Levels of HIV infection in the Middle East and North Africa are increasing and better education and prevention are urgently needed, a new UN report says.
The UNAids report details the incidence of HIV/Aids around the world
Some 510,000 people are now infected, with 67,000 new infections and 57,000 deaths, UNAids regional figures show. Worldwide 40.3m people are infected.
Sudan is the worst-hit, and two thirds of women there were unaware of condoms.
The report reveals that the chief means of infection is unprotected sex, with intravenous drug use also a concern.
Research pointed out that Iran and Libya had significant levels of HIV infection through intravenous drug use.
There were variations in infection patterns from country to country, but the report's authors said that a lack of adequate education was a key concern across the region.
Sudan was by far the worst-affected country in the region, the report said.
"Only 5% knew that condom use could prevent HIV infection and more than two-thirds of the women had never seen or heard of a condom," the authors said.
Algeria recorded twice as many new HIV cases in 2004 compared with a year earlier, with the highest infection levels among sex workers.
Research in the Saudi Arabian capital, Riyadh, showed many of the people affected were married women who had been infected by their husbands.
Official figures from Egypt indicated that HIV infections were passed on mainly through unprotected sex.
"Across the region, there is a clear need for more, better and in-depth information about the patterns of HIV transmission," the report says, calling for "substantive efforts" to prevent the disease spreading in future.
The report says access to anti-retroviral treatments for HIV has improved dramatically, with many more people across the world able to access the drugs.
It says: "It is no longer only in the wealthy countries of North America and Western Europe that persons in need of treatment have a reasonable chance of receiving it."
But Dr Peter Piot, UNAids executive director, said: "The reality is that the Aids epidemic continues to outstrip global and national efforts to contain it.
"It is clear that a rapid increase in the scale and scope of HIV prevention programmes is urgently needed."
Overall, the report says more than 3m people died of Aids-related illnesses in 2005. Of these, more than 500,000 were children.
The report says Sub-Saharan Africa is still hardest hit by HIV/Aids.
Two thirds of the people living with HIV - 25.8m - are in this area.
In 2005, 2.4m people in Sub-Saharan Africa died of an HIV-related illness, and a further 3.2m were infected with the virus.