By DAVID WILLIAMSON
UNC-CH News Services
CHAPEL HILL -- Rigorous analysis of the latest evidence on sexual transmission of HIV -- the virus that causes AIDS -- has identified three major factors that should be targeted to help curb the deadly epidemic, researchers say.
Other sexually transmitted infections, overlapping sexual relationships and having sex with people newly infected all significantly boost spread of HIV and urgently deserve more attention from government and health workers, according to the scientists.
"We are dealing with a major-league epidemic in this country, and it turns out that three of our best players are still on the bench," said Dr. Rachel A. Royce, assistant professor of epidemiology at the University of North Carolina at Chapel Hill. "We know that promoting sexual abstinence and male condom use and reducing the number of sexual partners all work, but these are not enough.
"Attention must focus on finding and treating other sexually transmitted diseases," Royce said. "We also must find people who recently have become HIV-infected to break the chain of transmission and emphasize the message that having several different sexual partnerships at the same time is particularly dangerous."
A paper on the findings appears in Thursday's (April 10) issue of the New England Journal of Medicine.
Researchers conducted an exhaustive computer search of thousands of scientific papers and analyzed 97 key studies of the HIV epidemic, including mathematical models of how it spreads.
"Seventy-five to 85 percent of the nearly 28 million HIV infections that have occurred worldwide have been through sexual contact," Royce said. "Although recent advances in treating HIV disease have led to a decline in the number of AIDS cases being diagnosed -- because fewer HIV-infected people are progressing to AIDS -- HIV continues to infect many people. Despite public health efforts, cases of newly infected people are increasing in the United States, especially among women and young people."
The scientists found evidence that:
- Having a sexually transmitted disease (STD) such as gonorrhea, herpes or syphilis makes contracting and passing on HIV up to seven times more likely. Significantly more AIDS virus can be found in genital secretions of people with other STDs than among those without them.
- People recently infected with HIV are more likely to transmit the virus than those infected longer.
- Multiple, overlapping sexual relationships boost odds of infection.
Renewed commitment to fund local and state health departments adequately is crucial, especially in rural areas where access to care and resources may be inadequate, she said.
"We need to use all the tools on hand to have the best shot at stopping HIV transmission," she added. "It is much safer and more effective to prevent HIV infections than to treat people once they become infected."
Besides Royce, a School of Public Health faculty member, co-authors are Drs. Myron S. Cohen and Arlene Sena, chief and fellow, respectively, of infectious diseases at the School of Medicine and Dr. Willard Cates Jr. of Family Health International and epidemiology at UNC-CH.
The authors disagreed with the suggestion elsewhere in the journal by Drs. Mitchell Katz and Julie L. Gerberding that people be treated with preventive drugs following unsafe sex or needle sharing.
"There are potential dangers to any such recommendations in the absence of hard data because the medicines are expensive and have side effects," Cohen said. "This approach might encourage unsafe behavior with the tenuous idea that there is an effective prevention for infection after exposure."
The U.S. Centers for Disease Control and Prevention, the National Institute of Diabetes and Digestive and Kidney Diseases and the UNC Lineberger Comprehensive Cancer Center were among the organizations supporting the UNC-CH research.
Note: Royce can be reached at (919) 966- 7440 (w) or 968-8593 (h). Cohen's number is 966-2536.
Contact: David Williamson