Experts on AIDS said Wednesday that it is highly unlikely Greg Louganis could have transmitted the human immunodeficiency virus to anyone when he struck his head on a diving board and bled into a pool during the Seoul Olympics in 1988.
Louganis, a former member of the Mission Viejo Nadadores, will reveal on Friday that he has AIDS and that he did not tell anyone he tested positive for the disease before the Olympic Games.
Doctors said the dilution of the virus in water, combined with the effectiveness of chlorine, make the likelihood of transmission of the virus in any swimming pool extremely remote.
"This would be something posing negligible risk, approaching zero," said Dr. Peter J. Katsufrakis, director of clinical training for the AIDS Education and Training Center at USC.
Other experts agreed.
"This is 1995, we've had years and years of experience (with HIV). It just doesn't happen that way," said Dr. Steven Miles, an assistant professor of medicine at UCLA Care Center, a clinical AIDS research and education center.
Miles said that a small amount of chlorine--1.5 parts per million--inactivates the virus, probably within seconds.
Even if the virus survived in sufficient quantities to be infectious, he and other experts said, it still would have to find some means of entering the bloodstream of an uninfected person for transmission to occur.
"You'd have to imagine a scenario where he bled off the diving board and somebody else came along and got an injury (causing an open wound) and instantly the virus got into the wound before the chlorine inactivated it," Miles said.
"That's why there are no documented cases" of HIV transmission in a swimming pool, Miles said.
Transmission through mucous membranes in a swimmer's mouth or nasal cavities is also unlikely, experts said.
"A number of studies of transmission by kissing have suggested this is an extremely inefficient means of transmission," said Dr. James W. Mosley, a professor of medicine at USC who has studied HIV transmission over the past decade.
Several experts said they also considered it unlikely that HIV would be transmitted in contact sports, though the risk is there and precautions are wise.
Miles, for example, said it is prudent to ensure that bleeding players stay on the sidelines and that any blood spilled is promptly cleaned up. But he said transmission of HIV, a relatively fragile virus outside the body, does not pose as great a risk as other blood-borne diseases such as Hepatitis B.
Others said sports officials in general have overreacted to the threat of HIV.
"I think the danger in physical contact sports has been greatly overstated," Mosley said. "There are just no cases that I know of that can be attributed to the sport itself.. . . I think there have been a few suspected cases, but none really demonstrated."
Requirements and recommendations in sports include:
* HIV-antibody testing is mandatory in some states, including Nevada and California, for boxers. Some states require ringside "seconds" to wear plastic gloves.
* In professional basketball, hockey and and rugby, the rules of the game require that a player who has an open or bleeding wound must leave the playing field until such time as the bleeding is controlled and the wound covered or dressed. Trainers must wear gloves while treating the wound. Many high school football leagues across the country have implemented similar procedures for treating wounds.
* Health professionals have recommended that water-impervious gloves, and, if necessary, eye shields, should be available for staff use when handling blood or other body fluids visibly contaminated with blood. If gloves are not available, use a bulky towel to cover the wound until a location is reached where gloves are available. Hands should be washed after glove removal.
* Blood-contaminated items, including gauze, bandages and towels, should be placed in receptacles separate from other waste containers.
* Many professional sports leagues, including the NFL and the NBA, have distributed AIDS fact sheets and other educational supplements. The National Federation of State High School Associations has also taken initiatives to distribute information about AIDS and sports.