Researchers, doctors and patients attending the world's largest AIDS conference are urging the world's governments not to cut back on the fight against the epidemic, even as new evidence suggests that the new drug-resistant mutations of the virus are on the rise.
There is no cure or vaccine for Acquired Immune Deficiency Syndrome (AIDS), but scientists say they have the tools to finally stem the spread of the virus - largely by using treatment not just to save patients but to make them less infectious, too.
"We must resolve together never to go backwards," said Dr Elly Katabira, president of the International AIDS Society, at the opening session of the International AIDS Conference on Sunday.
"Future generations are counting on our courage to think big, be bold and seize the opportunity before us," said Dr Diane Havlir of the University of California, San Francisco, a co-chair of the conference.
More than 20,000 scientists, people living with HIV and policymakers are meeting this week to figure out how to turn recent scientific advances into practical protections, providing additional ways beyond barrier birth control mechanisms to stop the spread of the disease.
Studies show that treating people with HIV early, before they are sick, is not only life-saving for them but also lowers their chances of spreading the virus through sexual intercourse.
Regions from San Francisco to South Africa that are pushing to get more people tested and rushed into treatment are already starting to see infection rates drop, said Dr Anthony Fauci, a leading US AIDS researcher.
Healthy people can also take the daily AIDS medicine Truvada to lower their risk of infection from a sexual partner.
Countries with high infection rates, however, are struggling with the question of how one gets the medicines to those who need them most.
Coinciding with the opening of the conference, a study published in The Lancet medical journal on Monday states that resistance to AIDS drugs is growing in parts of Africa.
The study indicated that tiny genetic mutations that make HIV immune to key frontline drugs have been increasing in eastern and southern Africa and should be a clear warning to health watchdogs.
Funded by the Bill and Melinda Gates Foundation and the European Union, the study is the widest-ever analysis of its kind. It looked at published cases of HIV resistance and supplemented this with data from the World Health Organisation.
Researchers Silvia Bertagnolio from the UN's WHO and Ravindra Gupta at University College London found that the prevalence of resistant viruses in untreated people soared from around one per cent to 7.3 per cent in eastern Africa, and from one per cent to 3.7 per cent in southern Africa, over an eight-year period.
Similar rates of 3.5-7.6 per cent were also found in western and central Africa, Latin America and the Caribbean.
The mutations, found in strains of the HIV-1 virus, made them resistant to first-option treatments that are used to control the virus and prevent transmission of it from pregnant women to their foetuses.
While alternate treatments do exist, the paper said that start-stop treatment that fuels the problem should be guarded against and that countries should step up monitoring of HIV resistance.
Despite the concern, the rollout should carry on, the paper stated.
"Estimated levels, although increasing, are not unexpected in view of the large expansion of antiretroviral treatment coverage seen in low-income and middle-income countries... no changes in antiretroviral treatment guidelines are warranted at the moment."
"Without continued and increased national and international efforts, rising HIV drug resistance could jeopardise a decade-long trend of decreasing HIV/AIDS-related illness and death in low- and middle-income countries," researchers said.
More money needed
Today, there are 34.2 million people currently living with HIV, and while infections are dropping slowly, 2.5 million are still infected every year.
In 2011, about eight million badly infected people in poorer countries had access to HIV-suppressing drugs, a figure 26 times greater than the number in 2003 but still only just over half of those in need.
Among the objectives of the six-day 19th International AIDS conference in Washington is to get more HIV-infected pregnant women treated to protect their babies, and getting more men circumcised in developing countries to protect them from heterosexual infection.
The world spent $16.8bn fighting AIDS in poor countries, the hardest-hit, last year.
That is still $7 billion a year shy of the amount needed to nearly double the eight million people getting life-saving drugs by world governments' goal of 2015.
Funding remains a challenge during a global recession, particularly for countries weary of the fight against a disease with an ever-growing number of people who need care.
"This gap is killing people," UNAIDS chief Michel Sidibe told the conference. "My friends, the end of AIDS is not free. It is not too expensive. It is priceless."