Aggressive, early anti-viral therapy might provide a way to derail the spread of AIDS, a battle where a successful vaccine remains elusive.
Called "test-and-treat," the goal is to catch new AIDS cases early and administer therapy to reduce the amount of virus in patients' systems in an effort to prevent them from spreading the illness.
While anti-retroviral therapy has increased in the last five years it has often been given too late in the course of infection. By the time people start therapy they have infected most of those that they would have infected anyway, Brian Williams of the South African Centre for Epidemiological Modelling and Analysis told the annual meeting on the American Association for the Advancement of Science on Saturday.
And the National Institutes of Health is now looking at testing the strategy in the United States.
Some 40 million people are infected with HIV/AIDS worldwide and the plague continues to spread, researchers said.
"The problem is we are using drugs to save lives, we're not using them to prevent infection," Williams said. Much of the spread of the infection is by people who are not yet aware they have the virus.
Even in the United States, 20 percent to 25 percent of infected people don't know it, added Dr. Kenneth H. Mayer of Brown University. They can be highly infectious if they engage in risky behavior, he said.
Aggressively testing people for HIV and then launching treatment with anti-retroviral drugs could set up a roadblock to the spread, Williams said.
Indeed, Mayer noted that Dr. Anthony Fauci of the U.S. National Institute of Allergy and Infectious Disease recently announced a series of initiatives including studies of test-and-treat in Washington, D.C. and New York City.
Early treatment can reduce the load of virus in the blood to one ten-thousandth of what it would be otherwise. Such a drop makes the carrier just one-twenty-fifth as likely to pass on the infection, Williams said. Such a reduction could help break the cycle of infection, he said.
Once treatment is started it's a lifetime commitment, Mayer added.
The test-and-treat idea was suggested by the World Health Organization and the programs in the Bronx and Washington are aimed at seeing if the idea can work in the real world.
"NIAID already is conducting several studies designed to answer the key research questions that underpin the test-and-treat concept," Carl Dieffenbach, director of NIAID's Division of AIDS said in a statement. "Through this partnership, NIAID is working with the Centers for Disease Control and Prevention to design a study to answer whether implementing a combined strategy of expanding HIV testing, diagnosing infection early and bringing HIV-infected patients to medical care and treatment is feasible."
Meanwhile, Dennis R. Burton of the Scripps Research Institute in La Jolla, Calif., told the AAAS meeting that while no successful AIDS vaccine has been developed, he remains optimistic.
Tests in monkeys have been encouraging and researchers continue their vaccine work, he said.
