CHAPEL HILL - Scientists have discovered high levels of HIV, the virus that causes AIDS, in the saliva, spinal fluid, semen and vaginal fluid, as well as in the blood, of patients newly infected by the virus, according to a new medical study. They believe their work suggests an important strategy for curbing the worldwide epidemic.
"The levels we found were as high or higher than those we see in people with long-standing infection," said Dr. Christopher D. Pilcher, assistant professor of medicine at the University of North Carolina at Chapel Hill. "But our patients had all been infected within the previous three months. Their body fluids had high concentrations of virus even within two to three weeks of the beginning of symptoms."
Flu-like symptoms are often the first signs of the deadly infection during the first weeks after first contracting HIV, the period scientists call "primary HIV infection." These symptoms are far less debilitating than those patients with full-blown AIDS experience and can include fever, muscle aches, rash, swollen glands and, sometimes, sore throat, Pilcher said. Those symptoms sent the 17 patients to the doctor for treatment in the first place.
A second key finding was that virus levels, which scientists call "viral load," dropped rapidly in all fluids analyzed after doctors began treating patients with the latest drugs, he said. Earlier, the UNC team and other researchers proved the drugs worked during chronic infections, but their effect on primary infection was unknown.
"Together, these findings suggest that combination anti-retroviral therapy -- the HIV 'cocktail' therapy -- is a potential avenue for public health intervention," Pilcher said. "In other words, such treatment could become a public health strategy to reduce shedding of virus from semen and vaginal fluid especially and possibly reduce the number of people contracting the virus to begin with."
Such a strategy might help curtail the epidemic by augmenting current prevention efforts involving education, treatment of other sexually transmitted diseases, condom distribution and tracing sexual partners, the physician said. However, one hurdle to diagnosing very early infections is that routine antibody tests to HIV are likely to be negative during this period. It's necessary to use other, more sophisticated tests such as polymerase chain reaction to directly detect the presence of the virus during primary HIV infection. Those more revealing tests were used to screen patients for the new study.
A report on the research appears in the current issue of the journal AIDS.
Co-authors of the report at UNC are Dr. Diane C. Shugars, Dr. Susan A. Fiscus, Dr. Kevin R. Robertson, Dr. Joseph Eron, Prema Menezes of the UNC schools of medicine and dentistry. Other authors are Dr. Charles C. Hicks and Julieta Giner of Duke University, Dr. Jeffrey L. Lennox and Beth Dean of Emory University and Dr. Clyde E. Hart of the Centers for Disease Control and Prevention.
For the past several years, medical scientists have focused heavily on early infection with HIV because it offers a window into the nature of the virus' attack on the body, Pilcher said. "We have wanted to know how quickly the virus gets into various body fluids, how widely it attacks different organs and what that says about ways the virus enters the body," Pilcher said. "In addition, there's also been the suspicion that primary HIV infection is a time of important infectiousness."
Therefore, a second goal has been to learn whether virus is shed specifically into genital and oral fluids during early infections because those fluids are the primary vehicles of sexual transmission of HIV, he said. The new findings, which involved 17 patient volunteers, show that conclusively. "Our results are not surprising since they are basically what those of us who study primary infection would have expected, but they've not been demonstrated before," Pilcher said. "This is fundamental information that has been very difficult to get in the past because it's extremely difficult to make this early diagnosis. You have to be suspicious enough to test for it and not just believe that a person has mononucleosus or the flu."
Another reason these studies are difficult, he said, is that researchers rarely have reason to ask patients suffering flu-like symptoms to donate semen, spinal fluids and other fluids.
A fairly large group of AIDS researchers now believe primary infection with HIV might drive the AIDS epidemic, the physician said. Primary infection might be a time of heightened infectiousness or even the peak of infectiousness.
"The Centers for Disease Control and Prevention and other public health agencies have not emphasized efforts to diagnose primary infection as part of prevention in the past," he said. "If primary infection is driving the epidemic, we'll need to pay a lot more -- and earlier -- attention to it. Our study provides the strongest direct evidence yet that patients are infectious during primary HIV infection, and that may be another reason to reconsider public health efforts to identify people early."
The National Institutes of Health, Roxane Pharmaceuticals and Bohringer-Ingelheim supported the research.
Materials provided by University Of North Carolina At Chapel Hill. Note: Content may be edited for style and length.
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