CAPE TOWN, South Africa — Southern African countries marked World AIDS Day on Sunday with hopes that the region, which has the highest rate of HIV positive people on the planet, can slow the spread of the disease.

There are 42 million HIV positive people worldwide, with sub-Saharan Africa home to 75 percent of them, according to UNAIDS, the U.N.’s AIDS agency.

South Africa has more HIV positive people than any other country in the world. Figures released by the government more than two years ago showed that 4.7 million people — one in nine — were infected, and the figure today is believed to be substantially higher.

The number of people with AIDS in Asia threatens to reach epidemic levels, and activists there also tried to raise awareness of the disease and how to prevent it. Events were also held in Cuba, Brazil, Peru and several other countries.

South Africa’s government had come under fire for not doing enough to combat the AIDS epidemic, and it has recently shown signs of taking the issue more seriously.

This year the government almost tripled its anti-AIDS budget to $108 million, and plans to up to $194 million in the next financial year.

Tony Leon, leader of the main opposition Democratic Alliance, said South African women’s average life expectancy would fall from 54 to 38 over the next 10 years and over 2 million children would be orphaned by AIDS.

“South Africa’s fight against AIDS has been massively hampered and harmed by government’s dithering, denial and dissent from the orthodoxies associated with the disease,” he said.

President Thabo Mbeki has questioned the link between HIV and AIDS in the past, but kept from commenting on the issue over the last few months.

Countries across Asia commemorated World AIDS Day with events to raise awareness of the disease amid warnings that the number of infected people in China and India, the world’s two most populous nations, will reach epidemic levels.

Carrying banners and signs, thousands took to the streets in Hanoi and Bangkok on Sunday to promote AIDS awareness. India staged a marathon to raise public knowledge of the disease, while Beijing’s imposing legislative hall hosted an awareness event.

“Silence is death when it comes to fighting HIV/AIDS,” said Jordan Ryan, the U.N. resident coordinator in Vietnam, at a rally in Hanoi that drew 3,000 people. “It’s time to tear down the walls of stigma and silence.”

The United Nations has estimated that at the end of 2001, 6.6 million people throughout Asia were living with HIV or AIDS, including about 1 million newly infected that year.

In India, where some 4 million people are infected with HIV, officials in the eastern city of Bhubaneshwar on Sunday unfurled a record-long 3.7-mile-long banner to mark the day.

In Thailand, a prison in Thailand opened its doors to family and friends of inmates in the final stages of the disease, the Bangkok Post newspaper reported Sunday.

World AIDS day events were low-key in most southern African countries.

In Malawi, where about 9 percent of the population is HIV positive, the government warned that AIDS was decimating the civil service and the economy.

“Every day we are burying our workers, our teachers, our doctors and other professionals,” Vice President Justin Malewezi said in a statement issued together with the findings of a new study on the impact of AIDS in Malawi.

The study found that high schools had to replace 77 percent of their staff every year because teachers die or are too ill to work.

In politically troubled Zimbabwe, President Robert Mugabe acknowledged that 2.2 million of the country’s 13 million people were HIV positive, and that 700,000 children had been orphaned by AIDS.

“The impact of this tragedy has been such that each and every one of us knows of a relative, a loved one or a friend who has either died of the epidemic or is living with it,” he said.