The scale of the worldwide AIDS crisis now outstrips even the worst-case scenarios of a decade ago with even worse yet to come.

According to the latest report released by the Joint United Nations Programme on AIDS (UNAIDS) the realisation is fast dawning that the epidemic is at an early stage of development while its long-term evolution is still unclear.

The Report on the Global HIV/AIDS epidemic said hopes of the epidemic reaching its natural limit, beyond which it would not grow, have been dashed particularly in southern Africa.

In Botswana for example, the average HIV prevalence among pregnant women in urban areas already stood at 38,5% in 1997. In 2001, it had risen to 44,9%.

Similar patterns are visible elsewhere in Zimbabwe, Namibia and Swaziland. In sub-Saharan Africa approximately 3,5-million new infections occurred in 2001, bringing to 28,5-million the total number of people in the region living with HIV/AIDS.

Fewer than 30 000 people were estimated to have been benefiting from anti-retroviral drugs at the end of 2001.

The estimated number of children orphaned by AIDS living in the region is a staggering 11-million.

The report predicts “Even if exceptionally effective prevention, treatment and care programmes take hold immediately, the scale of the crisis means that the human and socio-economic toll will remain significant for many generations”.

Around the world, an estimated five million people became infected last year, 800 000 of them children. Over the next decade, without effective treatment and care, they will join the ranks of the more than 20-million people who have died since the first clinical evidence of HIV/AIDS was reported in 1981.

Nonetheless, Uganda still underscores the fact that a rampant HIV/AIDS epidemic can be brought under control. In Kampala for example the HIV prevalence among pregnant women has fallen eight years in a row from a high of 29,5% in 1992 to 11,25% in 2000.

This has mostly been achieved through sustainable AIDS programmes, but huge challenges remain with new infections still occurring at a high rate.

One new study in Zambia shows urban men and women reporting less sexual activity, fewer multiple partners and more consistent use of condoms.

Although Zambia’s rates are still unacceptably high there has been a significant drop and if the country is to continue building its response it could become the second African country (after Uganda) to reverse an epidemic of crisis proportions.

The most potent way to avert the devastating impact of HIV/AIDS is to act before the epidemic spins out of control, according to the report.

UNAIDS state clearly that providing adequate and affordable treatment and care to people living with the virus represent two of the biggest challenges facing humankind today.

Calculations of the rates of return on Thailand’s investments in prevention suggest that, between 1990 and 2020, the avoided medical expenditures alone would have meant rates of return in the order of 12 to 33% for that period.

If averted income losses are added, the rate of return rises to between 37 and 55%.

Brazil’s widely praised efforts to provide universal treatment and care, in addition to its well planned prevention programmes, are estimated to have avoided 234 000 hospitalisations between 1996 and 2000.