Doctor Tiger.

A team of American scientists has discovered a molecule that could block transmission of HIV, the virus that causes AIDS.  Researchers say the preventive agent might someday be used in a topical cream to help prevent infection with the deadly virus.

Scientists have long known that after the HIV virus enters the human body, it struggles to gain a foothold.  But a naturally occurring protein in the male’s seminal fluid, called SEVI, makes the virus 100-thousand times more infectious than it would otherwise be, aiding HIV’s ability to attach itself to its victim’s white blood cells and in so doing, destroy the host immune system.

Now, US investigators have discovered that a molecule called surfen can interfere with SEVI’s action. Warner Greene is the director of the Gladstone Institute of virology and immunology in San Francisco, California, where the test-tube studies have been conducted.

“What we have found is this small molecule by the name of surfen can block SEVI binding to HIV virions [viruses] and thus interrupt the infectious cycle or the transmission cycle,” said Warner Greene.

Greene says surfen, first described by scientists back in 1939, is both an anti-inflammatory and anti-bacterial agent. He explains that surfen prevents infection by binding itself to both the AIDS virus and to the blood cells targeted by HIV. 

Research into topical medications know as microbicides – creams and gels containing anti-HIV agents that are usually applied before sexual intercourse – has been disappointing, and the method has not been effective preventing the spread of the AIDS virus.  But Greene is hopeful surfen will make a difference.

“I think that the concept of using agents that target not only the virus but the host factor propelling the virus infection – I think that combination might produce a therapeutic synergy [enhanced interaction] that could be quite effective,” he said.

Greene says similar so-called “cocktail” therapies have proved to be effective weapons in treating AIDS patients.

“Just as we use combination anti-retroviral therapy to treat patients with HIV infection, we might be able to prevent transmission of HIV using combination microbicides,” said Greene.

Warner Green and colleagues describe surfen’s anti-AIDS properties in the current issue of  the Journal of Biological Chemistry.

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PRASADA RAO

Doctor Tiger

A top United Nations official says much of the Asia-Pacific region is nearing full treatment coverage for patients with HIV. But Prasada Rao warns access to remote regions in China and India, and disrupted AIDS programs in Pakistan and Afghanistan leave millions at risk.

The departing head of the U.N. AIDS program in the Asia-Pacific region, Prasada Rao, says the region is within three years of “winning the battle” against the AIDS pandemic.

Rao, who has led the U.N. AIDS program in the region for the past five years, says increased treatment coverage and intervention programs are turning the tide against AIDS. 

In Thailand and Cambodia treatment coverage has reached almost 90 percent. In India 50 percent of patients get treatment, but in China the number stands at 30 percent and 35 percent in Burma.

By 2012, up to 2013, I can see that we’ll start winning the battle around that time. And by 2015 – this is the Millennium Development Goal of halting and reversing the epidemic – I can say that the majority of countries in this region would be in a position to say that ‘yes’ we can halt and reverse the epidemic,” he said.

In South and Southeast Asia the rate of new HIV infections has fallen by more than 10 percent since 2001, thanks to an increase in prevention and treatment programs. But there are still 4.7 million people living with AIDS in the region and around 350,000 new infections each year.

Rao acknowledges that concerns remain, especially because of problems expanding AIDS programs in remote locations in China, India and Indonesia. 

Indonesia’s Papua province and neighboring Papua New Guinea have seen cases rise sharply in the past few years. The U.N. predicts that by 2012 about five percent of Papua New Guinea’s population will be infected with HIV, the virus that causes AIDS – more than 208,000 people.

“The most challenging to me is the Papua New Guinea scenario where I think it’s not just the reachability [of treatment programs] that is important but the strength of the health system itself  by which it delivers services – it is a big question,” he said. 

Other problems facing the U.N. AIDS program in Asia include the fighting in Afghanistan and Pakistan, which blocks access to remote areas. But Rao says the U.N. is able to work elsewhere in Pakistan with the support of the central and provincial governments.

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