Almost one in three people infected with the virus that causes AIDS do not know they have the disease, increasing the risk of infection, the European Commission warned Monday.

In a document on combatting AIDS more than a quarter century after it surfaced, the EU's executive arm said now was not the time for Europe to drop its guard, noting that the figure was up to double in some neighbour nations.

And while efficient treatments exist to slow the evolution of the human immunodeficiency virus (HIV), no vaccine or cure has been found.

"We need to continue the political momentum in the fight against HIV/AIDS," EU Health Commissioner Androulla Vassiliou said in a statement.

"We need to encourage people to take responsibility for themselves and their partners by talking about and practicing safe sex and going for HIV testing," she said.

According to commission figures, the number of people living with HIV or AIDS in the 27 EU countries and its neighbours rose from 1.5 million in 2001 to 2.2 million in 2007, around 730,000 of whom live in the bloc.

Some 50,000 new cases of HIV were diagnosed in the EU and its neighbours in 2007.

The percentage of adults, ranging in age from 15 to 49, infected with HIV vary widely, from less than 0.1 percent in some countries to more than 1.0 percent in others.

France, Italy, Spain and Portugal have relatively high infection rates -- ranging from 0.4 percent to 0.5 percent -- but the number roughly triples in Estonia, which has a rate of 1.3 percent.

In Russia, around 1.1 percent of the population is HIV positive, while the figure climbs to 1.6 percent in Ukraine.