Arquivo da tag: AIDS

Mathematics Provides a Shortcut to Timely, Cost-Effective Interventions for HIV (Science Daily)

Apr. 15, 2013 — Mathematical estimates of treatment outcomes can cut costs and provide faster delivery of preventative measures.

South Africa is home to the largest HIV epidemic in the world with a total of 5.6 million people living with HIV. Large-scale clinical trials evaluating combination methods of prevention and treatment are often prohibitively expensive and take years to complete. In the absence of such trials, mathematical models can help assess the effectiveness of different HIV intervention combinations, as demonstrated in a new study by Elisa Long and Robert Stavert from Yale University in the US. Their findings appear in the Journal of General Internal Medicine, published by Springer.

Currently 60 percent of individuals in need of treatment for HIV in South Africa do not receive it. The allocation of scant resources to fight the HIV epidemic means each strategy must be measured in terms of cost versus benefit. A number of new clinical trials have presented evidence supporting a range of biomedical interventions that reduce transmission of HIV. These include voluntary male circumcision — now recommended by the World Health Organization and Joint United Nations Programme on HIV/AIDS as a preventive strategy — as well as vaginal microbicides and oral pre-exposure prophylaxis, all of which confer only partial protection against HIV. Long and Stavert show that a combination portfolio of multiple interventions could not only prevent up to two-thirds of future HIV infections, but is also cost-effective in a resource-limited setting such as South Africa.

The authors developed a mathematical model accounting for disease progression, mortality, morbidity and the heterosexual transmission of HIV to help forecast future trends in the disease. Using data specific for South Africa, the authors estimated the health benefits and cost-effectiveness of a “combination approach” using all three of the above methods in tandem with current levels of antiretroviral therapy, screening and counseling.

For each intervention, they calculated the HIV incidence and prevalence over 10 years. At present rates of screening and treatment, the researchers predict that HIV prevalence will decline from 19 percent to 14 percent of the population in the next 10 years. However, they calculate that their combination approach including male circumcision, vaginal microbicides and oral pre-exposure prophylaxis could further reduce HIV prevalence to 10 percent over that time scale — preventing 1.5 million HIV infection over 10 years — even if screening and antiretroviral therapy are kept at current levels. Increasing antiretroviral therapy use and HIV screening frequency in addition could avert more than 2 million HIV infections over 10 years, or 60 percent of the projected total.

The researchers also determined a hierarchy of effectiveness versus cost for these intervention strategies. Where budgets are limited, they suggest money should be allocated first to increasing male circumcision, then to more frequent HIV screening, use of vaginal microbicides and increasing antiretroviral therapy. Additionally, they calculate that omitting pre-exposure prophylaxis from their combination strategy could offer 90 percent of the benefits of treatment for less than 25 percent of the costs.

The authors conclude: “In the absence of multi-intervention randomized clinical or observational trials, a mathematical HIV epidemic model provides useful insights about the aggregate benefit of implementing a portfolio of biomedical, diagnostic and treatment programs. Allocating limited available resources for HIV control in South Africa is a key priority, and our study indicates that a multi-intervention HIV portfolio could avert nearly two-thirds of projected new HIV infections, and is a cost-effective use of resources.”

Journal Reference:

  1. Long, E.F. and Stavert, R.R. Portfolios of biomedical HIV interventions in South Africa: a cost-effectiveness analysisJournal of General Internal Medicine, 2013 DOI:10.1007/s11606-013-2417-1
Anúncios

Notificação de HIV no Brasil passará a ser obrigatória (OESP)

Por Felipe Frazão | Estadão Conteúdo – 11 horas atrás (Yahoo Notícias)

O Ministério da Saúde vai tornar compulsória a notificação de todas as pessoas infectadas com o vírus HIV, mesmo as que não desenvolveram a doença. A portaria ministerial que trata da obrigatoriedade de aviso de todos os casos de detecção do vírus da aids no País deve ser publicada em janeiro.

Atualmente, médicos e laboratórios informam ao Ministério da Saúde apenas os casos de pacientes que possuem o HIV e tenham, necessariamente, manifestado a doença. Os dados serão mantidos em sigilo. Somente as informações de perfil (sem a identificação do nome) poderão ser divulgadas para fins estatísticos.

Hoje, o governo monitora os soropositivos sem aids de maneira indireta. As informações disponíveis são de pessoas que fizeram a contagem de células de defesa nos serviços públicos ou estão cadastradas para receber antirretrovirais pelo Sistema Único de Saúde (SUS). O novo banco de dados será usado para planejamento de políticas públicas de prevenção e tratamento da aids.

“Para a saúde pública é extremamente importante, porque nós vamos poder saber realmente quantas pessoas estão infectadas e o tipo de serviços que vamos precisar”, explica Dirceu Grego, diretor do Departamento de DST, Aids e Hepatites Virais do Ministério da Saúde.

A mudança ocorre quatro meses após o governo anunciar a ampliação do acesso ao tratamento com medicação antirretroviral oferecido pelo SUS. A prescrição passou a ser feita em estágios menos avançados da aids.

Desde então, casais com um dos parceiros soropositivo passaram a ter acesso à terapia em qualquer estágio da doença.

O ministério também recomendou que a droga seja ministrada de forma mais precoce para quem não têm sintomas de aids, mas possui o vírus no organismo – uma tendência na abordagem da doença, reforçada na última Conferência Internacional de Aids, realizada em julho deste ano nos Estados Unidos.

À época, o ministério calculou que o número de brasileiros com HIV fazendo uso dos antirretrovirais aumentaria em 35 mil. Atualmente, são cerca de 220 mil pacientes com aids.

Outras 135 mil pessoas, estima o governo, têm o HIV, mas não sabem. Elas estão no foco da mudança na obrigatoriedade de notificação, porque não foram ainda diagnosticadas. Segundo Grego, essas pessoas devem ser incorporadas ao tratamento. Assim como ocorre quando os pacientes são diagnosticados com aids, caberá aos médicos e laboratórios avisar ao ministério sobre a descoberta de pessoas infectadas – os soropositivos. As informações são do jornal O Estado de S.Paulo.

Design Help for Drug Cocktails for HIV Patients: Mathematical Model Helps Design Efficient Multi-Drug Therapies (Science Daily)

ScienceDaily (Sep. 2, 2012) — For years, doctors treating those with HIV have recognized a relationship between how faithfully patients take the drugs they prescribe, and how likely the virus is to develop drug resistance. More recently, research has shown that the relationship between adherence to a drug regimen and resistance is different for each of the drugs that make up the “cocktail” used to control the disease.

HIV is shown attaching to and infecting a T4 cell. The virus then inserts its own genetic material into the T4 cell’s host DNA. The infected host cell then manufactures copies of the HIV. (Credit: iStockphoto/Medical Art Inc.)

New research conducted by Harvard scientists could help explain why those differences exist, and may help doctors quickly and cheaply design new combinations of drugs that are less likely to result in resistance.

As described in a September 2 paper in Nature Medicine, a team of researchers led by Martin Nowak, Professor of Mathematics and of Biology and Director of the Program for Evolutionary Dynamics, have developed a technique medical researchers can use to model the effects of various treatments, and predict whether they will cause the virus to develop resistance.

“What we demonstrate in this paper is a prototype for predicting, through modeling, whether a patient at a given adherence level is likely to develop resistance to treatment,” Alison Hill, a PhD student in Biophysics and co-first author of the paper, said. “Compared to the time and expense of a clinical trial, this method offers a relatively easy way to make these predictions. And, as we show in the paper, our results match with what doctors are seeing in clinical settings.”

The hope, said Nowak, is that the new technique will take some of the guesswork out of what is now largely a trial-and-error process.

“This is a mathematical tool that will help design clinical trials,” he said. “Right now, researchers are using trial and error to develop these combination therapies. Our approach uses the mathematical understanding of evolution to make the process more akin to engineering.”

Creating a model that can make such predictions accurately, however, requires huge amounts of data.

To get that data, Hill and Daniel Scholes Rosenbloom, a PhD student in Organismic and Evolutionary Biology and the paper’s other first author, turned to Johns Hopkins University Medical School, where Professor of Medicine and of Molecular Biology and Genetics Robert F. Siliciano was working with PhD student Alireza Rabi (also co-first author) to study how the HIV virus reacted to varying drug dosages.

Such data proved critical to the model that Hill, Rabi and Rosenbloom eventually designed, because the level of the drug in patients — even those that adhere to their treatment perfectly — naturally varies. When drug levels are low — as they are between doses, or if a dose is missed — the virus is better able to replicate and grow. Higher drug levels, by contrast, may keep the virus in check, but they also increase the risk of mutant strains of the virus emerging, leading to drug resistance.

Armed with the data from Johns Hopkins, Hill, Rabi and Rosenbloom created a computer model that could predict whether and how much the virus, or a drug-resistant strain, was growing based on how strictly patients stuck to their drug regimen.

“Our model is essentially a simulation of what goes on during treatment,” Rosenbloom said. “We created a number of simulated patients, each of whom had different characteristics, and then we said, ‘Let’s imagine these patients have 60 percent adherence to their treatment — they take 60 percent of the pills they’re supposed to.’ Our model can tell us what their drug concentration is over time, and based on that, we can say whether the virus is growing or shrinking, and whether they’re likely to develop resistance.”

The model’s predictions, Rosenbloom explained, can then serve as a guide to researchers as they work to design new drug cocktails to combat HIV.

While their model does hold out hope for simplifying the process of designing drug “cocktails,” Hill and Rosenbloom said they plan to continue to refine the model to take additional factors — such as multiple mutant-resistant strains of the virus and varying drug concentrations in other parts of the body — into effect.

“The prototype we have so far looks at concentrations of drugs in blood plasma,” Rosenbloom explained. “But a number of drugs don’t penetrate other parts of the body, like the brains or the gut, with the same efficiency, so it’s important to model these other areas where the concentrations of drugs might not be as high.”

Ultimately, though, both say their model can offer new hope to patients by helping doctors design better, cheaper and more efficient treatments.

“Over the past 10 years, the number of HIV-infected people receiving drug treatment has increased immensely,” Hill said. “Figuring out what the best ways are to treat people in terms of cost effectiveness, adherence and the chance of developing resistance is going to become even more important.”

Journal Reference:

  1. Daniel I S Rosenbloom, Alison L Hill, S Alireza Rabi, Robert F Siliciano, Martin A Nowak. Antiretroviral dynamics determines HIV evolution and predicts therapy outcomeNature Medicine, 2012; DOI: 10.1038/nm.2892

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Anti-HIV Drug Simulation Offers ‘Realistic’ Tool to Predict Drug Resistance and Viral Mutation

ScienceDaily (Sep. 2, 2012) — Pooling data from thousands of tests of the antiviral activity of more than 20 commonly used anti-HIV drugs, AIDS experts at Johns Hopkins and Harvard universities have developed what they say is the first accurate computer simulation to explain drug effects. Already, the model clarifies how and why some treatment regimens fail in some patients who lack evidence of drug resistance. Researchers say their model is based on specific drugs, precise doses prescribed, and on “real-world variation” in how well patients follow prescribing instructions.

Johns Hopkins co-senior study investigator and infectious disease specialist Robert Siliciano, M.D., Ph.D., says the mathematical model can also be used to predict how well a patient is likely to do on a specific regimen, based on their prescription adherence. In addition, the model factors in each drug’s ability to suppress viral replication and the likelihood that such suppression will spur development of drug-resistant, mutant HIV strains.

“With the help of our simulation, we can now tell with a fair degree of certainty what level of viral suppression is being achieved — how hard it is for the virus to grow and replicate — for a particular drug combination, at a specific dosage and drug concentration in the blood, even when a dose is missed,” says Siliciano, a professor at the Johns Hopkins University School of Medicine and a Howard Hughes Medical Institute investigator. This information, he predicts, will remove “a lot of the current trial and error, or guesswork, involved in testing new drug combination therapies.”

Siliciano says the study findings, to be reported in the journalNature Medicine online Sept. 2, should help scientists streamline development and clinical trials of future combination therapies, by ruling out combinations unlikely to work.

One application of the model could be further development of drug combinations that can be contained in a single pill taken once a day. That could lower the chance of resistance, even if adherence is not perfect. Such future drug regimens, he says, will ideally strike a balance between optimizing viral suppression and minimizing risk of drug resistance.

Researchers next plan to expand their modeling beyond blood levels of virus to other parts of the body, such as the brain, where antiretroviral drug concentrations can be different from those measured in the blood. They also plan to expand their analysis to include multiple-drug-resistant strains of HIV.

Besides Siliciano, Johns Hopkins joint medical-doctoral student Alireza Rabi was a co-investigator in this study. Other study investigators included doctoral candidates Daniel Rosenbloom, M.S.; Alison Hill, M.S.; and co-senior study investigator Martin Nowak, Ph.D. — all at Harvard University.

Funding support for this study, which took two years to complete, was provided by the National Institutes of Health, with corresponding grant numbers R01-MH54907, R01-AI081600, R01-GM078986; the Bill and Melinda Gates Foundation; the Cancer Research Institute; the National Science Foundation; the Howard Hughes Medical Institute; Natural Sciences and Engineering Research Council of Canada; the John Templeton Foundation; and J. Epstein.

Currently, an estimated 8 million of the more than 34 million people in the world living with HIV are taking antiretroviral therapy to keep their disease in check. An estimated 1,178,000 in the United States are infected, including 23,000 in the state of Maryland.

Journal Reference:

  1. Daniel I S Rosenbloom, Alison L Hill, S Alireza Rabi, Robert F Siliciano, Martin A Nowak. Antiretroviral dynamics determines HIV evolution and predicts therapy outcomeNature Medicine, 2012; DOI: 10.1038/nm.2892

Mário Scheffer: “Vivemos uma crise sem precedentes na resposta à epidemia de HIV/Aids” (viomundo.com.br)

31 de julho de 2012

por Conceição Lemes

Mário Scheffer: “A condução é conservadora, defasada. A criatividade, a ousadia e o diálogo permanente com a sociedade civil  cederam lugar à arrogância”

Terminou nesta sexta-feira, em Washington, Estados Unidos, a 19ª Conferência Internacional sobre Aids. O Programa Nacional de DST/Aids, que até então era festejado e apontado como modelo para o mundo, sofreu críticas de especialistas durante toda a semana.

“A história de sucesso do programa brasileiro de aids entrou em declínio por fatores como a saída de recursos internacionais e o enfraquecimento da relação entre o governo e a sociedade civil”, avalia Eduardo Gomez, pesquisador da Universidade Rutgers de Camden, em Nova Jersey, EUA. “Historicamente, o programa brasileiro de aids tinha uma conexão forte com as ONGs, mas agora elas estão sem recursos e sem motivação. O governo precisa delas para conscientizar as populações difíceis de atingir.”

“O aumento da pressão de grupos religiosos e a redução das campanhas de prevenção junto às populações de maior risco são a maior ameaça ao programa brasileiro anti-aids”, pondera Massimo Ghidinelli, coordenador de Aids/HIV da Organização Panamericana da Saúde (OPAS). “Parece que, nos últimos anos, os grupos religiosos ficaram mais fortes e há uma menor intensidade na maneira pela qual o programa lida com questões de homofobia e sexualidade.”

Ontem, quinta-feira 26, ativistas brasileiros presentes à 19ª Conferência Internacional de Aids, em Washington, protestaram em frente ao estande do Ministério da Saúde contra o que definem como “retrocesso na resposta contra a epidemia”. O objetivo, segundo eles, foi mostrar ao mundo que o País “não é mais o mesmo” e “vive do sucesso do passado” no enfrentamento da doença.

“Até agora, as críticas eram principalmente de ONGs e ativistas brasileiros. Agora, são de especialistas estrangeiros renomados”, observa Mário Scheffer, presidente do Grupo Pela Vidda-SP. “O programa brasileiro de aids parou no tempo e não é mais motivo de orgulho nacional. Tivemos uma sucessão de perdas acumuladas. Vivemos uma crise sem precedentes na resposta à epidemia de HIV/aids.”

Ativista há mais de 20 anos e também professor do Departamento de Medicina Preventiva da Faculdade de Medicina da USP, Mário acompanha a epidemia de HIV/Aids desde o seu início nos anos 80. Além do olhar afiado e da expertise em saúde pública, ele conhece bem toda a trajetória do Programa Nacional de DST/Aids. Daí esta nossa entrevista:

Viomundo – Começou no domingo (22) e terminou hoje (27) em Washington a 19ª Conferência Internacional sobre Aids. No decorrer da semana, foram feitas várias críticas ao momento atual do programa brasileiro de aids. Você concorda com elas?

Mário Scheffer – Com certeza. Até agora, as críticas eram principalmente de ONGs brasileiras. Agora, são de especialistas estrangeiros renomados. Elas são a prova maior de que o programa brasileiro não é mais a principal referência internacional, perdemos a liderança e o ineditismo, não ousamos mais nas respostas excepcionais que marcaram nossa história de combate à aids.

Viomundo – As ONGs de aids sempre tiveram boa interlocução com o Ministério da Saúde. O que aconteceu?

Mário Scheffer — As ONGs e os ativistas pioneiros que são obviamente mais críticos não são mais ouvidos. O governo atualmente elege os interlocutores que lhes são mais convenientes e deslegitima muitos daqueles que deram contribuições históricas.

Sinal de que as coisas não vão nada bem por aqui é que tanto a crítica ao programa quanto o reconhecimento às ONGs e aos ativistas brasileiros têm que vir de fora.

Aliás, o presidente do Banco Mundial, Jim Yong Kim, em seu discurso na abertura da Conferência Internacional de Aids, domingo passado em Washington, fez um vigoroso elogio aos ativistas e citou especificamente as ONGs brasileiras. Disse que se hoje é possível falar em controle da epidemia e vislumbrar o seu fim, isso se deve fundamentalmente às ações desses ativistas.

Viomundo –  ONGs de aids estão fechando as portas no Brasil. Por quê?

Mário Scheffer – Vários motivos. Crise de pessoal, financeira, de sustentabilidade, não têm sede física, não têm dinheiro para pagar aluguel e telefone, têm que compor diretorias com apenas três pessoas  porque não há mais gente disponível. Também não conseguem mais montar  equipes para executar projetos, para chegar até as populações vulneráveis, o que só as ONGs são capazes de fazer.

Em outras palavras: algumas ONGs estão fechando as portas, como você disse. Mas está havendo também retração das atividades de todas elas.

Viomundo – Mas as críticas não se devem apenas à crise financeira e de pessoal das ONGs de aids?

Mário Scheffer – Essa é apenas uma das pontas da crise sem precedentes da resposta brasileira à epidemia, que também perdeu tecnicamente. Além disso, não há sensibilidade nem determinação do governo para perceber e para contribuir com a superação da crise das ONGs. Pelo contrário. Atualmente há uma crise política de relacionamento e mesmo de desprezo pela história das ONGs. O governo federal tem feito a opção — e isso não é só na área de aids — pela relação paroquial com a sociedade civil, uma política de cooptação e quebra-galho. Não ha mais crítica nem debate qualificado de ideias. Tivemos uma sucessão de perdas acumuladas.

Viomundo – Quais?

Mário Scheffer – Primeiro, perdemos a força do trabalho voluntário por meio do qual as pessoas participavam de nossas ONGs, exprimiam sua solidariedade, doavam tempo, trabalho e talento para a luta contra a aids. Não é mais uma causa mobilizadora e isso tem a ver com a imagem trabalhada pelo governo de que temos o melhor programa do mundo e que por aqui está tudo resolvido.

Segundo, com a ascensão das ONGs picaretas e bandidas, criadas para alimentar a corrupção em vários ministérios, cresceu o preconceito e foram impostas mais barreiras para as organizações sérias, que já tinham dificuldade em acessar recursos públicos.

Desde que realizado com critério, transparência, concorrência pública e rigorosa prestação de contas, as ONGs deveriam ter o direito de acessar fundos públicos para exercer o controle, a fiscalização e a participação nas políticas públicas, como acontece em várias democracias.

Terceiro, diante da imagem de que o Brasil hoje é um país rico e resolveu o problema da aids (o que não é verdade), acabou o apoio internacional às ONGs brasileiras de aids.

Resultado: sem ajuda de comunidades e empresas e com uma causa que não toca mais o coração de doadores e voluntários, passamos a viver a dificuldade crescente de assegurar recursos institucionais para a manutenção das ONGs. Com isso, arrefeceu o nosso ativismo e controle sobre as políticas públicas.

Viomundo – E os financiamentos governamentais vinculados a projetos?

Mário Scheffer – Eles fazem parte de um modelo esgotado em que as ONGs de aids foram reduzidas a mão de obra barata para prestação de serviços que o Ministério da Saúde e secretarias estaduais e municipais de saúde não conseguem realizar. Não bastasse isso, muitas vezes estados e municípios não repassam esse recursos às ONGs e quando o fazem, não há continuidade nem avaliação da eficácia das ações financiadas.

Viomundo – Um pouco atrás você falou que o programa brasileiro de aids perdeu tecnicamente. Em que medida? 

Mário Scheffer — Não houve renovação nem atualização dos quadros técnicos. Os desafios hoje são outros, mas a condução é conservadora, defasada. A criatividade, a ousadia e o diálogo permanente com a sociedade civil  cederam lugar à arrogância. Sem a força e a autonomia de outrora, os programas de aids —  o nacional e vários estaduais e municipais — estão isolados e enfraquecidos politicamente dentro dos governos.

Em São Paulo, por exemplo, muitos serviços municipais de aids estão sem médicos,   os estaduais, superlotados, sendo privatizados, fechando leitos, e os programas de aids sem nenhuma governabilidade sobre isso.

Já o programa nacional nem sequer dá mais as fichas sobre a produção nacional de antirretrovirais genéricos. Hoje é um processo sem transparência. O Ministério da Saúde não dá um passo sem o amém da Casa Civil e dos fundamentalistas religiosos que integram a base governista, o que emperra programas de prevenção de aids.

Viomundo – O que ONGs e ativistas da área de aids querem?

Mário Scheffer — Queremos ser respeitados e ouvidos mas em novos patamares de relacionamento. Ninguém desistiu da luta. Nossas ONGs querem continuar atuando nas diversas frentes, na prevenção, na assistência das casas de apoio, nas assessorias jurídicas, na defesa dos direitos das pessoas que vivem com HIV. Queremos continuar fazendo o mesmo ativismo que nos levou a conquistar o acesso universal aos medicamentos, derrubar patentes, lutar contra a exclusão de coberturas pelos planos de saúde privados, acessar os vulneráveis e alçá-los à condição de cidadãos.

O mesmo ativismo que nos leva a apontar que, diferentemente do que dizem, o acesso aos antirretrovirais no Brasil não é universal, pois o diagnóstico tardio é altíssimo e ainda existem desabastecimentos ocasionais. Que nos leva a dizer que não existe política de prevenção adequada a um perfil de epidemia concentrada em certas populações, como os homossexuais, atualmente os maiores negligenciados de prevenção em aids no Brasil.

Hoje estão ameaçados princípios essenciais que forjaram o combate à aids no Brasil, que um dia chegou a quebrar barreiras e tabus. Essa ousadia necessária deu lugar a um programa sem vida, covarde, que promove autocensura, se alinha com forças retrógradas, como no caso recente da campanha dirigida aos gays.

Um programa que se debruça sobre glórias do passado e exibe uma real incapacidade , lentidão e perda da capacidade técnica e política . Não tem conseguido dar respostas à altura das novas dinâmicas e desafios da epidemia e a comunidade internacional passou a perceber isso.

Neste momento de grandes mudanças, com esperança concreta da cura e controle da aids, novas armas para prevenção, necessidade de ampliarmos a oferta de testagem e tratamento a todos os infectados, o Brasil está paralisado, com seus indicadores de mortalidade e de novas infecções pelo HIV estacionados. O programa brasileiro de aids parou no tempo e não é mais motivo de orgulho nacional.

Computers Can Predict Effects of HIV Policies, Study Suggests (Science Daily)

ScienceDaily (July 27, 2012) — Policymakers in the fight against HIV/AIDS may have to wait years, even decades, to know whether strategic choices among possible interventions are effective. How can they make informed choices in an age of limited funding? A reliable, well-calibrated, predictive computer simulation would be a great help.

A visualization generated by an agent-based model of New York City’s HIV epidemic shows the risky interactions of unprotected sex or needle sharing among injection drug users (red), non-injection drug users (blue) and non-users (green). (Credit: Brandon Marshall/Brown University)

Policymakers struggling to stop the spread of HIV grapple with “what if” questions on the scale of millions of people and decades of time. They need a way to predict the impact of many potential interventions, alone or in combination. In two papers to be presented at the 2012 International AIDS Society Conference in Washington, D.C., Brandon Marshall, assistant professor of epidemiology at Brown University, will unveil a computer program calibrated to model accurately the spread of HIV in New York City over a decade and to make specific predictions about the future of the epidemic under various intervention scenarios.

“It reflects what’s seen in the real world,” said Marshall. “What we’re trying to do is identify the ideal combination of interventions to reduce HIV most dramatically in injection drug users.”

In an analysis that he’ll present on July 27, Marshall projects that with no change in New York City’s current programs, the infection rate among injection drug users will be 2.1 per 1,000 in 2040. Expanding HIV testing would drop the rate only 12 percent to 1.9 per 1,000; increasing drug treatment would reduce the rate 26 percent to 1.6 per 1,000; providing earlier delivery of antiretroviral therapy and better adherence would drop the rate 45 percent to 1.2 per 1,000; and expanding needle exchange programs would reduce the rate 34 percent to 1.4 per 1,000. Most importantly, doing all four of those things would cut the rate by more than 60 percent, to 0.8 per 1,000.

Virtual reality, real choices

The model is unique in that it creates a virtual reality of 150,000 “agents,” a programming term for simulated individuals, who in the case of the model, engage in drug use and sexual activity like real people.

Like characters in an all-too-serious video game, the agents behave in a world governed by biological rules, such as how often the virus can be transmitted through encounters such as unprotected gay sex or needle sharing.

With each run of the model, agents accumulate a detailed life history. For example, in one run, agent 89,425, who is male and has sex with men, could end up injecting drugs. He participates in needle exchanges, but according to the built-in probabilities, in year three he shares needles multiple times with another injection drug user with whom he is also having unprotected sex. In the last of those encounters, agent 89,425 becomes infected with HIV. In year four he starts participating in drug treatment and in year five he gets tested for HIV, starts antiretroviral treatment, and reduces the frequency with which he has unprotected sex. Because he always takes his HIV medications, he never transmits the virus further.

That level of individual detail allows for a detailed examination of transmission networks and how interventions affect them.

“With this model you can really look at the microconnections between people,” said Marshall, who began working on the model as a postdoctoral fellow at Columbia University and has continued to develop it since coming to Brown in January. “That’s something that we’re really excited about.”

To calibrate the model, Marshall and his colleagues found the best New York City data they could about how many people use drugs, what percentage of people were gay or lesbian, the probabilities of engaging in unprotected sex and needle sharing, viral transmission, access to treatment, treatment effectiveness, participation in drug treatment, progression from HIV infection to AIDS, and many more behavioral, social and medical factors. They also continuously calibrated it until the model could faithfully reproduce the infection rates among injection drug users that were known to occur in New York between 1992 and 2002.

And they don’t just run the simulation once. They run it thousands of times on a supercomputer at Brown to be sure the results they see are reliable.

Future applications

At Brown, Marshall is continuing to work on other aspects of the model, including an analysis of the cost effectiveness of each intervention and their combinations. Cost is, after all, another fact of life that policymakers and public health officials must weigh.

And then there’s the frustrating insight that the infection rate, even with four strengthened interventions underway, didn’t reduce the projected epidemic by much more than half.

“I actually expected something larger,” Marshall said. “That speaks to how hard we have to work to make sure that drug users can access and benefit from proven interventions to reduce the spread of HIV.”

Marshall’s collaborators on the model include Magdalena Paczkowski, Lars Seemann, Barbara Tempalski, Enrique Pouget, Sandro Galea, and Samuel Friedman.

The National Institutes of Health and the Lifespan/Tufts/Brown Center for AIDS Research provide financial support for the model’s continued development.

World Bank’s Jim Yong Kim: ‘I want to eradicate poverty’ (The Guardian)

World Bank president says he will bring sense of urgency to efforts to end global poverty in exclusive Guardian interview

Sarah Boseley, health editor, in Washington
guardian.co.uk, Wednesday 25 July 2012 13.48 BST

Jim Yong KimJim Yong Kim, president of the World Bank, speaks at the opening session of the International Aids Conference in Washington on 22 July. Photograph: Jacquelyn Martin/AP

The new president of the World Bank is determined to eradicate globalpoverty through goals, targets and measuring success in the same way that he masterminded an Aids drugs campaign for poor people nearly a decade ago.

Jim Yong Kim, in an exclusive interview with the Guardian, said he was passionately committed to ending absolute poverty, which threatens survival and makes progress impossible for the 1.3 billion people living on less than $1.25 a day.

“I want to eradicate poverty,” he said. “I think that there’s a tremendous passion for that inside the World Bank.”

Kim, who took over at the World Bank three weeks ago and is not only the first doctor and scientist (he is also an anthropologist) to be president but the first with development experience, will set “a clear, simple goal” in the eradication of absolute poverty. Getting there, however, needs progress on multiple, but integrated, fronts.

“The evidence suggests that you’ve got to do a lot of good, good things in unison, to be able to make that happen,” said Kim. “The private sectorhas to grow, you have to have social protection mechanisms, you have to have a functioning health and education system. The scientific evidence strongly suggests that it has to be green – you have to do it in a way that is sustainable both for the environment and financially. All the great themes that we’ve been dealing with here have to come together to eradicate poverty from the face of the Earth.”

Kim, who was previously head of the Ivy League Dartmouth College, is probably best known for his stint at the World Health Organisation (WHO), where he challenged the system to move faster in making Aids drugs available to people with HIV in the developing world who were dying in large numbers. In 2003, he set a target of 3 million people being on treatment by 2005 – thereafter known as “3 by 5”. The target was not met on time, but it did focus minds and rapidly speed up the pace of the rollout, which included setting up clinics and training healthcare staff.

Now, he says, he thinks he can do the same for poverty. “What 3 by 5 did that we just didn’t expect was to set a tempo to the response; it created a sense of urgency. There was pace and rhythm in the way we did things. We think we can do something similar for poverty,” he said.

Asked if he would set a date this time, he said he was sorely tempted, but would not yet. “We don’t know what they will be yet, but [there will be] goals, and counting. We need to keep up and say where we are making successes and why, and when are we going to be held to account next for the level of poverty. If we can build that kind of pace and rhythm into the movement, we think we can make a lot more progress,” he said in his office at the Bank in Washington.

Kim was seen by many as a surprise choice for president. During the election, critics argued there should be an economist at the helm. Some said that, as a doctor, he would focus too much on health.

But Kim, who co-founded Partners In Health, which pioneered sustainable, high-quality healthcare for poor people, first in Haiti and later in Africa, said his three years at the WHO have been the only ones of his career that were solely devoted to health.

“It’s always been about poverty, so for me, making the switch to being here at the Bank is really not that much of a stretch. I’ve been doing this all my life and we’re in a bit of the spotlight because of the stuff we did in healthcare but it was really always about poverty,” he said.

Partners in Health offered HIV and tuberculosis treatment to poor people in Haiti for the first time. “We were trying to make a point. And the point we were trying to make was that just because people are poor shouldn’t mean that they shouldn’t have access to high quality healthcare. It was always based in social justice, it was always based in the notion that people had a right to live a dignified life. The good news is that this place – the Bank – is just full of people like that.”

Kim, who has spent his first weeks talking to Bank staff with expertise in a huge range of areas, strongly believes in the integration of all aspects of development, and says the staff do too. He cites a new hospital Partners built in Rwanda, which led to the building of a road to get there and then the expansion of mobile phone networks in the area. “In a very real sense, we’ve always believed that investing in health means investing in the wellbeing and development of that entire community,” he said.

Speaking to the International Aids Conference in Washington this week – the first World Bank president to do so – Kim told activists and scientists that the end of Aids no longer looked as far-fetched as the 3 by 5 plan had appeared in 2003. Science has delivered tools, such as drugs that not only treat but prevent infection.

But the cost of drugs for life for 15 million or more people is not sustainable, he says. Donors are unlikely to foot the bill. Hard-hit developing countries have to be helped to grow so they can pay for the drugs and healthcare systems they need.

Kim would like the highly active HIV community to broaden its focus. “We’ve had Aids exceptionalism for a long time and Aids exceptionalism has been incredibly important. It has been so productive for all of us,” he said. “But I think that as we go beyond the emergency response and think about the long-term sustainable response, conversations such as how do we spur growth in the private sector have to be part of the discussion.”

Every country wants economic growth, he says, and people want jobs. “If I care about poverty, I have to care a lot about investments in the private sector. The private sector creates the vast majority of jobs in the world and social protection only goes so far,” he said.

Nevertheless, he is a big proponent of social protection policies. “I’ve always been engaged in social protection programmes. But now it is really a signature of the World Bank. We’re very good at helping people look at their public expenditures and we say to them things like, fuel subsidies really aren’t very helpful to the poor – what you really need is to remove fuel subsidies and focus on things like conditional cash transfer plans. The Bank is great at that.”

New to him are climate change and sustainability, he says. “We are watching things happen with one degree changes in ocean temperature that we thought wouldn’t happen until there were two or three degree changes in ocean temperature. These are facts. These are things that have actually happened … I think we now have plenty of evidence that should push us into thinking that this is disturbing data and should spur us to think ever more seriously about clean energy and how can we move our focus more towards clean energy.”

But poor countries are saying they need more energy and we must respect that, he says. “It’s hard to say to them we still do it but you can’t … I think our role is to say the science suggests strongly to us that we should help you looking for clean energy solutions.”