Scientists studying biology and geography may seem worlds apart, but together they have answered a question that has defied explanation about the spread of the HIV-1 epidemic in Africa.

Writing in the September issue of AIDS, a research team led by scientists at the University of Florida explained why two subtypes of HIV-1 - the virus that causes acquired immunodeficiency syndrome, or AIDS - held steady at relatively low levels for more than 50 years in west central Africa before erupting as an epidemic in east Africa in the 1970s.

Essentially, the explanation for the HIV explosion - obscured until now - involves the relative ease with which people can travel from city to city in east Africa as opposed to the difficulties faced by people living in the population centers of the Democratic Republic of Congo, the point where HIV emerged from west central Africa in its spread to the east.

Later, as the epidemic raged in the east, cities in the Democratic Republic of Congo - a vast country almost as big as all of Western Europe - remained disconnected and isolated, explaining why the virus affected only about 5 percent of the country’s population, a level that has not changed much since the 1950s.

“We live in a world that is more interconnected every day, and we have all seen how pathogens such as HIV or the swine flu virus can arise in a remote area of the planet and quickly become a global threat,” said Marco Salemi, an assistant professor of pathology, immunology, and laboratory medicine at the UF College of Medicine and senior author of the study. “Understanding the factors that can lead to a full-scale pandemic is essential to protect our species from emerging dangers.”

Investigators used databases, including GenBank from the National Center for Biotechnology Information, as well as actual DNA samples, including samples recently collected in Uganda - the vicinity where HIV entered east Africa - to follow the virus’ molecular footprints since its emergence in the 1920s.

“HIV mutates rapidly,” said Rebecca Gray, a postdoctoral associate in the department of pathology, immunology and laboratory medicine. “This is a successful strategy for the virus, because it evolves quickly and develops drug resistance. But we can use these changes in the genome to follow it over time and develop a history of its progress.”

Researchers wanted to know why, the virus smoldered during the 1950s and `60s, before spreading like wildfire through east Africa in the 1970s.

A fateful piece of the puzzle came in the form of geographic information system data, which uses satellite imagery and painstakingly takes into account the availability and navigability of roads between population centers, transportation modes, elevation, climate, terrain and other factors that influence travel.

“We were able to use geographic data to interpret the genetic data,” said Andrew J. Tatem, Ph.D., an assistant professor of geography in the College of Liberal Arts and Sciences and a member of UF’s Emerging Pathogens Institute. “Genetic data showed once HIV moved out of the Democratic Republic of Congo, it expanded fast and moved rapidly across Uganda, Kenya and Tanzania, all while staying at low levels in the DRC. What was happening was the virus was circulating at stable levels in the urban centers of the DRC, but these centers were isolated. Once it hit east Africa, connectivity between population centers combined with better quality transportation networks, and higher rates of human movement caused HIV to spread exponentially.”

HIV was prevalent in about 15 percent of the population in Kenya in 1997, although it has since dropped to about 7 percent, according to the Kaiser Family Foundation. As of 2007, an estimated 22 million people were living with HIV/AIDS in sub-Saharan Africa. About 1.1 million Americans have HIV or AIDS, and an estimated 5.1 million people in India are HIV-positive. In Eastern Europe, HIV infections more than doubled from 420,000 in 1998 to 1 million in 2001.

“If we can predict the specific routes of an epidemic, we can find the geographic regions more at risk and target these areas with medical intervention and strategies for prevention,” Salemi said. “In terms of health-care applications, coupling genetic analysis with geographic information systems can give us a powerful tool to understand the spread of pathogens and contain emerging epidemics.”

Working with Maureen M. Goodenow, Ph.D., the Stephany W. Holloway university chair for AIDS research at the UF College of Medicine, UF researchers collaborated with an array of scientists hailing from the National Institute of Allergy and Infectious Diseases, the Rakai Health Sciences Program and Makerere University of Uganda, and the Johns Hopkins University. They refer to the combination of techniques that led to the discovery as “landscape phylodynamics.”

“It is the first study that has given us a clear picture of epidemic history of HIV in east Africa, including the geographic routes and the time scale that it occurred,” said Oliver Pybus, Ph.D., a researcher in the department of zoology at Oxford University who did not participate in the study. “Genetic analysis of the HIV genome provides the family tree of the virus, combined with spatial analysis of high-resolution data of land use, topology and other factors. There is a huge potential in doing that kind of analysis, but it requires a rare combination of specialists in different fields to come together.”

Source:
John Pastor

University of Florida

The international medical humanitarian organization Doctors Without Borders/Medecins Sans Frontières (MSF) today called on nine of the world’s largest pharmaceutical companies to help accelerate the availability of new treatments for millions of people living with HIV/AIDS, by pooling their patents on a list of key HIV medicines.

A patent pool is a mechanism in which a number of patents held by different parties are brought together and made available to others for production or further development. Patent holders receive royalties paid by those using the patents. The mechanism has been instrumental in promoting innovations in the aeronautics and digital telecommunications industries, for example.

Make It Happen - Help Us Get HIV Drugs in the Pool

“It’s a simple idea: companies share their knowledge in return for fair royalty payments,” said Michelle Childs, director of policy and advocacy at MSF’s Campaign for Access to Essential Medicines. “But it has the potential to transform companies’ approaches to access to HIV medicines and foster innovation in a way that marks an alternative to the confrontation and litigation of the past.”

UNITAID, the international drug purchasing agency, is currently establishing a medicines patent pool for HIV drugs. Critical to its success will be the willingness of patent owners to participate, by including their patent rights in the pool.

“The scheme is voluntary, so companies have a choice — and today we’re asking them to make that choice,” said Childs. “This is an opportunity for these drug companies to demonstrate that they are genuinely committed to effective measures that allow access to life-saving medicines for people with HIV in developing countries. Some companies have expressed interest in the idea, but we need them to go further and put key patents in the pool.”

For people living with HIV/AIDS, the impact could be considerable. A patent pool could speed up the availability of more affordable versions of new medicines, as generic production could begin well before the 20-year patent terms expire. Currently, patent barriers can also prevent innovation such as new pediatric formulations or much-needed fixed-dose combinations.

“This opportunity comes at a crucial time,” said Dr. Eric Goemaere, medical coordinator for MSF in South Africa. “Many patients in our programs have developed resistance to their medicines and need to switch to newer, more effective drugs now. Because these are either unavailable or unaffordable, patients face a return to AIDS death row as treatment options dry up.”

MSF is launching an e-mail writing campaign calling on Abbott Laboratories, Boehringer Ingelheim, Bristol-Myers Squibb, Johnson & Johnson, Gilead Sciences, GlaxoSmithKline , Merck & Co, Pfizer, and Sequoia Pharmaceuticals to meet the promise afforded by this mechanism and put their HIV drug patents in the pool.

Click here for the list of drugs that MSF is calling for to be included in the UNITAID patent pool, and to learn more about each medicine.

MSF currently treats over 140,000 people living with HIV/AIDS in 30 countries.

Source
Doctors Without Borders/Medecins Sans Frontières

More than 4 million people in low- and middle-income countries were receiving antiretroviral therapy (ART) at the close of 2008. This represents a 36% increase in one year and a ten-fold increase over five years, according to a new report released today by the World Health Organization (WHO), UNICEF and the Joint United Nations Programme on HIV/AIDS (UNAIDS).

Towards Universal Access: Scaling Up Priority HIV/AIDS Interventions in the Health Sector highlights other gains, including expanded HIV testing and counselling and improved access to services to prevent HIV transmission from mother to child.

“This report shows tremendous progress in the global HIV/AIDS response,” said WHO Director-General Margaret Chan. “But we need to do more. At least 5 million people living with HIV still do not have access to life-prolonging treatment and care. Prevention services fail to reach many in need. Governments and international partners must accelerate their efforts to achieve universal access to treatment.”

Treatment and care

Access to antiretroviral therapy continues to expand at a rapid rate. Of the estimated 9.5 million people in need of treatment in 2008 in low- and middle-income countries, 42% had access, up from 33% in 2007. The greatest progress was seen in sub-Saharan Africa, where two-thirds of all HIV infections occur.

Prices of the most commonly used antiretroviral drugs have declined significantly in recent years, contributing to wider availability of treatment. The cost of most first-line regimens decreased by 10-40% between 2006 and 2008. However, second-line regimens continue to be expensive.

Despite recent progress, access to treatment services is falling far short of need and the global economic crisis has raised concerns about their sustainability. Many patients are being diagnosed at a late stage of disease progression resulting in delayed initiation of ART and high rates of mortality in the first year of treatment.

Testing and counseling

Recent data indicate increasing availability of HIV testing and counselling services. In 66 reporting countries, the number of health facilities providing such services increased by about 35% between 2007 and 2008.

Testing and counselling services are also being used by an increasing number of people. In 39 countries, the total reported number of HIV tests performed more than doubled between 2007 and 2008. Ninety-three percent of all countries that reported data across all regions provided free HIV testing through public sector health facilities in 2008.

Nevertheless, the majority of those living with HIV remain unaware of their HIV status. Low awareness of personal risk of HIV infection and fear of stigma and discrimination account, in part, for low uptake of testing services.

Women and children

In 2008, access to HIV services for women and children improved. Approximately 45% of HIV-positive pregnant women received antiretroviral drugs to prevent HIV transmission to their children, up from 35% in 2007. Some 21% of pregnant women in low and middle-income countries received an HIV test, up from 15% in 2007.

More children are benefiting from paediatric antiretroviral therapy programmes: the number of children under 15 years of age who received ART rose from approximately 198 000 in 2007 to 275 700 in 2008, reaching 38% of those in need.

Globally, AIDS remains the leading cause of mortality among women of reproductive age. “Although there is increasing emphasis on women and children in the global HIV/AIDS response, the disease continues to have a devastating impact on their health, livelihood and survival,” said Ann M. Veneman, UNICEF Executive Director.

Most-at-risk populations

In 2008, more data became available on access to HIV services for populations at high risk of HIV infection, including sex workers, men who have sex with men and injecting drug users.

While HIV interventions are expanding in some settings, population groups at high risk of HIV infection continue to face technical, legal and sociocultural barriers in accessing health care services.

“All indications point to the number of people needing treatment rising dramatically over the next few years,” said Michel Sidibe, Executive Director of UNAIDS. “Ensuring equitable access will be one of our primary concerns and UNAIDS will continue to act as a voice for the voiceless, ensuring that marginalized groups and people most vulnerable to HIV infection have access to the services that are so vital to their wellbeing and to that of their families and communities.”

Source
UNICEF