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BACKGROUND:

The effect of adherence, treatment failure, and comorbidities on the cost of HIV care is not well understood.

OBJECTIVE:

To characterize the cost of HIV care including combination antiretroviral treatment (ART).

RESEARCH DESIGN:

Observational study of administrative data.

SUBJECTS:

Total 1896 randomly selected HIV-infected patients and 288 trial participants with multidrug-resistant HIV seen at the US Veterans Health Administration (VHA).

MEASURES:

Comorbidities, cost, pharmacy, and laboratory data.

RESULTS:

Many HIV-infected patients (24.5%) of the random sample did not receive ART. Outpatient pharmacy accounted for 62.8% of the costs of patients highly adherent with ART, 32.2% of the cost of those with lower adherence, and 6.2% of the cost of those not receiving ART. Compared with patients not receiving ART, high adherence was associated with lower hospital cost, but no greater total cost. Individuals with a low CD4 count (500. Most patients had medical, psychiatric, or substance abuse comorbidities. These conditions were associated with greater cost. Trial participants were less likely to have psychiatric and substance abuse comorbidities than the random sample of VHA patients with HIV.

CONCLUSIONS:

Patients receiving combination ART had higher medication costs but lower acute hospital cost. Poor control of HIV was associated with higher cost. The cost of psychiatric, substance abuse, rehabilitation, and long-term care and medications other than ART, often overlooked in HIV studies, was substantial.

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Medical Care
Authors
Mark Holodniy
Douglas K. Owens
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OBJECTIVE:

Acute HIV infection often causes influenza-like illness (ILI) and is associated with high infectivity. We estimated the effectiveness and cost-effectiveness of strategies to identify and treat acute HIV infection in men who have sex with men (MSM) in the USA.

DESIGN:

Dynamic model of HIV transmission and progression.

INTERVENTIONS:

We evaluated three testing approaches: viral load testing for individuals with ILI, expanded screening with antibody testing, and expanded screening with antibody and viral load testing. We included treatment with antiretroviral therapy for individuals identified as acutely infected.

MAIN OUTCOME MEASURES:

New HIV infections, discounted quality-adjusted life years (QALYs) and costs, and incremental cost-effectiveness ratios.

RESULTS:

At the present rate of HIV-antibody testing, we estimated that 538,000 new infections will occur among MSM over the next 20 years. Expanding antibody screening coverage to 90% of MSM annually reduces new infections by 2.8% and costs US$ 12,582 per QALY gained. Symptom-based viral load testing with ILI is more expensive than expanded antibody screening, but is more effective and costs US$ 22,786 per QALY gained. Combining expanded antibody screening with symptom-based viral load testing prevents twice as many infections compared to expanded antibody screening alone, and costs US$ 29,923 per QALY gained. Adding viral load testing to all annual HIV tests costs more than US$ 100,000 per QALY gained.

CONCLUSION:

Use of HIV viral load testing in MSM with ILI prevents more infections than does expanded annual antibody screening alone and is inexpensive relative to other screening interventions. Clinicians should consider symptom-based viral load testing in MSM, in addition to encouraging annual antibody screening.

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AIDS
Authors
Douglas K. Owens
Eran Bendavid
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BACKGROUND:

The prime-boost HIV vaccine regimen used in the recent RV144 trial resulted in modest efficacy of 31% over 3.5 years, but was substantially higher in the first year post-vaccination. We sought to explore the potential impact of a vaccine with rapidly waning efficacy in a South African population.

METHODS:

We explored two strategies using a dynamic compartmental epidemic model for heterosexual transmission of HIV: [1] vaccination of a single cohort (30%, 60% or 90% of the initial population), with exponentially waning efficacy, but booster vaccinations at 5- or 2-year intervals, and [2] continuous vaccination of the unvaccinated population at the same coverage levels (30%, 60% or 90%) but with a constant efficacy vaccine of short duration. We also examined potential changes in post-vaccination condom use.

RESULTS:

The single cohort vaccination strategies did not have a substantial impact on HIV prevalence, although without boosters they still prevented 2-6% of the expected infections at 20 years, depending on the population coverage. The 5-year and 2-year booster strategies prevented 8-24% and 17-45% of the expected infections, respectively. Continuous vaccination to maintain population coverage levels resulted in more substantial reductions in population HIV prevalence and greater numbers of infections prevented: HIV prevalence at 20 years was reduced from 23% to 8-14% and the number of expected infections was decreased by 34-59%, depending on the population coverage level. Moderate changes in post-vaccination condom use did not substantially affect these outcomes.

CONCLUSIONS:

An HIV vaccine with partial efficacy and declining protection similar to the RV144 vaccine could prevent a substantial proportion of HIV infections if booster vaccinations were effective and available. Our estimates of the population impact of vaccination would be improved by further understanding of the duration of protection, the effectiveness of booster vaccination, and whether the vaccine efficacy varies between subpopulations at higher and lower risk of exposure.

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Vaccine
Authors
Douglas K. Owens
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The mechanism by which strictly CCR5 using HIV-1 clade C variants exacerbate disease progression in absence of coreceptor switch is not clearly known. We previously reported HIV-1 cladeC envelopes (Env) obtained from late stage Indian patients with expanded coreceptor tropism. Here we compared such Envs (having expanded coreceptor tropism) with strictly CCR5 using Envs also obtained from late stage in their capacity to utilize CD4 and CCR5 for productive entry. We found that while envelopes with low CD4 dependence tend to infect primary CD4(+) T cells better than those required optimum CD4 for entry, no significant association was found between low CD4 usage and infectivity of primary CD4(+) T cells by Env-pseudotyped viruses and theirsensitivity to CCR5 antagonist TAK-779. Interestingly, Envs that readily infected HeLa cells expressing low CD4 showed relative resistance to T20 indicating that conformational intermediates of these envelopes remained for a shorter period of time than is required for efficient inhibition by T20.

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Virus Research
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Identification of vulnerability in the HIV-1 envelope (Env) will aid in Env-based vaccine design. We recently found an HIV-1 clade C Env clone (4-2.J45) amplified from a recently infected Indian patient showing exceptional neutralization sensitivity to autologous plasma in contrast to other autologous Envs obtained at the same time point. By constructing chimeric Envs and fine mapping between sensitive and resistant Env clones, we found that substitution of highly conserved isoleucine (I) with methionine (M) (ATA to ATG) at position 424 in the C4 domain conferred enhanced neutralization sensitivity of Env-pseudotyped viruses to autologous and heterologous plasma antibodies. When tested against monoclonal antibodies targeting different sites in gp120 and gp41, Envs expressing M424 showed significant sensitivity to anti-V3 monoclonal antibodies and modestly to sCD4 and b12. Substitution of I424M in unrelated Envs also showed similar neutralization phenotype, indicating that M424 in C4 region induces exposure of neutralizing epitopes particularly in CD4 binding sites and V3 loop.

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Virology
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Background

Cardiovascular diseases represent an increasing share of the global disease burden. There is concern that increased consumption of palm oil could exacerbate mortality from ischemic heart disease (IHD) and stroke, particularly in developing countries where it represents a major nutritional source of saturated fat.

Methods

The study analyzed country-level data from 1980-1997 derived from the World Health Organization's Mortality Database, U.S. Department of Agriculture international estimates, and the World Bank (234 annual observations; 23 countries). Outcomes included mortality from IHD and stroke for adults aged 50 and older. Predictors included per-capita consumption of palm oil and cigarettes and per-capita Gross Domestic Product as well as time trends and an interaction between palm oil consumption and country economic development level. Analyses examined changes in country-level outcomes over time employing linear panel regressions with country-level fixed effects, population weighting, and robust standard errors clustered by country. Sensitivity analyses included further adjustment for other major dietary sources of saturated fat.

Results

In developing countries, for every additional kilogram of palm oil consumed per-capita annually, IHD mortality rates increased by 68 deaths per 100,000 (95% CI [21-115]), whereas, in similar settings, stroke mortality rates increased by 19 deaths per 100,000 (95% CI [-12-49]) but were not significant. For historically high-income countries, changes in IHD and stroke mortality rates from palm oil consumption were smaller (IHD: 17 deaths per 100,000 (95% CI [5.3-29]); stroke: 5.1 deaths per 100,000 (95% CI [-1.2-11.0])). Inclusion of other major saturated fat sources including beef, pork, chicken, coconut oil, milk cheese, and butter did not substantially change the differentially higher relationship between palm oil and IHD mortality in developing countries.

Conclusions

Increased palm oil consumption is related to higher IHD mortality rates in developing countries. Palm oil consumption represents a saturated fat source relevant for policies aimed at reducing cardiovascular disease burdens.

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Globalization and Health
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In the present study, we investigated genetic divergence between complete autologous HIV-1 env genes amplified directly from plasma of two anti-retroviral naïve, slow progressing Indian patients with broad neutralizing antibody response. All the envelopes (Env) clones obtained from one patient (LT1) belonged to subtype C; the second patient (LT5) harbored quasispecies comprising of pure B, C and B/C recombinants with distinct breakpoints indicative of dual infection with genetically distinct strains. Further characterization of these Envs would provide insights to the biological properties under strong humoral immune response.

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AIDS Research and Human Retroviruses
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Abstract HIV-2 group A is predominant in different parts of the world, especially Africa, Portugal, Spain, France, the United Kingdom, the United States, Korea, and India. Among the Asian countries, India accounts for about 95% of all HIV-2 infections. The prevalence of HIV-2 has been reported from various states of India such as Maharashtra, Goa, Tamil Nadu, West Bengal, and Uttar Pradesh. In the present study, we analyzed transmembrane region (gp36) sequences of 10 HIV-2 group A Indian strains, isolated from Indian HIV-2-seropositive individuals. HIV Blast analysis for the 1.0-Kb region of the gp36 transmembrane region has shown that all these sequences belong to HIV-2 group A. Phylogenetic analysis indicated that the sequences cluster with HIV-2 group A sequences of Cameroon and Senegal. The epitope found at position 645-656 (YELQKLNSWDVF), previously reported as a broadly neutralizing determinant, was very well conserved in all 10 study sequences. The percentage similarity between Indian and South African HIV-2 group A gp36 sequences was 90% (range 86-100, SD 2.8) and with other nonsubtype A clades was 84% (range 77-100, SD 6.06) indicating overall less variability among the reported HIV-2 sequences. Similarly, the consensus amino acid sequences of the envelope transmembrane region of HIV-1 (gp41) and HIV-2 (gp36) is quite synonymous, indicating 87% similarity; however, limited information is available about the gp36 transmembrane region of the prevalent HIV 2 group A Indian strain. The rate of synonymous substitutions reported in the gp105 region was significantly higher, suggesting lower virulence of HIV-2, which does translate into a lower rate of evolution, while the dN/dS ratio for the gp36 transmembrane region was less than one, indicating its conservation and significance (p<0.05) in structural and functional constraints.

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AIDS Research and Human Retroviruses
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BACKGROUND: The recent RV144 clinical trial showed that an ALVAC/AIDSVAX prime-boost  HIV vaccine regimen may confer partial immunity in recipients and reduce transmission by 31%. Trial data suggest that efficacy may initially exceed 70% but decline over the following 3.5 years. Estimating the potential health benefits associated with a one-time vaccination campaign, as well as the projected benefits of repeat booster vaccination, may inform future HIV vaccine research and licensing decisions.

METHODS: We developed a mathematical model to project the future course of the HIV epidemic in the United States under varying HIV vaccine scenarios. The model accounts for disease progression, infection transmission, antiretroviral therapy, and HIV-related morbidity and mortality. We projected HIV prevalence and incidence over time in multiple risk groups, and we estimated quality-adjusted life years (QALYs) and costs over a 10-year time horizon. We used an exponentially declining efficacy curve fit to trial data, and we assumed subsequent vaccine boosters confer similar immunity. Variations in vaccine parameters were examined in sensitivity analysis.

RESULTS: Under existing HIV prevention and treatment efforts, an estimated 590,000 HIV infections occur over 10 years. One-time vaccination achieving 60% coverage of adults could prevent 9.8% of projected new infections over 10 years (and prevent 34% of new infections in the first year) and cost approximately $91,000/QALY gained relative to the status quo, assuming a vaccination price of $500. Targeted vaccination of high-risk groups results in net cost savings for vaccines costing less than $750. One-time vaccination of 60% of all adults coupled with three-year boosters only for men who have sex with men and injection drug users could prevent 21% of infections for $81,000/QALY gained relative to vaccination of high-risk groups only. A program attaining 90% vaccination coverage prevents 15% of new HIV cases over 10 years (and approximately50% of infections in the first year).

CONCLUSIONS: A partially effective HIV vaccine with effectiveness similar to that observed in the RV144 trial would provide large health benefits in the United States and could meet conventionally accepted cost-effectiveness thresholds. Strategies that target high-risk groups are most efficient, but broader strategies provide greater total population health benefit.

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Vaccine
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Douglas K. Owens
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