"The taking of drugs by a parenteral means remains the main way AIDS is transmitted, representing 65 percent of cases," the Rospotrebnadzor agency said in a statement released at a Moscow press conference.
Russia has a total of 448,000 HIV cases, representing about 0.3 percent of the population, with more than 80 percent of them between the ages of 15 and 30, the agency said.
"AIDS is mainly spreading in Russia among drug addicts, while sexual transmission is the second main cause," said Alexandre Golyussov, head of AIDS prevention at the agency.
Despite prevention programmes, nearly 37,000 Russians have contracted HIV since the beginning of the year and the figure could reach 50,000 by year's end, compared with 44,713 new cases in 2007, according to Russia's federal centre for the fight against AIDS.
Russia recently condemned the spread of Afghan drug trafficking into Russian territory, accusing Kabul and international coalition forces in Afghanistan of failing to stop the illegal trade, especially in opium.