A report in medical journal The Lancet, reveals another disappointing find in the search for a device to curb HIV infection in women.
Nancy Padian, executive director of the UCSF Women's Global Health Imperative, and team say that the 'female condom' used in conjunction with the male condom is in no way superior to the latter, in preventing infection by HIV virus.
The team, also part of the Methods for Improving Reproductive Health in Africa (MIRA), did a randomized trial of almost 5,000 sexually active, HIV-negative women in South Africa and Zimbabwe.
"Although the intervention seemed safe, our findings do not support addition of the diaphragm to current HIV-prevention strategies", the researchers write.
This trial was part of the $37-million clinical trial funded by the Bill and Melinda Gates Foundation in Africa. The news that the diaphragm, a sort of contraceptive device worn tightly to shield the cervix, failed to prevent HIV infection, is the latest in a growing list of disappointing efforts to curb the AIDS menace.
The study was the most closely watched HIV prevention trial for women since January, when researchers abruptly ended studies of a vaginal gel meant to block the virus after early results showed the women who used it had a slightly higher risk of becoming infected.
A similar trial testing whether the contraceptive jelly nonoxynol-9 might work as an anti-HIV microbicide, failed in 2000, when the study revealed that prostitutes in South Africa who used it had a significantly higher infection rate than those who were given an inactive placebo gel.
"It's very, very disappointing, of course," Padian was quoted.
"We were hoping to find a protective effect. ... It's taken me a long time to get over how devastating this is", she added.
Researchers are desperately seeking a low-cost method that women could use (without the consent of male partners) to protect themselves against HIV.
The study was conducted in Durban and Johannesburg, South Africa, and in Harare, Zimbabwe. It enrolled nearly 5,000 women ages 18-49 and followed them an average of 18 months. Half of the women were given diaphragms and a gel lubricant, while the other half were not. Both groups were also given condoms and extensive counseling to have their partners use them.
By the end of the study, HIV infection rates were high and almost identical: about 4 percent of the women in each arm of the study were infected per year. Infections were found in 158 women given diaphragms and condoms and counseling; 151 women were infected among those given condoms and counseling only.
Accordingly, about 20 percent of adults are infected in Zimbabwe and South Africa, where the experiment was conducted. Women there run twice the risk of infection as men. In cultures where women are traditionally subservient to men, they have less of a say about matters of sex - when to have it, whom to have it with, and whether condoms or other safer sexual practices will be used.
Padian said one of the more surprising and disappointing results was that the women provided diaphragms reported using them only 70 percent of the time. That finding nevertheless provides valuable information about the importance of monitoring compliance in complex trials such as this one, she says.
Since 1994, Padian and her team of researchers had been exploring the possibility that diaphragms might protect against the AIDS virus. The theory held that the cervix - which can be shielded from semen by a diaphragm - is the most vulnerable part of the female reproductive tract to HIV infection.
Yet now, the diaphragm in the use of HIV-prevention, may well be history. Padian was quoted that the diaphragm does not " warrant being used as a protective device now".