Science hopes to give women new tools against AIDS

Thu Jun 9, 2005 09:16 AM ET

By Andrew Quinn

DURBAN (Reuters) - New HIV prevention treatments for women may be available as early as 2009, a sign of hope for fighting a world AIDS epidemic with an increasingly feminine face, a top researcher said on Thursday.

Microbicides, which women might one day be able to use in gel or cream form to shield themselves from HIV infection, hold some of the best promise for fighting a disease which continues to defy efforts to create a vaccine, said Salim Abdool Karim.

"We need some kind of prevention technology that is designed for and under the control of women," Abdool Karim, of South Africa's University of KwaZulu-Natal, told an AIDS conference in Durban.

"Microbicides can be used completely surreptitiously, it does not need a partner's consent," he said.

U.N. estimates show 60 percent of almost 30 million people with HIV or AIDS in sub-Saharan Africa are women, a proportion growing particularly in societies where women are less able to refuse sex or negotiate condom use with a male partner.

Even female condoms, introduced in an effort to give women more control over their sexual health, have proven less than completely effective as men may sometimes refuse to agree to having sex with a woman who is wearing one, Abdool Karim said.

Microbicides, which use a variety of means to either kill the HIV virus in the vagina, block it from infecting other cells or prevent it from multiplying, could be an important tool and advanced studies are under way in South Africa and elsewhere to assess their effectiveness, he said.

"South Africa has a huge epidemic among younger women and therefore there is a huge need for microbicides in this setting," he said.

South Africa has the world's biggest single HIV/AIDS caseload with over 5 million of its 45 million people infected.

"INVISIBLE CONDOM"

Abdool Karim said initial results from some of the latest and most promising microbicide human trials could be available by early 2008.

If they proved effective, fast-track regulatory approval, manufacturing and distribution could make the treatments available to women within one or two years after that, he said.

AIDS experts estimate microbicides, some of which have names such as "Invisible Condom," could prevent 2.5 million deaths from AIDS over three years.

Abdool Karim, who is overseeing one of five advanced human clinical trials of microbicides, cautioned that it was still too early to say if the treatment would prove effective.

But he said in theory microbicides could protect women from HIV over a period of days, or could be applied after sex as a kind of "morning after pill" to prevent infection.

Microbicide research is complicated because no animal testing can exactly replicate the effects of human treatment.

Researchers only find out how effective their treatment is when they get the sad news that it has failed -- and a test subject has become HIV-positive despite using it.

Abdool Karim said another major obstacle was the lack of involvement by major pharmaceutical companies.

Most microbicide projects are being undertaken by small bio-technology companies, often funded only through donations from groups such as the U.S. National Institutes of Health and the Bill and Melinda Gates Foundation.

"If we were working on a microbicide for men, I'm sure we'd have every big pharmaceutical company involved," he said.

Threatened chimps may hold key to AIDS mystery

Wed Jun 8, 2005 02:43 PM ET

By Andrew Quinn

DURBAN (Reuters) - Chimpanzees may hold vital clues for mankind's war against the AIDS virus, but the apes could be wiped out before they reveal their secrets, a leading genetic expert warned on Wednesday.

Paul Sharp of Britain's University of Nottingham told an AIDS conference in Durban that the latest research indicated that chimpanzees -- humanity's closest living relative -- were an important but increasingly endangered resource for scientists hoping to better understand the HIV virus.

Chimpanzee populations are infected with viruses which closely resemble the HIV-1 strain of the AIDS virus which is most common among humans. Unlike humans, however, chimps do not progress to full-blown AIDS, an intriguing mystery for researchers who hope to discover how to slow or stop the deadly disease in humans.

"If we can understand chimpanzees maybe we can understand more about how the virus affects humans," Sharp said. "Of course, we need to do that before chimpanzees become extinct."

Some researchers fear Africa's chimpanzees could be wiped out in about 50 years -- even earlier for certain species -- because they are hunted for meat and threatened by deforestation and disease.

FOREST HOME VANISHING

One U.N. study last year said that less than 10 percent of the forest home of Africa's great apes will be left relatively undisturbed by 2030 if road building, construction of mining camps and other developments continue at current levels.

Sharp said researchers believed that chimpanzees originally contracted their version of the HIV virus -- known as SIV -- from other monkeys and that, at least initially, they likely suffered from AIDS-like symptoms which may have caused death.

He said it was now believed that either the virus evolved to become less deadly, a scenario he described as unlikely given the long incubation period, or that chimpanzees themselves developed physical strategies for disarming the virus or holding off its impact on their immune systems.

He said this natural coping mechanism may already be starting in some human populations, noting that studies have found isolated but as-yet unexplained instances of individuals where HIV infection does not progress at the same rate as seen in broader samples.

But in order to understand the process more fully, and perhaps find ways to accelerate it, it will be necessary to get a clearer picture of what happens with SIV-infected chimpanzees, he said.

"It gives obvious clues to how you can treat people successfully," he said.

Sharp added that the latest research on the genetic history of the HIV virus confirmed that it most likely first spread to humans in West Africa -- possibly in Cameroon -- as early as the 1930s, although initial cases were so rare that it took decades to establish the true threat posed by the disease.

The virus likely got its first major beachhead in a human population, what viral scientists term the "founder event," some decades later as it arrived in a major urban area, most likely teeming Kinshasa in Democratic Republic of Congo, he said.

But research into HIV history also reveals the astonishing complexity of the virus and its ability to mutate and recombine with other strains -- continually producing "new and improved" versions that outpace mankind's efforts at treatment, he said.

"What we know about how the virus evolves is not very good news for therapies and vaccines ... it is going to be very difficult," Sharp said.

Britain's John Sulston, who pioneered the sequencing of the human genome and won the Nobel prize for medicine in 2002, said politicians must address a fatal imbalance in the current drug development model.

According to the Drugs for Neglected Diseases Initiative, a mere 10 percent of health research resources go into diseases accounting for 90 percent of the global disease burden.

Infectious diseases that kill millions of people in the developing world every year have long been ignored by Western firms, because medicines to fight them make no money.

Recently a number of non-profit groups have been established to kickstart research into areas such as malaria and tuberculosis.

But these entities are largely funded by philanthropic organisations and individual donors, such as the Bill & Melinda Gates Foundation.

"The response remains insufficient with only marginal involvement by wealthier governments," the campaign's organisers said in a statement.

Other supporters of the campaign include Stephen Lewis, the UN Secretary General's special envoy for HIV/AIDS; Nobel literature laureate Nadine Gordimer; and Tido von Schoen-Angerer, head of research and development at medical charity Medecins Sans Frontieres.

They want world leaders, meeting next month at the G8 summit in Gleneagles, Scotland, to make research into neglected diseases a priority.

In addition to extra cash, they are urging governments to overhaul rules to stimulate research.

This should include a new framework that ensures access to knowledge, compounds and research tools currently protected by patents. In addition, the regulatory approval processes should be streamlined to speed delivery of essential medicines.

Drug-resistant TB coming to U.S. from abroad-study

Tue Jun 7, 2005 04:12 PM ET

By Maggie Fox, Health and Science Correspondent

WASHINGTON (Reuters) - Immigrants may be steadily bringing new cases of drug-resistant tuberculosis into the United States, hampering efforts to eradicate the deadly infection, researchers said on Tuesday.

The report, published in a special issue of the Journal of the American Medical Association focusing on TB, showed the need for global control of the ancient disease, the researchers said.

The World Health Organization estimates 2 billion people, or a third of the world's population, have tuberculosis. The disease, which has troubled humankind for thousands of years, kills 2 million people a year.

The AIDS epidemic has fueled a resurgence of TB, which is especially deadly to those with immune systems weakened by HIV. Efforts to treat TB have resulted in mutated forms called drug-resistant TB, which results when patients do not complete months of treatment with a cocktail of antibiotics.

Dr. Reuben Granich of the Centers for Disease Control and Prevention told a news conference that while TB fell overall by 33 percent in California between 1994 and 2003, the proportion of cases that resisted more than two drugs, called multidrug-resistant or MDR TB, remained steady.

His team studied all reported cases of tuberculosis on California, the state with the most cases of TB in the United States.

They looked at the more than 38,000 cases reported across the state over that time, especially the 28,700 tested for resistance to the two mainstay drugs, isoniazid and rifampin.

Of the 28,700 cases, 1.4 percent were resistant to the drugs, meaning a different cocktail would be needed to treat those patients.

That percentage stayed steady over the 10-year period.

IMPORTING DISEASE

Granich also found that 83 percent of the MDR cases were in foreign-born people, who came from 30 different countries.

"We didn't find multidrug-resistant TB was associated with homelessness or using injected drugs or HIV/AIDS or being incarcerated," Granich told a news conference.

Cases were spread across the state, meaning a big expense for some clinics that may not be set up to absorb the costs, or for insurers.

Treating a single case of MDR TB can cost anywhere between $28,217 and $1.2 million.

Only 67 percent of those in the study completed the 18 to 24 months of drug cocktail therapy needed to cure them. Fourteen percent died and 14 percent moved before they could finish -- meaning they could spread their drug-resistant infections to others.

"We need to ensure strong TB programs," Granich said.

Many of the immigrants had been vaccinated. The widely used BCG vaccine helps protect infants and young children against the deadliest effects of tuberculosis, but does not prevent infection and does little for adults.

"We desperately need a new vaccine to protect adults against pulmonary disease," said Chris Dye of the World Health Organization.

In the meantime, there may be cheap ways to prevent infection in the developing world, said Dr. Alison Grant of the London School of Hygiene and Tropical Medicine in London.

Her team gave the antibiotic isoniazid to HIV-infected gold miners in South Africa and found it prevented up to 42 percent of new tuberculosis infections.

"WHO recommends using isoniazid in HIV-positive patients but it is not widely done," Grant told the news conference.

She said her real-world study showed it could work.

TB still claiming two millions deaths a year: studies

DURBAN, June 7 (Reuters) - African countries must move quickly to roll-out public AIDS drug treatment before sufferers become too sick to benefit from it and must persuade people to get HIV tests earlier, a leading specialist said on Tuesday.

Ernest Darkoh, who managed the public anti-retroviral (ARV) drug programme in Botswana from 2002 until late last year, said early testing was key to success in fighting the epidemic.

"We can succeed in delivering large-scale ARV treatment ... You can reach millions of people, largely through existing resources," Darkoh told Reuters on the sidelines of a South African AIDS conference where he was keynote speaker.

Botswana, which has one of the highest HIV-infection rates with almost 40 percent of the adult population infected, introduced public ARV treatment in 2002 and now has close to 40,000 people enrolled out of a population of 1.5 million.

The country, which thanks to its diamond riches is one of Africa's wealthiest, also actively sought international help and received initial funding from foreign donors.

Neighbouring South Africa -- with an estimated five million HIV infections -- is slowly embarking on its public ARV programme, a task more complicated than that faced by Botswana.

EARLY TESTING

But Darkoh said the lessons of Botswana applied to South Africa and other developing countries seeking to implement drug programmes -- chief among them the need to test people early to avoid a sudden deluge of sick people hungry for treatment.

"The issues on the ground, at an operational level, are the same," he said. "You have to wake up and say you are going to do it -- it may take 20 years, but you are going to do it."

Darkoh said Botswana's decision in early 2004 to launch routine HIV testing of incoming patients had made a big difference in catching people before they are too sick to work and become a bigger burden on social services.

"You are overwhelmed at first by the very sick, and they are very resource intensive, if you at least get them while they are still ambulatory, you have a chance," Darkoh said.

Darkoh said 85 percent of those enrolled in Botswana's ARV programme were adhering to the sometimes complicated treatment schedule, a rate surpassing that seen in some Western projects.

The programme, known as Masa or "New Dawn", has an annual budget of about $30 million and has patient costs of between $500-$1,000 per person a year, less than it would have been several years ago but still expensive by African standards.

Darkoh said Botswana had shown that some of the most effective public ARV programmes can be built in cooperation with the private sector, a source of both expertise and funding as countries seek to ramp up the roll-out of ARV drugs and manage supply chains to ensure treatment is uninterrupted.

Botswana's first recipients of ARVs were beneficiaries of a programme run by diamond giant Debswana -- and managed in large part by specialists in Cape Town.

"They succeeded in delivering specialist services through non-specialists on the ground," he said. "That's an interesting model, and one that has wider applications in Africa."

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