AIDS Virus Highly Infectious Early On
HIV most virulent at the start, new study shows
WEDNESDAY, May 23, 2001 (HealthDayNews) -- Even if you test negative on a standard HIV test, that doesn't guarantee you're safe.
A new study found that HIV levels in semen, which transmits most AIDS infections, are highest when the disease first strikes your system.
Drug treatment did reduce the amount of the virus in newly infected patients, the study also shows. But the findings are bad news because ordinary HIV tests don't detect the virus until months after infection.
"Some people who are HIV-negative when they get tests in the doctor's office will very likely already be sexually infectious," says Dr. Christopher D. Pilcher, assistant professor of medicine at the University of North Carolina and a co-author of the study.
Researchers studied 17 patients who went to doctors because of flu-like symptoms and, through a sophisticated test, discovered they were HIV-positive. The results are reported in the current issue of the journal AIDS.
Within two to five weeks after infection, HIV-infected patients often come down with fever, muscle aches, swollen glands and sore throats. The symptoms seem to appear when the body's immune system begins to kick in and fight the virus, Pilcher says.
"It's a time of intense immune activity," he adds.
Researchers found that the HIV levels in the semen, vaginal fluid and saliva were about 10 times higher in the earliest stage of the infection than in another group of patients who had later stages of AIDS. The higher levels corresponded to differences in the virus levels in the blood of the two groups.
In the United States, HIV is mainly transmitted through semen, whether from men to men or men to women. It's not necessary that the non-infected partner have an opening in the skin where the semen can enter, Pilcher says. Contact with mucous membranes is enough for transmission to occur.
The study also found that the virus level in spinal fluid was 30-40 times as high as in long-term patients, he says. Researchers looked at spinal fluid because some scientists think the virus may lie in wait there in the early days of infection, Pilcher adds.
The findings support epidemiologists and public-health officials who believe that people in the first stages of infection are a "sort of engine driving the epidemic," he says.
That's not surprising, considering that patients still feel healthy at that time, says Carl Dieffenbach, who studies AIDS at the National Institute of Allergy and Infectious Diseases.
The virus simply takes a very long time to "wear out the immune system," he says. "It just points to this being a slowly debilitating disease."
Dieffenbach and Pilcher both say the research confirms the importance of raising awareness of how HIV is spread and how to protect yourself.
What To Do
"People need to make very certain that you know not just the HIV-antibody-test status of your partner, but also that you've been with them long enough to be confident of their sexual history," Pilcher says. "Even in the face of a negative antibody test, if you don't know that you're in a monogamous relationship, you should be having safe sex."
If you suffer from flu symptoms a few weeks after an unsafe sexual encounter, see your doctor.
For information about AIDS transmission, visit this fact sheet created by the Centers for Disease Control and Prevention.
Learn more about HIV testing at the National AIDS Treatment Information Project.
You also might want to read previous HealthDay articles on AIDS.
To find out what clinical trials are being done on AIDS, check Veritas Medicine.