Culminating his party’s momentous shift on AIDS, a disease that has led to plunging life expectancies here, President Jacob Zuma has definitively rejected his predecessor’s denial of the viral cause of AIDS and of the critical role of antiretroviral drugs in treating it.

Almost 10 years to the day after President Thabo Mbeki first suggested that AIDS drugs could pose “a danger to health” in an Oct. 28, 1999, speech in Parliament, Mr. Zuma declared in the same chamber, “Knowledge will help us to confront denialism and the stigma attached to the disease.”

In a country that now has more HIV-infected people and annual AIDS deaths than any other, Mr. Zuma’s clarion call for a battle against the disease, six months into his term as President, led to rejoicing among advocates who had long sought such national leadership.

Mr. Zuma said in his address: “All South Africans must know that they are at risk and must take informed decisions to reduce their vulnerability to infection or, if infected, to slow the advance of the disease. Most importantly, all South Africans need to know their HIV status, and be informed of the treatment options available to them.”

After Mr. Mbeki’s ouster from the presidency a year ago by his own party, the African National Congress, which has governed the country since 1994, a caretaker president appointed a new health minister, Barbara Hogan, who said in an interview that what she called “the era of denialism” was over.

Dr. Aaron Motsoaledi, her successor as Health Minister under Mr. Zuma, has accepted the government’s responsibility for past failings and begun charting a more comprehensive approach to the AIDS crisis here.

Plain-spoken national leadership has proven critical to combating the disease in Uganda, Kenya and Botswana — and disastrous where it was lacking, as here in South Africa. Harvard researchers estimated that South Africa could have prevented 365,000 premature deaths if it had acted sooner to provide antiretroviral drugs to treat people with AIDS and to prevent HIV-positive women from infecting their newborns.

In his speech, Mr. Zuma laid out the horrifying toll of AIDS in South Africa.

Overall deaths registered in South Africa in 2008 jumped to 756,000 from 573,000 the year before.

The electoral commission had to remove 396,336 dead voters from the rolls in September 2008 and August 2009. Life expectancy for South African men is 51, compared with 70 in Algeria and 60 in Senegal, said Mr. Zuma.

“These are some of the chilling statistics that demonstrate the devastating impact that HIV and AIDS is having on our nation,” he said. “Not even the youngest are spared.” And though the country now has a strategy to fight the disease and the largest antiretroviral treatment program , he said: “We are not yet winning this battle. We must come to terms with this reality as South Africans.” — © 2009 The New York Times News Service