Wednesday September 19 2:28 PM ET

Diaphragm, Microbicide Proposed as HIV Barrier

By Karla Gale


NEW YORK (Reuters Health) - Because the diaphragm protects the cervix and upper reproductive tract, which are vulnerable to infection, it could be an effective HIV prevention method when combined with microbicide, researchers suggest.

Another important advantage of the diaphragm, said Dr. Nancy S. Padian of the University of California at San Francisco and associates, is the fact that it is controlled by women.

``Widespread violence against women, double standards of sexual behavior, and the imbalance of power in many sexual partnerships make methods initiated and controlled by women critically important,'' the authors write in the September 7th issue of the journal AIDS.

The cervix is far more vulnerable to infection than the surface of the vagina, the researchers note. The top layer of cells covering the cervix is thinner and more friable, or subject to crumbling, than that of the vagina, and it is in the cervix that receptors required for HIV infection are concentrated, the authors point out.

Padian's team also notes that a cervical barrier can prevent virus particles from being transported into the fallopian tubes and peritoneal cavity by uterine contractions.

The investigators comment that the expense associated with the use of a diaphragm, because it is reusable, would probably be ``substantially lower than the cost of female condoms, and perhaps not much more expensive than male condoms.''

They add that because diaphragms are worn completely inside the vagina, they are viewed by men and women as more acceptable than condoms. In fact, most men cannot discern when their partner is wearing a diaphragm, protecting women from accusations of ``cheating, of being 'loose' women, or of accusing their partners of infidelity.''

In an interview with Reuters Health, Padian noted, ''Diaphragms in this country fell into disfavor with the advent of the (oral contraceptive) pill. Because of that, people think women won't want to use them.'' She suggested that now diaphragms should be weighed against male and female condoms.

Padian and her colleagues are in the process of conducting an acceptability study in Zimbabwe. She noted, ``The acceptability seems to be much greater than we thought it would be. We're not promoting this as a method that offers protection (against HIV). But for women who are unable to use condoms, we say, 'This might offer protection.'

``Even in that very tenuous promotion of it they're willing to use it,'' she said. ``Women are desperate for methods they can use to protect themselves.''

Padian acknowledged that no one knows whether the diaphragm in conjunction with a microbicide is as effective as a condom in preventing HIV transmission. ``Our point is that the evidence is sufficient to take the issue to the next level and do the studies,'' she said.