Narrator: This is Science Today. Fourteen years into the AIDS epidemic, experts still debate the best ways to prevent transmission of the disease. One proposal has been to test all hospital patients for HIV. Researcher Peter Lurie of the University of California, San Francisco led a group that investigated whether that would be a good idea.

Lurie: We found no justification whatsoever for testing inpatients if the purpose was to protect the health care worker. We estimated that it would cost about 2.7 billion dollars to conduct such a testing program, and that you would only prevent about four infections per year, or 753 million dollars for each infection that you prevented. That does not to us seem like a good way to spend scarce HIV prevention dollars.

Narrator: Instead, Lurie advocates funding needle exchange programs for drug users. Lurie led another group that looked at such programs around the world.

Lurie: From city to city, from country to country, there is evidence of decreases in the sharing of syringes, which is what transmits HIV infection from one drug user to the next.

Narrator: The result, says Lurie, is an overall decrease in the transmission of AIDS. For Science Today, I'm Steve Tokar.