Common Infection Raises Female to Male HIV Risk

It’s long been known that bacterial vaginosis, or BV, increases a woman’s risk of getting HIV. Now, research shows an HIV positive women, who also has the bacterial infection, has a three-fold greater risk of transmitting the AIDS virus to her male partner.

“BV is a condition where the normal vaginal flora, which is predominately Lactobacilli, get replaced by abnormal vaginal flora, predominantly anaerobic bacteria. There’s a large number of species that are associated with BV. It’s not a single bacteria that causes BV, but it’s multiple numbers of these abnormal vaginal flora that replace normal vaginal flora,” said Dr. Craig Cohen, lead author of the story.

Cohen is professor of obstetrics, gynecology and reproductive sciences at the University of California at San Francisco. He said women can be infected and not know it.

“Most women are asymptomatic. The most common symptom among those who do have symptoms is abnormal vaginal discharge, usually an increased vaginal discharge. Some women will complain of a smell or odor, especially after intercourse,” he said.

Despite the infection being so common in women, the cause still hasn’t been pinpointed.

“That we don’t know,” said Cohen, “and that’s one of the calls in the papers that we really need additional research. We know risk factors for BV, there are many, but we don’t know what actually causes it. It’s so common in Africa, for example, where in some populations between one-third and 50 percent of women live with this. It really beckons the question of what’s normal.”

There are a number of theories and hypotheses as to the cause. One is that the bacteria are transmitted to the man and cause inflammation, making him more susceptible to HIV transmission.

Cohen said there are treatments for bacterial vaginosis, but the effects don’t last very long.

“While they will reduce the symptoms in about 70 to 80 percent of women using metronidazole-- or otherwise known as Flagyl either orally or topically – within a 3 to 6 month period of time about 60 to 70 percent of women will actually have a recurrence of BV,” he said

Cohen and his fellow researchers said new treatments need to be developed. These include more effective drugs and possible use of probiotics or bacteria considered beneficial to people.

The study was published in the June 26 issue of PLos Medicine and was funded by the Bill and Melinda Gates Foundation.