"ONE OF the best investments the global community can make is in AIDS prevention," says Dr Michael H Mezon, director of the Global Programme on AIDS (GPA) of the World Health Organisation. "Money spent now on changing behaviour to slow the spread of infection will return billions of dollars of lost income and health care expenditure to the economy."

In the US, it costs around $100,000 to treat one AIDS patient. So, if 10 HIV infections are prevented, a million dollars can be saved in medical costs. Mezon estimates that at least $2.5 billion are needed every year to bring about a substantial reduction in the rate of new infections. But only $120 million were spent to prevent AIDS in the developing world in 1991.

A study in Thailand has estimated that the direct health care cost of treating one AIDS person is $615-1,000 per year. In addition, the indirect costs of losing an adult in the prime of his/her working life are estimated to be $22,000 per death. By 2000, the direct and indirect costs of AIDS to Thailand will be nearly $9 billion every year.

Between mid-1992 and end-1992, the total number of estimated AIDS cases rose by a million -- mostly in sub-Saharan Africa, South Asia and Southeast Asia.