Shortly after dawn on April 13, dozens of women gathered on a sandy street between shacks of raw wood and corrugated metal in the Khayelitsha township outside Cape Town, South Africa. Many wore the T-shirts of Free Gender, a local black lesbian rights organization. They were there to bury one of the group's members, Nomawabo Mahlungulu, who was known to her friends as Wawa. She died of AIDS on March 30.

Just after 7 a.m., the undertaker brought Mahlungulu's body from where a family member had watched it through the night, in keeping with Xhosa tradition. A group of men carried the simple wooden casket down the narrow lane to her family's house, which had metal walls painted a pale pink. An unframed 8-by-10 snapshot of Mahlungulu hung opposite her casket. Mourners crowded into the windowless room, which seemed to grow darker as the hot sun climbed in the sky. Many others spilled into the alleyway, dancing during the songs that punctuated the speeches and sermons in Xhosa.

The speeches contained a good deal of recrimination, and not just for the members of Mahlungulu's family who had shunned her. The deep stigma against HIV in South Africa has a particular bite among lesbians, and many who knew Mahlungulu believe this cost her the support network needed to help her fight the virus.

Mahlungulu had been HIV-positive for 10 years and had been active with the national organization Treatment Action Campaign, which campaigns for the rights of those with HIV and AIDS. Yet she had mystifyingly stopped keeping up with her medical treatment.

"One thing that I become worried [about] is our behavior as lesbians," said Funeka Soldaat, Free Gender's founder who's been an advocate in the township for more than 20 years, during an interview before the funeral.

A recent study found that around 10% of women who have sex with women in four southern African countries are HIV-positive. The study suggests that the main source of infection among lesbians is likely rape. Women are sexually assaulted in South Africa more often than almost anywhere in the world, and lesbians are often targeted out of the belief that it will "cure" them of same-sex attraction. And their trauma is often compounded when they seek help from police or health care workers after they've been attacked, keeping them from getting tested or treated for HIV.

But despite this fact, HIV also raises suspicion among lesbians that a woman has betrayed the community by choosing to have sex with men. And this can cause the support network women have struggled to build to evaporate.

Lesbians in her community, Soldaat said, feel they "can have that support system that's so great when your people assume that you are [HIV-]negative, and when you are [HIV-]positive you can't get that system anymore."

Muhlungulu's death raised concerns for lesbian activists across the country.

"She's left us with a lot of questions," said Nokhwezi Hoboyi during an interview in Johannesburg. Hoboyi has held leadership positions in the Treatment Action Campaign and helped found its LGBTI-interest caucus. She now works with the Forum for the Empowerment of Women.

Hoboyi was not close with Mahlungulu nor did she know the details of how she died, but her story echoed the experience of other lesbians Hoboyi knew fighting HIV.

"Understanding the stigma within lesbian relationships attached to being HIV positive... [I wonder,] what if the circle of lesbian women she was around were not the kind of women who understood that a lesbian woman could have HIV?" Hoboyi said. "Maybe she was scared to take her pills among her friends, maybe she was not comfortable, she had not disclosed her HIV status... I've got a lot of what ifs."

Rape occurs more frequently in South Africa than almost anywhere in the world, with more than 54,000 cases reported to police each year in a country with a population of less than 50 million. (Thousands more likely go unreported.) Lesbians are often targeted for what is often called "corrective rape." Although there are no accurate statistics on how frequently this occurs in South Africa, almost one in three women surveyed by the HIV study reported having been survivors of "forced sex" and these women were more likely to be HIV-positive.

Clinic workers and police often share the same homophobic attitudes as the attackers in these cases — a survey by the Human Sciences Research Council found 80% of South Africans disapprove of homosexuality even though the country has some of the world's most extensive legal protections for gays and lesbians. With those attitudes so prevalent in the country, rape survivors often are afraid to go to clinics to get medication to prevent contraction of HIV immediately after their assault and sometimes avoid getting tested at all.

Women who participated in a "Health Dialogue" sponsored by the Cape Town-based, LGBTI-services organization the Triangle Project reported being mocked by clinic workers or even being assaulted when they sought treatment.

"They said lesbians deserve this... I won't go back," said one woman, according to meeting notes taken by the group's acting director, Sharon Cox Ludwig, and told to BuzzFeed. The woman reported that clinic workers said to her, "[Lesbians] are from the devil. God did not make women for this. We are not acting like women."

But other sex with men may also be contributing to HIV. Though it is sensitive to talk about, the HIV study found that sex with men was not uncommon even among those who describe themselves as lesbians. In this survey, 76.2 percent identified themselves as lesbians. But almost half said they had engaged in consensual sex with a man at least once; one out of five said they'd done so in the last year.

This doesn't necessarily mean all these women experience opposite-sex attraction. They could have sex with men out of pressure to be straight; one in 10 of the women surveyed are married to men or have been in the past. And 18.6% of the women surveyed reported having engaged in "transactional sex," the trading of sex for money, food, or something else.

These circumstances push that sexual activity underground, lesbian activists say, making it harder to get them to engage in safe sex.

"They don't talk about it—they hide it from their friends," said Ntsupe Mohapi, who heads the grassroots LGBT organization EPOC — the Ekurhuleni Pride Organizing Committee — in a township outside of Johannesburg. "It's hard to practice safe sex … if you do something behind close doors."

Mohapi adds that the problem is compounded by the fact that transactional sex often occurs when women are most vulnerable and unable to insist on protection — when they are supporting a drug or alcohol habit or have no money for food.

There is also a lot of hostility toward women who are bisexual, said the Forum for the Empowerment of Women's Hoboyi, who has had relationships with both men and women. Some believe that bisexuals make lesbians more vulnerable to rape because they confirm the perception that even women who date women are secretly attracted to men.

"Especially now in an era in South Africa where there's a lot of hate crimes, some lesbian women feel that women who date men and women, or who are attracted to men and women, are the ones who [cause] men to target lesbian women," Hoboyi said.

Mohapi said she sees the same in her township.

"The problem that we're facing even now is that in the gay community [bisexuals] are not accepted very easily," she said. Lesbians may turn their backs on them saying, "You're going to put us in danger."

The layered issues that HIV raises makes it harder to get lesbians to practice safe sex with their female partners. Those who know their status may be afraid to tell their partners, and asking someone to use protection may imply you suspect they have been choosing to have sex with men.

Even those who want to practice safe sex can have a very hard time getting protection. Dental dams and other safe-sex supplies for lesbians are very hard to come by and can be expensive. Free condoms are widely available and can be cut into barriers for oral sex, but lesbians open themselves up to humiliation by asking for them at public clinics.

"There's a lot of, 'Why, what are you gonna do with it?'" from clinic staff when a lesbian asks for safe-sex supplies, said Hoboyi. "That's why lesbian women are very reluctant to go to clinics and ask for any protection."

The climate makes life very difficult for lesbian and bisexual women and very frustrating for lesbian, bisexual, and HIV activists.

These women regularly bury women who have lost their lives in homophobic assaults and fighting an incredibly difficult campaign to try to get authorities to take the threat of hate crimes seriously. They are burying still more whose lives are cut short by HIV. At the same time, though, many of those HIV-related deaths seem to result from the stigma that remains not confronted within their own community.

Just as lesbians ask their families and communities to be accepting of them, they must be accepting of those who are HIV-positive, Soldaat said during Mahlungulu's funeral.

"The reality is lesbians are HIV-positive," she said. "The reality is lesbians are so in denial."

J. Lester Feder is a BuzzFeed contributor and a 2013 Alicia Patterson Foundation journalism fellow. Additional reporting and translation contributed by Martha Qumba.