high levels of access and with high adherence, has the potential to substantially reduce new HIV infections. There was broad agreement regarding the short-term epidemiologic impact of ambitious treatment scale-up, but more variation in longer term projections and in the efficiency with which treatment can reduce new infections. Differences between model predictions could not be explained by differences in model structure or parameterization that were hypothesized to affect intervention impact.

Rare serotype adenoviral vectors for HIV vaccine development

Human adenoviral vectors are being developed for use in candidate vaccines for HIV-1 and other pathogens. However, this approach suffered a setback when an HIV-1 vaccine using an adenovirus type 5 (Ad5) vector failed to reduce, and might even have increased, the rate of HIV infection in men who were uncircumcised and who had preexisting antibodies specific for Ad5. This increased interest in the evaluation of serologically distinct adenoviral vectors. In this issue of the JCI, Frahm and coworkers report evidence that preexisting cellular immune responses directed toward Ad5 reduce the immunogenicity of antigens expressed in Ad5-vectored vaccines and have cross-reacting potential with non-Ad5 adenoviral vectors. The implications of this observation need to be carefully evaluated in future clinical trials of all serotypes of adenovirus-vectored vaccines.

Australian gay men who have taken nonoccupational postexposure prophylaxis for HIV are in need of effective HIV prevention methods

BACKGROUND

Gay men who request nonoccupational postexposure prophylaxis (PEP) may seek preexposure prophylaxis (PrEP) should this become available. We explored trends and predictors of PEP use among Australian gay men to inform future biomedical prevention programs.

METHODS

We used 2001-2010 data from Gay Community Periodic Surveys in 3 Eastern Australian states and assessed PEP awareness and use in the 6 months before each survey, and among HIV-uninfected men in all surveys predictors of PEP use. Analytical methods included chi-square test for trend and multivariate log-binomial estimation of associations.

RESULTS

The awareness of PEP significantly increased from 23% in 2001 to 64% in 2010. PEP use also increased from 2.3% to 3.9%, respectively. PEP use was significantly associated with being in a regular relationship with an HIV-serodiscordant partner, higher number of sex partners, engaging in anal intercourse with casual partners, and regularly testing for HIV/sexually transmitted infections. However, fewer than 8% of men who engaged in these practices reported PEP use.

CONCLUSIONS

Our findings highlight the profiles of current PEP users: men in HIV-serodiscordant relationships, and men having high numbers of casual partners and unprotected anal intercourse with them. These men are in need of effective HIV prevention strategies and may be receptive to preexposure prophylaxis in the future. Presently, targeted HIV education to improve risk assessment skills may prevent some seroconversions through the appropriate use of PEP.

Modeling the population-level effects of male circumcision as an HIV-preventive measure: a gendered perspective

Background

Evidence from biological, epidemiological, and controlled intervention studies has demonstrated that male circumcision (MC) protects males from HIV infection, and MC is now advocated as a public-health intervention against HIV. MC provides direct protection only to men, but is expected to provide indirect protection to women at risk of acquiring HIV from heterosexual transmission. How such indirect protection interacts with the possibility that MC campaigns will lead to behavior changes, however, is not yet well understood. Our objective here is to investigate the link between individual-level effects of MC campaigns and long-term population-level outcomes resulting from disease dynamics, looking at both genders separately, over a broad range of parameters.

Methods and Findings

We use simple mathematical models of heterosexual transmission to investigate the potential effects of a circumcision scale-up, combined with possible associated behavioral disinhibition. We examine patterns in expected long-term prevalence using a simple equilibrium model based on transmission factors, and validate our results with ODE-based simulations, focusing on the link between effects on females and those on males.We find that the long-term population-level effects on females and males are not strongly linked: there are many possible ways in which an intervention which reduces prevalence in males might nonetheless increase prevalence in females.

Conclusions

Since an intervention that reduces long-term male prevalence could nonetheless increase long-term female prevalence, MC campaigns should explicitly consider both the short-term and long-term effects of MC interventions on females. Our findings strongly underline the importance of pairing MC programs with education, support programs and HIV testing and counseling, together with other prevention measures.

What is the impact of home-based HIV counseling and testing on the clinical status of newly enrolled adults in a large HIV care program in Western Kenya?

BACKGROUND

This article describes the effect point of entry into the human immunodeficiency virus (HIV) care program had on the clinical status of adults presenting for the first time to USAID-AMPATH (US Agency for International Development-Academic Model Providing Access to Healthcare) Partnership clinics for HIV care.

METHODS

All patients aged ≥ 14 years enrolled between August 2008 and April 2010 were included. Points of entry to USAID-AMPATH clinics were home-based counseling and testing (HBCT), provider-initiated testing and counseling (PITC), HIV testing in the tuberculosis clinic, and voluntary counseling and testing (VCT). Tests for trend were calculated, and multivariable logistic regression was used to compare the effect of HBCT versus other points of entry on primary outcomes controlling for age and sex.

RESULTS

There were 19,552 eligible individuals. Of these, 946 tested in HBCT, 10,261 in VCT, 8073 in PITC, and 272 in the tuberculosis clinic. The median (interquartile range) enrollment CD4 cell counts among those who tested HIV positive was 323 (194-491), 217 (87-404), 190 (70-371), and 136 cells/mm(3) (59-266) for HBCT, VCT, PITC, and the tuberculosis clinic, respectively (P < .001). Compared with those patients whose HIV infection was diagnosed in the tuberculosis clinic, those who tested positive in HBCT were, controlling for age and sex, less likely to have to have World Health Organization stage III or IV HIV infection at enrollment (adjusted odds ratio [AOR], 0.04; 95% confidence interval [CI], .03-.06), less likely to enroll with a CD4 cell count of <200 cells/mm(3) (AOR, 0.20; 95% CI, .14-.28), and less likely to enroll into care with a chief complaint (AOR, 0.08; 95% CI, .05-.12).

CONCLUSIONS

HBCT is effective at getting HIV-infected persons enrolled in HIV care before they become ill.

Modelling the spread of HIV immune escape mutants in a vaccinated population

Because cytotoxic T-lymphocytes (CTLs) have been shown to play a role in controlling human immunodeficiency virus (HIV) infection and because CTL-based simian immunodeficiency virus (SIV) vaccines have proved effective in non-human primates, one goal of HIV vaccine design is to elicit effective CTL responses in humans. Such a vaccine could improve viral control in patients who later become infected, thereby reducing onwards transmission and enhancing life expectancy in the absence of treatment. The ability of HIV to evolve mutations that evade CTLs and the ability of these ‘escape mutants’ to spread amongst the population poses a challenge to the development of an effective and robust vaccine. We present a mathematical model of within-host evolution and between-host transmission of CTL escape mutants amongst a population receiving a vaccine that elicits CTL responses to multiple epitopes. Within-host evolution at each epitope is represented by the outgrowth of escape mutants in hosts who restrict the epitope and their reversion in hosts who do not restrict the epitope. We use this model to investigate how the evolution and spread of escape mutants could affect the impact of a vaccine. We show that in the absence of escape, such a vaccine could markedly reduce the prevalence of both infection and disease in the population. However the impact of such a vaccine could be significantly abated by CTL escape mutants, especially if their selection in hosts who restrict the epitope is rapid and their reversion in hosts who do not restrict the epitope is slow. We also use the model to address whether a vaccine should span a broad or narrow range of CTL epitopes and target epitopes restricted by rare or common HLA types. We discuss the implications and limitations of our findings.

The evolution and spread of HIV strains that evade the immune response poses a major challenge to the development of an effective and robust HIV vaccine. We present a new mathematical tool that we use to dissect the drivers of the spread of these ‘immune escape mutants’ in a vaccinated population. Our study focuses on a vaccine that can reduce infectiousness and enhance longevity but does not provide sterilizing immunity. We show that in the absence of escape such a vaccine could reduce the prevalence of both infection and disease in the population. However, vaccine impact could be significantly abated by immune escape mutants, especially if they emerge rapidly and revert very slowly after transmission to hosts in whom the original selection pressure is absent. We also discuss the effect that vaccine breadth and the frequency with which different epitopes are targeted have upon vaccine impact.

Commentary: thirty years of AIDS in America: a story of infinite hope

The year 2011 marks the thirtieth anniversary of the first case reports in the United States of what we now know to be end-stage HIV disease. This chronological milestone provides an opportunity to reflect upon the changing context of the American HIV/AIDS epidemic. Using two seminal documents as a framework, the 1986 Institute of Medicine Report, "Confronting AIDS," and the 2010 National HIV/AIDS Strategy, this descriptive analysis details our accomplishments in addressing the domestic U.S. epidemic and outlines what remains to be done on the long road to eradication of HIV disease. The past three decades have witnessed tremendous biomedical and behavioral advances in preventing, diagnosing, and treating HIV disease. However, to fully realize the promise of these scientific advances, such that we achieve the vision of the National HIV/AIDS Strategy, we must develop effective strategies to surmount a number of salient challenges, including: unbalanced combinations of prevention interventions; programs that are not of adequate scale to achieve population-level results; systems of service delivery that do not function in an integrated fashion; and social and economic structures that increase the vulnerability of populations who are at risk for or living with HIV disease.

Essential components of effective HIV care: a policy paper of the HIV Medicine Association of the Infectious Diseases Society of America and the Ryan White Medical Providers Coalition

Human immunodeficiency virus (HIV) antiretroviral agents and effective HIV care management transformed HIV disease from a death sentence to a chronic condition for many in the United States. A comprehensive HIV care model was developed to meet the complex needs of HIV patients, with support from the Ryan White program, the Veterans Administration, and others. This paper identifies the essential components of an effective HIV care model. As access to health care expands under the National HIV/AIDS Strategy and the Patient Protection and Affordable Care Act, it will be critical to build upon the HIV care model to realize positive health outcomes for people with HIV infection.

Microbicides for HIV prevention

Although the HIV incidence rate has slowed in some countries, HIV remains a serious health challenge, particularly in the developing world. The epidemic is increasingly feminised, with young women at high risk of acquiring the virus. There is thus a clear requirement for acceptable woman-initiated methods of HIV prevention. Foremost among these are vaginally-applied substances known as microbicides; early research into potential microbicides focussed on non-HIV-specific compounds such as surfactants and polyanionic entry inhibitors. However, proof of the microbicide concept as a viable prevention strategy was not provided until the CAPRISA 004 trial of a microbicide containing the HIV-specific antiretroviral tenofovir was completed in mid-2010. Confirmation of the proof of concept provided by CAPRISA 004 by at least two major trials will hopefully lead to licensure of the product by 2018. Parallel studies are planned to ascertain the feasibility of implementation of these products in the public sector with subsequent research focussed on appropriate and acceptable methods of delivery of the active ingredient, and to increase adherence through other delivery systems such as vaginal rings.

Interventions to prevent sexually transmitted infections, including HIV infection

The Centers for Disease Control and Prevention (CDC) Sexually Transmitted Disease (STD) Treatment Guidelines were last updated in 2006. To update the "Clinical Guide to Prevention Services" section of the 2010 CDC STD Treatment Guidelines, we reviewed the recent science with reference to interventions designed to prevent acquisition of STDs, including human immunodeficiency virus (HIV) infection. Major interval developments include (1) licensure and uptake of immunization against genital human papillomavirus, (2) validation of male circumcision as a potent prevention tool against acquisition of HIV and some other sexually transmitted infections (STIs), (3) failure of a promising HIV vaccine candidate to afford protection against HIV acquisition, (4) encouragement about the use of antiretroviral agents as preexposure prophylaxis to reduce risk of HIV and herpes simplex virus acquisition, (5) enhanced emphasis on expedited partner management and rescreening for persons infected with Chlamydia trachomatis and Neisseria gonorrhoeae, (6) recognition that behavioral interventions will be needed to address a new trend of sexually transmitted hepatitis C among men who have sex with men, and (7) the availability of a modified female condom. A range of preventive interventions is needed to reduce the risks of acquiring STI, including HIV infection, among sexually active people, and a flexible approach targeted to specific populations should integrate combinations of biomedical, behavioral, and structural interventions. These would ideally involve an array of prevention contexts, including (1) communications and practices among sexual partners, (2) transactions between individual clients and their healthcare providers, and (3) comprehensive population-level strategies for prioritizing prevention research, ensuring accurate outcome assessment, and formulating health policy.

Experience in international clinical research: the HIV Prevention Trials Network

The HIV Prevention Trials Network (HPTN) is supported by the NIH to conduct randomized clinical trials to assess the efficacy of HIV prevention strategies and technologies to reduce HIV transmission between adults. A special focus of attention is on the use of antiretroviral drugs to prevent HIV transmission, both by reducing infectiousness among HIV-infected persons taking combination antiretroviral therapy (cART) and also by reducing susceptibility among HIV-uninfected persons taking antiretrovirals for pre-exposure prophylaxis. Studies may be developmental in nature to assess novel ideas for interventions or for assessing trial feasibility. However, pivotal efficacy trials to test HIV-specific prevention strategies and technologies are the main HPTN priority. Examples include a major protocol investigating the impact of expanded testing and linkage to care on HIV surveillance indicators in the USA (HPTN 065). Another protocol is addressing similar issues while also investigating how combinations of prevention approaches are best deployed to make a community-level impact in southern Africa (HPTN 071). HPTN 068 is evaluating a novel conditional cash transfer structural intervention to increase school completion rates in young girls and thereby reduce their HIV risk. Studies outside the US address the epidemic in most at-risk populations and include an assessment of opiate agonist therapy to reduce risk of HIV seroconversion among injection drug users (HTPN 058), methods to increase HIV testing rates (HTPN 043), as well as methods for reducing high-risk behaviors, and increasing adherence to cART in HIV-infected individuals (HPTN 062 and HPTN 063, respectively). The recent HPTN 052 study demonstrated that a 96% reduction in HIV transmission could be achieved between serodiscordant sexual partners by providing the infected partners with cART at a CD4(+) cell count (350-550/µl) above the level that would usually qualify them for therapy in low- and middle-income countries. The immediate relevance to public health policy showcased in these trials is a paradigm for the HPTN: design and conduct of clinical trials using available licensed tools that can be rapidly translated for implementation ('Prevention NOW!').

HIV testing and antiretroviral treatment strategies for prevention of HIV infection: impact on antiretroviral drug resistance

'Test and treat' is a strategy in which widespread screening for human immunodeficiency virus (HIV) is followed by immediate antiretroviral therapy for those testing positive, thereby potentially reducing infectiousness in larger cohorts of infected patients. However, there is a concern that test and treat could lead to increased the levels of transmissible drug-resistant HIV, especially if viral load and/or drug resistance is not routinely monitored. Reviews of the existing literature show that up to now, even in the absence of laboratory tests, drug resistance has not created major problems in sub-Saharan Africa. Here, we discuss the current evidence for the effectiveness of a preventive test and treat approach and the challenges and implications for daily clinical practice and public health.

Update of the past year: a review from IDSA 2011

The Infectious Diseases Society of America Annual Meeting serves as a time of expert review of the year's most important innovations. Important new information on HIV infection incidence was discussed. The remarkable efficacy of "treatment as prevention" in the HIV Prevention Trials Network (HPTN) 052 study and the proper place of oral preexposure prophylaxis were among the important prevention topics. Key engagement-in-care research indicates that only 19% of HIV-infected persons in the United States have a plasma HIV RNA level below the limits of assay detection. Among antiretroviral topics, the role of the newly approved nonnucleoside reverse transcriptase inhibitor (NNRTI) rilpivirine was discussed. Primary care topics for the HIV-infected population included treatment of triglyceride level elevations and bone health. The newly published data on the proper timing of antiretroviral therapy initiation after starting tuberculosis treatment were highlighted. Finally, exciting advances in the treatment of hepatitis C virus (HCV) infection necessitate that practitioners understand the complexities of treating HIV/HCV coinfections.

Modeling the impact on the HIV epidemic of treating discordant couples with antiretrovirals to prevent transmission

BACKGROUND

The HPTN 052 study demonstrated a 96% reduction in HIV transmission in discordant couples using antiretroviral therapy (ART).

OBJECTIVE

To predict the epidemic impact of treating HIV-discordant couples to prevent transmission.

DESIGN

Mathematical modeling to predict incidence reduction and the number of infections prevented.

METHODS

Demographic and epidemiological data from Ghana, Lesotho, Malawi and Rwanda were used to parameterize the model. ART was assumed to be 96% effective in preventing transmission.

RESULTS

Our results show there would be a fairly large reduction in incidence and a substantial number of infections prevented in Malawi. However, in Ghana a large number of infections would be prevented, but only a small reduction in incidence. Notably, the predicted number of infections prevented would be similar (and low) in Lesotho and Rwanda, but incidence reduction would be substantially greater in Lesotho than Rwanda. The higher the proportion of the population in stable partnerships (whether concordant or discordant), the greater the effect of a discordant couple's intervention on HIV epidemics.

CONCLUSION

The effectiveness of a discordant couples intervention in reducing incidence will vary among countries due to differences in HIV prevalence and the percentage of couples that are discordant (i.e. degree of discordancy). The number of infections prevented within a country, as a result of an intervention, will depend upon a complex interaction among three factors: population size, HIV prevalence and degree of discordancy. Our model provides a quantitative framework for identifying countries most likely to benefit from treating discordant couples to prevent transmission.

Multiple routes of drug administration and HIV risk among injecting drug users

This study assesses relationships between drug administration routes and HIV serostatus, drug use, and sexual behaviors among current injecting drug users (IDUs) in Tallinn, Estonia. We recruited 350 IDUs for a cross-sectional risk behavior survey. Adjusted odds ratios (AORs) were calculated to explore injection risk behavior, sexual behavior, and HIV serostatus associated with multiple route use. Focus groups explored reasons why injectors might use non-injecting routes of administration. Those reporting multiple drug administration routes were less likely to be HIV seropositive (AOR = 0.49, 95% confidence interval [CI] = 0.25-0.97) and had almost twice the odds of having more than one sexual partner (AOR = 1.90, 95% CI = 1.01-3.60) and of reporting having sexually transmitted diseases (AOR = 2.38, 95% CI = 1.02-5.59). IDUs who engage in noninjecting drug use may be reducing their risk of acquiring HIV though sharing injection equipment, but if infected may be a critical group for sexual transmission of HIV to people who do not inject drugs.

What works to meet the sexual and reproductive health needs of women living with HIV/AIDS

It is critical to include a sexual and reproductive health lens in HIV programming as most HIV transmission occurs through sexual intercourse. As global attention is focusing on the sexual and reproductive health needs of women living with HIV, identifying which interventions work becomes vitally important. What evidence exists to support sexual and reproductive health programming related to HIV programmes?

This article reviews the evidence of what works to meet the sexual and reproductive health needs of women living with HIV in developing countries and includes 35 studies and evaluations of eight general interventions using various methods of implementation science from 15 countries. Data are primarily from 2000-2009. Searches to identify effective evaluations used SCOPUS, Popline, Medline, websites and consultations with experts. Evidence was ranked using the Gray Scale.

A range of successful and promising interventions to improve the sexual and reproductive health and rights of women living with HIV include: providing contraceptives and family planning counselling as part of HIV services; ensuring early postpartum visits providing family planning and HIV information and services; providing youth-friendly services; supporting information and skills building; supporting disclosure; providing cervical cancer screening; and promoting condom use for dual protection against pregnancy and HIV. Provision of antiretrovirals can also increase protective behaviours, including condom use.

While many gaps in programming and research remain, much can be done now to operationalize evidence-based effective interventions to meet the sexual and reproductive health needs of women living with HIV.

Adherence to highly active antiretroviral treatment in HIV-infected Rwandan women

BACKGROUND

Scale-up of highly active antiretroviral treatment therapy (HAART) programs in Rwanda has been highly successful but data on adherence is limited. We examined HAART adherence in a large cohort of HIV+ Rwandan women.

METHODS

The Rwanda Women's Interassociation Study Assessment (RWISA) was a prospective cohort study that assessed effectiveness and toxicity of ART. We analyzed patient data 12±3 months after HAART initiation to determine adherence rates in HIV+ women who had initiated HAART.

RESULTS

Of the 710 HIV+ women at baseline, 490 (87.2%) initiated HAART. Of these, 6 (1.2%) died within 12 months, 15 others (3.0%) discontinued the study and 80 others (19.0%) remained in RWISA but did not have a post-HAART initiation visit that fell within the 12±3 month time points leaving 389 subjects for analysis. Of these 389, 15 women stopped their medications without being advised to do so by their doctors. Of the remaining 374 persons who reported current HAART use 354 completed the adherence assessment. All women, 354/354, reported 100% adherence to HAART at the post-HAART visit. The high self-reported level of adherence is supported by changes in laboratory measures that are influenced by HAART. The median (interquartile range) CD4 cell count measured within 6 months prior to HAART initiation was 185 (128, 253) compared to 264 (182, 380) cells/mm(3) at the post-HAART visit. Similarly, the median (interquartile range) MCV within 6 months prior to HAART initiation was 88 (83, 93) fL compared to 104 (98, 110) fL at the 12±3 month visit.

CONCLUSION

Self-reported adherence to antiretroviral treatment 12±3 months after initiating therapy was 100% in this cohort of HIV-infected Rwandan women. Future studies should explore country-specific factors that may be contributing to high levels of adherence to HAART in this population.

Provider-initiated HIV testing and counseling: increased uptake in two public community health centers in South Africa and implications for scale-up

Background

International guidance recommends the scale up of routinely recommended, offered, and delivered health care provider-initiated HIV testing and counseling (PITC) to increase the proportion of persons who know their HIV status. We compared HIV test uptake under PITC to provider-referral to voluntary counseling and testing (VCT referral) in two primary health centers in South Africa.

Methods

Prior to introducing PITC, clinical providers were instructed to refer systematically selected study participants to VCT. After PITC and HIV rapid test training, providers were asked to recommend, offer and provide HIV testing to study participants during the clinical consultation. Participants were interviewed before and after their consultation to assess their HIV testing experiences.

Results

HIV test uptake increased under PITC (OR 2.85, 95% CI 1.71, 4.76), and more patients felt providers answered their questions on HIV (104/141 [74%] versus 73/118 [62%] for VCT referral; p 0.04). After three months, only 4/106 (3.8%) HIV-positive patients had registered for onsite HIV treatment. Providers found PITC useful, but tested very few patients (range 0–15).

Conclusion

PITC increased the uptake of HIV testing compared with referral to onsite VCT, and patients reported a positive response to PITC. However, providing universal PITC will require strong leadership to train and motivate providers, and interventions to link HIV-positive persons to HIV treatment centers.

Antiretroviral therapy refusal among newly diagnosed HIV-infected adults

OBJECTIVE

To determine rates and predictors of treatment refusal in newly identified HIV-infected individuals in Soweto, South Africa.

DESIGN

It is designed as a cross-sectional study.

METHODS

We analyzed data from adult clients (>18 years) presenting for voluntary counseling and testing (VCT) at the Zazi Testing Center, Perinatal HIV Research Unit to determine rates of antiretroviral therapy (ART) refusal among treatment-eligible, HIV-infected individuals (CD4(+) cell count < 200 cells/μl or WHO stage 4). Multiple logistic regression models were used to investigate factors associated with refusal.

RESULTS

From December 2008 to December 2009, 7287 adult clients were HIV tested after counseling. Two thousand, five hundred and sixty-two (35%) were HIV-infected, of whom 743 (29%) were eligible for immediate ART. One hundred and forty-eight (20%) refused referral to initiate ART, most of whom (92%) continued to refuse after 2 months of counseling. The leading reason for ART refusal was given as 'feeling healthy' (37%), despite clients having a median CD4(+) cell count of 110 cells/μl and triple the rate of active tuberculosis as seen in nonrefusers. In adjusted models, single clients [adjusted odds ratio (AOR) 1.80, 95% confidence interval (CI) 1.06-3.06] and those with active tuberculosis (AOR 3.50, 95% CI 1.55-6.61) were more likely to refuse ART.

CONCLUSION

Nearly one in five treatment-eligible HIV-infected individuals in Soweto refused to initiate ART after VCT, putting them at higher risk for early mortality. 'Feeling healthy' was given as the most common reason to refuse ART, despite a suppressed CD4(+) count and comorbidities such as tuberculosis. These findings highlight the urgent need for research to inform interventions targeting ART refusers.

Late presentation of HIV infection among adults in New Zealand: 2005-2010

BACKGROUND

Early diagnosis of HIV infection is important for the individual and for disease control. A consensus was recently reached among European countries on definitions of timing of presentation for care: 'Late presentation' refers to entering care with a CD4 count <350 cells/μL or an AIDS-defining event, regardless of the CD4 count. Presentation with 'advanced HIV disease' is a subset having a CD4 count <200 cells/μL and also includes all who have an AIDS-defining event regardless of CD4 count. This study examines timing of presentation in New Zealand from 2005 to 2010.

METHODS

Since 2005, information on the initial CD4 cell count has been requested on all people newly diagnosed with HIV infection through antibody testing in New Zealand. Excluded in this analysis were those previously diagnosed overseas or for an immigration medical.

RESULTS

A CD4 cell count was provided for 606 (80.3%) of the 755 newly diagnosed adults. Overall, 50.0% were 'late presenters' and 32.0% had 'advanced HIV disease'. Compared with men who have sex with men (MSM), people heterosexually infected were more likely to present late. 'Late presentation' and presentation with 'advanced HIV disease' were significantly more common among older MSM. Māori and Pacific MSM were more likely to present with 'advanced HIV disease'. Compared with European MSM, the age-adjusted relative risks for Māori and Pacific MSM were 2.1 [95% confidence interval (CI) 1.4-3.2] and 2.5 (95% CI 1.2-5.0), respectively.

CONCLUSIONS

The high proportion of people presenting late reflects inadequate levels of HIV testing. The lower proportion of late presentations among MSM compared with those heterosexually infected may be explained by a higher proportion of recent locally acquired infections together with different testing patterns.

Safer conception interventions for HIV-affected couples: implications for resource-constrained settings

Developing and testing safer conception methods that reduce HIV transmission to HIV-seronegative partners in serodiscordant couples and reduce superinfection in HIV-seroconcordant couples is a crucial but often unaddressed component of HIV prevention programs. Most research has focused on developed-world settings, where "high-technology" assisted reproduction techniques are used for HIV-serodiscordant couples in which the male is HIV-infected. There is a dearth of research on safer conception methods for HIV-seropositive women and "low-technology" harm-reduction strategies for HIV-affected couples, including vaginal insemination for HIV-seropositive women and natural conception methods for HIV-seroconcordant and -serodiscordant couples. This review summarizes international studies of safer conception interventions for HIV-affected couples, with a focus on feasibility in public-sector health settings where assisted reproductive technology is not readily available. Given that such low-technology options are feasible in most settings, well-designed, prospective interventions offering low-technology safer conception methods need to be developed and tested.

Optimal uses of antiretrovirals for prevention in HIV-1 serodiscordant heterosexual couples in South Africa: a modelling study

BACKGROUND

Antiretrovirals have substantial promise for HIV-1 prevention, either as antiretroviral treatment (ART) for HIV-1-infected persons to reduce infectiousness, or as pre-exposure prophylaxis (PrEP) for HIV-1-uninfected persons to reduce the possibility of infection with HIV-1. HIV-1 serodiscordant couples in long-term partnerships (one member is infected and the other is uninfected) are a priority for prevention interventions. Earlier ART and PrEP might both reduce HIV-1 transmission in this group, but the merits and synergies of these different approaches have not been analyzed.

METHODS AND FINDINGS

We constructed a mathematical model to examine the impact and cost-effectiveness of different strategies, including earlier initiation of ART and/or PrEP, for HIV-1 prevention for serodiscordant couples. Although the cost of PrEP is high, the cost per infection averted is significantly offset by future savings in lifelong treatment, especially among couples with multiple partners, low condom use, and a high risk of transmission. In some situations, highly effective PrEP could be cost-saving overall. To keep couples alive and without a new infection, providing PrEP to the uninfected partner could be at least as cost-effective as initiating ART earlier in the infected partner, if the annual cost of PrEP is <40% of the annual cost of ART and PrEP is >70% effective.

CONCLUSIONS

Strategic use of PrEP and ART could substantially and cost-effectively reduce HIV-1 transmission in HIV-1 serodiscordant couples. New and forthcoming data on the efficacy of PrEP, the cost of delivery of ART and PrEP, and couples behaviours and preferences will be critical for optimizing the use of antiretrovirals for HIV-1 prevention. Please see later in the article for the Editors' Summary.

Redesigning the AIDS response for long-term impact

Three decades since the human immunodeficiency virus (HIV) was identified, the pandemic of acquired immunodeficiency syndrome (AIDS) has developed into diverse epidemics around the world. In many populations, HIV infection has become endemic. While there is good progress on expanding access to treatment, with an estimated 6.6 million people on antiretroviral therapy at the end of 2010, prevention efforts are still highly inadequate with 2.6 million new infections occurring in 2009. Demand for treatment is increasing while funding is becoming more scarce and activism is waning. In 2007, the Joint United Nations Programme on HIV/AIDS (UNAIDS) established an independent forum called aids2031 to take a critical look at the global HIV/AIDS response. This paper outlines four key areas for a re-designed AIDS response based on the deliberations of this initiative and on the learning and experience of the first three decades of the epidemic: (i) a new culture of knowledge generation and utilization; (ii) transformed prevention and treatment to increase effectiveness; (iii) increased efficiency through better management and maximizing synergies with other programmes; and (iv) investment for the long term. Across all these areas is a strong emphasis on local capacity building, leadership, programme priorities and budgets.

Voluntary medical male circumcision: modeling the impact and cost of expanding male circumcision for HIV prevention in eastern and southern Africa

BACKGROUND

There is strong evidence showing that voluntary medical male circumcision (VMMC) reduces HIV incidence in men. To inform the VMMC policies and goals of 13 priority countries in eastern and southern Africa, we estimate the impact and cost of scaling up adult VMMC using updated, country-specific data.

METHODS AND FINDINGS

We use the Decision Makers' Program Planning Tool (DMPPT) to model the impact and cost of scaling up adult VMMC in Botswana, Lesotho, Malawi, Mozambique, Namibia, Rwanda, South Africa, Swaziland, Tanzania, Uganda, Zambia, Zimbabwe, and Nyanza Province in Kenya. We use epidemiologic and demographic data from recent household surveys for each country. The cost of VMMC ranges from US$65.85 to US$95.15 per VMMC performed, based on a cost assessment of VMMC services aligned with the World Health Organization's considerations of models for optimizing volume and efficiencies. Results from the DMPPT models suggest that scaling up adult VMMC to reach 80% coverage in the 13 countries by 2015 would entail performing 20.34 million circumcisions between 2011 and 2015 and an additional 8.42 million between 2016 and 2025 (to maintain the 80% coverage). Such a scale-up would result in averting 3.36 million new HIV infections through 2025. In addition, while the model shows that this scale-up would cost a total of US$2 billion between 2011 and 2025, it would result in net savings (due to averted treatment and care costs) amounting to US$16.51 billion.

CONCLUSIONS

This study suggests that rapid scale-up of VMMC in eastern and southern Africa is warranted based on the likely impact on the region's HIV epidemics and net savings. Scaling up of safe VMMC in eastern and southern Africa will lead to a substantial reduction in HIV infections in the countries and lower health system costs through averted HIV care costs.

Voluntary medical male circumcision: an introduction to the cost, impact, and challenges of accelerated scaling up

Scaling up voluntary medical male circumcision (VMMC) for HIV prevention is cost saving and creates fiscal space in the future that otherwise would have been encumbered by antiretroviral treatment costs. An investment of US$1,500,000,000 between 2011 and 2015 to achieve 80% coverage in 13 priority countries in southern and eastern Africa will result in net savings of US$16,500,000,000. Strong political leadership, country ownership, and stakeholder engagement, along with effective demand creation, community mobilisation, and human resource deployment, are essential. This collection of articles on determining the cost and impact of VMMC for HIV prevention signposts the way forward to scaling up VMMC service delivery safely and efficiently to reap individual- and population-level benefits.

Implementation of an innovative, integrated electronic medical record (EMR) and public health information exchange for HIV/AIDS

Louisiana is severely affected by HIV/AIDS, ranking fifth in AIDS rates in the USA. The Louisiana Public Health Information Exchange (LaPHIE) is a novel, secure bi-directional public health information exchange, linking statewide public health surveillance data with electronic medical record data. LaPHIE alerts medical providers when individuals with HIV/AIDS who have not received HIV care for >12 months are seen at any ambulatory or inpatient facility in an integrated delivery network. Between 2/1/2009 and 1/31/2011, 488 alerts identified 345 HIV positive patients. Of those identified, 82% had at least one CD4 or HIV viral load test over the study follow-up period. LaPHIE is an innovative use of health information exchange based on surveillance data and real time clinical messaging, facilitating rapid provider notification of those in need of treatment. LaPHIE successfully reduces critical missed opportunities to intervene with individuals not in care, leveraging information historically collected solely for public health purposes, not health care delivery, to improve public health.

Is expanded HIV treatment preventing new infections? Impact of antiretroviral therapy on sexual risk behaviors in the developing world

There have been dramatic increases in access to antiretroviral therapy (ART) across the developing world, and growing public health attention has focused on the possibility of utilizing ART as a means of slowing the global HIV epidemic. The preventive impact of ART will likely depend on decreasing levels of sexual risk behaviors following treatment initiation. The current review study examines the impact of wider access to ART on sexual risk behaviors among HIV-infected individuals in the developing world. The observational studies to date demonstrate that ART is associated with a significant reduction in unprotected sex following treatment initiation. Although data on the impact of ART on possible risk compensation are rapidly expanding across the developing world, more evidence is still needed before we can safely conclude expanded treatment will result in durable decreases in sexual risk behaviors.

Analysis of genetic linkage of HIV from couples enrolled in the HIV Prevention Trials Network 052 trial

BACKGROUND

The HIV Prevention Trials Network (HPTN) 052 trial demonstrated that early initiation of antiretroviral therapy (ART) reduces human immunodeficiency virus (HIV) transmission from HIV-infected adults (index participants) to their HIV-uninfected sexual partners. We analyzed HIV from 38 index-partner pairs and 80 unrelated index participants (controls) to assess the linkage of seroconversion events.

METHODS

Linkage was assessed using phylogenetic analysis of HIV pol sequences and Bayesian analysis of genetic distances between pol sequences from index-partner pairs and controls. Selected samples were also analyzed using next-generation sequencing (env region).

RESULTS

In 29 of the 38 (76.3%) cases analyzed, the index was the likely source of the partner's HIV infection (linked). In 7 cases (18.4%), the partner was most likely infected from a source other than the index participant (unlinked). In 2 cases (5.3%), linkage status could not be definitively established.

CONCLUSIONS

Nearly one-fifth of the seroconversion events in HPTN 052 were unlinked. The association of early ART and reduced HIV transmission was stronger when the analysis included only linked events. This underscores the importance of assessing the genetic linkage of HIV seroconversion events in HIV prevention studies involving serodiscordant couples.

Characteristics of HIV-1 serodiscordant couples enrolled in a clinical trial of antiretroviral pre-exposure prophylaxis for HIV-1 prevention

Introduction

Stable heterosexual HIV-1 serodiscordant couples in Africa have high HIV-1 transmission rates and are a critical population for evaluation of new HIV-1 prevention strategies. The Partners PrEP Study is a randomized, double-blind, placebo-controlled trial of tenofovir and emtricitabine-tenofovir pre-exposure prophylaxis to decrease HIV-1 acquisition within heterosexual HIV-1 serodiscordant couples. We describe the trial design and characteristics of the study cohort.

Methods

HIV-1 serodiscordant couples, in which the HIV-1 infected partner did not meet national guidelines for initiation of antiretroviral therapy, were enrolled at 9 research sites in Kenya and Uganda. The HIV-1 susceptible partner was randomized to daily oral tenofovir, emtricitabine-tenofovir, or matching placebo with monthly follow-up for 24–36 months.

Results

From July 2008 to November 2010, 7920 HIV-1 serodiscordant couples were screened and 4758 enrolled. For 62% (2966/4758) of enrolled couples, the HIV-1 susceptible partner was male. Median age was 33 years for HIV-1 susceptible and HIV-1 infected partners [IQR (28–40) and (26–39) respectively]. Most couples (98%) were married, with a median duration of partnership of 7.0 years (IQR 3.0–14.0) and recent knowledge of their serodiscordant status [median 0.4 years (IQR 0.1–2.0)]. During the month prior to enrollment, couples reported a median of 4 sex acts (IQR 2–8); 27% reported unprotected sex and 14% of male and 1% of female HIV-1 susceptible partners reported sex with outside partners. Among HIV-1 infected partners, the median plasma HIV-1 level was 3.94 log₁₀ copies/mL (IQR 3.31–4.53) and median CD4 count was 496 cells/µL (IQR 375–662); the majority (64%) had WHO stage 1 HIV-1 disease.

Conclusions

Couples at high risk of HIV-1 transmission were rapidly recruited into the Partners PrEP Study, the largest efficacy trial of oral PrEP. (ClinicalTrials.gov NCT00557245)

Tracking the evolution of HIV/AIDS in China from 1989-2009 to inform future prevention and control efforts

Background

To determine policy implications, this analysis tracks the evolution of HIV/AIDS infection across China to understand current trends and potential risk factors.

Methods and Principal Findings

A retrospective study with spatial analytical model and multilevel spatial models was conducted among 326,157 HIV/AIDS cases reported from 1989–2009. The results indicate that the distribution of HIV/AIDS was clustered at the county level with different directional distributions across China from 2003 to 2009. Compared to 2003, by 2009 there was a 122% increase in HIV cases among rural residents, 294% increase among urban residents, 211% increase among migrants, and 237% increase among permanent residents. The overall proportion of HIV by different routes of transmission showed dramatic changes with a 504% increase in sexual transmission of HIV, 90% decrease in blood/plasma transmission, and 35% decrease in injecting drug user transmission. Sexual transmission was the major transmission route among women (44%) and the elderly (59% in men, 44% in women) as well as among permanent (36%) and urban residents (33%). Among those <65 years old, women increased more than men, but among those ≥65 years, men increased more than women. Migrants contributed to the variance of HIV infection between counties but not within counties. The length of highway and urbanization combined with illiteracy were risk factors for HIV/AIDS.

Conclusions/Significance

Rates of HIV/AIDS among permanent urban residents, particularly women and elderly men, have increased significantly in recent years. To prevent HIV from spreading further among the general population, additional attention should be paid to these populations as well as to migrants.

The first decade of antiretroviral therapy in Africa

The past decade has seen remarkable progress in increasing access to antiretroviral therapy in resource-limited settings. Early concerns about the cost and complexity of treatment were overcome thanks to the efforts of a global coalition of health providers, activists, academics, and people living with HIV/AIDS, who argued that every effort must be made to ensure access to essential care when millions of lives depended on it. The high cost of treatment was reduced through advocacy to promote access to generic drugs; care provision was simplified through a public health approach to treatment provision; the lack of human resources was overcome through task-shifting to support the provision of care by non-physicians; and access was expanded through the development of models of care that could work at the primary care level. The challenge for the next decade is to further increase access to treatment and support sustained care for those on treatment, while at the same time ensuring that the package of care is continuously improved such that all patients can benefit from the latest improvements in drug development, clinical science, and public health.

Harnessing the prevention benefits of antiretroviral therapy to address HIV and tuberculosis

After 30 years we are still struggling to address a devastating HIV pandemic in which over 25 million people have died. In 2010, an estimated 34 million people were living with HIV, around 70% of whom live in sub-Saharan Africa. Furthermore, in 2009 there were an estimated 1.2 million new HIV-associated TB cases, and tuberculosis (TB) accounted for 24% of HIV-related deaths. By the end of 2010, 6.6 million people were taking antiretroviral therapy (ART), around 42% of those in need as defined by the 2010 World Health Organization (WHO) guidelines. Despite this achievement, around 9 million people were eligible and still in need of treatment, and new infections (approximately 2.6 million in 2010 alone) continue to add to the future caseload. This combined with the international fiscal crisis has led to a growing concern regarding weakening of the international commitment to universal access and delivery of the Millennium Development Goals by 2015. The recently launched UNAIDS/WHO Treatment 2.0 platform calls for accelerated simplification of ART, in line with a public health approach, to achieve and sustain universal access to ART, including maximizing the HIV and TB preventive benefit of ART by treating people earlier, in line with WHO 2010 normative guidance. The potential individual and public health prevention benefits of using treatment in the prevention of HIV and TB enhance the value of the universal access pledge from a life-saving initiative, to a strategic investment aimed at ending the HIV epidemic. This review analyzes the gaps and summarizes the evidence regarding ART in the prevention of HIV and TB.