The case for earlier treatment of HIV infection

Patient acceptance of HIV rapid testing in the dental care setting

Dental settings are untapped venues to identify patients with undiagnosed HIV who may otherwise lack testing opportunities. Perceived lack of patient acceptance has been a significant barrier limiting dentists' willingness to offer HIV testing. This study implemented rapid HIV testing in dental settings located in an HIV prevalent region to evaluate patient acceptance. Two South Florida community health centers implemented routine oral rapid HIV testing as part of clinical practice, followed by exit interviews with patients immediately after to determine patient acceptance. The binary primary outcome was patient's acceptance of the rapid HIV test. Multivariable logistic regression assessed associations between patient characteristics and acceptance. Overall acceptance by dental patients (N = 600) was 84.5%. Patients who were more likely to participate in other medical screenings in dental settings were more than twice as likely to accept the test compared to those who were neutral/less likely (OR: 2.373; 95% CI: 1.406-4.004). Study findings highlight the high patient acceptance of HIV testing in dental settings. Widespread implementation of such testing will require an expanded societal view of the traditional role of the dentist that will embrace the potentially valuable role of dentistry in preventive health screenings and population health.

Reducing False-Positive Results With Fourth-Generation HIV Testing at a Veterans Affairs Medical Center

Background

In 2006, the Centers for Disease Control and Prevention issued guidelines advocating routine HIV screening for all patients. However, false-positive results are a potential patient care threat for low-risk populations even with accurate screening assays. A reduction in HIV false-positive screening results can potentially be seen by switching from the third-generation to a more sensitive and specific fourth-generation screening assay.

Methods

We studied the impact on the false-positive screening rate of a change to a fourth-generation assay at a regional US Department of Veteran Affairs Medical Center. HIV screening tests performed by the laboratory from March 1, 2016 to February 28, 2017, prior to implementation of the new assay were compared with fourth-generation HIV screening tests performed from March 1, 2017 to February 28, 2018.

Results

Of 7,516 third-generation HIV screening tests reviewed, 52 were reactive on the screening assay; 24 were true positives, 28 were false positives. The following year 7,802 fourth-generation HIV screening tests were performed and 23 were reactive on the screening assay; 16 were true positives and 7 were false positives. The positive predictive value for the third-generation test was 46% and 70% for the fourth-generation test.

Conclusions

There were fewer false-positive results with testing with the more specific fourth- vs third-generation assay (0.09% vs 0.37%, respectively), which was statistically significant (P = .002). This reduction in false-positive screening would reduce the laboratory workload and would save an estimated $3,875 yearly and reduce the adverse effects of false-positive screening results for patients.

Screening for Military Sexual Trauma Is Associated With Improved HIV Screening in Women Veterans

OBJECTIVE

To examine factors associated with HIV screening among women veterans receiving health care in the Department of Veterans Affairs.

MATERIALS AND METHODS

Cross-sectional study of women veterans receiving Veterans Affairs care between 2001 and 2014 derived from the Women Veteran's Cohort Study. Descriptive and bivariate statistics were calculated comparing patients with and without an HIV screen. Generalized estimating equations were conducted to estimate the odds of HIV screening among women screened for military sexual trauma (MST) and the subset with a positive MST screen. Multivariable analyses were adjusted for demographic characteristics, mental health diagnoses, pregnancy, HIV risk factors, and facility level clustering.

RESULTS

Among the 113,796 women veterans in the sample, 84.3% were screened for MST and 13.2% were screened for HIV. Women screened for MST were over twice as likely to be tested for HIV (odds ratio, 2.8; 95% confidence interval, 2.2-3.5). A history of MST was inversely associated with HIV screening (odds ratio, 0.9; 95% confidence interval, 0.8-0.9).

CONCLUSIONS

Women veterans screened for sexual trauma received more comprehensive preventive health care in the form of increased HIV screening.

Trigger-oriented HIV testing at Internal Medicine hospital Departments in Northern Italy: an observational study (Fo.C.S. Study)

BACKGROUND

Early detection of undiagnosed HIV infected patients is of paramount importance. The attitude of Italian hospital-based Internal Medicine physicians to prescribe HIV testing following the detection of HIV-associated signs, symptoms and behaviours (triggers) has been reported to be poor. The aim of the study is to quantify the extent of the missed opportunities for early HIV diagnosis in Internal Medicine Departments (IMD).

METHODS

Patients admitted to IMD of a General University Hospital in Italy in March-June 2013 were interviewed using a structured questionnaire investigating the presence of triggers for HIV testing, including patient's characteristics, symptoms and conditions associated with HIV infection. HIV tests performed during hospitalisation were recorded.

RESULTS

HIV testing was performed in 73 (6.6%) out of 1113 hospitalisations (1072 patients), providing positive results in three cases (4.1%). All of them presented ≥1 triggers. Conversely, 853 triggers were identified in 528 hospitalisations with at least one trigger (47.4%). The proportion of hospitalisations where an HIV testing was prescribed was 3.1%, 9.5% and 16.0% in the presence of zero, one-to-two or more triggers, respectively. Age <70 years, female gender, length of hospital stay, haematological disease, HBV infection, multiple sexual partners and lymphadenopathy were predictors of HIV testing by logistic regression analysis.

CONCLUSIONS

Although chances of an HIV test being performed in patients hospitalised in IMD increases along with the number of triggers, the number of tests being performed in people presenting with triggers is unacceptably low and requires educational interventions in order to obtain individual and public health advantages.

Factors associated with HIV testing among male injecting drug users: findings from a cross-sectional behavioural and biological survey in Manipur and Nagaland, India

Background

Although targeted interventions in India require all high-risk groups, including injecting drug users (IDUs), to test for HIV every 6 months, testing uptake among IDUs remains far from universal. Our study estimates the proportion of IDUs who have taken an HIV test and identifies the factors associated with HIV testing uptake in Nagaland and Manipur, two high HIV prevalence states in India where the epidemic is driven by injecting drug use.

Methods

Data are drawn from the cross-sectional Integrated Behavioural and Biological Assessment (2009) of 1650 male IDUs from two districts each of Manipur and Nagaland. Participants were recruited using respondent-driven sampling (RDS). Descriptive data were analysed using RDSAT 7.1. Multivariate logistic regression analysis was undertaken using STATA 11 to examine the association between HIV testing and socio-demographic, behavioural and programme exposure variables.

Results

One third of IDUs reported prior HIV testing, of whom 8 % had tested HIV-positive. Among those without prior testing, 6.2 % tested HIV-positive in the current survey. IDUs aged 25–34 years (adjusted odds ratio (OR) = 1.41; 95 % confidence interval (CI) = 1.03–1.93), married (Adjusted OR = 1.56; 95 % CI = 1.15–2.12), had a paid sexual partner (Adjusted OR = 1.64; 95 % CI = 1.24–2.18), injected drugs for more than 36 months (Adjusted OR = 1.38; 95 % CI = 1.06–1.81), injected frequently (Adjusted OR = 1.49; 95 % CI = 1.12–1.98) and had high-risk perception (Adjusted OR = 1.68; 95 % CI = 1.32–2.14) were more likely than others to test for HIV. Compared to those with no programme exposure, IDUs who received counselling, or counselling and needle/syringe services, were more likely to test for HIV.

Conclusions

HIV testing uptake among IDUs is low in Manipur and Nagaland, and a critical group of HIV-positive IDUs who have never tested for HIV are being missed by current programmes. This study identifies key sub-groups—including early initiators, short duration and less frequent injectors, perceived to be at low risk—for promoting HIV testing. Providing needles/syringes alone is not adequate to increase HIV testing; additionally, interventions must provide counselling services to inform all IDUs about HIV testing benefits, facilitate visits to testing centres and link those testing positive to timely treatment and care.

Should expectations about the rate of new antiretroviral drug development impact the timing of HIV treatment initiation and expectations about treatment benefits?

Background

Many analyses of HIV treatment decisions assume a fixed formulary of HIV drugs. However, new drugs are approved nearly twice a year, and the rate of availability of new drugs may affect treatment decisions, particularly when to initiate antiretroviral therapy (ART).

Objectives

To determine the impact of considering the availability of new drugs on the optimal initiation criteria for ART and outcomes in patients with HIV/AIDS.

Methods

We enhanced a previously described simulation model of the optimal time to initiate ART to incorporate the rate of availability of new antiviral drugs. We assumed that the future rate of availability of new drugs would be similar to the past rate of availability of new drugs, and we estimated the past rate by fitting a statistical model to actual HIV drug approval data from 1982–2010. We then tested whether or not the future availability of new drugs affected the model-predicted optimal time to initiate ART based on clinical outcomes, considering treatment initiation thresholds of 200, 350, and 500 cells/mm³. We also quantified the impact of the future availability of new drugs on life expectancy (LE) and quality-adjusted life expectancy (QALE).

Results

In base case analysis, considering the availability of new drugs raised the optimal starting CD4 threshold for most patients to 500 cells/mm³. The predicted gains in outcomes due to availability of pipeline drugs were generally small (less than 1%), but for young patients with a high viral load could add as much as a 4.9% (1.73 years) increase in LE and a 8% (2.43 QALY) increase in QALE, because these patients were particularly likely to exhaust currently available ART regimens before they died. In sensitivity analysis, increasing the rate of availability of new drugs did not substantially alter the results. Lowering the toxicity of future ART drugs had greater potential to increase benefit for many patient groups, increasing QALE by as much as 10%.

Conclusions

The future availability of new ART drugs without lower toxicity raises optimal treatment initiation for most patients, and improves clinical outcomes, especially for younger patients with higher viral loads. Reductions in toxicity of future ART drugs could impact optimal treatment initiation and improve clinical outcomes for all HIV patients.

Depressive symptoms and antiretroviral therapy (ART) initiation among HIV-infected Russian drinkers

The impact of depressive symptoms on ART initiation among Russian HIV-infected heavy drinkers enrolled in a secondary HIV prevention trial (HERMITAGE) was examined. We assessed 133 participants eligible for ART initiation (i.e., CD4 count <350 cells/μl) who were not on ART at baseline. Depressive symptom severity and ART use were measured at baseline, 6- and 12-months. Association between depressive symptoms and subsequent ART initiation was evaluated using GEE logistic regression adjusting for gender, past ART use, injection drug use and heavy drinking. Depressive symptom severity was not significantly associated with lower odds of initiating ART. Cognitive depression symptoms were not statistically significant (global p = 0.05); however, those with the highest level of severity had an AOR of 0.25 (95 % CI 0.09-0.71) for delayed ART initiation. Although the effect of depression severity was not significant, findings suggest a potential role of cognitive depression symptoms in decisions to initiate ART in this population.

Dentists' willingness to provide expanded HIV screening in oral health care settings: results from a nationally representative survey

OBJECTIVES

Using a nationally representative survey, we determined dentists' willingness to provide oral rapid HIV screening in the oral health care setting.

METHODS

From November 2010 through November 2011, a nationally representative survey of general dentists (sampling frame obtained from American Dental Association Survey Center) examined barriers and facilitators to offering oral HIV rapid testing (n = 1802; 70.7% response). Multiple logistic regression analysis examined dentists' willingness to conduct this screening and perceived compatibility with their professional role.

RESULTS

Agreement with the importance of annual testing for high-risk persons and familiarity with the Centers for Disease Control and Prevention's recommendations regarding routine HIV testing were positively associated with willingness to conduct such screening. Respondents' agreement with patients' acceptance of HIV testing and colleagues' improved perception of them were also positively associated with willingness.

CONCLUSIONS

Oral HIV rapid testing is potentially well suited to the dental setting. Although our analysis identified many predictors of dentists' willingness to offer screening, there are many barriers, including dentists' perceptions of patients' acceptance, that must be addressed before such screening is likely to be widely implemented.

A stochastic multi-scale model of HIV-1 transmission for decision-making: application to a MSM population

BACKGROUND

In the absence of an effective vaccine against HIV-1, the scientific community is presented with the challenge of developing alternative methods to curb its spread. Due to the complexity of the disease, however, our ability to predict the impact of various prevention and treatment strategies is limited. While ART has been widely accepted as the gold standard of modern care, its timing is debated.

OBJECTIVES

To evaluate the impact of medical interventions at the level of individuals on the spread of infection across the whole population. Specifically, we investigate the impact of ART initiation timing on HIV-1 spread in an MSM (Men who have Sex with Men) population.

DESIGN AND METHODS

A stochastic multi-scale model of HIV-1 transmission that integrates within a single framework the in-host cellular dynamics and their outcomes, patient health states, and sexual contact networks. The model captures disease state and progression within individuals, and allows for simulation of therapeutic strategies.

RESULTS

Early ART initiation may substantially affect disease spread through a population.

CONCLUSIONS

Our model provides a multi-scale, systems-based approach to evaluate the broader implications of therapeutic strategies.

Rating evidence in treatment guidelines: a case example of when to initiate combination antiretroviral therapy (cART) in HIV-positive asymptomatic persons

Guidelines for the initiation of combination antiretroviral therapy (cART) in those living with HIV are provided by several national and international treatment guidelines committees. Following recent changes to some of these guidelines, there is now considerable variation between the guidelines in terms of the recommendations for initiation of cART among asymptomatic individuals with high (>350 cells/µl) CD4 cell counts. In this review we compare the schemes used for rating evidence by the various committees and assess the strengths and weaknesses of the available evidence for initiating cART at higher CD4 cell counts.

Missed opportunities for HIV testing in newly-HIV-diagnosed patients, a cross sectional study

BACKGROUND

In France, 1/3 HIV-infected patients is diagnosed at an advanced stage of the disease. We describe missed opportunities for earlier HIV testing in newly-HIV-diagnosed patients.

METHODS

Cross sectional study. Adults living in France for ≥1 year, diagnosed with HIV-infection ≤6 months earlier, were included from 06/2009 to 10/2010. We collected information on patient characteristics at diagnosis, history of HIV testing, contacts with healthcare settings, and occurrence of HIV-related events 3 years prior to HIV diagnosis. During these 3 years, we assessed whether or not HIV testing had been proposed by the healthcare provider upon first contact in patients notifying that they were MSM or had HIV-related conditions.

RESULTS

1,008 newly HIV-diagnosed patients (mean age: 39 years; male: 79%; MSM: 53%; diagnosed with an AIDS-defining event: 16%). During the 3-year period prior to HIV diagnosis, 99% of participants had frequented a healthcare setting and 89% had seen a general practitioner at least once a year. During a contact with a healthcare setting, 91/191 MSM (48%) with no HIV-related conditions, said being MSM; 50 of these (55%) did not have any HIV test proposal. Only 21% (41/191) of overall MSM who visited a healthcare provider received a test proposal. Likewise, 299/364 patients (82%) who sought care for s had a missed opportunity for HIV testing.

CONCLUSIONS

Under current screening policies, missed opportunities for HIV testing remain unacceptably high. This argues in favor of improving risk assessment, and HIV-related conditions recognition in all healthcare facilities.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

The cost-effectiveness of rapid HIV testing in substance abuse treatment: results of a randomized trial

BACKGROUND

The President's National HIV/AIDS Strategy calls for coupling HIV screening and prevention services with substance abuse treatment programs. Fewer than half of US community-based substance abuse treatment programs make HIV testing available on-site or through referral.

METHODS

We measured the cost-effectiveness of three HIV testing strategies evaluated in a randomized trial conducted in 12 community-based substance abuse treatment programs in 2009: off-site testing referral, on-site rapid testing with information only, on-site rapid testing with risk-reduction counseling. Data from the trial included patient demographics, prior testing history, test acceptance and receipt of results, undiagnosed HIV prevalence (0.4%) and program costs. The Cost-Effectiveness of Preventing AIDS Complications (CEPAC) computer simulation model was used to project life expectancy, lifetime costs, and quality-adjusted life years (QALYs) for HIV-infected individuals. Incremental cost-effectiveness ratios (2009 US $/QALY) were calculated after adding costs of testing HIV-uninfected individuals; costs and QALYs were discounted at 3% annually.

RESULTS

Referral for off-site testing is less efficient (dominated) compared to offering on-site testing with information only. The cost-effectiveness ratio for on-site testing with information is $60,300/QALY in the base case, or $76,300/QALY with 0.1% undiagnosed HIV prevalence. HIV risk-reduction counseling costs $36 per person more without additional benefit.

CONCLUSIONS

A strategy of on-site rapid HIV testing offer with information only in substance abuse treatment programs increases life expectancy at a cost-effectiveness ratio <$100,000/QALY. Policymakers and substance abuse treatment leaders should seek funding to implement on-site rapid HIV testing in substance abuse treatment programs for those not recently tested.

The unanswered question: when to initiate antiretroviral therapy in children with HIV infection

PURPOSE OF REVIEW

The question of when to initiate antiretroviral treatment for children is perhaps the most critical unanswered question in pediatric HIV therapeutics. With large numbers of children throughout the world acquiring HIV infection and with improved global access to HIV treatment it is particularly timely to consider the optimal time to initiate antiretroviral therapy in infants, children and adolescents.

RECENT FINDINGS

Early treatment can result in suppression of HIV viremia, immune preservation and prevention of disease progression. This must be balanced by the challenges of maintaining adherence to multidrug regimens, the risks of selecting drug-resistant virus, and long and short-term toxicities of medications.

SUMMARY

This review provides a framework within which to consider when to initiate children on antiretroviral treatment. A child's age and developmental status, where they live, and the goals and expectations for treatment provide a context for balancing the risks of disease progression with the risks of drug-related toxicities and viral resistance.

Considerations in the rationale, design and methods of the Strategic Timing of AntiRetroviral Treatment (START) study

BACKGROUND

Untreated human immunodeficiency virus (HIV) infection is characterized by progressive depletion of CD4+ T lymphocyte (CD4) count leading to the development of opportunistic diseases (acquired immunodeficiency syndrome (AIDS)), and more recent data suggest that HIV is also associated with an increased risk of serious non-AIDS (SNA) diseases including cardiovascular, renal, and liver diseases and non-AIDS-defining cancers. Although combination antiretroviral treatment (ART) has resulted in a substantial decrease in morbidity and mortality in persons with HIV infection, viral eradication is not feasible with currently available drugs. The optimal time to start ART for asymptomatic HIV infection is controversial and remains one of the key unanswered questions in the clinical management of HIV-infected individuals.

PURPOSE

In this article, we outline the rationale and methods of the Strategic Timing of AntiRetroviral Treatment (START) study, an ongoing multicenter international trial designed to assess the risks and benefits of initiating ART earlier than is currently practiced. We also describe some of the challenges encountered in the design and implementation of the study and how these challenges were addressed.

METHODS

A total of 4000 study participants who are HIV type 1 (HIV-1) infected, ART naïve with CD4 count > 500 cells/µL are to be randomly allocated in a 1:1 ratio to start ART immediately (early ART) or defer treatment until CD4 count is <350 cells/µL (deferred ART) and followed for a minimum of 3 years. The primary outcome is time to AIDS, SNA, or death. The study had a pilot phase to establish feasibility of accrual, which was set as the enrollment of at least 900 participants in the first year.

RESULTS

Challenges encountered in the design and implementation of the study included the limited amount of data on the risk of a major component of the primary endpoint (SNA) in the study population, changes in treatment guidelines when the pilot phase was well underway, and the complexities of conducting the trial in a geographically wide population with diverse regulatory requirements. With the successful completion of the pilot phase, more than 1000 participants from 100 sites in 23 countries have been enrolled. The study will expand to include 237 sites in 36 countries to reach the target accrual of 4000 participants.

CONCLUSIONS

START is addressing one of the most important questions in the clinical management of ART. The randomization provided a platform for the conduct of several substudies aimed at increasing our understanding of HIV disease and the effects of antiretroviral therapy beyond the primary question of the trial. The lessons learned from its design and implementation will hopefully be of use to future publicly funded international trials.

Modelling the impact of antiretroviral therapy on the epidemic of HIV

Thirty years after HIV first appeared it has killed close to 30 million people but transmission continues unchecked. In 2009, an estimated 1.8 million lives were lost and 2.6 million more people were infected with HIV [1]. To cut transmission, many social, behavioural and biomedical interventions have been developed, tested and tried but have had little impact on the epidemic in most countries. One substantial success has been the development of combination antiretroviral therapy (ART) that reduces viral load and restores immune function. This raises the possibility of using ART not only to treat people but also to prevent new HIV infections. Here we consider the impact of ART on the transmission of HIV and show how it could help to control the epidemic. Much needs to be known and understood concerning the impact of early treatment with ART on the prognosis for individual patients and on transmission. We review the current literature on factors associated with modelling treatment for prevention and illustrate the potential impact using existing models. We focus on generalized epidemics in sub- Saharan Africa, with an emphasis on South Africa, where transmission is mainly heterosexual and which account for an estimated 17% of all people living with HIV. We also make reference to epidemics among men who have sex with men and injection drug users where appropriate. We discuss ways in which using treatment as prevention can be taken forward knowing that this can only be the beginning of what must become an inclusive dialogue among all of those concerned to stop acquired immune deficiency syndrome (AIDS).

Acceptability of rapid oral fluid HIV testing among male injection drug users in Taiwan, 1997 and 2007

Rapid oral fluid HIV testing (rapid oral testing) is in the process of being adapted in Taiwan and elsewhere given its advantages over prior HIV testing methods. To guide this process, we examined the acceptability of rapid oral testing at two time points (i.e., 1997 and 2007) among one of the highest risk populations, male injection drug users (IDUs). For this purpose, an anonymous self-administered survey was completed by HIV-negative IDUs involved in the criminal justice system in 1997 (N (1)=137 parolees) and 2007 (N (2)=106 prisoners). A social marketing model helped guide the design of our questionnaire to assess the acceptability of rapid oral testing. This included assessing a new product, across four marketing dimensions: product, price, promotion, and place. Results revealed that in both 1997 and 2007, over 90% indicated that rapid oral testing would be highly acceptable, particularly if the cost was under US$6, and that a pharmacy would be the most appropriate and accessible venue for selling the rapid oral testing kits. The vast majority of survey respondents believed that the cost of rapid oral testing should be federally subsidized and that television and newspaper advertisements would be the most effective media to advertise for rapid oral testing. Both the 1997 and 2007 surveys suggested that rapid oral HIV testing would be particularly accepted in Taiwan by IDUs after release from the criminal justice system.

Modelling the impact of acute infection dynamics on the accumulation of HIV-1 mutations

Events over the past year have brought hope and have re-energized the interest in targeting pre-infection or early infection period with preventative or therapeutic interventions such as vaccines and pre-exposure prophylaxis (PrEP). In breakthrough infections, the incidence, long term prognosis and clinical significance of early infection events is not well understood but it is possible that these early events may be crucial in determining the subsequent course of disease. We use a branching process model in a deterministically varying environment to explore how the dynamics of early infection affects the accumulation of mutations which lay the seeds for long term evolution of drug resistance and immune system evasion. We relate this exploration to regimes of impact, on diversity, of tropical interventions strategies such as PrEP and vaccines. As a metric of diversity we compute the probability of existence of particular genomes which potentially arise. Using several model scenarios, we demonstrate various regimes of 'response' of evolution to 'intervention'. Transient effects of therapeutic interventions early in infection that impose a fitness cost on early viruses can significantly reduce the probability of diversity later during the chronic state of infection. This stands in contrast to the concern that early selective pressure may increase the probability of later existence of drug resistance mutations, for example. The branching process paradigm offers the ability to efficiently compute important indicators of viral diversity, in a framework with a modest number of simplifying assumptions, without simulating the full range of individual level scenarios. These models may be useful to illustrate the impact of vaccines and PrEP on viral evolution in the case of breakthrough infection. They also suggest that new measures of viral diversity which correlate to prognosis should be sought in trials for PrEP and vaccines.

Rapid HIV tests in acute care settings in an area of low HIV prevalence in Canada

Rapid HIV testing has the potential to improve medical care and reduce the transmission of infection. In this study, rapid HIV testing was performed on serum samples in acute care settings in five hospitals from urban and rural regions using the INSTI™ HIV-1/HIV-2 Rapid Antibody Test (bioLytical Laboratories, Richmond, British Columbia). Parallel standard HIV antibody tests were performed at the provincial reference laboratory. Patient demographics, indication for testing and risk behaviours were collected. From April 30, 2007 and November 23, 2009, 1708 individuals were tested: 875 (50.3%) tests in pregnant women, 730 (42%) in source individuals in blood and body fluid exposures and 119 (5.8%) in acutely ill persons. Twenty-five (1.4%) samples were reactive by rapid HIV testing, of which 13 were reactive previously and 1 was a false reactive. Sensitivity of the rapid HIV test compared to standard HIV testing was 100%, specificity was 99.9%, the positive predictive value was 96% and the negative predictive value was 100%. The median time from specimen collection to availability of the rapid HIV result varied by site and ranged from 54 min to 1h 42 min. In this study, the INSTI™ HIV-1 Rapid Antibody test identified reactive and non-reactive samples with similar accuracy to the conventional testing algorithm and provided a reliable way to perform rapid HIV testing in acute care settings.

Cohort studies: to what extent can they inform treatment guidelines?

PURPOSE OF REVIEW

This review examines situations in which information from cohort studies has proved to be useful for the development of treatment guidelines.

RECENT FINDINGS

Although there are several reasons why randomized controlled trials (RCTs) are felt to provide the most robust evidence for treatment guidelines, they may suffer from insufficient duration of follow-up, inadequate power to consider differences in important adverse events and highly selected patient populations. Furthermore, as most RCTs are performed for licensing purposes, strategic treatment decisions often lack supportive evidence from RCTs. Although data from cohort studies may be used to complement information from RCTs, cohort studies themselves are susceptible to several biases (most notably confounding) which may limit their findings. However, in the HIV field, information from such studies has been influential in guiding decisions relating to when to start highly active antiretroviral therapy, what drugs to use in the initial highly active antiretroviral therapy regimen and when to switch highly active antiretroviral therapy should virological failure occur.

SUMMARY

Given the biases that may be present, caution should be exercised when interpreting findings from cohort studies, particularly if comparisons are made of treatment strategies that involve some element of patient or clinician choice.

The impact of disease stage on direct medical costs of HIV management: a review of the international literature

The global prevalence of HIV infection continues to grow, as a result of increasing incidence in some countries and improved survival where highly active antiretroviral therapy (HAART) is available. Growing healthcare expenditure and shifts in the types of medical resources used have created a greater need for accurate information on the costs of treatment. The objectives of this review were to compare published estimates of direct medical costs for treating HIV and to determine the impact of disease stage on such costs, based on CD4 cell count and plasma viral load. A literature review was conducted to identify studies meeting prespecified criteria for information content, including an original estimate of the direct medical costs of treating an HIV-infected individual, stratified based on markers of disease progression. Three unpublished cost-of-care studies were also included, which were applied in the economic analyses published in this supplement. A two-step procedure was used to convert costs into a common price year (2004) using country-specific health expenditure inflators and, to account for differences in currency, using health-specific purchasing power parities to express all cost estimates in US dollars. In all nine studies meeting the eligibility criteria, infected individuals were followed longitudinally and a 'bottom-up' approach was used to estimate costs. The same patterns were observed in all studies: the lowest CD4 categories had the highest cost; there was a sharp decrease in costs as CD4 cell counts rose towards 100 cells/mm³; and there was a more gradual decline in costs as CD4 cell counts rose above 100 cells/mm³. In the single study reporting cost according to viral load, it was shown that higher plasma viral load level (> 100,000 HIV-RNA copies/mL) was associated with higher costs of care. The results demonstrate that the cost of treating HIV disease increases with disease progression, particularly at CD4 cell counts below 100 cells/mm³. The suggestion that costs increase as the plasma viral load rises needs independent verification. This review of the literature further suggests that publicly available information on the cost of HAART by disease stage is inadequate. To address the information gap, multiple stakeholders (governments, pharmaceutical industry, private insurers and non-governmental organizations) have begun to establish and support an independent, high quality and standardized multicountry data collection for evaluating the cost of HIV management. An accurate, representative and relevant cost-estimate data resource would provide a valuable asset to healthcare planners that may lead to improved policy and decision-making in managing the HIV epidemic.

Early antiretroviral therapy: the role of cohorts

PURPOSE OF REVIEW

To review the data that contribute to the debate on the optimal time to initiate highly active antiretroviral therapy in HIV-infected individuals, with a focus on the information that is available from cohort studies.

RECENT FINDINGS

The findings from cohort studies generally support initiation of highly active antiretroviral therapy at CD4 cell counts more than 350 cells/microl. In particular, the findings that death rates among treated HIV-infected individuals are higher than those in the general population, and that the risks of AIDS and serious non-AIDS events are higher in those with lower CD4 cell counts (even when the count remains >350 cells/microl), suggest that earlier initiation of highly active antiretroviral therapy may prevent some excess morbidity and mortality. However, given the lack of adjustment for lead-time bias in many analyses, the potential for residual confounding and the possible incomplete ascertainment of relevant outcomes in cohorts, it cannot be concluded that the benefits of highly active antiretroviral therapy when started at higher CD4 cell counts will outweigh the possible detrimental effects.

SUMMARY

Whereas the data from cohort studies currently support initiation of highly active antiretroviral therapy at CD4 cell counts more than 350 cells/microl, there is an urgent need for data from randomized trials to inform this decision.

Should HIV therapy be started at a CD4 cell count above 350 cells/microl in asymptomatic HIV-1-infected patients?

PURPOSE OF REVIEW

The aim is to review the available data that contribute to the debate on the optimal time to initiate highly active antiretroviral therapy (HAART) in HIV-infected individuals with a CD4 cell count more than 350 cells/microl.

RECENT FINDINGS

Although few randomized data exist that can contribute to this debate, a number of findings from observational studies generally support earlier initiation of HAART. In particular, the findings that death rates remain higher in HIV-infected individuals than in uninfected individuals, even when successfully treated, and that both AIDS and several serious non-AIDS events are more common in those with a lower CD4 cell count (even when this count is above 350 cells/microl), suggest that earlier initiation of HAART may prevent much of the excess morbidity and mortality that remains in this patient group.

SUMMARY

Currently, the data would generally support initiation of HAART in patients with CD4 cell counts more than 350 cells/microl. However, given the strong potential for confounding in observational studies and the lack of adjustment for lead-time bias in many analyses, it is not possible to rule out possible long-term detrimental effects of earlier use of HAART until the results from fully powered randomized trials that directly address this issue become available.

Timing of initiation of antiretroviral therapy in AIDS-free HIV-1-infected patients: a collaborative analysis of 18 HIV cohort studies

BACKGROUND

The CD4 cell count at which combination antiretroviral therapy should be started is a central, unresolved issue in the care of HIV-1-infected patients. In the absence of randomised trials, we examined this question in prospective cohort studies.

METHODS

We analysed data from 18 cohort studies of patients with HIV. Antiretroviral-naive patients from 15 of these studies were eligible for inclusion if they had started combination antiretroviral therapy (while AIDS-free, with a CD4 cell count less than 550 cells per microL, and with no history of injecting drug use) on or after Jan 1, 1998. We used data from patients followed up in seven of the cohorts in the era before the introduction of combination therapy (1989-95) to estimate distributions of lead times (from the first CD4 cell count measurement in an upper range to the upper threshold of a lower range) and unseen AIDS and death events (occurring before the upper threshold of a lower CD4 cell count range is reached) in the absence of treatment. These estimations were used to impute completed datasets in which lead times and unseen AIDS and death events were added to data for treated patients in deferred therapy groups. We compared the effect of deferred initiation of combination therapy with immediate initiation on rates of AIDS and death, and on death alone, in adjacent CD4 cell count ranges of width 100 cells per microL.

FINDINGS

Data were obtained for 21 247 patients who were followed up during the era before the introduction of combination therapy and 24 444 patients who were followed up from the start of treatment. Deferring combination therapy until a CD4 cell count of 251-350 cells per microL was associated with higher rates of AIDS and death than starting therapy in the range 351-450 cells per microL (hazard ratio [HR] 1.28, 95% CI 1.04-1.57). The adverse effect of deferring treatment increased with decreasing CD4 cell count threshold. Deferred initiation of combination therapy was also associated with higher mortality rates, although effects on mortality were less marked than effects on AIDS and death (HR 1.13, 0.80-1.60, for deferred initiation of treatment at CD4 cell count 251-350 cells per microL compared with initiation at 351-450 cells per microL).

INTERPRETATION

Our results suggest that 350 cells per microL should be the minimum threshold for initiation of antiretroviral therapy, and should help to guide physicians and patients in deciding when to start treatment.

Universal voluntary HIV testing with immediate antiretroviral therapy as a strategy for elimination of HIV transmission: a mathematical model

BACKGROUND

Roughly 3 million people worldwide were receiving antiretroviral therapy (ART) at the end of 2007, but an estimated 6.7 million were still in need of treatment and a further 2.7 million became infected with HIV in 2007. Prevention efforts might reduce HIV incidence but are unlikely to eliminate this disease. We investigated a theoretical strategy of universal voluntary HIV testing and immediate treatment with ART, and examined the conditions under which the HIV epidemic could be driven towards elimination.

METHODS

We used mathematical models to explore the effect on the case reproduction number (stochastic model) and long-term dynamics of the HIV epidemic (deterministic transmission model) of testing all people in our test-case community (aged 15 years and older) for HIV every year and starting people on ART immediately after they are diagnosed HIV positive. We used data from South Africa as the test case for a generalised epidemic, and assumed that all HIV transmission was heterosexual.

FINDINGS

The studied strategy could greatly accelerate the transition from the present endemic phase, in which most adults living with HIV are not receiving ART, to an elimination phase, in which most are on ART, within 5 years. It could reduce HIV incidence and mortality to less than one case per 1000 people per year by 2016, or within 10 years of full implementation of the strategy, and reduce the prevalence of HIV to less than 1% within 50 years. We estimate that in 2032, the yearly cost of the present strategy and the theoretical strategy would both be US$1.7 billion; however, after this time, the cost of the present strategy would continue to increase whereas that of the theoretical strategy would decrease.

INTERPRETATION

Universal voluntary HIV testing and immediate ART, combined with present prevention approaches, could have a major effect on severe generalised HIV/AIDS epidemics. This approach merits further mathematical modelling, research, and broad consultation.

The therapeutic implications of timely linkage and early retention in HIV care

Following HIV diagnosis, linkage to outpatient treatment, antiretroviral initiation, and longitudinal retention in care represent the foundation for successful treatment. While prior studies have evaluated these processes in isolation, a systematic evaluation of successive steps in the same cohort of patients has not yet been performed. To ensure optimal long-term outcomes, a better understanding of the interplay of these processes is needed. Therefore, a retrospective cohort study of patients initiating outpatient care at the University of Alabama at Birmingham 1917 HIV=AIDS Clinic between January 2000 and December 2005 was undertaken. Multivariable models determined factors associated with: late diagnosis=linkage to care (initial CD4 < 350 cells=mm3), timely antiretroviral initiation, and retention across the first two years of care. Delayed linkage was observed in two-thirds of the overall sample (n = 567) and was associated with older age (odds ratio [OR] = 1.31 per 10 years; 95%confidence interval [CI] = 1.06-1.62) and African American race (OR = 2.45; 95% CI = 1.60-3.74). Attending all clinic visits (hazard ratio [HR] = 6.45; 95% CI = 4.47-9.31) and lower initial CD4 counts led to earlier antiretroviral initiation. Worse retention in the first 2 years was associated with younger age (OR = 0.68 per 10 years;95% CI = 0.56-0.83), higher baseline CD4 count, and substance abuse (OR = 1.78; 95% CI = 1.16-2.73). Interventions to improve timely HIV diagnosis and linkage to care should focus on older patients and African Americans while efforts to improve retention should address younger patients, those with higher baseline CD4 counts, and substance abuse. Missed clinic visits represent an important obstacle to the timely initiation of antiretroviral therapy. These data inform development of interventions to improve linkage and retention in HIV care, an emerging area of growing importance.

Cost-effectiveness of HIV testing and treatment in the United States

In September 2006, the US Centers for Disease Control and Prevention (CDC) released new guidelines calling for routine, voluntary human immunodeficiency virus (HIV) testing for all persons aged 13-64 years in health care settings. These guidelines were motivated, in part, by mounting evidence that the traditional approach of using risk factors to identify candidates for HIV testing is inadequate. Of the 1.0-1.2 million people in the United States thought to be infected with HIV, approximately 25% remain unaware of their infection, and nearly half of all infected patients develop acquired immunodeficiency syndrome < or = 1 year after testing positive for HIV. Also contributing to the change in testing guidelines was recent evidence that routine HIV testing is cost-effective. Cost-effectiveness analysis, a method of assessing health care interventions in terms of the value they confer, reports results in terms of the resources that are required for the intervention to produce an additional unit of change in health effectiveness; more economically efficient programs are those with lower cost-effectiveness ratios. This article reviews the methods and results of cost-effectiveness studies in the United States and articulates why routine, voluntary HIV testing is not only of crucial public health importance but also economically justified.

CCL3L1-CCR5 genotype improves the assessment of AIDS Risk in HIV-1-infected individuals

BACKGROUND

Whether vexing clinical decision-making dilemmas can be partly addressed by recent advances in genomics is unclear. For example, when to initiate highly active antiretroviral therapy (HAART) during HIV-1 infection remains a clinical dilemma. This decision relies heavily on assessing AIDS risk based on the CD4+ T cell count and plasma viral load. However, the trajectories of these two laboratory markers are influenced, in part, by polymorphisms in CCR5, the major HIV coreceptor, and the gene copy number of CCL3L1, a potent CCR5 ligand and HIV-suppressive chemokine. Therefore, we determined whether accounting for both genetic and laboratory markers provided an improved means of assessing AIDS risk.

METHODS AND FINDINGS

In a prospective, single-site, ethnically-mixed cohort of 1,132 HIV-positive subjects, we determined the AIDS risk conveyed by the laboratory and genetic markers separately and in combination. Subjects were assigned to a low, moderate or high genetic risk group (GRG) based on variations in CCL3L1 and CCR5. The predictive value of the CCL3L1-CCR5 GRGs, as estimated by likelihood ratios, was equivalent to that of the laboratory markers. GRG status also predicted AIDS development when the laboratory markers conveyed a contrary risk. Additionally, in two separate and large groups of HIV+ subjects from a natural history cohort, the results from additive risk-scoring systems and classification and regression tree (CART) analysis revealed that the laboratory and CCL3L1-CCR5 genetic markers together provided more prognostic information than either marker alone. Furthermore, GRGs independently predicted the time interval from seroconversion to CD4+ cell count thresholds used to guide HAART initiation.

CONCLUSIONS

The combination of the laboratory and genetic markers captures a broader spectrum of AIDS risk than either marker alone. By tracking a unique aspect of AIDS risk distinct from that captured by the laboratory parameters, CCL3L1-CCR5 genotypes may have utility in HIV clinical management. These findings illustrate how genomic information might be applied to achieve practical benefits of personalized medicine.

Late HIV diagnosis and delay in CD4 count measurement among HIV-infected patients in Southern Thailand

The objectives of this study were to evaluate timeliness of HIV testing and of getting CD4 count measured and their associated factors in Southern Thailand. Between July 2004 and February 2005, consenting HIV-positive patients from seven public hospitals in Songkhla province, Southern Thailand were interviewed. Outcomes were late HIV diagnosis (having HIV-related symptoms at the time of first positive test) and the time between HIV diagnosis and first CD4 count being measured. Of 402 study patients, 55% were late HIV-diagnosed. Factors independently associated with late HIV diagnosis were age above 30 years, male and being unemployed with respective odd ratios (95% CI) of 3.10 (1.90-5.07), 7.95 (4.52-13.99), and 2.14 (1.22-3.76). Only 34% and 47% received CD4 assessment within 6 and 12 months of HIV diagnosis, respectively. Median of first-known CD4 count was 73 (IQR 16-169) and 22 (IQR 9-85) cells/microl among asymptomatic and symptomatic HIV-diagnosed patients, respectively. Common predictors for shortened delay of CD4 count measured among symptomatic and asymptomatic HIV-diagnosed patients were: infection through sexual contact (HR=1.61; 95%CI 1.12-2.33) and receiving posttest counseling (HR 1.71; 95%CI 1.15-2.52). Among the asymptomatic, those aged >25-30 years had significantly shortened delay (HR=2.18; 95%CI 1.50-3.18) compared with the younger age group as did those aged >30 years (HR=1.94; 95%CI 1.32-2.85). Such age effect on the delay was absent in the symptomatic group. Attempts to diagnose HIV at an earlier stage and timely CD4 count measured are needed.

Implications and impact of the new US Centers for Disease Control and prevention HIV testing guidelines

Of the 1.2 million Americans estimated to be living with HIV in the United States, approximately 250,000 are unaware of their diagnosis and therefore unable to access clinical care and life-sustaining treatment. The revised 2006 US Centers for Disease Control and Prevention's guidelines for HIV testing recommend universal, routine, and voluntary HIV screening in public and private health care settings for all adults and adolescents between 13 and 64 years old. These major revisions present new challenges for health care providers, hospitals, government agencies, and community advocacy groups. In this review, we discuss the important issues in diverse care venues such as opt-out testing, consent and confidentiality, barriers to treatment, and financial impact. The implications of the revised recommendations for HIV testing are addressed in the context of a fragmented, overstressed, underfunded US health care system.

Low HIV-testing rates and awareness of HIV infection among high-risk heterosexual STI clinic attendees in The Netherlands

OBJECTIVES

Since 1999, HIV testing is routinely offered to all attendees of the sexually transmitted infections (STI) outpatient clinic in Amsterdam, the Netherlands. This study evaluates whether this more active HIV-testing policy increased uptake of HIV testing and awareness of an HIV-positive serostatus among heterosexual attendees.

METHODS

In addition to routine data collected at each STI consultation, data from half-yearly HIV surveys were used from 1994 to 2004. During each survey period, 1000 consecutive attendees are enrolled voluntary and anonymously for HIV testing and are interviewed on previous HIV testing and outcome. Trends in and predictors for uptake of HIV testing as offered during routine STI consultation were analysed by logistic regression. Trends in awareness of an HIV-positive serostatus as obtained from the anonymous HIV surveys were likewise analysed.

RESULTS

The percentage of heterosexual attendees opting for an HIV test during consultation increased from 13% in 1996 to 56% in 2004. However, the proportion of individuals aware of their HIV infection did not change over time and only a minority (19%) of the 108 attendees found HIV-positive in the anonymous surveys were aware of their HIV infection. Persons being or visiting a commercial sex worker, having a non-Dutch ethnicity, lacking health insurance and having an STI diagnosed were less likely to opt for an HIV test.

CONCLUSIONS

Although heterosexual attendees increased their uptake of HIV testing during STI consultation over time, uptake of testing by attendees at risk for HIV infection, such as those infected with an STI, remained low. As a result, the percentage of persons aware of their HIV infection remained low, posing a risk for their individual health and for ongoing HIV transmission. Current testing strategies, therefore, misses the group that most needs testing. Based on these results, 'opt-out' HIV testing is now the standard procedure at the Amsterdam STI clinic.

CCL3L1-CCR5 genotype influences durability of immune recovery during antiretroviral therapy of HIV-1-infected individuals

The basis for the extensive variability seen in the reconstitution of CD4(+) T cell counts in HIV-infected individuals receiving highly active antiretroviral therapy (HAART) is not fully known. Here, we show that variations in CCL3L1 gene dose and CCR5 genotype, but not major histocompatibility complex HLA alleles, influence immune reconstitution, especially when HAART is initiated at <350 CD4(+) T cells/mm(3). The CCL3L1-CCR5 genotypes favoring CD4(+) T cell recovery are similar to those that blunted CD4(+) T cell depletion during the time before HAART became available (pre-HAART era), suggesting that a common CCL3L1-CCR5 genetic pathway regulates the balance between pathogenic and reparative processes from early in the disease course. Hence, CCL3L1-CCR5 variations influence HIV pathogenesis even in the presence of HAART and, therefore, may prospectively identify subjects in whom earlier initiation of therapy is more likely to mitigate immunologic failure despite viral suppression by HAART. Furthermore, as reconstitution of CD4(+) cells during HAART is more sensitive to CCL3L1 dose than to CCR5 genotypes, CCL3L1 analogs might be efficacious in supporting immunological reconstitution.

HIV-1 coreceptor usage and CXCR4-specific viral load predict clinical disease progression during combination antiretroviral therapy

BACKGROUND

Although combination antiretroviral therapy (cART) dramatically reduces rates of AIDS and death, a minority of patients experience clinical disease progression during treatment.

OBJECTIVE

To investigate whether detection of CXCR4(X4)-specific strains or quantification of X4-specific HIV-1 load predict clinical outcome.

METHODS

From the Swiss HIV Cohort Study, 96 participants who initiated cART yet subsequently progressed to AIDS or death were compared with 84 contemporaneous, treated nonprogressors. A sensitive heteroduplex tracking assay was developed to quantify plasma X4 and CCR5 variants and resolve HIV-1 load into coreceptor-specific components. Measurements were analyzed as cofactors of progression in multivariable Cox models adjusted for concurrent CD4 cell count and total viral load, applying inverse probability weights to adjust for sampling bias.

RESULTS

Patients with X4 variants at baseline displayed reduced CD4 cell responses compared with those without X4 strains (40 versus 82 cells/microl; P = 0.012). The adjusted multivariable hazard ratio (HR) for clinical progression was 4.8 [95% confidence interval (CI) 2.3-10.0] for those demonstrating X4 strains at baseline. The X4-specific HIV-1 load was a similarly independent predictor, with HR values of 3.7 (95% CI, 1.2-11.3) and 5.9 (95% CI, 2.2-15.0) for baseline loads of 2.2-4.3 and > 4.3 log10 copies/ml, respectively, compared with < 2.2 log10 copies/ml.

CONCLUSIONS

HIV-1 coreceptor usage and X4-specific viral loads strongly predicted disease progression during cART, independent of and in addition to CD4 cell count or total viral load. Detection and quantification of X4 strains promise to be clinically useful biomarkers to guide patient management and study HIV-1 pathogenesis.

Influence of alternative thresholds for initiating HIV treatment on quality-adjusted life expectancy: a decision model

BACKGROUND

The optimal threshold for initiating HIV treatment is unclear.

OBJECTIVE

To compare different thresholds for initiating HIV treatment.

DESIGN

A validated computer simulation was used to weigh important harms from earlier initiation of antiretroviral therapy (toxicity, side effects, and resistance accumulation) against important benefits (decreased HIV-related mortality).

DATA SOURCES

Veterans Aging Cohort Study (5742 HIV-infected patients and 11 484 matched uninfected controls) and published reports.

TARGET POPULATION

Individuals with newly diagnosed chronic HIV infection and varying viral loads (10,000, 30,000, 100,000, and 300,000 copies/mL) and ages (30, 40, and 50 years).

TIME HORIZON

Unlimited.

PERSPECTIVE

Societal.

INTERVENTION

Alternative thresholds for initiating antiretroviral therapy (CD4 counts of 200, 350, and 500 cells/mm3).

OUTCOME MEASURES

Life-years and quality-adjusted life-years (QALYs).

RESULTS OF BASE-CASE ANALYSIS

Although the simulation was biased against earlier treatment initiation because it used an upper-bound assumption for therapy-related toxicity, earlier treatment increased life expectancy and QALYs at age 30 years regardless of viral load (life expectancies with CD4 initiation thresholds of 500, 350, and 200 cells/mm3 were 18.2 years, 17.6 years, and 17.2 years, respectively, for a viral load of 10,000 copies/mL and 17.3 years, 15.9 years, and 14.5 years, respectively, for a viral load of 300,000 copies/mL), and increased life expectancies at age 40 years if viral loads were greater than 30 000 copies/mL (life expectancies were 12.5 years, 12.0 years, and 11.4 years, respectively, for a viral load of 300,000 copies/mL).

RESULTS OF SENSITIVITY ANALYSIS

Findings favoring early treatment were generally robust.

LIMITATIONS

Results favoring later treatment may not be valid. The findings may not be generalizable to women.

CONCLUSION

This simulation suggests that earlier initiation of combination antiretroviral therapy is often favored compared with current recommendations.

Antiretroviral treatment strategies in resource-limited settings

To date, a minority of persons living with HIV worldwide has benefited from the advances in HIV therapeutics fueled by the scientific community, policy-makers, advocates, and the pharmaceutical industry in the global North. A growing body of evidence demonstrates that access to highly active antiretroviral therapy can be successfully scaled-up in less wealthy nations in the South. High rates of adherence correspond with clinical, immunologic, and virologic outcomes similar to those seen in wealthier nations. Recent reports of successful programs highlight the provision of free care, reliance on the international funding sources, and proactive adherence counseling. As access to antiretroviral therapy has improved, there is an urgent need to develop better strategies for initiating and monitoring therapy, including the scale-up of viral load testing.

Predicting CD4 lymphocyte count <200 cells/mm(3) in an HIV type 1-infected African population

Clinical criteria are recommended to select HIV-infected patients for initiation of antiretroviral therapy when CD4 lymphocyte testing is unavailable. We evaluated the performance characteristics of WHO staging criteria, anthropometrics, and simple laboratory measurements for predicting CD4 lymphocyte count (CD4 count) <200 cells/mm(3) among HIV-infected patients in Tanzania. A total of 202 adults, diagnosed with HIV infection through community-based testing, underwent a detailed evaluation including staging history and examination, anthropometry, complete blood count, erythrocyte sedimentation rate (ESR), and CD4 count. Univariable analysis and recursive partitioning were used to identify characteristics associated with CD4 count 200 cells/mm(3). Of 202 participants 109 (54%) had a CD4 count <200 cells/mm(3). Characteristics most strongly associated with CD4 count <200 cells/mm(3) (p-value <0.0001) were the presence of mucocutaneous manifestations (72% vs. 28%), lower total lymphocyte count (TLC) (median 1,450 vs. 2,200 cells/mm(3)), lower total white blood cell count (median 4,200 vs. 5,500 cells/mm(3)), and higher ESR (median 95 vs. 53 mm/h). In a partition tree model, TLC <1,200 cells/mm(3), ESR >or=120 mm/h, or the presence of mucocutaneous manifestations yielded a sensitivity of 0.85 and specificity of 0.63 for predicting CD4 count <200 cells/mm(3). The sensitivity of the 2006 WHO Staging system improved from 0.75 to 0.93 with inclusion of these parameters, at the expense of specificity (0.36 to 0.26). The presence of mucocutaneous manifestations, TLC <1,200 cells/mm(3), or ESR >or=120 mm/h was a strong predictor of CD4 count <200 cells/mm(3) and enhanced the sensitivity of the 2006 WHO staging criteria for identifying patients likely to benefit from antiretrovirals.

Pathogenesis of HIV in the gastrointestinal tract

Gut-associated lymphoid tissue (GALT) is an important site for early HIV replication and severe CD4+ T-cell depletion. Initiation of highly active antiretroviral therapy leads to incomplete suppression of viral replication and substantially delayed and only partial restoration of CD4+ T cells in GALT compared with peripheral blood. Persistent viral replication in GALT leads to replenishment and maintenance of viral reservoirs. Increased levels of inflammation, immune activation, and decreased levels of mucosal repair and regeneration contribute to enteropathy. Assessment of gut mucosal immune system will provide better insights into the efficacy of highly active antiretroviral therapy in immune restoration and suppression of viral reservoirs.

Viral suppression and immune restoration in the gastrointestinal mucosa of human immunodeficiency virus type 1-infected patients initiating therapy during primary or chronic infection

Although the gut-associated lymphoid tissue (GALT) is an important early site for human immunodeficiency virus (HIV) replication and severe CD4+ T-cell depletion, our understanding is limited about the restoration of the gut mucosal immune system during highly active antiretroviral therapy (HAART). We evaluated the kinetics of viral suppression, CD4+ T-cell restoration, gene expression, and HIV-specific CD8+ T-cell responses in longitudinal gastrointestinal biopsy and peripheral blood samples from patients initiating HAART during primary HIV infection (PHI) or chronic HIV infection (CHI) using flow cytometry, real-time PCR, and DNA microarray analysis. Viral suppression was more effective in GALT of PHI patients than CHI patients during HAART. Mucosal CD4+ T-cell restoration was delayed compared to peripheral blood and independent of the time of HAART initiation. Immunophenotypic analysis showed that repopulating mucosal CD4+ T cells were predominantly of a memory phenotype and expressed CD11 alpha, alpha(E)beta 7, CCR5, and CXCR4. Incomplete suppression of viral replication in GALT during HAART correlated with increased HIV-specific CD8+ T-cell responses. DNA microarray analysis revealed that genes involved in inflammation and cell activation were up regulated in patients who did not replenish mucosal CD4+ T cells efficiently, while expression of genes involved in growth and repair was increased in patients with efficient mucosal CD4+ T-cell restoration. Our findings suggest that the discordance in CD4+ T-cell restoration between GALT and peripheral blood during therapy can be attributed to the incomplete viral suppression and increased immune activation and inflammation that may prevent restoration of CD4+ T cells and the gut microenvironment.

Similar changes in plasmacytoid dendritic cell and CD4 T-cell counts during primary HIV-1 infection and treatment

OBJECTIVES

Reduced dendritic cell (DC) frequencies and functions in individuals with longstanding HIV-1 infection are predictive of opportunistic infections and AIDS. To investigate possible early alterations in DC levels after HIV infection, we prospectively examined plasmacytoid dendritic cell (pDC) and myeloid dendritic cell (mDC) frequencies and plasma IFN-alpha levels in patients undergoing primary HIV-1 infection (PHI).

METHODS

Peripheral blood DC frequencies and absolute counts were determined by flow cytometry. Plasma IFN-alpha levels were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

In comparison to uninfected subjects, pDC, but not mDC, levels were reduced (P < 0.001) in subjects with PHI, especially in those with high viral loads or low CD4 T-cell counts. During 24-48 weeks of observation, untreated subjects experienced slight declines in pDC and CD4 T-cell levels. In contrast, subjects initiating early antiretroviral therapy (ART) exhibited increases (P < 0.001) in pDC and CD4 T-cell counts. No effect of treatment on mDC counts was observed. Circulating plasma IFN-alpha was undetectable by ELISA regardless of the duration of HIV-1 infection.

CONCLUSION

PHI is characterized by a reduction in pDC and CD4 T-cell counts that correlates with the magnitude of virus replication and is not evidenced by the mDC count or plasma IFN-alpha level. Early ART appears to have similar restorative effects on pDC and CD4 T-cell counts.

Tracking the prevalence of transmitted antiretroviral drug-resistant HIV-1: a decade of experience

Transmitted resistance to antiretroviral drugs in acute and early HIV-1 infection has been well documented, although overall trends vary depending on geography and cohort characteristics. To describe the changing pattern of transmitted drug-resistant HIV-1 in a well-defined cohort in New York City, a total of 361 patients with acute or recent HIV-1 infection were prospectively studied over a decade (1995-2004) with respect to HIV-1 genotypes and longitudinal T-cell subsets and HIV-1 RNA levels. The prevalence of overall transmitted resistance changed from 13.2% to 24.1% (P = 0.11) during the periods 1995 to 1998 and 2003 to 2004. Nonnucleoside reverse transcriptase inhibitor resistance prevalence increased significantly from 2.6% to 13.4% (P = 0.007) during the same periods, whereas prevalence of multidrug-resistant virus shifted from 2.6% to 9.8% (P = 0.07) but did not achieve statistical significance. A comparable immunologic and virologic response of appropriately treated individuals was observed regardless of viral drug susceptibility status, suggesting that initial combination therapy guided by baseline resistance testing in the case of acute and early infection may result in a favorable treatment response even in the case of a drug-resistant virus. These data have important implications for selection of empiric first-line regimens for treatment of acutely infected antiretroviral-naive individuals and reinforce the need for baseline resistance testing in acute and early HIV-1 infection.

Impact of baseline viral load and adherence on survival of HIV-infected adults with baseline CD4 cell counts > or = 200 cells/microl

BACKGROUND

Baseline plasma HIV RNA levels > 100 000 copies/ml have been associated with elevated mortality rates after the initiation of HAART. There is uncertainty regarding the optimal strategy for patients with high plasma HIV RNA but CD4 cell count > or = 200 cells/microl.

OBJECTIVE

To evaluate the impact of baseline plasma HIV RNA on survival among patients with CD4 cell counts > or = 200 cells/microl.

METHODS

Patients were stratified by plasma HIV RNA, CD4 cell count and adherence level. Mortality rates were evaluated using Kaplan-Meier methods and Cox regression.

RESULTS

Among 1166 patients initiating HAART with a CD4 cell count > or = 200 cells/microl, a baseline HIV RNA > or = 100 000 copies/ml was statistically associated with elevated mortality among non-adherent patients (log-rank P = 0.032), but not for adherent patients (log-rank P = 0.690). In a multivariate Cox model comparing patients with a baseline CD4 cell count > or = 200 cells/microl and a baseline plasma HIV RNA < 100 000 copies/ml, the mortality rate was statistically similar among patients with a baseline CD4 cell count > or = 200 cells/microl and a baseline plasma HIV RNA > or = 100 000 copies/ml (relative hazard, 1.21; 95% confidence interval, 0.89-1.65; P = 0.232).

CONCLUSION

HIV RNA > or = 100 000 copies/ml was only associated with mortality among HIV-infected patients initiating HAART with CD4 cell counts > or= 200 cells/microl if the patients were non-adherent.

Care of HIV-infected patients in China

Compared with high infection areas of the world, the total HIV infection rate in China is relatively low. Nonetheless, because of China's vast territory and large population, the potential infection risk must be taken seriously. In the next few years, needle sharing among injection drug users will remain the most common route of transmission for the HIV/AIDS epidemic in China. Unprotected sex is gradually becoming a major route of transmission. China began to implement HAART in 1999 according to international standards. Prior to 2003, there were only about 150 HIV/AIDS patients were treated with HAART in some clinical trials and about 100 HIV/AIDS patients were treated by private sources. Results of those treatments are the scientific basis for development of the therapeutic strategies in China. In March of 2003, the Chinese government initiated China CARES program. In November of 2003, the Chinese Ministry of Health announced a national policy of free ARV treatment to all HIV+ Chinese citizens who were in poverty and required ARV therapy. There are total of 19,456 HIV/AIDS patients received free ARV drugs to date in 159 regions and 441 towns. Current challenges are how to follow-up and evaluate those patients in the clinical settings. The longer the therapy is postponed, the more side effects and the higher probability of drug resistance are going to occur. It remains unclear, therefore, when HAART regimen should be started in the HIV/AIDS population in China.

When to Initiate Highly Active Antiretroviral Therapy in Sub-Saharan Africa? A South African Cost-Effectiveness Study

Background

Large-scale programmes increasing access to highly active antiretroviral therapy (HAART) are being implemented in sub-Saharan Africa. However, cost-effectiveness of initiating treatment at different CD4 count thresholds has not been explored in resource-poor settings.

Methods

A cost-effectiveness analysis was conducted from a public health perspective using primary treatment outcomes, healthcare utilisation and cost data (Jan 2004 local prices; US$1=7.6 Rands) derived from the Cape Town AIDS Cohort. A Markov state-transition model was developed to estimate life-expectancy, lifetime costs, quality-adjusted life-years (QALYs), cost per life-year and QALY gained for initiating HAART at three CD4 cell count thresholds (<200/μl, 200–350/μl and >350/μl), including the no antiretroviral therapy (No-ART) alternative. Each treatment option was compared with the next most effective undominated option.

Results

Mean life-expectancy was 6.2, 18.8, 21.0 and 23.3 years; discounted (8%) QALYs were 3.1, 6.2, 6.7 and 7.4; and discounted lifetime costs were US$5,250, US$5,434, US$5,740, US$6,588 for No-ART, and therapy initiation at <200/μl, 200–350/μl and >350/μl scenarios respectively. Clinical benefits increased significantly with early therapy initiation. Initiating therapy at <200/μl had an incremental cost-effectiveness ratio (ICER) of US$54 per QALY versus No-ART, 200–350/μl had an ICER of US$616 versus therapy initiation at <200/μl, and >350/μl had an ICER of US$1,137 versus therapy initiation at 200–350/μl ICERs were sensitive to HAART cost.

Conclusions

HAART is reasonably cost-effective for HIV-infected patients in South Africa, and most effective if initiated when CD4 count >200/μl. Deferring treatment to <200/μl would reduce the aggregate cost of treatment, but this should be balanced against the significant clinical benefits associated with early therapy.