Cambodia is the latest developing country to achieve falling HIV prevalence rates in the midst of a national epidemic (alongside Thailand and Uganda). Between 1997 and 2000, HIV prevalence in Cambodia dropped from 3.9% of the adult (15-49) population – the highest national figure in Asia – to 2.8%. Cambodia is one of the world's poorest, least-developed countries, making the achievement all the more impressive.

The rapid spread of HIV/AIDS in Cambodia has been driven by sexual transmission, and seems to be concentrated in the cities. Other sexually transmitted infections (STIs) are common and often go untreated among the most vulnerable populations because they cannot afford or access the proper drugs, adding to the likelihood of HIV transmission.

The commercial sex industry has burgeoned in Cambodia, fuelled by poverty and decades of armed conflict that officially halted in the late 1990s. Young men were taken away from their families for extended periods and depriving families of their traditional breadwinners. In 2000, around 23% of commercial sex workers under 20 years old were thought to be infected with HIV – down from 42.6% two years earlier. The success of the 100% Condom Use campaign targetting sex workers and sex establishments probably contributed to both the reduced prevalence among sex workers and the overall reduction in new infections.

Condom use in Cambodia remains far less common in non-commercial sex encounters. Many women have been infected by their established partners who have visited commercial sex workers or had casual sex outside the relationship. Reducing parent-to-child HIV transmission has become an urgent challenge.

Rural poverty and the lack of opportunity in rural areas have been major factors in the spread of HIV/AIDS. Around 100,000 young women working in city garment factories are rural migrants and around 30,000 Cambodians work in the fishing industry in Thailand. Many other young Cambodians have ended up in Thailand or other neighbouring countries as direct or indirect sex workers, or in service jobs where pressure to have sex is high. In parts of Cambodia, however, Vietnamese sex workers far outnumber Cambodians. Paedophilia, both in and outside commercial sex settings, is also placing Cambodia's children at risk.

Annual AIDS deaths already outnumber hospital beds in Cambodia's public health system, making family or community-based care and support increasingly important. As experience in Thailand experience has shown, a rapid rise in the number of children affected or orphaned by the disease is inevitable over the next few years, even if prevalence rates continue to fall.

While we celebrate Cambodia's success in reducing new HIV infections, the HIV/AIDS epidemic and its impacts on society are far from over.