Measuring the Potential Impact of Combination HIV Prevention in Sub-Saharan Africa

A public health approach to combination HIV prevention is advocated to contain the epidemic in sub-Saharan Africa. We explore the implications of universal access to treatment along with HIV education scale-up in the region. We develop an HIV transmission model to investigate the impacts of universal access to treatment, as well as an analytical framework to estimate the effects of HIV education scale-up on the epidemic. We calibrate the model with data from South Africa and simulate the impacts of universal access to treatment along with HIV education scale-up on prevalence, incidence, and HIV-related deaths over a course of 15 years. Our results show that the impact of combined interventions is significantly larger than the summation of individual intervention impacts (super-additive property). The combined strategy of universal access to treatment and HIV education scale-up decreases the incidence rate by 74% over the course of 15 years, whereas universal access to treatment and HIV education scale up will separately decrease that by 43% and 8%, respectively. Combination HIV prevention could be notably effective in transforming HIV epidemic to a low-level endemicity. Our results suggest that in designing effective combination prevention in sub-Saharan Africa, priorities should be given to achieving universal access to treatment as quickly as possible and improving compliance to condom use

Managing HIV treatment in resource-limited and dynamic environments

Containing the HIV epidemic is one of the most pressing global health care issues. Antiretroviral therapy, the only treatment option for chronic HIV, inhibits the progression of the disease. However, there is a severe shortage of treatment in the developing world, particularly in Sub-Saharan Africa, the area hit the hardest by the epidemic. The current guidelines recommend treating HIV patients until death, known as a nonabandonment policy. HIV-infected patients develop resistant mutations and they benefit marginally from treatment. Therefore, there is an opportunity cost for treating patients until they die. We estimate the price of nonabandonment policies in HIV treatment where resources are limited. We develop a mathematical framework to optimize the allocation of scarce HIV treatment for a broad class of admissible policies. Pursuant to this goal, we develop a Markov model of the progression of a population of susceptible and infected individuals. Then, we restrict our attention to two classes of admissible policies: (i) nonabandonment policies, and (ii) abandonment-permitted policies. The price of nonabandonment policies is estimated by the difference between the optimal solution of these two classes of admissible policies. Since the state spaces of the models are unbounded, solving the allocation problems is intractable. Therefore, we approximate the price of nonabandonment policies by the difference between a lower bound on the best performance of allocation policies in abandonment-permitted settings and an upper bound of that in nonabandonment settings. We show that the price of following the nonabandonment policies in HIV treatment is as much as 41%. Moreover, they shed light on the key role allocation policies play in containing the epidemic. In resource-rich environments, when to start HIV treatment is a fundamental question. Current models do not consider the rate of new antiretroviral development in their analysis. We model the arrival of HIV pipeline drugs in resource-rich environments as a split Poisson process and incorporate it in a validated simulation model to measure the effect of HIV pipeline drugs on HIV treatment. The model with the inclusion of pipeline drugs recommends earlier treatment

Priority Hypertension Management Strategies for At-risk African Americans as Perceived by Medical Clinicians and Academic Scholars

African American adults, in the United States (US), bear the greatest burden of high blood pressure (HBP)--a primary risk factor for cardiovascular disease and premature death. Current research does not adequately inform the design of multi-level interventions that work to control HBP in this at-risk population. The purpose of this study was to uncover information about priority strategies recommended for HBP control in African American adults. Research questions are 1) what are factors that reduce or manage HBP in at-risk African Americans and 2) what factors are important to the design and implementation of successful HBP interventions in at-risk African Americans? A qualitative interpretive descriptive design and in-depth interview were used with a purposive sample (n=10) of doctorate-educated healthcare clinicians (i.e., physicians) and academicians (i.e., researchers) based on eligibility criteria: a) experience in treating or conducting research about HBP in African American adults, b) located within the Southern US, and c) consent to participate. Thematic analysis of audio-taped interview transcripts yielded a theoretical framework that consists of three multi-level elements believed to be critical components of interventions that can successfully manage HBP in at-risk African Americans: 1) social support, 2) lifestyle coaching, and 3) personalized medical management. Unique domains within the each element were revealed that ranged from stress management and holism to emotional resonant patient-caregiver partnership and experiential learning. Our findings were consistent with the social ecological model and have the potential to help address racial/ethnic-based health disparities through the design of patient-centered interventions. Findings will also be used to identify parameters available to simulation modelers in the design of models for optimal population level HBP control policy

Averting HIV Infections in New York City: A Modeling Approach Estimating the Future Impact of Additional Behavioral and Biomedical HIV Prevention Strategies

Background:New York City (NYC) remains an epicenter of the HIV epidemic in the United States. Given the variety of evidence-based HIV prevention strategies available and the significant resources required to implement each of them, comparative studies are needed to identify how to maximize the number of HIV cases prevented most economically.Methods:A new model of HIV disease transmission was developed integrating information from a previously validated micro-simulation HIV disease progression model. Specification and parameterization of the model and its inputs, including the intervention portfolio, intervention effects and costs were conducted through a collaborative process between the academic modeling team and the NYC Department of Health and Mental Hygiene. The model projects the impact of different prevention strategies, or portfolios of prevention strategies, on the HIV epidemic in NYC.Results:Ten unique interventions were able to provide a prevention benefit at an annual program cost of less than $360,000, the threshold for consideration as a cost-saving intervention (because of offsets by future HIV treatment costs averted). An optimized portfolio of these specific interventions could result in up to a 34$106,378; the total cost was in excess of $2 billion (over the 20 year period, or approximately$100 million per year, on average). The cost-savings of prevented infections was estimated at more than $5 billion (or approximately$250 million per year, on average).Conclusions:Optimal implementation of a portfolio of evidence-based interventions can have a substantial, favorable impact on the ongoing HIV epidemic in NYC and provide future cost-saving despite significant initial costs. © 2013 Kessler et al

Averting HIV Infections in New York City: A Modeling Approach Estimating the Future Impact of Additional Behavioral and Biomedical HIV Prevention Strategies

Background: New York City (NYC) remains an epicenter of the HIV epidemic in the United States. Given the variety of evidence-based HIV prevention strategies available and the significant resources required to implement each of them, comparative studies are needed to identify how to maximize the number of HIV cases prevented most economically. Methods: A new model of HIV disease transmission was developed integrating information from a previously validated micro-simulation HIV disease progression model. Specification and parameterization of the model and its inputs, including the intervention portfolio, intervention effects and costs were conducted through a collaborative process between the academic modeling team and the NYC Department of Health and Mental Hygiene. The model projects the impact of different prevention strategies, or portfolios of prevention strategies, on the HIV epidemic in NYC. Results: Ten unique interventions were able to provide a prevention benefit at an annual program cost of less than$360,000, the threshold for consideration as a cost-saving intervention (because of offsets by future HIV treatment costs averted). An optimized portfolio of these specific interventions could result in up to a 34$106,378; the total cost was in excess of $2 billion (over the 20 year period, or approximately$100 million per year, on average). The cost-savings of prevented infections was estimated at more than $5 billion (or approximately$250 million per year, on average). Conclusions: Optimal implementation of a portfolio of evidence-based interventions can have a substantial, favorable impact on the ongoing HIV epidemic in NYC and provide future cost-saving despite significant initial costs

Study of two common P53 gene mutations in gastric cancer using PCR-RFLP in Chaharmahal va Bakhtiari province, Iran, 2003

Background and aim: Gastric cancer is the most common cause of cancer death world wide after lung cancer. Genetic factors including oncogenes and tumor suppressor genes are always involved in progression of this cancer. The P53 tumor suppressor gene is believed to have a broad role in the cell such as programmed cell death and stop cell replicating damaged DNA which has been summarized as the guardian of the genome. This study aims to determine the frequency of two common P53 gene mutations using PCR-RFLP in gastric cancer in Chaharmahal va Bakhtiari province. Methods: This descriptive – lab based study describes the mutation analysis of paraffin embedded gastric samples from 38 patients in Chaharmahal va Bakhtiari province. We have investigated the frequency of P53 gene mutation in exons 7 and 8 by PCR-RFLP to detect alteration in two common hot spots in codon 248 and 282. Results: We determined no mutation in P53 gene hot spots in codon 248 and 282. Conclusion: We conclude that association of P53 gene mutations with gastric cancer is very low in Chaharmahal va Bakhtiari province. However we have examined only 38 gastric samples and more samples need to be investigated to reveal the contribution of P53 gene mutation in causing gastric cancer in this province. Also it is necessary to study the entire coding region and promoter of the gene in patients from different population and ethnic groups

A study on carbon sequestration in an area afforested by Black Locust (Robinia pseudoacacia L.)

The increasing concern on global warming and climate change has resulted in a special awareness to the potential of forest and soil for sustainable carbon sequestration. Therefore, an optimal management of afforestation established in barren lands notably influences the soil carbon sequestration which consequently turns the forest coverage (and underlying soil) to a major organic carbon sink. This study aims to quantify the amount of carbon storage in a selected area afforested Black Locust in Malayer, Iran. Initially, the land units including Black Locust trees were indicated on map polygons, followed by the measurement of all trees within the polygons. Then, five samples in each diameter class were selected, within which the amount of biomass, carbon storage and co2 uptake were estimated. To determine the amount of stored carbon in the soil, samples were collected from two soil depths of 0-10 and 10-30 cm. The amount of the annual sequestrated carbon in biomass and soil was then estimated to be 0.351 and 1.253 tons per ha, respectively. In addition, the annual co2 uptake was 5.87 tons per ha. The results indicate significant differences between the amount of carbon storage in different diameter classes of R. pseudoacacia trees