The HIV epidemic is worse than ever. In 2003, around 4.8 million people became infected with HIV, more than in any previous year. Today, some 37.8 million people live with HIV, and although effective prevention strategies exist, the numbers are still rising.

Poor countries are hardest hit. They need access to lifesaving drugs, interventions to halt the virus's spread, and the money to pay for it all. By 2007, UNAIDS, the Joint UN Programme on HIV/AIDS, estimates annual global spending on AIDS prevention and treatment will have to rise to $20 billion per year, if the developing world's needs are to be met. Currently the figure stands at just $5 billion.

But success stories do exist. More people are now receiving treatments with cocktails of antiretroviral drugs than ever before. Vaccines are being tweaked and tested. And microbicides, creams and gels that may help to prevent HIV transmission are entering large-scale trials.

So where do we go from here? Read our interactive guide to the HIV epidemic, including all the latest news from the XV International AIDS Conference in Bangkok, Thailand.