The campaign against AIDS marks an important anniversary this week, bringing to mind victories of science and the human spirit but also defeats, stigma and ignorance in a combat that has claimed more lives than World War I.

On May 20 1983, in a paper published in the US journal Science, a team from France's Pasteur Institute, led by Luc Montagnier, described a suspect virus found in a patient who had died of AIDS.

Montagnier's groundbreaking work led to the determination by US researcher Robert Gallo that the virus was indeed the cause of acquired immune deficiency syndrome (AIDS).

At last, a key had been found to understanding the mysterious immune-ravaging disease -- the "gay plague" as British tabloids smugly called it -- which had surfaced among American homosexuals two years earlier.

It took another three years to resolve a spat over the pair's rival claims to be first to discover the AIDS virus, enabling the duo to share equally in the glory.

The mood was upbeat.

Never had a new, killer pathogen been identified so quickly.

Stoked by the success of antibiotics and the polio vaccine, optimism was brimming that this threat would now be stopped in its tracks.

"Today's discovery represents the triumph of science over a dreaded disease," the then US health secretary Margaret Heckler declared, when Gallo staked his claim on the virus discovery in April 1984.

"We hope to have a vaccine ready for testing in about two years."

Few promises have been so tragically premature.

When Heckler uttered those words, the tally of known cases of AIDS was less than 3,000.

Today, the number stands at 25 million dead, heterosexual and homosexual alike, and another 33 million infected.

The scale of human misery, though, is incalculable. A ragged army of more than 11 million children have lost one or both parents to the disease.

So what happened?

"In the field of AIDS, a huge number of mistakes have been made over the past 25 years," sighs a leading French researcher, Olivier Schwartz.

On the plus side, the men and women in lab coats made good headway against HIV.

They provided an arsenal of drugs that, with the advent of the triple "cocktail" of antiretrovirals in the mid-1990s, have helped turn HIV from a death sentence to a manageable disease.

But there is still no vaccine, for the virus has turned out to be an unimaginably slippery, mutating foe -- quite possibly the most elusive pathogen to have emerged in human history.

Attempts to make an HIV-thwarting vaginal gel, or microbicide, have been similarly frustrating.

Thus, in the 21st century, the main shield against HIV is the rubber condom, invented in the 19th century -- or sexual abstention, which is timeless.

Then there was catastrophic delay, among politicians, policymakers, religious leaders and the public too, about rooting out the taboo, stigma, myth and complacency in which AIDS proliferates.

This work still remains dangerously incomplete.

In China, India and the countries of the former Soviet Union, the peril remains of the virus leaping from niches of infection among drug users, homosexuals and prostitutes to a mainstream epidemic.

Even more culpable was the horrific wait, of nearly a decade, before antiretrovirals started to fall sharply in price and become available to sub-Saharan Africa, where two-thirds of people with HIV or AIDS live.

Price is no longer the big problem. Political denial and lack of infrastructure to distribute the precious drugs are.

"In Africa, not even 10 percent of the people who need treatment are getting it," says Schwartz, noting that for every person in low- or mid-income countries who began receiving antiretrovirals in 2006, six new people became infected.

The UN Millennium Goals and G8 pledges testify that political commitment on AIDS is strong and that the world is now aware that novel infectious diseases are everyone's problem. No country, however strong or secure its borders, is secure.

Billions of dollars are being marshalled by the Global Fund, and the United States, under President George W. Bush, has boosted its spending on AIDS emphatically.

But to meet the goal of universal access to AIDS treatment and care by 2010 would require a quadrupling of funds to an estimated 42 billion dollars annually, if overhauling healthcare systems is included, according to some estimates.

Today, the terror of AIDS that prevailed 25 years ago has disappeared -- but so has the burning optimism.

"I would have preferred to celebrate the anniversary of the end of the epidemic than of the publication" of the isolation of the virus, Montagnier told AFP.

Lars Kallings, a Swedish microbiologist who is the founding president of the International AIDS Society, gives a bleak assessment: "HIV/AIDS may never disappear from mankind."

The abused and orphaned children in Pastor Julius Bonani's church are the face of an AIDS epidemic that is killing nearly 1,000 South Africans a day and infecting even more.

And yet, the 18 children who live in Bonani's heartbreak home, in a shanty town filled with dust and despair, also personify a tortuous journey toward hope in the country most affected by the AIDS crisis. After a decade of denial under a president who has disputed the cause of AIDS and a health minister who thinks garlic is a remedy, there is growing political will to tackle the crisis.

The challenges are overwhelming. An estimated 5.4 million of South Africa's 48 million people have the virus — the highest total of any country. But after years of pressure from activists, South Africa now boasts the world's biggest AIDS treatment program.

The number of people receiving therapy has more than tripled in just two years, from 143,000 in March 2006 to 456,000 at the end of February, according to government statistics. That's still only half the estimated 900,000 who have developed full-blown AIDS and need treatment, but a national plan launched a year ago aims to provide care and treatment to 80 percent by 2011 and halving the number of new infections.

Some 40,000 children nationwide are receiving AIDS drugs, including the 18 in Bonani's church — children such as Thandiswa, who was found sucking at the wizened breast of her dying mother, her dead twin at her side. And Abina, who still bears the scars of cigarettes her drunken father extinguished on her skin in fury that she had HIV. And Siphosethu, who was abandoned just after birth, smothered in rags, crawling with ants and reeking of festering sores.

They are being transformed into bubbly, bossy 6-year-old Thandiswa; giggling, wriggling Abina; and Siphosethu, whose name means "our gift." They are given their medicine every day with a helping of porridge and a big dollop of love.

"Not one child in our care has died," says Bonani, with a smile. "We are so very, very proud of them."

Bonani and his wife, Lulama, who have looked after their 13-year-old HIV-positive grandson since their own daughter died of AIDS, hope the children in their care will be the last generation infected with HIV through their mother's womb or breast milk.

More than 90 percent of pregnant women with HIV in the Western Cape province around Cape Town now receive drugs to prevent the virus from passing to their unborn children. But in poorer areas like the rural Eastern Cape, the number of women on medication is nearer half.

Health professionals and activists say the biggest test of the government's commitment will be what it does to reduce mother-to-child transmission.

Mortality rates for women and young children are higher now than they were in 1990, before the end of apartheid, according to a study by the Medical Research Council, which said South Africa was one of only 12 countries suffering such increases.

The report, titled "Every Death Counts," said at least 260 mothers, newborns and children under 5 die every day in South Africa, with HIV, AIDS and related infections like tuberculosis and pneumonia responsible for about two-thirds of the deaths.

After four years of delay, Health Minister Manto Tshabalala-Msimang in February issued guidelines that comply with World Health Organization recommendations: Doctors should give two drugs, nevirapine and AZT, to pregnant women, not just nevirapine, because the dual therapy is much more effective than the single drug. It is now up to individual provinces to implement the new strategy.

The Western Cape didn't wait for the official go-ahead. It broke free of the national health ministry's straitjacket in 2004 and prescribed both drugs, slashing mother-to-child transmission to less than 5 percent — compared with more than 20 percent in some other provinces.

Gauteng, home of Johannesburg and the most populous province, and KwaZulu-Natal, the worst affected, started using both drugs at the start of April. KwaZulu-Natal authorities say they hoped to cut the rate of mother-to-child transmission from the current 32 percent to about 10 percent.

Francois Venter, a doctor who heads the Southern African Clinicians Society, said the dual therapy guidelines had "rejuvenated" prevention efforts. "There's quite a vibe about clinics trying to do better than each other," he said. "People are getting excited about trying to fix the problem."

But doctors often have to battle bureaucracy. A clinic in rural KwaZulu-Natal suspended two doctors for giving women dual therapy ahead of its local authorization and other "misdemeanors." The health chief in the province, which is also suffering sky-high rates of TB which feeds off AIDS, makes no secret of her dislike of conventional treatment.

Much of the blame for South Africa's AIDS disaster is laid at the door of its health minister, Tshabalala-Msimang, and President Thabo Mbeki, who gained notoriety after he came to office in 1999 by questioning the link between HIV and AIDS.

Mbeki for years supported Tshabalala-Msimang, dubbed "Dr. Garlic" for her mistrust of AIDS drugs and her espousal of garlic, olive oil and lemon. Instead, he axed her respected deputy, Nozizwe Madlala-Routledge, whom he accused of being insubordinate, but who was a driving force behind the new AIDS strategy launched last year.

Mbeki has said nothing to indicate he has reversed his position on the causes of AIDS, and Tshabalala-Msimang continues to advocate nutritional remedies, although she now extols the virtues of the new national campaign.

"The sustained and expanded national response to HIV and AIDS is beginning to pay some dividends," she wrote in the foreword of a report to the U.N. General Assembly.

Events may simply be overtaking the controversies. Mbeki has only one more year in office. His deputy heads the revamped South African National AIDS Council and has mended fences with activists, and the Treasury has announced a massive increase in spending on HIV.

Jacob Zuma, who is first in line to succeed Mbeki as president, says taming the epidemic is a top priority.

But there is a snag. Zuma was in 2006 acquitted of rape in a trial in which he confessed to having knowingly had unprotected sex with the woman, who had the AIDS virus. His defense: He showered afterward, believing it reduced the risk of infection. He has since apologized and AIDS activists hope he will try to silence his critics by getting tough on AIDS.

Prevention is the weakest link in South Africa's shaky chain.

The Human Sciences Research Council estimated that there were 1,500 new infections per day in 2005.

"For every two people put on treatment, five get infected. It's just unbelievable. You are chasing the tail the whole time," exclaims Venter, the doctor. "Prevention is just a disaster zone."

South Africa is not alone. Major initiatives like the WHO's "3 by 5" campaign, which aimed to put 3 million people worldwide on AIDS drugs by 2005, and much of the Bush administration's AIDS funding, are criticized by experts for focusing on treatment rather than building up the health system, condom distribution or HIV testing.

Male circumcision is the only new tool in the prevention armory. But unlike other African health ministers, Tshabalala-Msimang is skeptical. She says there is not enough information available about its effect on AIDS infection — this despite its endorsement by WHO and UNAIDS, based on "extensive and convincing" evidence that the procedure cuts the risk for infection for men by about 60 percent.

The government says education campaigns among the young are beginning to pay off. The prevalence rate among girls aged 15 to 19 fell to 13.5 percent in 2006, down from 16 percent two years previously.

South Africa still lacks extensive public anti-AIDS publicity, too many of its men still shun condoms, and the biggest obstacle remains the stigma associated with the virus. But Bonani believes that, too, is beginning to change, at least in his community.

When Bonani first took in AIDS orphans, his church congregation vanished. One of his workers was accused of being a witch. But now AIDS is discussed openly in the community, he said, and his congregation is back up to 70, of whom 17 have revealed they have the virus.

"It took them three years to come back and to rebuild the trust," Bonani says, smiling. "Now they apologize, and they accept us."

BUJUMBURA (AFP) - HIV/AIDS prevalence in the small central African nation of Burundi rose to 4.2 percent last year from 3.5 percent in 2002, health officials said Thursday.

The increase is due to "the situation in our country which is emerging from war, poverty and strong beliefs (among people) in the countryside..," said Speciose Baransata, the deputy minister in charge of combating the disease.

Of its seven million people, around 250,000 are living with the virus and only some 11,000 have access to treatment.

"We call on the government to truly re-commit itself to the fight against the scourge," said Jeanne Gapiya, the head of National Association of People infected with HIV.

"Otherwise we are headed for a catastrophe," she told AFP.

Benjamin Nicayenzi, an official with a non-governmental organisation involved in the fight against AIDS, lamented the withdrawal of key donors and few tests currently being conducted.

"There are practically no condoms in (health) centres in the countryside," he said.

War-wracked Burundi is struggling to rise from the ravages of a civil war which erupted in 1993 and killed an estimated 300,000 people.