Healthy Women At Greater Risk of Contracting HIV Than Previously Thought

The deadly HIV virus and disease leave the body totally defenseless against many illnesses that would otherwise be mild in healthy people, making each one life threatening for victims. It attacks the immune system, and shuts down its effectiveness against anything from pneumonia to even the common cold. The victim has no way of combating the illness. HIV enters and destroys white blood cells, leading to a collapse of the immune system, and finally to AIDS.

There are several common ways a person can be put at risk for contracting HIV. The virus can be passed on through perinatal contact, meaning that children born to women infected with HIV can also become infected with the virus. In addition, blood-to-blood contact, meaning that your blood comes in to contact with someone else’s, as well as sharing previously used needles or syringes. And, of course, having unprotected sex certainly makes you a target for the disease. You can get HIV whether you have anal, oral, or phallic sex. What all of these risks factors have in common is that they are associated with some type of body fluid.

Until now, researchers have assumed that HIV searched out breaks in the skin, such as a herpes sore, as a route to infiltrate immune system cells located deeper in the tissue. In women, it was even believed by some that a normal vaginal tract lining provided a barrier against the disease during sexual intercourse. However, scientists have recently discovered that HIV attacks the normal, healthy genital tissue of women. This finding offers new insight into how the AIDS virus spreads. The study findings were presented at the American Society for Cell Biology annual meeting, in San Francisco.

Professor Thomas Hope, from the Feinberg School of Medicine at Northwestern University, and colleagues, studied vaginal tissue that was introduced to HIV viruses labeled with photo-activated fluorescent tags. The tissue samples were taken from tissue recently removed during hysterectomy surgeries.

In only four hours, the laboratory studies showed that viral particles had moved between skin cells, reaching a depth of 50 microns, which is similar to the width of a human hair, and were able to pursue immune cells. During normal turnover and shedding of skin cells, the cells are not as tightly bound together, which allows viral particles to get between them and begin the assault on immune cells.

According to Professor Hope, “This is an unexpected and important result. We have a new understanding of how HIV can invade the female vaginal tract. Until now, science has really had no idea about the details of how sexual transmission of HIV actually works. The mechanism was all very murky.” He offered that this could also explain why certain preventative efforts have failed in the past.

Hope also acknowledged that if confirmed in future studies, these findings, could help in the development of new microbicides and vaccines designed to protect women against HIV. “We urgently need new prevention strategies or therapeutics to block the entry of HIV through a woman's genital skin,” he said. In addition, although condoms are proven to be100 percent effective in preventing HIV, Hope noted, “people don't always use them, for cultural or other reasons.”

According to the U.S. Centers for Disease Control and Prevention (CDC), U.S. HIV cases most often involve men who have sex with men, yet, females account for 26 percent of all new HIV infections. Based on CDC’s last analysis conducted in 2005, an estimated 56,300 people were newly infected with HIV with 31 percent being due to high-risk heterosexual contact.