A volunteer working to persuade South Africans not to discriminate against H.I.V.-infected people was beaten to death last week by her neighbors, who accused her of bringing shame on their community by revealing that she was H.I.V.-positive.
The killing scared other anti-AIDS advocates, who said it proved what they have said for years -- although three million South Africans are infected with the virus that causes AIDS, nearly all are afraid to admit it because of the hostility they face.
The slain woman, Gugu Dlamini, 36, a volunteer field worker for the National Association of People Living With H.I.V./AIDS, went public on World AIDS Day, Dec. 1, speaking about her H.I.V. infection on Zulu-language radio and on television.
Since then, according to nurses who knew her, she was repeatedly threatened by neighbors in her township of KwaMashu, outside Durban, who said she was giving their community a bad reputation. Last Monday, she was punched and slapped by a man who told her that many others who were sick kept quiet about it.
South Africa has the world's fastest-growing AIDS epidemic, according to the latest U.N. AIDS reports, and KwaZulu-Natal, where Ms. Dlamini lived, is the worst-hit province, with 30 percent of adults infected.
Although Ms. Dlamini called the police that day, they did nothing, friends told a local newspaper. That night, a mob attacked her house and stoned her, kicked her and beat her with sticks. She died the next day.
"She was a nice, bright woman, and now her child is an orphan because of AIDS," said Mercy Makhalemele, a Durban-area administrator for the association. "But not because she died of it. Because she was trying to exercise her constitutional right to freedom of speech."
Prudence Mabele, the first black South African woman to admit being H.I.V.-positive, said she was threatened many times after coming forward in 1994. She moved out of her township into downtown Pretoria largely out of fear, she said. A gay San Francisco group wrote letters to her local police station then, and it seemed to help. "But I just don't know if people should come out now," she said today.
Kevin Osborn, a former local leader of the association, said he thought the killing would "put the cause of people with AIDS two steps back."
Ms. Makhalemele said she was not sure, thinking it might galvanize anger in the small activist community.
They have an uphill task. The head of the association, Peter Busse, said last month that fewer than 100 of the country's 3 million infected people were completely open about it.
"When something like World AIDS Day comes around, we have trouble finding 20 people to go on television and radio shows," he said.
Ms. Dlamini's death is not going to galvanize much right now. American-style activism about AIDS does not exist in South Africa, and all the association's chapters are closed for Christmas-summer vacation.
"I'm waiting for Jan. 4. to make a big hoo-hah about this," Ms. Mabele said. Ms. Makhalemele said she hoped to have a protest march in Ms. Dlamini's memory by late March.
A spokesman for the KwaZulu-Natal health department called the attack "sheer stupidity" and Deputy President Thabo Mbeki, who promoted AIDS awareness in his Christmas message to the nation, said: "It is a terrible story. We have to treat people who have H.I.V. with care and support, and not as if they have an illness that is evil."