The HIV/Aids epidemic appears to be slowing, as evidence emerges of more cautious sexual behaviour and improved treatment in some of the worst-hit countries of the world, according to a new UN study.
Signs that work on preventing the spread of HIV is bearing fruit are flagged up today by UNAids' two-yearly report on the state of the epidemic.
In Rwanda and Zimbabwe, it finds, fewer people appear to be getting infected, apparently as the dangers of careless sex become better understood.
In Zimbabwe, a drop in infection among pregnant women, from 26% in 2002 to 18% in 2006, is being linked to reports of fewer people having casual sexual partners and fewer men paying for sex.
Condom use also appears to be increasing and in seven badly affected countries - Burkina Faso, Cameroon, Ethiopia, Ghana, Malawi, Uganda and Zambia - young people appear to be waiting longer before starting to have sex. In Cameroon, the percentage of under-15 year-olds having sex fell from 35% to 14%.
The UN warns against complacency, however. Fewer people are dying - the numbers are down from 2.2 million to 2 million HIV-related deaths in 2007 - because drugs to suppress the virus and prevent full-blown Aids have been rolled out in Africa and Asia and 3 million people are now surviving who would have died.
But though new infections dropped from 3m to 2.7m last year, the rate of decline is not fast enough. As more and more people are infected, the task of keeping patients alive will become much harder and more expensive. "The global HIV epidemic cannot be reversed, and gains in expanding treatment access cannot be sustained, without greater progress in reducing the rate of new HIV infections," the report says, adding that prevention efforts have lagged.
Peter Piot, executive director of UNAids, said: "Gains in saving lives, by preventing new infections and providing treatment to people living with HIV, must be sustained over the long term. Short-term gains should ... not spur complacency."
There are 33 million people living with HIV, who will die without antiretroviral drugs. There has been an increase in children under 15 living with the virus - from 1.6 million in 2001 to 2 million last year - partly because of treatment. But children are less likely to get the drugs than adults. Without treatment, about half of all infected babies die before they are two.
Between 2001 and 2007 there was a six-fold increase in the amount of funding available for HIV/Aids in low- and middle-income countries, but the UNAids report says it is important that rich countries continue their financial commitment.
An argument is raging over support for HIV/Aids programmes, with some claiming that too much money has been spent on this one disease and that funds should now go towards improving the health systems of poor countries.
The UN report claims both tactics are needed; the drugs roll-out is leading to improvements in healthcare systems, though health workers have been taken away from treating other conditions.
The report says there is much still to do. Too many young people do not know how they can avoid becoming infected with HIV, and too many people are stigmatised and do not get help.
