GENEVA - By the end of 2006 some 2 million people in low and middle-income countries were receiving the anti-retroviral drugs that help treat the symptoms of HIV, according to WHO's annual progress report.

This represents an increase of 54 per cent on the 1.3 million people treated the year before, meaning about 28 per cent of those in need now receive the drugs.

"The encouraging progress that was made ... has been sustained," Dr. Charlie Gilks, the head of WHO's HIV treatment department, told reporters in Geneva.

One of the main reasons for the success is the significant drop in the cost of drugs, he said.

Price competition from manufacturers of generic drugs has forced pharmaceutical companies to lower the cost of treatment. Negotiations between governments, drug makers and non-governmental organizations to offer cheaper treatment to poor countries have also paid off, he said.

Another reason for the increase in access is greater political commitment by governments, and better funding for treatment through programs such as the U.S. President's Emergency Plan and the intergovernmental Global Fund, Gilks added.

"We have every reason to believe that this success will continue," he said, but warned that greater effort was needed if the U.N. is to reach its target of universal access in three years' time.

While Latin America leads the way with treatment available for 72 per cent of those who need it, sub-Saharan Africa has also made significant progress and now provides the drugs to 28 per cent availability, up from only two per cent in 2003.

The lowest access rate in poor countries is in the North Africa and Middle East region, where about six per cent of people who need HIV drugs receive them, the report says.

Gilks said greater access to treatment for children, and better prevention of mother-to-child transmission, need to be tackled as well. At present, only 15 per cent of children in need have access to drugs, partly because of difficulties diagnosing HIV in infants.