African women who were testing a gel or a pill to protect them from the AIDS virus weren’t able to use either consistently enough to tell if they worked, researchers reported Monday.

The news is a disappointment to the field, especially since an earlier study suggested the gel could really lower the infection rate.

“The bottom line is the women were not using the products,” Jeanne Marrazzo of the University of Washington in Seattle told a news conference. And the women who were the least likely to use the pills or gel as directed were those most at risk – young women under 25, who weren’t married and may have had multiple sex partners.

The findings are “disappointing,” Marrazzo told a meeting of AIDS researchers in Atlanta called the Conference on Retroviruses and Opportunistic Infections.

Researchers have been trying for years to find good ways that women, especially, can use to protect themselves from the human immunodeficiency virus that causes AIDS. More than 60 percent of adults newly diagnosed with HIV in Africa -- where the epidemic is worst -- are women infected by husbands and other male sex partners.

Studies have shown that microbicide gels or creams can work -- at the last AIDS conference in Vienna in 2010, researchers reported on one that reduced a woman’s risk of infection by 39 percent. And other studies have shown that taking a daily AIDS drug in pill form can also protect people at high risk -- such as the spouses and partners of infected people. The trials have worked well in some countries, but not others. Experts fear inconsistent use may be one problem.

The trial reported Monday confirms these fears.

Marrazzo and colleagues tested three different approaches in more than 5,000 women in Uganda, South Africa and Zimbabwe. They tried two pills containing HIV medicines and a vaginal gel. After the study started in 2009, 312 of the 5,029 women became infected – an infection rate of 5.7 percent. That was almost double the rate the researchers had expected.

“The women who were most likely to take the drugs were women who were older than 25 and who were married,” Marrazzo said. They were probably the women at the lowest risk, but because so few women used the gel or took the pills as directed, the researchers couldn’t really tell anything about how well the drugs worked.

"No intervention is going to be effective if it's not used,” Dr.  Zvavahera Mike Chirenje of the University of Zimbabwe in Harare, who helped direct the study, said in a statement.

Researchers are looking for approaches that won’t require people to remember to take a pill or use a gel every single day. One team has begun a trial of a device called a vaginal ring impregnated with dapivirine, a drug used to treat people with HIV. Researchers will enroll 3,500 women in the two-year study to be conducted in Africa. Women could insert the ring and not think about it for as long as a month at a time.

Products that are long-acting, such as the dapivirine vaginal ring … and that women use for a month at a time, may be more suitable for this vulnerable population,” said Sharon Hillier of the University of Pittsburgh School of Medicine, who is helping to lead that trial.

The AIDS virus infects 34 million people globally and has killed 25 million more, according to the United Nations. Every year, more than 2 million more people are infected. There’s no vaccine and no cure, although cocktails of strong drugs can keep patients healthy, and low doses of certain drugs can help prevent infection.

Related news:

• Baby free of HIV, but is it a cure?
• The female faces of HIV
• How microbicides might work

Shawn Thew / EPA

US Secretary of State Hillary Clinton appeared on a large video screen at the 19th International AIDS Conference this week. Many presentations target women, who make up more than a quarter of new HIV infections in the U.S.

Del’Rosa Winston thought she’d done everything right. She kept herself in steady employment, and waited until she was married to start having children. When her marriage ended, she started having regular HIV tests, just in case. So when she settled into a new, steady relationship, she never dreamed she’d end up infected with the AIDS virus.

“I had a job. I had been in the military. I was educated,"  said Winston, a soft-spoken, well-groomed woman with fashionably cropped red hair. "I just got it from a straight man in a monogamous relationship."

More than a quarter of new infections in the United States every year are in women, and of the 1.1 million Americans with the AIDS virus, 280,000 are women, according to the Centers for Disease Control and Prevention. Black women are especially vulnerable – their infection rate is 15 times the infection rate for white American women.

Winston’s smooth skin and easy smile represent the hidden face of the AIDS epidemic in the United States – the people who don’t look like “typical” HIV patients. The 50-year-old mother of three hopes that speaking out at the 19^th International AIDS Conference, being held in Washington, D.C., will help reduce the stigma and ignorance that fuel the spread of the virus.

 “There are so many people who are getting it because they loved someone,” Winton told NBC News in an interview. Winston couldn’t wait to be in a steady, safe relationship so she could stop using condoms, which she found uncomfortable to use. Her boyfriend, who has since died, told her he had no idea he was infected. But he was, and so was Winston. “We didn’t fit the parameters of what an HIV-positive person looked like,” she said.

She can remember the moment in 1990 when she was told her test came back positive. “The room was gray,” she said. “Like stainless steel. I know there were objects in it but I couldn’t see them. I just flowed like water to the floor.”

Health experts at the conference say they are trying to find new and better ways to reach not only the people at the highest risk – young gay and bisexual men – but others, like Winston, who may not intuitively know how easily and insidiously the virus can move during a moment of passion.  “Everyone’s at risk, whether you have the greatest trust relationship or not,” Winston, who now works as an HIV counselor in Atlanta, said.

Health experts are also trying to figure out some of the factors that make women vulnerable and keep them from protecting themselves even if they do understand the risks. Winston has some ideas – women are often too busy looking after others. “We put everyone else first – kids, school, even the PTA. We get into the mind frame that we don’t have to care for ourselves,” she said.

Another factor may be domestic abuse. A team at the University of California San Francisco published a study on Monday showing that physical and sexual abuse and trauma are major factors affecting which women become infected.

“For a long time we have been looking for clues as to why so many women are becoming infected with HIV and why so many are doing poorly despite the availability of effective treatment,” said Dr. Edward Machtinger, who led the study. “Women who report experiencing trauma often do not have the power or self-confidence to protect themselves from acquiring HIV.”

Their team did a study called a meta-analysis, looking at data from other studies involving 5,900 women. They found 30 percent of women infected with HIV had post-traumatic stress disorder, or PTSD, compared to 5 percent of the general population.  Twice as many women with HIV reported they had been victims of partner violence as women without the virus, they found.

Kat Griffith thinks she knows why. The slender redhead from Peoria, Illinois has been HIV positive for 21 years and she blames a violent boyfriend from high school. “I had a jealous and controlling partner who called me names, demeaned me,” she said. “I had no self-esteem.”

But Griffith went away to college and, she thought, started a fresh new life. “I knew that HIV could affect me and I thought I asked all the right questions,” she said. “But my abuse made me feel I was not worthy of protection." Her college boyfriend infected her.

Women may often put others first but they also lack a good way to protect themselves, Griffith noted.

For years, researchers have been looking for ways to protect women against the virus. There’s been hit-and-miss progress with microbicides – gels or creams that women can use quietly to reduce the chance they’ll become infected during sex. On Tuesday, researchers will announce the start of an advanced, Phase 3 trial of a device called a vaginal ring impregnated with dapivirine, a drug used to treat people with HIV. Researchers will enroll 3,500 women in the two-year study to be conducted in Africa, where half of all HIV patients are women.

Studies have shown that microbicide gels or creams can work - at the last AIDS conference in Vienna in 2010, researchers reported on one that reduced a woman’s risk of infection by 39 percent. But other studies haven’t done so well and experts fear inconsistent use may be one problem.

A flexible, silicone ring may be easier to use and less intrusive than a gel that must be applied before and after sex, the researchers hope. So does Griffith. “After 30 years, we still do not have a completely female controlled prevention technique,” she said.