This is the 19th World AIDS Day, the 25th year since the first case of AIDS was identified and 10 years since UNAIDS was established.

The latest global AIDS figures give us reason for concern and for some hope. The number of new infections rose to 4.3 million this year, at the same time 2.9 million people died of AIDS-related illnesses. Multi-drug and extremely drug resistant tuberculosis highlight new challenges in our collective response. The issue of women and girls within the AIDS epidemic needs continued and increased attention. At the same time there is evidence of positive trends in young people's sexual behaviours -- increased use of condoms, delay of sexual debut, and fewer sexual partners. Declines in HIV prevalence among young people between 2000 and 2005 are evident in several countries.

Over the last few years we have seen stronger leadership and an increase in global resources to address the AIDS pandemic. The need for a sustained and exceptional response was highlighted and endorsed at the United Nations General Assembly High Level Meeting on AIDS in June of this year. It adopted a resolution committing the global community to scaling up towards universal access. Ambitious targets have been set and we should hold ourselves mutually accountable to deliver support to reach them.

Access to treatment and care has greatly increased in recent years. However we must increase the scale and impact of HIV prevention activities, including those directed at the drivers of the epidemic. New data show that HIV prevention programmes have better results if focused on reaching people most at risk and adapted to changing national epidemics. We also need to sustain this response. Where HIV prevention programmes have not been continued or adapted, infection rates have stayed the same or are going back up.

The theme of this World AIDS Day is accountability. If we are to reach the targets that countries have set for themselves then, now more than ever, we need to make the money work. Collectively and with civil society we need to strengthen national ownership, improve processes of coordination and harmonization, continue to reform the multilateral response, and define clear means of accountability and oversight for these changes.

Dr. Peter Piot is Executive Director of UNAIDS.