Red ribbon symbolizing AIDS awareness is displayed at the North Portico of the White House, Monday, Dec. 1, 2008, in Washington to help bring attention to World AIDS Day. AP STOCKHOLM, Sweden (AP) - The rate of HIV infection in Europe almost doubled between 2000 and 2007, reaching the highest level ever recorded in Europe, the European Union's disease center and the United Nations' health agency said Monday.

The annual rate of newly diagnosed cases of HIV infection rose to 75 per million people in 2007 from 39 per million people in 2000.

In 2007, 48,892 newly diagnosed cases of HIV infection were reported from 49 European countries. Austria, Italy, Monaco and Russia were excluded from the survey due to lack of data.

"One challenge faced by all countries is that many of the people living with HIV are unaware that they are infected," said Zsuzsanna Jakab, director of the European Center for Disease Prevention and Control.

She said the data revealed that the main groups infected by the HIV virus varies from country to country, hence prevention needs to be targeted in different ways across countries.

The report issued jointly by the European center and the U.N.'s World Health Organization showed Estonia, Ukraine, Portugal and the Republic of Moldova had the highest rates of newly transmitted HIV infections, and that drug injections were the main reason for infection in all of Eastern Europe. Other countries with high rates were Latvia, Kazakhstan, Uzbekistan, the United Kingdom, Belarus and Switzerland.

In Central and Western Europe sexual contact between heterosexuals was the primary reason for infection although infections among homosexual men were also rising.

Around 40 percent of cases where the virus has been transmitted heterosexually were found among people originating from countries with generalized epidemics, the report said.

The EU and U.N. agencies released the joint report in conjunction with World AIDS Day.