By Christopher Vaughan

A unique teleconference last week enabled researchers from the United States and Africa to share and compare strategies for preventing children and infants from being infected with HIV -- the AIDS virus.

The Nov. 21 teleconference was organized by Stanford researcher Yvonne Maldonado, with support from the Centers for Disease Control and Prevention in Atlanta and the California Department of Health Services.

"This was a one-of-a-kind event," said Maldonado, MD, an associate professor of pediatrics. "This sort of international teleconference has never been conducted before."

Maldonado said the international linkup was a cost-effective way to bring together about 100 researchers and field workers across two continents. "The teleconference cost less than bringing 10 people together physically," she said.

The other advantage was that it brought together the foot soldiers in the fight against AIDS -- the physicians and public-health field workers who are in direct contact with at-risk women. Field workers encourage the women to get tested, and women of childbearing age who have the virus are urged to take drugs that block transmission of HIV to their babies.

"The cost of getting people to international conferences is high and field workers are seldom able to attend," Maldonado said. "We can't have a top-down approach to these problems. Everyone is part of the effort, but ultimately it is the people in the field who get the job done. Without them you can have the greatest scientific ideas in the world and it won't help."

Maldonado said the field workers in Zimbabwe and the United States found it useful to compare effective strategies. For instance, women in both countries are often hesitant to get tested for HIV, but field workers have found that the women are more responsive when they understand the benefits to their unborn babies.

Field workers have also found that the AIDS prevention message must be refreshed periodically in order to be effective. "If the same message is used for a long period, people start blocking it out," Maldonado said.

The differences between the two nations can be huge, however. For one thing, the HIV infection rate in California women is about 0.6 per 1,000, and many infected women are intravenous drug users or sexual partners of men at risk for HIV. In Zimbabwe the infection rate among women of childbearing age is 300-400 per 1,000, and most of them contract the disease through heterosexual contact, Maldonado said.

An even greater difference is the social context of HIV testing. "In Zimbabwe women are much more hesitant to be tested because a positive test can literally be life-threatening," Maldonado said. "Their husbands may blame the women for bringing the infection into their family."

The teleconference was transmitted over the Internet between Harare, Zimbabwe, and five U.S. sites: San Francisco, the Atlanta CDC offices, Los Angeles, Minneapolis and Washington, D.C. Maldonado would like to do a satellite teleconference next, although it would cost about twice as much.

Organizing the teleconference was the latest effort in Maldonado's years-long battle against pediatric AIDS. After graduating from Stanford School of Medicine in the 1980s, she studied public health at Johns Hopkins University and then worked as an investigator at the CDC in Atlanta before returning to Stanford. Maldonado was the Stanford principal investigator in a clinical trial of perinatal HIV prevention in Zimbabwe as well as principal investigator of a joint effort by California and the CDC to monitor and prevent pediatric AIDS in the state.

Maldonado said that unlike the 1980s, when 2,000-3,000 new cases of pediatric HIV infections were reported in the United States each year, research and prevention efforts have helped reduce the rate to about 200-250 new cases annually.

She said she hopes the U.S. success in preventing pediatric AIDS can be repeated in Africa. "We hope to be able to bring effective preventive therapies while allowing infected women to breastfeed."

Although health workers have made few inroads in AIDS prevention in Africa generally, they have had great success in pediatric AIDS prevention, Maldonado said. "If we can implement these programs effectively we can have a huge effect on the next generation's rate of infection."